Effect of Maternal Ursodeoxycholic Acid Treatment on Fetal Atrioventricular Conduction in Patients with Intrahepatic Cholestasis of Pregnancy.

Introduction: The aim of this study was, first, to investigate the difference in fetal atrioventricular conduction in patients with and without intrahepatic cholestasis of pregnancy (ICP) by measuring the fetal PR interval; second, to evaluate the altering effect of ursodeoxycholic acid (UDCA) treatment on the fetal PR interval in ICP patients.

Methods: The study consisted of 42 ICP patients and 48 healthy pregnant women. Fetal echocardiography was performed to measure the mechanical PR interval. The fetal PR interval and the clinical characteristics were compared between the two groups. The effect of UDCA treatment on the fetal PR interval in ICP patients was evaluated.

Results: In ICP patients, significantly longer fetal PR intervals were observed than in the control group (123.21 ± 8.54 vs. 115.13 ± 5.95 ms, p < 0.001). In the ICP group, there was a positive correlation between the fetal PR interval and maternal fasting total bile acid (TBA) levels (r = 0.514, p = 0.001). After 1 week of treatment with UDCA in patients with ICP, the PR interval was shorter than before, although the reduction was not statistically significant (120.98 ± 6.70 vs. 123.21 ± 8.54 ms, p = 0.095). In patients with severe ICP (TBA >40 mmol/L, n = 10), a significant reduction in the fetal PR interval was observed after treatment with UDCA (127.5 ms [IQR, 118.0-134.75] before vs. 122 ms [IQR, 109.5-126.5] after, p = 0.037).

Conclusion: Fetal PR interval increased in ICP patients in correlation with maternal serum TBA concentration. Treatment with UDCA may have limited positive effects on the fetal AV conduction system. The beneficial effects of UDCA on the fetal PR interval may be more pronounced in patients with higher bile acid levels.