Cholelithiasis during pregnancy and lactation. Prospective study.

OBJECTIVE: To assess the incidence of formation of gallstones during pregnancy and lactation, the time when gallstones first appear, and any changes in predisposing factors.

DESIGN: Prospective study.

SETTING: District hospital, Greece.

SUBJECTS: 669 pregnant women seen between 1988 and 1991.

MAIN OUTCOME MEASURES: Body mass index (kg/m2); real time ultrasonography; and measurements of serum concentrations of bilirubin, total cholesterol, low density lipoprotein cholesterol, and triglycerides, and of activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and amylase. All measurements were made at the beginning of pregnancy; at the third, sixth and ninth months; and 7 days and 6 months after delivery.

RESULTS: 6 women (1%) mean age 26 years, had pre-existent gallstones and 14 further women (2%) mean age 27 years, developed gallstones; 13 were discovered during pregnancy (8 during the second trimester, and 5 during the third) and one during lactation. Women who had 3 or more pregnancies (6/110, 5%) were significantly more likely to develop gallstones than those who had not been pregnant before (3/304, 1%, p = 0.01). Gallbladder volume more than doubled during pregnancy from a mean (SD) of 12 (4) to 26 (4) ml. Total cholesterol, low density lipoprotein cholesterol and triglyceride concentrations, and alkaline phosphatase activity increased gradually, and reverted to the value found at the beginning of pregnancy immediately after delivery.

CONCLUSIONS: The risk of developing gallstones increased with the number of pregnancies, and most of the stones developed during the second or third trimester.