DDW 2011: Attention to Diet May Lower Gallstone Formation Risk during Pregnancy

High consumption carbohydrates, starch, and fructose may increase the risk of developing biliary sludge and stones during pregnancy.

Gallstone disease is among the most common non-obstetrical causes of morbidity both during and after pregnancy and is the most common non-obstetrical causes of maternal rehospitalizations in the first 60 days after deliver. “Dietary modification during pregnancy,” stated Alan C. Wong, MD, MPH, University of Washington Medical Center, Seattle, WA, “may reduce this risk.” Gallstone disease leads to >700,000 cholecystectomies each year, he said further.

High carbohydrate intake has been shown to cause insulin resistance and derangement of serum lipid profiles, conditions thought to favor gallstone formation, Wong said during an oral presentation at Digestive Disease Week 2011. He noted further that female gender is a risk factor for gallstones, and pregnancy is a high-risk period for gallstone development. The effect of carbohydrate consumption on gallbladder disease during pregnancy, however, is unclear. With the aim of examining the effect of dietary carbohydrate intake on formation of biliary sludge and stones during pregnancy, Wong and colleagues prospectively examined 3070 pregnant adult women (mean age 25.2 years) who underwent gallbladder ultrasound during each trimester of pregnancy and at 4-6 weeks postpartum. Included women underwent at least two study ultrasounds. Investigators excluded women with stones detected in the first ultrasound or with prior cholecystectomy. Women were considered to have incident gallbladder disease if ultrasound revealed new sludge, new stones or progression of baseline sludge to stones. The ultrasonographic definition of sludge was low-level echoes, shift in positional changes with no post-acoustic shadowing. Stones were defined by high-amplitude echoes, >2 mm in diameter with post-acoustic shadowing present.

Early in the third trimester, women completed a semi-quantitative food frequency questionnaire from which average daily intake of dietary factors was computed with standard food composition data. A multivariate logistic regression adjusting for age, pre-pregnancy body mass index, weight gain during pregnancy, parity, Hispanic origin, smoking, history of diabetes, and intake of alcohol, caffeine, total calories, protein, fat, fiber, cholesterol, and fatty acids (saturated, monounsaturated, polyunsaturated, trans) assessed risk of incident gallbladder disease across quartiles of intake of total carbohydrate and individual carbohydrates (starch, sucrose, galactose, fructose, lactose, and maltose).

Four-to-six weeks postpartum, the cumulative incidence of new sludge or stones or progression of baseline sludge to stones was 10.2%. New sludge was identified in 5.1% of patients, new stones in 2.8% and conversion of baseline sludge to stones in 2.3%. Looking at the risk of incident gallbladder disease during pregnancy by quartile of total carbohydrate intake revealed a significantly higher rate among women in the highest as compared to those in the lowest quartile (adjusted odds ratio [OR] 2.295; 95% confidence interval [CI] 1.130-4.661). High intake of starch (OR 1.812; CI 1.002-3.277) or fructose (OR 2.054; CI 1.183-3.568) was associated with increased risk even after additional adjustment for total carbohydrate intake, while galactose was associated with decreased risk (OR 0.664; CI 0.441-0.999). The fructose analysis did not differentiate between fructose sources.

Wong concluded, “High consumption of total carbohydrate, starch, and fructose may increase the risk of developing biliary sludge and stones during pregnancy. Dietary modification during pregnancy may reduce this risk.”