Intrahepatic Cholestasis of Pregnancy: Toward Improving Perinatal Outcome

Bile acid-gut microbiota imbalance in cholestasis and its long-term effect in mice

Cholestasis is a common morbid state that may occur in different phases; however, a comprehensive evaluation of the long-term effect post-recovery is still lacking. In the hepatic cholestasis mouse model, which was induced by a temporary complete blockage of the bile duct, the stasis of bile acids and liver damage typically recovered within a short period. However, we found that the temporary hepatic cholestasis had a long-term effect on gut microbiota dysbiosis, including overgrowth of small intestinal bacteria, decreased diversity of the gut microbiota, and an overall imbalance in its composition accompanied by an elevated inflammation level. Additionally, we observed an increase in Escherichia-Shigella (represented by ASV136078), rich in virulence factors, in both small and large intestines following cholestasis. To confirm the causal role of dysregulated gut microbiota in promoting hepatic inflammation and injury, we conducted gut microbiota transplantation into germ-free mice. We found that recipient mice transplanted with feces from cholestasis mice exhibited liver inflammation, damage, and accumulation of hepatic bile acids. In conclusion, our study demonstrates that cholestasis disrupts the overall load and structural composition of the gut microbiota in mice, and these adverse effects persist after recovery from cholestatic liver injury. This finding suggests the importance of monitoring the structural composition of the gut microbiota in patients with cholestasis and during their recovery.

IMPORTANCE

Our pre-clinical study using a mouse model of cholestasis underscores that cholestasis not only disrupts the equilibrium and structural configuration of the gut microbiota but also emphasizes the persistence of these adverse effects even after bile stasis restoration. This suggests the need of monitoring and initiating interventions for gut microbiota structural restoration in patients with cholestasis during and after recovery. We believe that our study contributes to novel and better understanding of the intricate interplay among bile acid homeostasis, gut microbiota, and cholestasis-associated complications. Our pre-clinical findings may provide implications for the clinical management of patients with cholestasis.

Systematic review and meta-analysis: Evaluating the influence of intrahepatic cholestasis of pregnancy on obstetric and neonatal outcomes

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a serious liver conditions that negatively impacts obstetric and neonatal outcomes. Elevated levels of bile acid, particularly glycine conjugate, may compromise blood flow and cause functional hypoxia-ischemia.

AIMS

This meta-analysis aims to assess the association between ICP and key pregnancy outcomes including emergency caesarian sections (C-sections), preeclampsia, hemorrhage, preterm birth, small for gestational age, admission rate to neonatal intensive care union (NICU), gestational age, and stillbirth.

MATERIALS AND METHODS

Literature search across five databases (PubMed, Embase, Web of Science) was done to detect relevant studies published up until June 2023. Meta-analysis of the identified studies was done using a random-effects model, and the results presented as Odds ratio (OR).

RESULTS

A literature search identified 662 studies. Of them, 21 met the inclusion criteria. There was a significant association between ICP and odds of C-section (OR: 1.42, p <0.001), preeclampsia (OR: 2.64, p <0.001), NICU admission (OR: 2.1, p <0.001), and pre-term birth (OR: 2.64, p <0.001). ICP was not associated with postpartum hemmorhage (OR: 1.31, p = 0.13), small for gestational age (OR: 0.87, p = 0.07), stillbirth (OR: 1.49, p = 0.29).

CONCLUSIONS

Our results confirm the adverse effects of ICP on co-existing pregnancy complications, obstetric and neonatal outcomes. ICP in associated with severe complications including increased rates of preeclampsia, emergency C-sections, preterm births, l gestational periods and higher rates of NICU admissions. These results may assist healthcare professionals in formulating comprehensive care guidelines for expectant mothers and newborns.

