Most pregnancies implant in the uterus, which has room for a fetus to grow during pregnancy. The Merck Manual reports that around 2 percent of pregnancies implant in the fallopian tubes, which connect the ovaries and the uterus. Due to limited space in the tube, tubal pregnancies never carry to term. Lower abdominal pain in early pregnancy, the classic sign of ectopic, or tubal pregnancy, requires immediate investigation.
Causes
Pain in ectopic pregnancy may occur as the fetus grows and the tube stretches. Pain after rupture occurs from blood accumulation in the abdominal cavity placing pressure on nearby structures.
Symptoms
Pain may occur before the fallopian tube ruptures; early pain may feel like cramping. Pain may occur just on the side of the ectopic or may be felt all over the abdomen. Once the fallopian tube ruptures, pain often intensifies, becoming severe, and may be felt in the shoulder as blood in the abdominal cavity irritates the diaphragm, which separates the abdomen from the chest cavity. Intense pressure sensations in the rectum may also occur, according to MedlinePlus. Fifty percent of women have no pain until the tube actually ruptures, according to Togas Tulandi, M.D. of McGill University, a medical professional writing for the Up to Date website, which specializes in patient care. Bleeding, lightheadedness or fainting may accompany pain.
Diagnosis
Pain leads to suspicion of ectopic pregnancy in women of childbearing age. Blood tests to confirm a positive pregnancy test and pelvic ultrasound to check for fetal growth in the uterus confirm the diagnosis. An empty uterus combined with a positive beta hCG, or human chorionic gonadotropin level, greater than 1,500 International Units per milliliter, or IU/mL, indicate ectopic pregnancy. Visualization on ultrasound of an ectopic pregnancy occurs in only 30 percent of tubal pregnancies, Tulandi reports.
Treatment
Surgical or chemical removal of an ectopic pregnancy relieves pain. If the pregnancy is less than 3 cm in diameter and the hCG levels are between less than 15,000 IU/mL, methotrexate, a chemotherapy agent given as an injection, may end the pregnancy and allow the fetus to dissolve, avoiding surgical loss of the fallopian tube. Under optimal conditions, methotrexate successfully terminates the pregnancy without rupture of the tube in 98 percent of cases, Tulandi stresses. If rupture occurs or the pregnancy grows beyond 3 cm, surgical removal cures the pain and stops the bleeding.
Complications
Severe pain indicates rupture of the fallopian tube. Hemorrhage can occur, leading to maternal death. Around 9 percent of all maternal deaths in the United States occur because of ectopic tubal rupture, according to the Merck Manual. Surgical removal of the fallopian tube can cause decreased fertility, although women with one tube can still get pregnant. One third of women who have an ectopic pregnancy will have another ectopic pregnancy, according to MedlinePlus, a website devoted to professional health care and advise.
