https://www.gastrojournal.org/article/0016-5085(80)90072-4/pdf

A critical evaluation of real-time ultrasonography for the study of gallbladder volume and contraction

We used real-time ultrasonography to study gallbladder kinetics in 11 nonpregnant women, 17 women using steroid contraceptives, and 33 pregnant women. Gallbladder volume was determined after an overnight fast and serially for 90 minutes after a standard liquid meal. After the first trimester of pregnancy, gallbladder volume during fasting and residual volume after contraction were twice as large as in control subjects. The rate of emptying and the percentage emptied were reduced. In early pregnancy the only important abnormality was a 30 per cent decrease in emptying rate. Gallbladder function was not affected by contraceptive steroids. Incomplete empyting of the gallbladder in late pregnancy leaves a large residual volume and may cause retention of cholesterol crystals, a prerequisite for cholesterol-gallstone formation. These findings are consistent with the view that pregnancy increases the risk of cholesterol gallstones. The increased incidence of gallstones associated with contraceptive steroids does not involve abnormal gallbladder kinetics.

https://www.nejm.org/doi/pdf/10.1056/NEJM198002143020702?listPDF=true

Effects of pregnancy and contraceptive steroids on gallbladder function

https://www.gastrojournal.org/article/0016-5085(82)90316-X/pdf

Gallbladder function in the human female: Effect of the ovulatory cycle, pregnancy, and contraceptive steroids

To study the events that might lead to an increased risk of cholesterol gallstones, we examined biliary lipid composition and secretion and bile acid composition and kinetics at different stages of pregnancy or ovulation in young, nonobese, healthy women. Lipid composition and bile acid distribution were determined in duodenal fluid obtained in the fasting state and after stimulation of the gallbladder. Biliary lipid secretion was measured by the marker-perfusion technique. Bile acid kinetics were determined with cholic and chenodeoxycholic acids labeled with carbon13, by measuring the relative abundance of 13C in duodenal bile acids for 4--5 d. In a subset of patients we measured gallbladder storage and emptying during the kinetic study. The phase of the ovulatory cycle had no effects, but there were significant changes during pregnancy. The lithogenic or cholesterol saturation index of fasting hepatic and gallbladder bile increased during the second and third trimesters. The mean secretion rate of biliary lipids was not altered, but in the last two-thirds of pregnancy, cholesterol secretion increased in relation to bile acid and phospholipid secretion. There was a progressive decrease in the percentage of chenodeoxycholic acid and a similar increase in the percentage of cholic acid. The pool size of each major bile acid increased in the first trimester. Chenodeoxycholic acid and deoxycholic acid pools, but not cholic acid pools, subsequently decreased. The fractional turnover rate of both primary bile acids was slower during pregnancy. The synthesis rate of chenodeoxycholic but not cholic acid decreased in a linear manner during the first 20 wk of pregnancy. The rate of enterohepatic cycling of the bile acid pool was reduced throughout pregnancy. The volume of the fasting gallbladder and the residual volume after a physiologically stimulated contraction were directly correlated with bile acid pool size. The residual volume was also directly related to total bile acid synthesis.

/pdf/biliary-lipids-bile-acids-and-gallbladder-function-in-the-4prg5nimw7.pdf

Kenneth C. Hanson

Papers

Role of gallbladder emptying and small bowel transit in regulation of bile acid pool size in man.