Intrahepatic Cholestasis of Pregnancy: Role of Baby’s Sex on Itch Severity and Bile Acid Levels

Background Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disorder of pregnancy. It occurs when bile flow from the liver is obstructed, causing bile acid to accumulate. ICP usually presents with itching that lasts for the remainder of pregnancy. Untreated ICP has been shown to increase the incidence of adverse outcomes for the baby, including respiratory distress, meconium aspiration, neonatal intensive care unit hospitalization, and stillbirth. The probability of these events increases when bile acid levels are greater than 40 mmol/L. The current standard of care for ICP patients is a combination of ursodeoxycholic acid by mouth and early delivery, as the risk of stillbirth due to ICP increases in the last weeks of pregnancy. ICP has been linked to preeclampsia and gestational diabetes; studies have shown that the occurrence of both diseases is greater when the baby is male. The purpose of this study was to investigate if the occurrence, timing of diagnosis, peak bile acid levels, or severity of itching is dependent on the baby’s sex in mothers who had ICP. Methods An online question-set (survey) was offered to women who had had ICP and were members of three different online support groups. Results A total of 1,502 women responded for a total of 2,289 documented ICP pregnancies, in which there were 1,059 female babies and 1,230 male babies. Based on chi-square analysis of differences in frequencies, no difference was found between pregnancies with male versus female babies regarding the occurrence, timing of diagnosis, peak bile acid levels, or severity of itching in the evaluated population. However, surprisingly, the findings revealed that first-trimester diagnosis of ICP was made in 5.6% of the pregnancies, and there were 30 (1.8%) cases of ICP diagnosed in the absence of itching. Conclusions The findings suggest that the baby’s sex does not impact the occurrence, timing of diagnosis, peak bile acid levels, or itch severity in ICP. The findings that 5.6% of the ICP pregnancies in the present study were diagnosed in the first trimester and 1.8% were diagnosed without the presence of itching reinforce the need to investigate these less common presentations. More studies are needed to determine if these findings are consistent across other populations.