If Chlamydia trachomatis is not treated, PID may develop in a significant number of patients. This can lead to serious consequences such as infertility, chronic pain, and ectopic pregnancy caused by scarring.

Pelvic inflammatory disease (PID) is a condition where the female pelvic organs, including the uterus, fallopian tubes, ovaries, and surrounding peritoneum, become infected and inflamed. It is typically caused by an infection that spreads from the endocervix. The most common causative organism is Chlamydia trachomatis, followed by Neisseria gonorrhoeae, Mycoplasma genitalium, and Mycoplasma hominis. Symptoms of PID include lower abdominal pain, fever, dyspareunia, dysuria, menstrual irregularities, vaginal or cervical discharge, and cervical excitation.

To diagnose PID, a pregnancy test should be done to rule out an ectopic pregnancy, and a high vaginal swab should be taken to screen for Chlamydia and gonorrhoeae. However, these tests may often be negative, so consensus guidelines recommend having a low threshold for treatment due to the potential complications of untreated PID. Management typically involves oral ofloxacin and oral metronidazole or intramuscular ceftriaxone, oral doxycycline, and oral metronidazole. In mild cases of PID, intrauterine contraceptive devices may be left in, but the evidence is limited, and removal of the IUD may be associated with better short-term clinical outcomes according to recent guidelines.

Complications of PID include perihepatitis (Fitz-Hugh Curtis Syndrome), which occurs in around 10% of cases and is characterized by right upper quadrant pain that may be confused with cholecystitis, infertility (with a risk as high as 10-20% after a single episode), chronic pelvic pain, and ectopic pregnancy.

The gubernaculum is responsible for assisting the testicles in descending from the abdomen to the scrotum, while the processus vaginalis precedes this descent and then closes. Abnormalities such as a patent processus vaginalis, also known as bell clapper deformity, can increase the risk of testicular torsion. Nutcracker syndrome occurs when the left renal vein is compressed between the superior mesenteric artery and the aorta, leading to a varicocele due to the left gonadal vein draining into the left renal vein. Acute testicular pain may be caused by epididymitis or mumps orchitis, but these conditions are not related to defects in the processus vaginalis. Signs of bowel obstruction may indicate an incarcerated inguinal hernia.

The Development of Testicles in Foetal Life

During foetal life, the testicles are situated within the abdominal cavity. They are initially found on the posterior abdominal wall, at the same level as the upper lumbar vertebrae. The gubernaculum testis, which is attached to the inferior aspect of the testis, extends downwards to the inguinal region and through the canal to the superficial skin. Both the testis and the gubernaculum are located outside the peritoneum.

As the foetus grows, the gubernaculum becomes progressively shorter. It carries the peritoneum of the anterior abdominal wall, known as the processus vaginalis. The testis is guided by the gubernaculum down the posterior abdominal wall and the back of the processus vaginalis into the scrotum. By the third month of foetal life, the testes are located in the iliac fossae, and by the seventh month, they lie at the level of the deep inguinal ring.

After birth, the processus vaginalis usually closes, but it may persist and become the site of indirect hernias. Partial closure may also lead to the development of cysts on the cord.

Smoking while pregnant has been linked to the birth of a Small for Gestational Age baby. This is indicated by the baby’s birth weight being below the 10th percentile and fetal measurements suggesting asymmetrical intrauterine growth restriction (IUGR), with the head circumference being significantly higher than the abdominal circumference and femur length. Maternal smoking is a possible cause of the baby’s small size, as it has been associated with reduced birth weight and asymmetrical IUGR. Multiple gestation is a known risk factor for fetal growth restriction, but singleton gestation is not. Maternal rubella infection and advanced maternal age may also cause small for gestational age babies, but these are less likely causes in this case as the mother’s immunisations are up to date and she is only 23 years old.

Small for Gestational Age (SGA) is a statistical definition used to describe babies who are smaller than expected for their gestational age. Although there is no universally agreed percentile, the 10th percentile is often used, meaning that 10% of normal babies will be below this threshold. SGA can be determined either antenatally or postnatally. There are two types of SGA: symmetrical and asymmetrical. Symmetrical SGA occurs when the fetal head circumference and abdominal circumference are equally small, while asymmetrical SGA occurs when the abdominal circumference slows relative to the increase in head circumference.

There are various causes of SGA, including incorrect dating, constitutionally small (normal) babies, and abnormal fetuses. Symmetrical SGA is more common and can be caused by idiopathic factors, race, sex, placental insufficiency, pre-eclampsia, chromosomal and congenital abnormalities, toxins such as smoking and heroin, and infections such as CMV, parvovirus, rubella, syphilis, and toxoplasmosis. Asymmetrical SGA is less common and can be caused by toxins such as alcohol, cigarettes, and heroin, chromosomal and congenital abnormalities, and infections.

The management of SGA depends on the type and cause. For symmetrical SGA, most cases represent the lower limits of the normal range and require fortnightly ultrasound growth assessments to demonstrate normal growth rates. Pathological causes should be ruled out by checking maternal blood for infections and searching the fetus carefully with ultrasound for markers of chromosomal abnormality. Asymmetrical SGA also requires fortnightly ultrasound growth assessments, as well as biophysical profiles and Doppler waveforms from umbilical circulation to look for absent end-diastolic flow. If results are sub-optimal, delivery may be considered.

During pregnancy, a woman’s body undergoes various physiological changes. The cardiovascular system experiences an increase in stroke volume, heart rate, and cardiac output, while systolic blood pressure remains unchanged and diastolic blood pressure decreases in the first and second trimesters before returning to normal levels by term. The enlarged uterus may cause issues with venous return, leading to ankle swelling, supine hypotension, and varicose veins.

The respiratory system sees an increase in pulmonary ventilation and tidal volume, with oxygen requirements only increasing by 20%. This can lead to a sense of dyspnea due to over-breathing and a fall in pCO2. The basal metabolic rate also increases, potentially due to increased thyroxine and adrenocortical hormones.

Maternal blood volume increases by 30%, with red blood cells increasing by 20% and plasma increasing by 50%, leading to a decrease in hemoglobin levels. Coagulant activity increases slightly, while fibrinolytic activity decreases. Platelet count falls, and white blood cell count and erythrocyte sedimentation rate rise.

The urinary system experiences an increase in blood flow and glomerular filtration rate, with elevated sex steroid levels leading to increased salt and water reabsorption and urinary protein losses. Trace glycosuria may also occur.

Calcium requirements increase during pregnancy, with gut absorption increasing substantially due to increased 1,25 dihydroxy vitamin D. Serum levels of calcium and phosphate may fall, but ionized calcium levels remain stable. The liver experiences an increase in alkaline phosphatase and a decrease in albumin levels.

