MSFinals-3447
A Cardiotocogram (CTG) is performed on a 29-year-old female at 37 weeks gestation who has arrived at labour ward in spontaneous labour. The CTG shows a foetal heart rate of 120 bpm and variable decelerations and accelerations are present. There are no late decelerations. However, the midwife notices a 15 minute period where the foetal heart rate only varies by 2-3bpm. The mum is worried as she has not felt her baby move much for about 15 mins and would like to know what the likely cause is. She starts crying when she tells you that she took some paracetamol earlier as she was in so much pain from the contractions and is concerned this has harmed her baby. What is the most probable reason for this reduced variability?