During pregnancy, a disorder that requires surgery may develop. Major surgery, particularly if it involves the abdomen, increases the risk of preterm labor Preterm Labor Labor that occurs before 37 weeks of pregnancy is considered preterm. Babies born prematurely can have serious health problems. The diagnosis of preterm labor is usually obvious. Measures such... read more and can cause a miscarriage Miscarriage A miscarriage is the loss of a fetus before 20 weeks of pregnancy. Miscarriages may occur because of a problem in the fetus (such as a genetic disorder or birth defect) or in the woman (such... read more , especially early in pregnancy. Thus, surgery is usually delayed if possible. However, if necessary, surgery should proceed without delay and is still usually reasonably safe.
Appendicitis
If appendicitis Appendicitis Appendicitis is inflammation and infection of the appendix. Often a blockage inside the appendix causes the appendix to become inflamed and infected. Abdominal pain, nausea, and fever are common... read more develops during pregnancy, surgery to remove the appendix (appendectomy) is done immediately because a ruptured appendix may be fatal. An appendectomy is not likely to harm the fetus or cause a miscarriage. However, appendicitis may be difficult to recognize during pregnancy. The cramping pain of appendicitis resembles uterine contractions, which are common during pregnancy. The appendix is pushed higher in the abdomen as the pregnancy progresses, so the location of pain due to appendicitis may not be what is expected.
If women have any symptoms that might indicate appendicitis, they should report them to their doctor. These symptoms include abdominal pain that lasts more than 6 hours, particularly if it is accompanied by nausea and vomiting.
Gallbladder disease
If the gallbladder Overview of Gallbladder and Bile Duct Disorders The liver produces bile, a greenish yellow, thick, sticky fluid. Bile aids digestion by making cholesterol, fats, and fat-soluble vitamins easier to absorb from the intestine. Bile also helps... read more 
becomes inflamed (usually because of gallstones that block the gallbladder), doctors give analgesics for pain and fluids through a catheter inserted into a vein. Women are not allowed to eat anything until the inflammation subsides.
If an infection develops, women are given antibiotics. If women do not improve, surgery is done.
Ovarian cyst
Noncancerous (benign) ovarian cysts Ovarian Cysts and Other Benign Ovarian Masses Noncancerous (benign) ovarian growths include cysts (mainly functional cysts) and masses, including noncancerous tumors. Most noncancerous cysts and tumors do not cause any symptoms, but some... read more 
are common during early pregnancy.
If an ovarian cyst persists during pregnancy, surgery is usually postponed until after the 14th week of pregnancy. The cyst may be producing hormones that are supporting the pregnancy and often disappears without treatment.
However, if a cyst or another mass is enlarging, is very tender, or has certain characteristics (seen on an ultrasound), surgery may be necessary before the 14th week. Such a mass may be cancerous.
Obstruction of the intestine
During pregnancy, a blockage in the intestine (intestinal obstruction Intestinal Obstruction An obstruction of the intestine is a blockage that completely stops or seriously impairs the passage of food, fluid, digestive secretions, and gas through the intestines. The most common causes... read more ) can be very serious. If obstruction leads to gangrene of the intestine and peritonitis (inflammation of the membrane that lines the abdominal cavity), the woman may miscarry and her life is endangered.
Exploratory surgery is usually done promptly when pregnant women have symptoms of intestinal obstruction, particularly if they have had abdominal surgery or an abdominal infection. Symptoms of intestinal obstruction include cramping abdominal pain, loss of appetite, bloating, vomiting, severe constipation or severe diarrhea, and sometimes fever.