The uterus undergoes significant changes, increasing in weight from 100g to 1100g and transitioning from hyperplasia to hypertrophy. Cervical ectropion and discharge may increase, and Braxton-Hicks contractions may occur in late pregnancy. Retroversion may lead to retention in the first trimester but usually self-corrects.

The likely cause of this patient’s amenorrhoea and galactorrhoea is a prolactinoma, which inhibits the secretion of GnRH and leads to low levels of oestrogen. Further tests, including a urinary pregnancy test and blood tests for various hormones, should be conducted to confirm the diagnosis. Asherman’s syndrome, intraductal papilloma, and pregnancy are less likely causes, as they do not present with the same symptoms or do not fit the patient’s reported history.

Understanding Amenorrhoea: Causes, Investigations, and Management

Amenorrhoea is a condition characterized by the absence of menstrual periods. It can be classified into two types: primary and secondary. Primary amenorrhoea occurs when menstruation fails to start by the age of 15 in girls with normal secondary sexual characteristics or by the age of 13 in girls with no secondary sexual characteristics. On the other hand, secondary amenorrhoea is the cessation of menstruation for 3-6 months in women with previously normal and regular menses or 6-12 months in women with previous oligomenorrhoea.

The causes of amenorrhoea vary depending on the type. Primary amenorrhoea may be caused by gonadal dysgenesis, testicular feminization, congenital malformations of the genital tract, functional hypothalamic amenorrhoea, congenital adrenal hyperplasia, imperforate hymen, hypothalamic amenorrhoea, polycystic ovarian syndrome, hyperprolactinemia, premature ovarian failure, and thyrotoxicosis. Meanwhile, secondary amenorrhoea may be caused by stress, excessive exercise, PCOS, Sheehan’s syndrome, Asherman’s syndrome, and other underlying medical conditions.

To diagnose amenorrhoea, initial investigations may include pregnancy tests, full blood count, urea & electrolytes, coeliac screen, thyroid function tests, gonadotrophins, prolactin, and androgen levels. Management of amenorrhoea involves treating the underlying cause. For primary amenorrhoea, it is important to investigate and treat any underlying cause. For secondary amenorrhoea, it is important to exclude pregnancy, lactation, and menopause and treat the underlying cause accordingly. Women with primary ovarian insufficiency due to gonadal dysgenesis may benefit from hormone replacement therapy to prevent osteoporosis and other complications.

In conclusion, amenorrhoea is a condition that requires proper diagnosis and management. Understanding the causes and appropriate investigations can help in providing the necessary treatment and care for women experiencing this condition.

The patient is experiencing secondary amenorrhoea, which is indicative of hypothalamic amenorrhoea due to low-level gonadotrophins. This could be caused by the patient’s intensive training for marathons, as well as other risk factors such as stress and anorexia nervosa. Hyperthyroidism is unlikely as the patient does not exhibit any symptoms or abnormal thyroid function test results. Polycystic ovarian syndrome (PCOS) can be ruled out as the patient does not have hirsutism, a high BMI, or elevated LH and FSH levels. Pregnancy is also not a possibility as the patient’s test was negative and she does not exhibit any signs of pregnancy.

Understanding Amenorrhoea: Causes, Investigations, and Management

Amenorrhoea is a condition characterized by the absence of menstrual periods. It can be classified into two types: primary and secondary. Primary amenorrhoea occurs when menstruation fails to start by the age of 15 in girls with normal secondary sexual characteristics or by the age of 13 in girls with no secondary sexual characteristics. On the other hand, secondary amenorrhoea is the cessation of menstruation for 3-6 months in women with previously normal and regular menses or 6-12 months in women with previous oligomenorrhoea.

The causes of amenorrhoea vary depending on the type. Primary amenorrhoea may be caused by gonadal dysgenesis, testicular feminization, congenital malformations of the genital tract, functional hypothalamic amenorrhoea, congenital adrenal hyperplasia, imperforate hymen, hypothalamic amenorrhoea, polycystic ovarian syndrome, hyperprolactinemia, premature ovarian failure, and thyrotoxicosis. Meanwhile, secondary amenorrhoea may be caused by stress, excessive exercise, PCOS, Sheehan’s syndrome, Asherman’s syndrome, and other underlying medical conditions.

To diagnose amenorrhoea, initial investigations may include pregnancy tests, full blood count, urea & electrolytes, coeliac screen, thyroid function tests, gonadotrophins, prolactin, and androgen levels. Management of amenorrhoea involves treating the underlying cause. For primary amenorrhoea, it is important to investigate and treat any underlying cause. For secondary amenorrhoea, it is important to exclude pregnancy, lactation, and menopause and treat the underlying cause accordingly. Women with primary ovarian insufficiency due to gonadal dysgenesis may benefit from hormone replacement therapy to prevent osteoporosis and other complications.

In conclusion, amenorrhoea is a condition that requires proper diagnosis and management. Understanding the causes and appropriate investigations can help in providing the necessary treatment and care for women experiencing this condition.

The most likely cause of the patient’s intractable vomiting during pregnancy is multiple gestation. This condition, known as hyperemesis gravidarum, is characterized by vomiting, dehydration, weight loss, and ketonuria. Multiple gestations can lead to hormone imbalances due to increased levels of βhCG, which can increase vomiting. Risk factors for multiple gestations include the use of fertility-enhancing treatments like IVF and older maternal age. The presence of the placental lambda sign is characteristic of a dichorionic pregnancy.

Complete molar pregnancy is an unlikely diagnosis as it typically presents with abnormal uterine bleeding, pelvic pain, and a snowstorm appearance on ultrasound. Partial molar pregnancy is also unlikely as it is associated with lower levels of βhCG and often has fetal parts present on ultrasound. Physiological vomiting, while common in pregnancy, is not the most likely cause in this case as the patient is experiencing weight loss and ketonuria.

Hyperemesis gravidarum is a severe form of nausea and vomiting that affects around 1% of pregnancies. It is usually experienced between 8 and 12 weeks of pregnancy but can persist up to 20 weeks. The condition is thought to be related to raised beta hCG levels and is more common in women who are obese, nulliparous, or have multiple pregnancies, trophoblastic disease, or hyperthyroidism. Smoking is associated with a decreased incidence of hyperemesis.

The Royal College of Obstetricians and Gynaecologists recommend that a woman must have a 5% pre-pregnancy weight loss, dehydration, and electrolyte imbalance before a diagnosis of hyperemesis gravidarum can be made. Validated scoring systems such as the Pregnancy-Unique Quantification of Emesis (PUQE) score can be used to classify the severity of NVP.