Proteomic Biomarkers of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease, which can lead to adverse fetal outcomes, including preterm labor and intrauterine death. The pathogenesis of ICP is still unclear. We hypothesized that pathological index leads to abnormal placenta changes in ICP. Investigation of these differences in protein expression in parallel profiling is essential to understand the comprehensive pathophysiological mechanism underlying ICP. The present study screened differentially expressed proteins (DEPs) as novel diagnostic markers for ICP. Proteomic profiles of placental tissues from 32 ICP patients and 24 healthy volunteers (controls) were analyzed. Our founding was valid by following western blotting and immunohistochemistry staining, respectively. The association of the key protein expression with clinicopathological features of ICP was further analyzed. A total of 178 DEPs were identified between the ICP and control groups. Functional enrichment analysis showed these proteins were significantly enriched in the PPAR singling pathway by KEGG and PPARα/RXRα activation by IPA. Apolipoprotein A2 (APOA2) was the only upregulated protein, which uniquely identified in ICP groups and related to both pathways. Validation of western blotting and immunohistochemical staining analysis showed significantly higher APOA2 expression in the ICP group than in the control group. Furthermore, the expression of APOA2 is associated with clinicopathological features in ICP groups. Receiver operating characteristic (ROC) curve analyses showed that the AUC of APOA2 was 0.8984 (95% confidence interval (CI): 0.772-1.000). This study has identified up-regulated APOA2 associated with PPAR singling pathway and PPARα/RXRα activation in ICP. Thus, APOA2 may be involved in ICP pathogenesis, serving as a novel biomarker for its diagnosis.

Genetically predicted lipids mediate the association between intrahepatic cholestasis of pregnancy and cardiovascular disease

Introduction

Intrahepatic cholestasis of pregnancy (ICP), the most prevalent liver disorder specific to pregnancy, affects approximately 1.5%-4% of pregnancies. However, the influence of ICP on cardiovascular disease (CVD), including hypertension (HTN) and coronary artery disease (CAD), has not been thoroughly investigated.

Methods

This study explores the causal relationship between ICP and CVD (HTN, CAD) using Mendelian Randomization (MR). Utilizing summary-level data from Genome-Wide Association Studies (GWAS), we applied the inverse-variance weighted (IVW) method, supplemented by sensitivity and reverse MR analyses, to ascertain robustness.

Results

Our findings reveal significant causal links, indicating ICP notably increases the risk of CVD (P = 0.001), hypertension (HTN, P = 0.024), and coronary artery disease (CAD, P = 0.039). A two-step MR analysis highlighted the mediation role of lipid profiles, with LDL, TC, and Apo-B contributing to increased CVD risk by 25.5%, 12.2%, and 21.3%, respectively. Additionally, HTN was identified as a mediator in the ICP-CAD association, accounting for a 14.5% mediation effect.

Discussion

The results underscore the genetic predisposition of ICP to elevate CVD risk and the critical mediating role of lipid levels, emphasizing the need for vigilant lipid monitoring and early intervention in individuals with ICP.

Predictors of Adverse Fetal Outcomes in Intrahepatic Cholestasis of Pregnancy (ICP): a Narrative Review

Intrahepatic cholestasis of pregnancy (ICP) is a hepatic disorder in pregnancy linked with adverse fetal outcomes, which primarily manifests in the late second and third trimesters of pregnancy. This review aims to recapitulate the existing evidence on factors that can predict detrimental perinatal outcomes in pregnant women diagnosed with intrahepatic cholestasis of pregnancy. We searched PubMed, Web of Science, Cochrane Library, Scopus, Medline, and Embase databases and selected studies related to predictors of fetal outcome in intrahepatic cholestasis of pregnancy. Studies of the articles showed that predictors of an adverse fetal outcome include in vitro fertilization (IVF) pregnancy, multifetal pregnancy, biochemical markers, gestational age of ICP onset, presence of comorbidities (preeclampsia and gestational diabetes mellitus), maternal history of ICP, and hepatobiliary disease.Intrahepatic cholestasis of pregnancy (ICP) complicates the pregnancy. Hence, early assessment of low-risk and high-risk groups will help to administer definite management protocols and strategies to prevent adverse neonatal outcomes. Further research should concentrate on the number of conditions/factors and the predictive power of different factors to determine the most reliable predictors and biomarkers that can predict adverse fetal outcomes and improve the assessment of risk in pregnancy complicated with ICP.