Bile Acid Effects in Fetal Arrhythmia Study

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder of pregnancy that typically presents in late pregnancy with generalised itching. ICP is associated with an increased risk of pregnancy complications, including premature labour, fetal distress, and stillbirth. Models of the fetal heart (using cells from rodents) have shown that high bile acids levels cause an abnormal heart rhythm (arrhythmia), which may be the cause of stillbirth. High levels of bile acids also cause preterm labour in animal models. This pilot study aims to assess whether severe ICP, defined as maternal serum bile acid levels ≥40μmol/L, is associated with abnormal fetal heart rhythms and abnormal myometrial contractility, which may lead to preterm birth. Fetal heart rhythms and myometrial contractility will be recorded using a portable electrocardiogram (ECG) device, the Monica AN24. This monitors the fetal heart and myometrial activity via stickers applied to the mother's abdomen. It also records the maternal ECG. It will also study women with uncomplicated pregnancy, in order to make comparisons. The importance of maternal position during sleep has also more recently been established, with some studies demonstrating an association between the risk of stillbirth and the position the mother was sleeping in. Work by Stone et al published this year has shown that the maternal sleep position has a significant impact on the fetal sleep state and fetal heart rate, (in particular something called the fetal RMSSD value). The researchers therefore wish to identify any potential correlation between fetal heart arrhythmia and maternal sleep position. To do this they will use a Zephyr BioPatchTM which provides a clear indication of whether the patient was in left lateral, right lateral or supine position.