Management of hyperemesis gravidarum involves using antihistamines as a first-line treatment, with oral cyclizine or oral promethazine being recommended by Clinical Knowledge Summaries. Oral prochlorperazine is an alternative, while ondansetron and metoclopramide may be used as second-line treatments. Ginger and P6 (wrist) acupressure can be tried, but there is little evidence of benefit. Admission may be needed for IV hydration.

Complications of hyperemesis gravidarum can include Wernicke’s encephalopathy, Mallory-Weiss tear, central pontine myelinolysis, acute tubular necrosis, and fetal growth restriction, pre-term birth, and cleft lip/palate (if ondansetron is used during the first trimester). The NICE Clinical Knowledge Summaries recommend considering admission if a woman is unable to keep down liquids or oral antiemetics, has ketonuria and/or weight loss (greater than 5% of body weight), or has a confirmed or suspected comorbidity that may be adversely affected by nausea and vomiting.

In most women, the uterus is positioned in an anteverted and anteflexed manner. Anteversion refers to the uterus being tilted forward towards the bladder in the coronal plane, while retroversion describes a posterior tilt towards the rectum. Anteflexion refers to the position of the uterus body in relation to the cervix, with the fundus being anterior to the cervix in the sagittal plane.

Anatomy of the Uterus

The uterus is a female reproductive organ that is located within the pelvis and is covered by the peritoneum. It is supplied with blood by the uterine artery, which runs alongside the uterus and anastomoses with the ovarian artery. The uterus is supported by various ligaments, including the central perineal tendon, lateral cervical, round, and uterosacral ligaments. The ureter is located close to the uterus, and injuries to the ureter can occur when there is pathology in the area.

The uterus is typically anteverted and anteflexed in most women. Its topography can be visualized through imaging techniques such as ultrasound or MRI. Understanding the anatomy of the uterus is important for diagnosing and treating various gynecological conditions.

The symptoms and indications described indicate that the patient is suffering from severe pre-eclampsia. It should be noted that not all antihypertensive drugs are safe for use during pregnancy due to their teratogenic effects. Therefore, hydrocortisone is the only drug mentioned that is not an antihypertensive. Among the antihypertensive drugs mentioned, labetalol is the most suitable option as it is recommended as a first-line drug for managing severe hypertension in pregnant patients according to NICE guidelines.

Hypertension during pregnancy is a common condition that can be managed effectively with proper care. In normal pregnancy, blood pressure tends to decrease in the first trimester and then gradually increase to pre-pregnancy levels by term. However, if a pregnant woman develops hypertension, it is usually defined as a systolic blood pressure of over 140 mmHg or a diastolic blood pressure of over 90 mmHg. Additionally, an increase of more than 30 mmHg systolic or 15 mmHg diastolic from booking readings can also indicate hypertension.

After confirming hypertension, the patient should be categorized into one of three groups: pre-existing hypertension, pregnancy-induced hypertension (PIH), or pre-eclampsia. PIH, also known as gestational hypertension, occurs in 3-5% of pregnancies and is more common in older women. If a pregnant woman takes an ACE inhibitor or angiotensin II receptor blocker for pre-existing hypertension, it should be stopped immediately, and alternative antihypertensives should be started while awaiting specialist review.

Pregnancy-induced hypertension in association with proteinuria, which occurs in around 5% of pregnancies, may also cause oedema. The 2010 NICE guidelines recommend oral labetalol as the first-line treatment for hypertension during pregnancy. Oral nifedipine and hydralazine may also be used, depending on the patient’s medical history. It is important to manage hypertension during pregnancy effectively to reduce the risk of complications and ensure the health of both the mother and the baby.

Smoking is a protective factor against only one type of cancer, which is endometrial cancer (3), as found by a meta-analysis. However, smoking is a risk factor for all the other types of cancer mentioned.

For bladder cancer (1), it is suggested that the aromatic amines found in cigarettes are a known carcinogen of the bladder, thus contributing to the increased risk of bladder cancer with smoking.

Although smoking is a well-established co-factor for the development of cervical cancer (2), the mechanism by which smoking increases the risk is not known, although there are two theories.

Smoking has been found to cause numerous DNA changes in laryngeal cancer (4), including TP53 gene mutations.

Smoking is also theorized to cause renal cell cancer (5) as cigarette smoke induces oxidative stress and injury in the kidney, and free radicals in cigarettes can cause DNA damage that may lead to the development of cancer.

Endometrial cancer is a type of cancer that is commonly found in women who have gone through menopause, but it can also occur in around 25% of cases before menopause. The prognosis for this type of cancer is usually good due to early detection. There are several risk factors associated with endometrial cancer, including obesity, nulliparity, early menarche, late menopause, unopposed estrogen, diabetes mellitus, tamoxifen, polycystic ovarian syndrome, and hereditary non-polyposis colorectal carcinoma. Symptoms of endometrial cancer include postmenopausal bleeding, which is usually slight and intermittent at first before becoming heavier, and changes in intermenstrual bleeding for premenopausal women. Pain is not common and typically signifies extensive disease, while vaginal discharge is unusual.

When investigating endometrial cancer, women who are 55 years or older and present with postmenopausal bleeding should be referred using the suspected cancer pathway. The first-line investigation is trans-vaginal ultrasound, which has a high negative predictive value for a normal endometrial thickness of less than 4 mm. Hysteroscopy with endometrial biopsy is also commonly used for diagnosis. Treatment for localized disease typically involves total abdominal hysterectomy with bilateral salpingo-oophorectomy, while patients with high-risk disease may require postoperative radiotherapy. Progestogen therapy may be used in frail elderly women who are not considered suitable for surgery. It is important to note that the combined oral contraceptive pill and smoking are protective against endometrial cancer.

To promote a healthy pregnancy, it is recommended that women take 400mcg of folic acid daily for three months before conception and up to 12 weeks into gestation. However, pregnant women should avoid vitamin A supplements and liver-based products as they can be harmful to the developing fetus. While iron supplements may be recommended for those with iron deficiency anemia, they are not necessary for this patient. It is important for pregnant women to avoid all types of pâté, including vegetable pâtés, as they may contain listeria bacterium.

Antenatal Care: Lifestyle Advice for Pregnant Women

During antenatal care, healthcare providers should provide pregnant women with lifestyle advice to ensure a healthy pregnancy. The National Institute for Health and Care Excellence (NICE) has made several recommendations regarding the advice that pregnant women should receive. These recommendations include nutritional supplements, alcohol consumption, smoking, food-acquired infections, work, air travel, prescribed medicines, over-the-counter medicines, complimentary therapies, exercise, and sexual intercourse.

