Gallstones, much like kidney stones, are crystalline formations caused by the build-up of bile compounds. They are formed in the gallbladder, which is small organ mainly responsible for the digestion of fat. It’s found directly beneath the liver, and many humans can live without it after surgical removal. Removal might be necessary in the case of gallbladder disease, which can be easily caused by gallstones. Unfortunately, gallstones form more easily in the pregnant body.

Gallstones are more common during pregnancy because of the increased level of estrogen in the body. When you’re pregnant, your estrogen levels are higher than ever, and estrogen is partly responsible for the increased concentration of cholesterol in the gallbladder. Approximately 5-8% of women will experience gallstones during their pregnancy, and they are actually the second most common reason women go under the knife while pregnant.

Not all women will have typical symptoms for gallstones during their pregnancy. With the usual pains and discomfort of your enlarged belly, it’s often difficult to discern indigestion from a gallstone. However, symptoms are more obvious and problematic in some women. Common symptoms of gallstones include vomiting, nausea, and sharp pain in the upper right area of your belly. The position of the gallbladder might change as your baby grows larger, so the sharp pain might present itself elsewhere.

Whether you are pregnant or not, with typical gallbladder stone symptoms gallstones are best treated surgically by removal of the gallbladder. This is usually done through "lapsky" or laparoscopy, through several small holes on your abdomen. The human body can function normally without it, so removal is usually the safest solution. Once your doctor has determined that you have gallstones with symptoms and an ultrasound, the indication for removal may depend on the stage of pregnancy and your symptoms.

It is safest to remove the gallbladder before the third trimester of the pregnancy, before your uterus has grown too big to make the surgery too difficult. In the second trimester, it will likely be removed via laparoscopy. If your gallstones are discovered in the third trimester, depending on your symptoms your doctor may recommend that you wait until you’ve had your baby to remove the organ. Your baby’s size will make it difficult to access the gallbladder especially in the latter part of the third trimester, and the procedure could induce preterm labor. Luckily, your gallbladder can be surgically removed safely during your pregnancy as long as gallstones are discovered in the first or second trimester.

Source: Charles H Dietrich III et al: Surgical Diseases Presenting During Pregnancy. Surgical Clinics of North America Volume 88 Issue 2 pp. 403-419 April 2008