By Dr. Amy Stump
Every year in the United States, 10-15% of the adult population develops gallstones, making it the most common gastrointestinal issue requiring hospitalization. More women develop gallstones than men across all ages, partially due to physiological changes that occur during pregnancy. Classically, gallstones occur in women over the age of 60. However, most research has identified pregnancy as a period of heightened risk, estimating a 5-12% prevalence of gallstones in pregnancies.
Gallstones are hard formations that develop in the gallbladder, an organ located on the right side of the abdomen beneath the liver. The gallbladder is responsible for storing digestive bile that helps to break down the fats in food. If chemicals within the digestive bile become unbalanced then gallstones are likely to form. A similar process causes a mixture of microscopic gallstones and bile called biliary sludge to form.
Both sludge and stones can be present with or without symptoms. Characteristic symptoms of gallstones and sludge include nausea, bloating, and pain in the upper abdomen that may radiate to the right side or the upper back. These symptoms are usually experienced for a range of time lasting from a few minutes to a few hours. If your doctor suspects you are suffering from symptomatic gallstones, also called biliary colic, he or she will likely order an ultrasound to evaluate the area.
Research has identified physiological changes brought on by pregnancy which might account for the increase risk of gallstones. For instance, the chemical composition of bile in the gallbladder becomes supersaturated with cholesterol due to the natural increase of hormones like estrogen and progesterone when a woman becomes pregnant. This surge of cholesterol increases the likelihood of gallstones forming.
Changes in the gallbladder muscular function compounds the risk introduced by changes in hormone levels. During pregnancy, the gallbladder is slower to perform the regular function of emptying the bile it stores, leaving more time for bile to congeal and form into stones. Both chemical and muscular function changes have been shown to stay with a woman up to five years after delivery, increasing her chances for developing stones during this time.
Research has found certain factors that might increase a woman’s risk for developing gallstones during and after pregnancy. Higher pre-pregnancy body mass index has been associated with an increased risk of gallstones, a link between weight and stoned development that is found in the general population as well. Research published in the Clinical Gastroenterology and Hepatology journal in 2008 suggests that higher insulin resistance could be the connecting factor between gallstones and high BMI.
Cholesterol levels also play a role in a pregnant woman’s risk of developing gallstones. In 2006, a study published by the American Association for the Study of Liver Diseases found a negative relationship between HDL cholesterol levels and gallstone formation, meaning that women with high levels of the good cholesterol were less likely to developed gallstones.
The number of times a woman has been pregnant, called parity, also influences the risk of gallstone formation. The same 2006 research study found that as a woman’s parity increased, the chances of developing gallstone doubles between the first and third pregnancy.
Research unanimously supports controlling pre-pregnancy body weight as the best way to reduce the risk of developing gallstones during pregnancy. If gallstones do develop during pregnancy, the gallbladder is usually removed through minimally invasive laparoscopic surgery after delivery. While not all pregnancies result in the development of gallstones, it is important to be aware of the increased risk that pregnancy brings.
Dr. Amy Stump is a general surgeon at University of Maryland Baltimore Washington Medical Center and can be reached by calling 410-553-8384.
© 2015 Capital Gazette Media