Nutritional supplements such as folic acid and vitamin D are recommended to reduce the risk of neural tube defects and ensure adequate bone health, respectively. However, iron supplementation should not be offered routinely, and vitamin A supplementation should be avoided due to its teratogenic effects. Pregnant women should also avoid alcohol consumption as it can lead to long-term harm to the baby. Smoking should also be avoided, and NRT may be used only after discussing the risks and benefits.

Food-acquired infections such as listeriosis and salmonella should be avoided by avoiding certain foods. Pregnant women should also be informed of their maternity rights and benefits and consult with the Health and Safety Executive if there are any concerns about possible occupational hazards during pregnancy. Air travel during pregnancy should also be avoided after a certain gestational age, and prescribed medicines should be avoided unless the benefits outweigh the risks.

Over-the-counter medicines should be used as little as possible during pregnancy, and few complementary therapies have been established as being safe and effective during pregnancy. Pregnant women should also be informed that moderate exercise is not associated with adverse outcomes, but certain activities should be avoided. Sexual intercourse is not known to be associated with any adverse outcomes. By following these recommendations, pregnant women can ensure a healthy pregnancy and reduce the risk of complications.

The Onufs nucleus, which is responsible for providing neurons to the external urethral sphincter, is located in the anterior horn of S2. In females, the sphincter complex at the bladder neck is not well-developed, making the external sphincter complex more important. It is innervated by the pudendal nerve, and damage to this nerve due to obstetric events can lead to stress urinary incontinence. The bladder is innervated by the pudendal, hypogastric, and pelvic nerves, which also carry autonomic nerves. Sympathetic nerves cause detrusor relaxation and sphincter contraction during bladder filling, while parasympathetic nerves cause detrusor contraction and sphincter relaxation. The Pons is responsible for centrally mediating control of micturition.

Urinary incontinence is a common condition that affects approximately 4-5% of the population, with elderly females being more susceptible. There are several risk factors that can contribute to the development of urinary incontinence, including advancing age, previous pregnancy and childbirth, high body mass index, hysterectomy, and family history. The condition can be classified into different types, such as overactive bladder, stress incontinence, mixed incontinence, overflow incontinence, and functional incontinence.

Initial investigation of urinary incontinence involves completing bladder diaries for at least three days, performing a vaginal examination to exclude pelvic organ prolapse, and conducting urine dipstick and culture tests. Urodynamic studies may also be necessary. Management of urinary incontinence depends on the predominant type of incontinence. For urge incontinence, bladder retraining and bladder stabilizing drugs such as antimuscarinics are recommended. For stress incontinence, pelvic floor muscle training and surgical procedures may be necessary. Duloxetine, a combined noradrenaline and serotonin reuptake inhibitor, may also be offered to women who decline surgical procedures.

In summary, urinary incontinence is a common condition that can be caused by various risk factors. It can be classified into different types, and management depends on the predominant type of incontinence. Initial investigation involves completing bladder diaries, performing a vaginal examination, and conducting urine tests. Treatment options include bladder retraining, bladder stabilizing drugs, pelvic floor muscle training, surgical procedures, and duloxetine.

Placental insufficiency is linked to asymmetrical growth restriction in small for gestational age babies.

When a fetus or infant experiences growth restriction, it can be categorized as either symmetrical or asymmetrical.

Asymmetrical growth restriction occurs when the weight or abdominal circumference is lower than the head circumference. This is typically caused by inadequate nutrition from the placenta in the later stages of pregnancy, with brain growth being prioritized over liver glycogen and skin fat. Placental insufficiency is often associated with this type of growth restriction.

Symmetrical growth restriction, on the other hand, is characterized by a reduction in head circumference that is equal to other measurements. This type of growth restriction is usually caused by factors such as congenital infection, fetal chromosomal disorder (such as Down syndrome), underlying maternal hypothyroidism, or malnutrition. It suggests a prolonged period of poor intrauterine growth that begins early in pregnancy.

In reality, it is often difficult to distinguish between asymmetrical and symmetrical growth restriction.

Small for Gestational Age (SGA) is a statistical definition used to describe babies who are smaller than expected for their gestational age. Although there is no universally agreed percentile, the 10th percentile is often used, meaning that 10% of normal babies will be below this threshold. SGA can be determined either antenatally or postnatally. There are two types of SGA: symmetrical and asymmetrical. Symmetrical SGA occurs when the fetal head circumference and abdominal circumference are equally small, while asymmetrical SGA occurs when the abdominal circumference slows relative to the increase in head circumference.

There are various causes of SGA, including incorrect dating, constitutionally small (normal) babies, and abnormal fetuses. Symmetrical SGA is more common and can be caused by idiopathic factors, race, sex, placental insufficiency, pre-eclampsia, chromosomal and congenital abnormalities, toxins such as smoking and heroin, and infections such as CMV, parvovirus, rubella, syphilis, and toxoplasmosis. Asymmetrical SGA is less common and can be caused by toxins such as alcohol, cigarettes, and heroin, chromosomal and congenital abnormalities, and infections.

The management of SGA depends on the type and cause. For symmetrical SGA, most cases represent the lower limits of the normal range and require fortnightly ultrasound growth assessments to demonstrate normal growth rates. Pathological causes should be ruled out by checking maternal blood for infections and searching the fetus carefully with ultrasound for markers of chromosomal abnormality. Asymmetrical SGA also requires fortnightly ultrasound growth assessments, as well as biophysical profiles and Doppler waveforms from umbilical circulation to look for absent end-diastolic flow. If results are sub-optimal, delivery may be considered.

The gubernaculum is a strip of mesenchymal tissue that links the testis to the lower part of the scrotum. In the initial stages of embryonic development, the gubernaculum is lengthy and the testis are situated on the back abdominal wall. As the fetus grows, the body expands in proportion to the gubernaculum, causing the testis to descend.

The Development of Testicles in Foetal Life

During foetal life, the testicles are situated within the abdominal cavity. They are initially found on the posterior abdominal wall, at the same level as the upper lumbar vertebrae. The gubernaculum testis, which is attached to the inferior aspect of the testis, extends downwards to the inguinal region and through the canal to the superficial skin. Both the testis and the gubernaculum are located outside the peritoneum.

As the foetus grows, the gubernaculum becomes progressively shorter. It carries the peritoneum of the anterior abdominal wall, known as the processus vaginalis. The testis is guided by the gubernaculum down the posterior abdominal wall and the back of the processus vaginalis into the scrotum. By the third month of foetal life, the testes are located in the iliac fossae, and by the seventh month, they lie at the level of the deep inguinal ring.

After birth, the processus vaginalis usually closes, but it may persist and become the site of indirect hernias. Partial closure may also lead to the development of cysts on the cord.

The peritoneum gives rise to the tunica vaginalis, which produces the fluid that occupies the hydrocele space.

