What happens to bile acid levels during pregnancy?

Cholestasis sometimes starts in early pregnancy. But it is more common in the second and third trimesters. It most often goes away within a few days after delivery. The high levels of bile may cause serious problems for your developing baby (fetus).

What are unconjugated bile acids?

Bacterial biotransformations of bile acids occur on the side chain and the nucleus. On the side chain, bile acids undergo deconjugation to form an unconjugated bile acid and glycine or taurine. Deoxycholic and lithocholic acids are called “secondary bile acids” because they are formed from primary bile acids.

What should bile acid levels be in pregnancy?

Most important for the diagnosis of ICP is a notable (>11-μmol/L) elevation of total serum bile acid levels. Total serum bile acid levels are slightly higher in pregnant than in nonpregnant women (mean ± SD, 6.6 ± 0.3 μmol/L vs 5.7 ± 0.4 μmol/L),16 and levels up to 11.0 μmol/L are accepted as normal in late gestation.

Do bile acids increase in pregnancy?

Symptoms and Causes In some people, when levels of hormones such as estrogen increase during pregnancy, the flow of bile in the liver stops or slows down. This slowdown can cause bile to build up in the liver and enter the bloodstream.

When do bile acids change in the second trimester?

Unconjugated bile acids dominate the bile acid profile in the second trimester, while conjugated bile acids, especially (taurine-conjugated) dominate in the third trimester. 28–31 weeks gestation was the notable change period of bile acid metabolism.

Why are bile acids so important in pregnancy?

Their homeostatic control is essential to the physiology of the normal pregnancy. Abnormalities of bile acids regulation in pregnancy lead to intrahepatic cholestasis of pregnancy, a serious condition associated with a number of fetal and maternal morbidities.

How are bile acids deconjugated in the hepatocyte?

Bile acids conjugate with glycine or taurine in the hepatocyte. Before 7-dehydroxylation, bile acids are deconjugated by bacterial enzymes. Sulfation of lithocholic acid conjugates prevents ileal conservation and results in rapid excretion from the body. Figure 1 has been published previously. Figure 2.

What is the concentration of bile acids in plasma?

The concentration of bile acids in plasma is always low. Portal venous plasma has a concentration of 20 to 50 µmol/L in humans. Because of efficient first-pass extraction, the concentration of bile acids in systemic venous plasma is less than 5 µmol/L during the fasting state.