Abstract Intrahepatic cholestasis of pregnancy, also known as obstetric cholestasis, is a pruritic condition of pregnancy characterized by an underlying elevation in circulating bile acids and liver ...derangement, and associated with adverse fetal outcomes, such as preterm labor and stillbirth. Limited understanding of the underlying pathophysiology and mechanisms involved in adverse outcomes has previously restricted treatment options and pregnancy management. Recent advances in these research fields provide tantalizing targets to improve the care of pregnant women affected by this condition.
Pregnancy is associated with progressive hypercholanemia, hypercholesterolemia, and hypertriglyceridemia, which can result in metabolic disease in susceptible women. Gut signals modify hepatic ...homeostatic pathways, linking intestinal content to metabolic activity. We sought to identify whether enteric endocrine signals contribute to raised serum bile acids observed in human and murine pregnancies, by measuring fibroblast growth factor (FGF) 19/15 protein and mRNA levels, and 7α‐hydroxy‐4‐cholesten‐3‐one. Terminal ileal farnesoid X receptor (FXR)‐mediated gene expression and apical sodium bile acid transporter (ASBT) protein concentration were measured by qPCR and western blotting. Shotgun whole‐genome sequencing and ultra‐performance liquid chromatography tandem mass spectrometry were used to determine the cecal microbiome and metabonome. Targeted and untargeted pathway analyses were performed to predict the systemic effects of the altered metagenome and metabolite profiles. Dietary CA supplementation was used to determine whether the observed alterations could be overcome by intestinal bile acids functioning as FXR agonists. Human and murine pregnancy were associated with reduced intestinal FXR signaling, with lower FGF19/15 and resultant increased hepatic bile acid synthesis. Terminal ileal ASBT protein was reduced in murine pregnancy. Cecal bile acid conjugation was reduced in pregnancy because of elevated bile salt hydrolase‐producing Bacteroidetes. CA supplementation induced intestinal FXR signaling, which was not abrogated by pregnancy, with strikingly similar changes to the microbiota and metabonome as identified in pregnancy. Conclusion: The altered intestinal microbiota of pregnancy enhance bile acid deconjugation, reducing ileal bile acid uptake and lowering FXR induction in enterocytes. This exacerbates the effects mediated by reduced bile acid uptake transporters in pregnancy. Thus, in pregnant women and mice, there is reduced FGF19/15‐mediated hepatic repression of hepatic bile acid synthesis, resulting in hypercholanemia.
Abstract
Background
Each year in the UK, approximately 35,000 women develop gestational diabetes mellitus (GDM). The condition increases the risk of obstetric and neonatal complications for mother ...and child, including preeclampsia, preterm birth, and large for gestational age babies. Biochemical consequences include maternal hyperglycemia, neonatal hypoglycemia, and dyslipidemia. Metformin is the most commonly used firstline pharmacological treatment. However, there are concerns about its widespread use during pregnancy, due to its limited efficacy and potential safety concerns. Therefore, there is a need for additional therapies that improve both maternal–fetal glucose and lipid metabolism.
Ursodeoxycholic acid (UDCA) is not currently used for treatment for GDM. However, it can improve glucose control in type 2 diabetes, and it improves fetal lipid profiles in gestational cholestasis. Consequentially, it is hypothesized that treatment with UDCA for women with GDM may improve both maternal metabolism and neonatal outcomes. The primary outcome of this trial is to assess the efficacy of UDCA compared with metformin to improve glucose levels in women with GDM.
Methods
The trial is a two-armed, open-label, multi-center, randomized controlled trial. Women are eligible if they have been diagnosed with GDM by an oral glucose tolerance test between 24 + 0 and 30 + 6 weeks’ gestation, and if they require pharmacological intervention. In total, 158 pregnant women will be recruited across seven NHS Trusts in England and Wales. Women who consent will be recruited and randomized to either metformin or UDCA, which will be taken daily until the birth of their baby. Maternal and neonatal blood samples will be taken to evaluate the impact of the treatments on maternal glucose control, and maternal and neonatal lipid metabolism. Maternal and fetal outcomes will be evaluated, and acceptability of UDCA compared with metformin will be assessed.
Discussion
This trial has the potential to identify a potential new treatment for women with GDM. If successful, a future large multi-center trial will be designed to investigate where decisions can be personalized to identify which women will respond more effectively to UDCA than alternatives to improve maternal and baby outcomes.
Trial registration
ClinicalTrials.gov NCT04407650.
Severe early onset (less than 34 weeks gestation) intrahepatic cholestasis of pregnancy (ICP) affects 0.1% of pregnant women in Australia and is associated with a 3-fold increased risk of stillbirth, ...fetal hypoxia and compromise, spontaneous preterm birth, as well as increased frequencies of pre-eclampsia and gestational diabetes. ICP is often familial and overlaps with other cholestatic disorders. Treatment options for ICP are not well established, although there are limited data to support the use of ursodeoxycholic acid (UDCA) to relieve pruritus, the main symptom. Rifampicin, a widely used antibiotic including in pregnant women, is effective in reducing pruritus in non-pregnancy cholestasis and has been used as a supplement to UDCA in severe ICP. Many women with ICP are electively delivered preterm, although there are no randomised data to support this approach.
We have initiated an international multicentre randomised clinical trial to compare the clinical efficacy of rifampicin tablets (300 mg bd) with that of UDCA tablets (up to 2000 mg daily) in reducing pruritus in women with ICP, using visual pruritus scores as a measuring tool.
Our study will be the first to examine the outcomes of treatment specifically in the severe early onset form of ICP, comparing "standard" UDCA therapy with rifampicin, and so be able to provide for the first-time high-quality evidence for use of rifampicin in severe ICP. It will also allow an assessment of feasibility of a future trial to test whether elective early delivery in severe ICP is beneficial.
Australian New Zealand Clinical Trials Registration Number (ANZCTR): 12618000332224p (29/08/2018). HREC No: HREC/18/WCHN/36. EudraCT number: 2018-004011-44. IRAS: 272398. NHMRC registration: APP1152418 and APP117853.
While we welcome the intention of Li et al. (1) to assess the effect of intrahepatic cholestasis of pregnancy (ICP) upon newborn birthweight, we have concerns about the authors’ interpretation of ...their findings because the birthweights in their meta-analysis were not corrected for gestational week or reported as a customised birthweight centile.
The incidence of gestational diabetes is increasing, with higher obesity in the pregnant population, lifestyle changes and migration thought to underlie this. Recent large studies, such as the MiG, ...HAPO and ACHOIS trials, have furthered our understanding of both the implications of the disease and the management options available. Previous CEMACH (Confidential Enquiries into Maternal and Child Health) studies of diabetes in pregnancy have shown a significant proportion of patients receiving sub-optimal care. We aim to summarise the current standard of management strategies in pregnancy, whilst acknowledging controversies and limitations in the existing evidence. Antenatal management involves service organisation to provide multi-disciplinary team reviews to address glycaemic control, fetal monitoring and associated conditions such as obesity and hypertensive disorders of pregnancy. The use of diet, exercise, oral hypoglycaemic agents and insulins will be discussed, along with specific considerations for the management of preterm labour and administration of corticosteroids for fetal lung maturity. The timing and management of labour, including mechanisms of delivery, will be covered, including neonatal considerations and the use of breast feeding. Finally, a discussion of appropriate post delivery care will consider the prevention of, and screening for, the development of type 2 diabetes.
PDF