Anatomy of the Scrotum and Testes

The scrotum is composed of skin and dartos fascia, with an arterial supply from the anterior and posterior scrotal arteries. It is also the site of lymphatic drainage to the inguinal lymph nodes. The testes are surrounded by the tunica vaginalis, a closed peritoneal sac, with the parietal layer adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta, just below the renal arteries, and the pampiniform plexus drains into the testicular veins. The left testicular vein drains into the left renal vein, while the right testicular vein drains into the inferior vena cava. Lymphatic drainage occurs to the para-aortic nodes.

The spermatic cord is formed by the vas deferens and is covered by the internal spermatic fascia, cremasteric fascia, and external spermatic fascia. The cord contains the vas deferens, testicular artery, artery of vas deferens, cremasteric artery, pampiniform plexus, sympathetic nerve fibers, genital branch of the genitofemoral nerve, and lymphatic vessels. The vas deferens transmits sperm and accessory gland secretions, while the testicular artery supplies the testis and epididymis. The cremasteric artery arises from the inferior epigastric artery, and the pampiniform plexus is a venous plexus that drains into the right or left testicular vein. The sympathetic nerve fibers lie on the arteries, while the parasympathetic fibers lie on the vas. The genital branch of the genitofemoral nerve supplies the cremaster. Lymphatic vessels drain to lumbar and para-aortic nodes.

Rh disease is commonly linked with hydrops fetalis, a form of Haemolytic Disease of the Newborn. While Kernicterus is a possible outcome of Rh disease, it is not accurate to associate it with hepato-splenomegaly. Haemolysis leads to bilirubinemia, which is highly toxic to the nervous system, but it does not cause an enlargement of the liver and spleen. Although foetal heart failure can cause hepatomegaly, it is not related to Rh disease. Foetal liver failure, which may cause hepatomegaly, does not necessarily result in splenomegaly and is not associated with Rh disease.

Rhesus negative mothers can develop anti-D IgG antibodies if they deliver a Rh +ve child, which can cause haemolysis in future pregnancies. Prevention involves testing for D antibodies and giving anti-D prophylaxis at 28 and 34 weeks. Anti-D should also be given in various situations, such as delivery of a Rh +ve infant or amniocentesis. Tests include cord blood FBC, blood group, direct Coombs test, and Kleihauer test. Affected fetuses may experience oedema, jaundice, anaemia, hepatosplenomegaly, heart failure, and kernicterus, and may require transfusions and UV phototherapy.

The axillary nodes are responsible for draining the majority of lymphatic fluid from breast tissue. These nodes are located under the arms and are often affected by tumour invasion. If lymphatic spread is confirmed, a surgical procedure called axillary lymph node dissection may be performed to remove the affected nodes. The contralateral axillary nodes are not involved in the drainage of the affected breast. The infraclavicular nodes primarily drain the forearm and hand, and are not commonly affected by breast tumour metastasis. The parasternal nodes are a potential site of metastasis from all quadrants of the breast, but do not play a major role in breast tissue lymphatic drainage.

The breast is situated on a layer of pectoral fascia and is surrounded by the pectoralis major, serratus anterior, and external oblique muscles. The nerve supply to the breast comes from branches of intercostal nerves from T4-T6, while the arterial supply comes from the internal mammary (thoracic) artery, external mammary artery (laterally), anterior intercostal arteries, and thoraco-acromial artery. The breast’s venous drainage is through a superficial venous plexus to subclavian, axillary, and intercostal veins. Lymphatic drainage occurs through the axillary nodes, internal mammary chain, and other lymphatic sites such as deep cervical and supraclavicular fossa (later in disease).

The preparation for lactation involves the hormones oestrogen, progesterone, and human placental lactogen. Oestrogen promotes duct development in high concentrations, while high levels of progesterone stimulate the formation of lobules. Human placental lactogen prepares the mammary glands for lactation. The two hormones involved in stimulating lactation are prolactin and oxytocin. Prolactin causes milk secretion, while oxytocin causes contraction of the myoepithelial cells surrounding the mammary alveoli to result in milk ejection from the breast. Suckling of the baby stimulates the mechanoreceptors in the nipple, resulting in the release of both prolactin and oxytocin from the pituitary gland (anterior and posterior parts respectively).

Breastfeeding has been linked to prolonged neonatal jaundice, which is characterized by high levels of bilirubin in an otherwise healthy breastfed newborn after the first week of life. This type of jaundice lasts longer than normal and has no other identifiable cause. It is important to consider the age at which jaundice appears in order to determine potential underlying causes, such as haemolytic disease, infections, G6PD deficiency, sepsis, polycythaemia, extrahepatic biliary atresia, congenital hypothyroidism, or breastfeeding.

Advantages and Disadvantages of Breastfeeding

Breastfeeding has numerous advantages for both the mother and the baby. For the mother, it promotes bonding with the baby and helps with the involution of the uterus. It also provides protection against breast and ovarian cancer and is a cheap alternative to formula feeding as there is no need to sterilize bottles. However, it should not be relied upon as a contraceptive method as it is unreliable.

Breast milk contains immunological components such as IgA, lysozyme, and lactoferrin that protect mucosal surfaces, have bacteriolytic properties, and ensure rapid absorption of iron so it is not available to bacteria. This reduces the incidence of ear, chest, and gastrointestinal infections, as well as eczema, asthma, and type 1 diabetes mellitus. Breastfeeding also reduces the incidence of sudden infant death syndrome.

One of the advantages of breastfeeding is that the baby is in control of how much milk it takes. However, there are also disadvantages such as the transmission of drugs and infections such as HIV. Prolonged breastfeeding may also lead to nutrient inadequacies such as vitamin D and vitamin K deficiencies, as well as breast milk jaundice.

In conclusion, while breastfeeding has numerous advantages, it is important to be aware of the potential disadvantages and to consult with a healthcare professional to ensure that both the mother and the baby are receiving adequate nutrition and care.

Anatomy of the Scrotum and Testes

The scrotum is composed of skin and dartos fascia, with an arterial supply from the anterior and posterior scrotal arteries. It is also the site of lymphatic drainage to the inguinal lymph nodes. The testes are surrounded by the tunica vaginalis, a closed peritoneal sac, with the parietal layer adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta, just below the renal arteries, and the pampiniform plexus drains into the testicular veins. The left testicular vein drains into the left renal vein, while the right testicular vein drains into the inferior vena cava. Lymphatic drainage occurs to the para-aortic nodes.

