Assessment of Mechanical Fetal PR Interval in Intrahepatic Cholestasis of Pregnancy and Its Relationship with the Severity of the Disease

Fetal PR Interval in Pregnancies with Intrahepatic Cholestasis of Pregnancy: A Case-Control Study

OBJECTIVE

 This study had three purposes: first, to explore differences in fetal cardiac function in patients with and without intrahepatic cholestasis of pregnancy (ICP) based on PR interval (the interval between the beginning of the atrial contraction and the beginning of the ventricular contraction). Second, to explore a potential correlation between PR interval and bile acid levels in pregnant women with ICP. Third, to study changes in PR interval of fetuses from pregnant women with ICP after administration of ursodeoxycholic acid (UDCA).

STUDY DESIGN

 This was a prospective observational case-control study. ICP was defined as palmar plantar pruritus of nocturnal predominance for more than 1 week associated with a total bile acid level >10 μmol/L. Control cases were women with pregnancies scheduled for induction or elective cesarean section at term.

RESULTS

 One hundred and ten women with ICP and 72 controls were included in the study. Median gestational age at inclusion was 35.9 weeks. Median PR interval was significantly longer in fetuses of women with ICP (122 vs. 102 ms, p < 0.001). There was a significant correlation between bile acid levels and PR interval (rho = 0.723, p < 0.001). In 22 fetuses, the median PR interval decreased significantly following UDCA administration (134 vs. 118 ms, p = 0.004).

CONCLUSION

 PR interval is longer in fetuses of women with ICP. PR interval was significantly correlated with bile acid levels, and administration of UDCA significantly reduced PR interval.

KEY POINTS

· Differences in fetal cardiac function in patients with and without intrahepatic cholestasis.. · PR interval and bile acid levels in pregnant women with intrahepatic cholestasis.. · Changes in PR interval of fetuses from pregnant women with ICP after use of UDCA..

Intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction: a systematic review and meta-analysis

OBJECTIVE

Intrahepatic cholestasis of pregnancy is associated with adverse perinatal outcomes. Fetal cardiac dysfunction may be 1 part of the pathophysiology of pregnancies complicated by intrahepatic cholestasis of pregnancy. This systematic review and meta-analysis aimed to evaluate the association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction.

DATA SOURCES

Systematic searches were performed on the databases of Medline, Embase, and Cochrane Library (up to March 2, 2023) for studies evaluating fetal cardiac function in pregnancies complicated by intrahepatic cholestasis of pregnancy in addition to the reference lists of included studies.

STUDY ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they assessed the fetal cardiac function by fetal echocardiography in women with intrahepatic cholestasis of pregnancy (mild or severe) and compared with fetuses of healthy pregnant women. The studies published in English were included.

METHODS

The quality of the retrieved studies was assessed using the Newcastle-Ottawa Scale. Data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were pooled for the meta-analysis using random-effects models. The results were presented as weighted mean differences and 95% confidence intervals. This meta-analysis was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42022334801).

RESULTS

A total of 14 studies were included in this qualitative analysis. Of note, 10 studies that reported data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were included in the quantitative analysis and showed a significant association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction. Significantly higher fetal left ventricular myocardial performance index values (weighted mean difference, 0.10; 95% confidence interval, 0.04-0.16) and longer fetal PR intervals (weighted mean difference, 10.10 ms; 95% confidence interval, 7.34-12.86) were revealed in pregnancies complicated by intrahepatic cholestasis of pregnancy. Compared with the situation in pregnancies complicated by mild intrahepatic cholestasis of pregnancy, PR intervals were even longer in pregnancies complicated by severe intrahepatic cholestasis of pregnancy (weighted mean difference, 5.98 ms; 95% confidence interval, 0.20-11.77). There was no significant difference in fetal E wave/A wave peak velocities ratio between the group with intrahepatic cholestasis of pregnancy and the healthy pregnant group (weighted mean difference, 0.01; 95% confidence interval, -0.03 to 0.05).

CONCLUSION

Our findings supported the idea that intrahepatic cholestasis of pregnancy is associated with overall impaired fetal myocardial performance and impaired fetal cardiac conduction system. However, current evidence about the association between fetal cardiac dysfunction and intrahepatic cholestasis of pregnancy-induced stillbirth is lacking. Further studies are needed to reveal the relationship between fetal cardiac dysfunction and adverse perinatal outcomes in pregnancies complicated by intrahepatic cholestasis of pregnancy.

Fetal cardiac dysfunction in pregnancies affected by intrahepatic cholestasis of pregnancy: A cohort study

AIM

To analyze the presence of fetal myocardial dysfunction in intrahepatic cholestasis of pregnancy (ICP) at diagnosis.

METHODS

This prospective cohort study included 49 pregnant participants with ICP at diagnosis and 49 nonaffected controls from a single public hospital. ICP was diagnosed based on clinical symptoms after excluding other causes of pruritus and presence of autoimmune diseases. Total bile acids were not obtained in this cohort. ICP pregnancies were assessed with a functional echocardiography at diagnosis including PR-interval, isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) for electrical, systolic, and diastolic function, respectively. Controls were assessed at recruitment. Perinatal outcomes were obtained from delivery books. The main outcome was the presence of PR-interval prolongation or first-degree fetal heart block, and echographic signs of diastolic and systolic dysfunction.

RESULTS

Compared to controls, ICP were above upper limit in conjugated bilirubin (2.0% vs. 20.4%; p = 0.008), aspartate aminotransferase (2.0% vs. 24.5%; p = 0.002), and alanine aminotransferase (4.1% vs. 28.6%; p = 0.002). ICP was associated with a higher PR-interval (130 ± 12 ms vs. 121 ± 6 ms; p < 0.0001) with five first-degree fetal heart blocks. IRT was significantly higher in ICP (42 ± 6 ms vs. 37 ± 5 ms; p = 0.0001), with no differences in ICT and ET. PR-interval trend was only positively correlated with IRT in ICP pregnancies (p = 0.04 and p = 0.34, in ICP and controls, respectively).

CONCLUSIONS

Our study demonstrates that fetuses affected by maternal ICP are associated with electrical and diastolic myocardial dysfunction. More studies focused on antenatal and postnatal functional echocardiography are necessary to validate our results and consider these markers in the clinical management of ICP pregnancies.