The bile and bile acid that aid digestion and ensure good nutrition can make life uncomfortable for some pregnant women. Their babies may also be at risk for dangerous breathing problems.
The trouble begins when the normal flow of bile acid and bile from the liver is interrupted during pregnancy. Bile acid is a key component of bile. The blockage leads to a buildup of both in the liver and blood stream. Women with the problem have itchy skin until the baby is born. But about 30% of the newborns develop life-threatening respiratory distress.
The disorder is called intrahepatic cholestasis of pregnancy. It affects as many as 5% of pregnant women with no history of liver disease. St. Jude research has dramatically improved our understanding of the problem. The study also identified a lead on how to protect newborns.
Working in a mouse model of the human disease, scientists found evidence that bile acid can cross the placenta and build up in fetal lungs. The results also suggest bile prevents proper assembly of a chemical that helps keep newborn lungs inflated. Investigators found that blocking the reabsorption of bile acid in the intestines of the pregnant mouse eased that risk.
“The results suggest it may be possible to develop drugs to reduce the risk of newborn respiratory distress by reducing bile acid levels in maternal blood and preventing its reabsorption in the intestines,” said John Schuetz, PhD, Pharmaceutical Sciences vice chair.
Zhang Y, Li F, Wang Y, Pitre A, Fang ZZ, Frank MW, Calabrese C, Krausz KW, Neale G, Frase S, Vogel P, Rock CO, Gonzalez FJ, Schuetz JD. Maternal bile acid transporter deficiency promotes neonatal demise. Nature Comm Sep 29, 2015. Epub ahead of print. doi:10.1038/ncomms9186.