The spermatic cord is formed by the vas deferens and is covered by the internal spermatic fascia, cremasteric fascia, and external spermatic fascia. The cord contains the vas deferens, testicular artery, artery of vas deferens, cremasteric artery, pampiniform plexus, sympathetic nerve fibers, genital branch of the genitofemoral nerve, and lymphatic vessels. The vas deferens transmits sperm and accessory gland secretions, while the testicular artery supplies the testis and epididymis. The cremasteric artery arises from the inferior epigastric artery, and the pampiniform plexus is a venous plexus that drains into the right or left testicular vein. The sympathetic nerve fibers lie on the arteries, while the parasympathetic fibers lie on the vas. The genital branch of the genitofemoral nerve supplies the cremaster. Lymphatic vessels drain to lumbar and para-aortic nodes.

Spermatogonia are male germ cells that are not yet differentiated and undergo spermatogenesis in the seminiferous tubules of the testes. Leydig cells are interstitial cells found in the testes that secrete testosterone in response to LH secretion. Sertoli cells are part of the seminiferous tubule of the testes and are activated by FSH. They nourish developing sperm cells. Myoid cells are contractile cells that generate peristaltic waves. They surround the basement membrane of the testes.

Anatomy of the Scrotum and Testes

The scrotum is composed of skin and dartos fascia, with an arterial supply from the anterior and posterior scrotal arteries. It is also the site of lymphatic drainage to the inguinal lymph nodes. The testes are surrounded by the tunica vaginalis, a closed peritoneal sac, with the parietal layer adjacent to the internal spermatic fascia. The testicular arteries arise from the aorta, just below the renal arteries, and the pampiniform plexus drains into the testicular veins. The left testicular vein drains into the left renal vein, while the right testicular vein drains into the inferior vena cava. Lymphatic drainage occurs to the para-aortic nodes.

The spermatic cord is formed by the vas deferens and is covered by the internal spermatic fascia, cremasteric fascia, and external spermatic fascia. The cord contains the vas deferens, testicular artery, artery of vas deferens, cremasteric artery, pampiniform plexus, sympathetic nerve fibers, genital branch of the genitofemoral nerve, and lymphatic vessels. The vas deferens transmits sperm and accessory gland secretions, while the testicular artery supplies the testis and epididymis. The cremasteric artery arises from the inferior epigastric artery, and the pampiniform plexus is a venous plexus that drains into the right or left testicular vein. The sympathetic nerve fibers lie on the arteries, while the parasympathetic fibers lie on the vas. The genital branch of the genitofemoral nerve supplies the cremaster. Lymphatic vessels drain to lumbar and para-aortic nodes.

Hypergonadotropic hypogonadism occurs when the gonads fail to respond to gonadotropins produced by the anterior pituitary gland. This is commonly seen in Turner’s syndrome, where gonadal dysgenesis leads to low sex steroid levels despite elevated levels of LH and FSH. On the other hand, hypogonadotropic hypogonadism can be caused by Kallmann syndrome, Sheehan’s syndrome, and anorexia nervosa. In Asherman’s syndrome, intrauterine adhesions develop, often due to surgery.

Understanding Infertility: Initial Investigations and Key Counselling Points

Infertility is a common issue that affects approximately 1 in 7 couples. However, it is important to note that around 84% of couples who have regular sex will conceive within 1 year, and 92% within 2 years. The causes of infertility can vary, with male factor accounting for 30%, unexplained causes accounting for 20%, ovulation failure accounting for 20%, tubal damage accounting for 15%, and other causes accounting for the remaining 15%.

To determine the cause of infertility, basic investigations are typically conducted. These include a semen analysis and a serum progesterone test, which is done 7 days prior to the expected next period. The interpretation of the serum progesterone level is as follows: if the level is less than 16 nmol/l, it should be repeated and if it consistently remains low, referral to a specialist is necessary. If the level is between 16-30 nmol/l, it should be repeated, and if it is greater than 30 nmol/l, it indicates ovulation.

In addition to these investigations, there are key counselling points that should be addressed. These include advising the patient to take folic acid, aiming for a BMI between 20-25, and having regular sexual intercourse every 2 to 3 days. Patients should also be advised to quit smoking and limit alcohol consumption.

By understanding the initial investigations and key counselling points for infertility, healthcare professionals can provide their patients with the necessary information and support to help them conceive.

When a cervical smear sample tests positive for high-risk HPV (hrHPV), it undergoes cytological examination to check for abnormal cellular changes that may indicate early cervical cancer. In the UK, cervical screening is offered to women between the ages of 25 and 65, with those aged 25-50 offered a smear every 3 years and those aged 50-65 offered a smear every 5 years. The aim of the screening programme is to detect cervical changes early on. HPV, a sexually transmitted virus, is present in almost all sexually active individuals, and HPV 16 or 18 is present in almost all cases of cervical cancer. If hrHPV is not detected, no further testing is required, and the patient can return to routine screening. Repeating the smear is not necessary following the presence of hrHPV, but a repeat smear may be required if the laboratory report an inadequate sample. Prior to colposcopy investigation, the sample must be positive for hrHPV and dyskaryosis.

Understanding Cervical Cancer Screening Results

The cervical cancer screening program has evolved significantly in recent years, with the introduction of HPV testing allowing for further risk stratification. The NHS now uses an HPV first system, where a sample is tested for high-risk strains of human papillomavirus (hrHPV) first, and cytological examination is only performed if this is positive.

If the hrHPV test is negative, individuals can return to normal recall, unless they fall under the test of cure pathway, untreated CIN1 pathway, or require follow-up for incompletely excised cervical glandular intraepithelial neoplasia (CGIN) / stratified mucin producing intraepithelial lesion (SMILE) or cervical cancer. If the hrHPV test is positive, samples are examined cytologically, and if the cytology is abnormal, individuals will require colposcopy.

If the cytology is normal but the hrHPV test is positive, the test is repeated at 12 months. If the repeat test is still hrHPV positive and cytology is normal, a further repeat test is done 12 months later. If the hrHPV test is negative at 24 months, individuals can return to normal recall, but if it is still positive, they will require colposcopy. If the sample is inadequate, it will need to be repeated within 3 months, and if two consecutive samples are inadequate, colposcopy will be required.

For individuals who have previously had CIN, they should be invited for a test of cure repeat cervical sample in the community 6 months after treatment. The most common treatment for cervical intraepithelial neoplasia is large loop excision of transformation zone (LLETZ), which may be done during the initial colposcopy visit or at a later date depending on the individual clinic. Cryotherapy is an alternative technique.

The first step in screening for cervical cancer in women aged 25-64 is to test their cervical smear samples for high-risk HPV. If the test is positive, the same sample is then analyzed for abnormal cytology. The recommended frequency of smear tests is every 3 years for women aged 25-49 and every 5 years for women aged 50-64 in the UK screening programme. Therefore, the statements All women are initially screened for abnormal cytology between the ages of 18-64, All women are initially screened for abnormal cytology between the ages of 25-64, and All women are initially screened for abnormal cytology between the ages of 30-64 are incorrect as they either refer to the wrong screening test or age range.

