Increased PR Interval in Fetuses of Patients with Intrahepatic Cholestasis of Pregnancy

Objective: To evaluate the fetal mechanical PR interval in fetuses from pregnancies with intrahepatic cholestasis of pregnancy (ICP). Methods: A case-control study was conducted in the Maternal-Fetal Medicine Unit at Hospital Carlos Van Buren between 2011 and 2013. Fetal echocardiography was performed in patients with ICP and normal pregnancies. Demographic and clinical characteristics were compared using the Mann-Whitney U test for continuous variables. A p value <0.05 was considered significant. Results: 51 patients with ICP were compared with 51 unaffected pregnancies. There were no significant differences in neither demographic nor clinical characteristics between the two groups. The fetal PR interval was significantly longer in the ICP group when compared to the control group (134.6 ± 12 vs. 121.4 ± 10 ms, p < 0.001). Moreover, four fetuses from the ICP group had a mechanical PR interval >150 ms, which is compatible with a first-degree atrioventricular block. Two fetuses were identified in the neonatal period and were transferred to pediatric cardiology for follow-up, with a normal mechanical PR after the first month of life. Conclusions: We demonstrated that the fetal cardiac conduction system is altered in fetuses of patients with ICP. Further research is necessary to determine whether this alteration is related to stillbirths seen in ICP.