Bile-Acid Levels and Lung Maturity Test in Patients With Intrahepatic Cholestasis of Pregnancy

OBJECTIVES: Prolonged fetal exposure to maternal bile acids have been linked to fetal lung injury, but it is not known if it affects production of surfactant or fetal lung maturity tests. We set out to determine if elevated total bile acid (TBA) levels predict delayed fetal lung maturity (FLM) in patients with intrahepatic cholestasis of pregnancy (ICP). METHODS: A retrospective cohort study examining patients with ICP who underwent amniocentesis between 36+0 and 37+6 between 2005 and 2014. Primary goal was to identify if a relationship exists between TBA levels and FLM defined as Lecithin:Sphingomyelin \u3e2.5, detectable Phosphatidylglycerol, or lamellar body count of \u3e50,000. RESULTS: Among the 113 patients, there was no statistically significant difference in TBA levels between women with FLM and those with immaturity (31.3 [21.6, 44.5] μmol/L and 34.9 [23.9, 62.3] μmol/L respectively; p=0.16). Logistic regression performed using predefined TBA levels of 20, 30, 40 and 50 μmol/L revealed that TBA levels did not predict a negative FLM test at time of amniocentesis. CONCLUSIONS: TBA levels do no predict presence or absence of FLM between 36+0 and 37+6 weeks of gestation. Though certain pregnancy complications can affect FLM, we could not identify a correlation between TBA levels and an accelerated or delayed lung maturation process