Understanding Cervical Cancer Screening Results

The cervical cancer screening program has evolved significantly in recent years, with the introduction of HPV testing allowing for further risk stratification. The NHS now uses an HPV first system, where a sample is tested for high-risk strains of human papillomavirus (hrHPV) first, and cytological examination is only performed if this is positive.

If the hrHPV test is negative, individuals can return to normal recall, unless they fall under the test of cure pathway, untreated CIN1 pathway, or require follow-up for incompletely excised cervical glandular intraepithelial neoplasia (CGIN) / stratified mucin producing intraepithelial lesion (SMILE) or cervical cancer. If the hrHPV test is positive, samples are examined cytologically, and if the cytology is abnormal, individuals will require colposcopy.

If the cytology is normal but the hrHPV test is positive, the test is repeated at 12 months. If the repeat test is still hrHPV positive and cytology is normal, a further repeat test is done 12 months later. If the hrHPV test is negative at 24 months, individuals can return to normal recall, but if it is still positive, they will require colposcopy. If the sample is inadequate, it will need to be repeated within 3 months, and if two consecutive samples are inadequate, colposcopy will be required.

For individuals who have previously had CIN, they should be invited for a test of cure repeat cervical sample in the community 6 months after treatment. The most common treatment for cervical intraepithelial neoplasia is large loop excision of transformation zone (LLETZ), which may be done during the initial colposcopy visit or at a later date depending on the individual clinic. Cryotherapy is an alternative technique.

The process of preparing for lactation involves the hormones oestrogen, progesterone, and human placental lactogen. Oestrogen promotes the development of ducts, while high levels of progesterone stimulate the formation of lobules. Human placental lactogen prepares the mammary glands for lactation.

The two hormones responsible for stimulating lactation are prolactin and oxytocin. Prolactin stimulates milk production, while oxytocin causes the contraction of myoepithelial cells surrounding the mammary alveoli, resulting in milk ejection from the breast.

When the baby suckles, the mechanoreceptors in the nipple are stimulated, leading to the release of both prolactin and oxytocin from the anterior and posterior parts of the pituitary gland, respectively.

Endocrine Changes During Pregnancy

During pregnancy, there are several physiological changes that occur in the body, including endocrine changes. Progesterone, which is produced by the fallopian tubes during the first two weeks of pregnancy, stimulates the secretion of nutrients required by the zygote/blastocyst. At six weeks, the placenta takes over the production of progesterone, which inhibits uterine contractions by decreasing sensitivity to oxytocin and inhibiting the production of prostaglandins. Progesterone also stimulates the development of lobules and alveoli.

Oestrogen, specifically oestriol, is another major hormone produced during pregnancy. It stimulates the growth of the myometrium and the ductal system of the breasts. Prolactin, which increases during pregnancy, initiates and maintains milk secretion of the mammary gland. It is essential for the expression of the mammotropic effects of oestrogen and progesterone. However, oestrogen and progesterone directly antagonize the stimulating effects of prolactin on milk synthesis.

Human chorionic gonadotropin (hCG) is secreted by the syncitiotrophoblast and can be detected within nine days of pregnancy. It mimics LH, rescuing the corpus luteum from degenerating and ensuring early oestrogen and progesterone secretion. It also stimulates the production of relaxin and may inhibit contractions induced by oxytocin. Other hormones produced during pregnancy include relaxin, which suppresses myometrial contractions and relaxes the pelvic ligaments and pubic symphysis, and human placental lactogen (hPL), which has lactogenic actions and enhances protein metabolism while antagonizing insulin.

Breast malignancy often leads to skin dimpling and nipple retraction, which are caused by the tumour infiltrating the breast ligaments and ducts. The axillary contents are enclosed by the clavipectoral fascia, and the breast’s lymphatic drainage occurs in both the axilla and internal mammary chain. The breast is highly vascularized, with the internal mammary artery being a subclavian artery branch.

The breast is situated on a layer of pectoral fascia and is surrounded by the pectoralis major, serratus anterior, and external oblique muscles. The nerve supply to the breast comes from branches of intercostal nerves from T4-T6, while the arterial supply comes from the internal mammary (thoracic) artery, external mammary artery (laterally), anterior intercostal arteries, and thoraco-acromial artery. The breast’s venous drainage is through a superficial venous plexus to subclavian, axillary, and intercostal veins. Lymphatic drainage occurs through the axillary nodes, internal mammary chain, and other lymphatic sites such as deep cervical and supraclavicular fossa (later in disease).

The preparation for lactation involves the hormones oestrogen, progesterone, and human placental lactogen. Oestrogen promotes duct development in high concentrations, while high levels of progesterone stimulate the formation of lobules. Human placental lactogen prepares the mammary glands for lactation. The two hormones involved in stimulating lactation are prolactin and oxytocin. Prolactin causes milk secretion, while oxytocin causes contraction of the myoepithelial cells surrounding the mammary alveoli to result in milk ejection from the breast. Suckling of the baby stimulates the mechanoreceptors in the nipple, resulting in the release of both prolactin and oxytocin from the pituitary gland (anterior and posterior parts respectively).

Fertilization happens when a sperm reaches an egg that has been released during ovulation. The process begins with the sperm penetrating the outer layer of the egg, called the corona radiata, using enzymes in the plasma membrane of its head. These enzymes bind to receptors on the next inner layer of the egg, called the zona pellucida, triggering the acrosome reaction. This reaction causes the acrosomal hydrolytic enzymes to digest the zona pellucida, creating a pathway to the egg’s plasma membrane. The sperm then enters the egg’s cytoplasm, and the two cells fuse together to form a diploid zygote. The sperm also stimulates the release of calcium ions from the cortical granules of the egg, which inactivate the receptors on the zona pellucida to prevent polyspermy. After fertilization, the zygote undergoes rapid mitotic cell divisions to form an embryo.

The Process of Fertilisation

Fertilisation is the process by which a sperm cell reaches and penetrates an egg cell that has been released during ovulation. The first step involves the sperm penetrating the corona radiata, which is the outer layer of the ovum, using enzymes in the plasma membrane of the sperm’s head. These enzymes bind to the ZP3 receptors on the zona pellucida, which is the next inner layer of the ovum, triggering the acrosome reaction. This reaction involves the acrosomal hydrolytic enzymes digesting the zona pellucida, creating a pathway to the ovum plasma membrane.

Once the sperm enters the ovum cytoplasm, the two cells fuse together, resulting in the formation of a diploid zygote. The sperm also stimulates the release of calcium ions from the cortical granules of the ovum, which inactivate the ZP3 receptors to prevent polyspermy. After fertilisation, rapid mitotic cell divisions occur, resulting in the production of an embryo.

In summary, fertilisation is a complex process that involves the penetration of the ovum by the sperm, the fusion of the two cells, and the subsequent development of the zygote into an embryo.

Anastrozole and letrozole are medications that inhibit the production of oestrogen in peripheral tissues through the enzyme aromatase. These drugs are commonly used to treat breast cancer in postmenopausal women.

Trastuzumab is a monoclonal antibody that targets HER2 receptors on cancer cells, inhibiting their growth and proliferation. It is effective in treating HER2-positive breast cancer.

Fulvestrant is a selective oestrogen receptor degrader that breaks down oestrogen receptors without activating them, unlike tamoxifen. This leads to downregulation of the receptor.

Goserelin is an LHRH agonist that suppresses oestrogen production by the ovaries. It is often used as adjuvant therapy in premenopausal women.

Tamoxifen is an antagonist (and partial agonist) of the oestrogen receptor. It is particularly useful in treating oestrogen-receptor positive breast cancer, especially in patients who have not yet gone through menopause.

Anti-oestrogen drugs are used in the management of oestrogen receptor-positive breast cancer. Selective oEstrogen Receptor Modulators (SERM) such as Tamoxifen act as an oestrogen receptor antagonist and partial agonist. However, Tamoxifen may cause adverse effects such as menstrual disturbance, hot flushes, venous thromboembolism, and endometrial cancer. On the other hand, aromatase inhibitors like Anastrozole and Letrozole reduce peripheral oestrogen synthesis, which is important in postmenopausal women. Anastrozole is used for ER +ve breast cancer in this group. However, aromatase inhibitors may cause adverse effects such as osteoporosis, hot flushes, arthralgia, myalgia, and insomnia. NICE recommends a DEXA scan when initiating a patient on aromatase inhibitors for breast cancer.

A pregnant woman who has 3 risk factors should receive LMWH from 28 weeks until 6 weeks after giving birth. If she has more than 3 risk factors, she should start LMWH immediately and continue until 6 weeks postnatal.

The risk factors for thromboprophylaxis include age over 35, a body mass index over 30, parity over 3, smoking, gross varicose veins, current pre-eclampsia, immobility, family history of unprovoked VTE, low risk thrombophilia, multiple pregnancy, and IVF pregnancy.

In this particular case, the woman has 4 risk factors, including being 36 years old, a smoker, having a parity over 3, and a body mass index of 33. Therefore, she needs to begin taking low molecular weight heparin immediately and continue until 6 weeks after giving birth.

While all pregnant women should be advised to stay mobile and hydrated, this woman requires medical treatment due to her increased risk factors.

Pregnancy increases the risk of developing venous thromboembolism (VTE), which is why it is important to assess a woman’s individual risk during pregnancy and take appropriate prophylactic measures. A risk assessment should be conducted at the time of booking and on any subsequent hospital admission. Women with a previous VTE history are automatically considered high risk and require low molecular weight heparin throughout the antenatal period, along with input from experts. Women at intermediate risk due to hospitalization, surgery, comorbidities, or thrombophilia should also be considered for antenatal prophylactic low molecular weight heparin.

The risk assessment at booking should include factors that increase the likelihood of developing VTE, such as age over 35, body mass index over 30, parity over 3, smoking, gross varicose veins, current pre-eclampsia, immobility, family history of unprovoked VTE, low-risk thrombophilia, multiple pregnancy, and IVF pregnancy. If a woman has four or more risk factors, immediate treatment with low molecular weight heparin should be initiated and continued until six weeks postnatal. If a woman has three risk factors, low molecular weight heparin should be initiated from 28 weeks and continued until six weeks postnatal.

If a diagnosis of DVT is made shortly before delivery, anticoagulation treatment should be continued for at least three months, as in other patients with provoked DVTs. Low molecular weight heparin is the preferred treatment for VTE prophylaxis in pregnancy, while Direct Oral Anticoagulants (DOACs) and warfarin should be avoided. By taking these measures, the risk of developing VTE during pregnancy can be reduced.

Monozygotic twins with one chorion and two amnions are the result of division between days 4 and 8 after fertilization. This type of twinning has diamniotic, monochorionic placentation. Division between days 8 and 12 after fertilization leads to monozygotic twins with monoamniotic, monochorionic placentation, while fertilization of two separate eggs with two separate sperm results in dizygotic twins with diamniotic, dichorionic placentation. It’s important to note that division between days 4 and 8 after fertilization does not result in dizygotic twins.

Twin Pregnancies: Incidence, Types, and Complications

Twin pregnancies occur in approximately 1 out of 105 pregnancies, with the majority being dizygotic or non-identical twins. Monozygotic or identical twins, on the other hand, develop from a single ovum that has divided to form two embryos. However, monoamniotic monozygotic twins are associated with increased risks of spontaneous miscarriage, perinatal mortality rate, malformations, intrauterine growth restriction, prematurity, and twin-to-twin transfusions. The incidence of dizygotic twins is increasing due to infertility treatment, and predisposing factors include previous twins, family history, increasing maternal age, multigravida, induced ovulation, in-vitro fertilisation, and race, particularly Afro-Caribbean.

Antenatal complications of twin pregnancies include polyhydramnios, pregnancy-induced hypertension, anaemia, and antepartum haemorrhage. Fetal complications include perinatal mortality, prematurity, light-for-date babies, and malformations, especially in monozygotic twins. Labour complications may also arise, such as postpartum haemorrhage, malpresentation, cord prolapse, and entanglement.

Management of twin pregnancies involves rest, ultrasound for diagnosis and monthly checks, additional iron and folate, more antenatal care, and precautions during labour, such as having two obstetricians present. Most twins deliver by 38 weeks, and if longer, most are induced at 38-40 weeks. Overall, twin pregnancies require close monitoring and management to ensure the best possible outcomes for both mother and babies.

Anti-oestrogen drugs are used in the management of oestrogen receptor-positive breast cancer. Selective oEstrogen Receptor Modulators (SERM) such as Tamoxifen act as an oestrogen receptor antagonist and partial agonist. However, Tamoxifen may cause adverse effects such as menstrual disturbance, hot flushes, venous thromboembolism, and endometrial cancer. On the other hand, aromatase inhibitors like Anastrozole and Letrozole reduce peripheral oestrogen synthesis, which is important in postmenopausal women. Anastrozole is used for ER +ve breast cancer in this group. However, aromatase inhibitors may cause adverse effects such as osteoporosis, hot flushes, arthralgia, myalgia, and insomnia. NICE recommends a DEXA scan when initiating a patient on aromatase inhibitors for breast cancer.