Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptoms. The pain may be described as sharp, dull, or crampy. Pain may also spread to the shoulder if bleeding into the abdomen has occurred. Severe bleeding may result in a fast heart rate, fainting, or shock. With very rare exceptions, the fetus is unable to survive.
Overall, ectopic pregnancies annually affect less than 2% of pregnancies worldwide. Risk factors for ectopic pregnancy include pelvic inflammatory disease, often due to chlamydia infection; tobacco smoking; prior tubal surgery; a history of infertility; and the use of assisted reproductive technology. Those who have previously had an ectopic pregnancy are at much higher risk of having another one. Most ectopic pregnancies (90%) occur in the fallopian tube, which are known as tubal pregnancies, but implantation can also occur on the cervix, ovaries, caesarean scar, or within the abdomen. Detection of ectopic pregnancy is typically by blood tests for human chorionic gonadotropin (hCG) and ultrasound. This may require testing on more than one occasion. Other causes of similar symptoms include: miscarriage, ovarian torsion, and acute appendicitis.
Prevention is by decreasing risk factors such as chlamydia infections through screening and treatment. While some ectopic pregnancies will miscarry without treatment, the standard treatment for ectopic pregnancy is a procedure to either remove the embryo from the fallopian tube or to remove the fallopian tube all together. The use of the medication methotrexate works as well as surgery in some cases. Specifically it works well when the beta-HCG is low and the size of the ectopic is small. Surgery such as a salpingectomy is still typically recommended if the tube has ruptured, there is a fetal heartbeat, or the woman's vital signs are unstable. The surgery may be laparoscopic or through a larger incision, known as a laparotomy. Maternal morbidity and mortality are reduced with treatment.
The rate of ectopic pregnancy is about 11 to 20 per 1,000 live births in developed countries, though it may be as high as 4% among those using assisted reproductive technology. It is the most common cause of death among women during the first trimester at approximately 6-13% of the total. In the developed world outcomes have improved while in the developing world they often remain poor. The risk of death among those in the developed world is between 0.1 and 0.3 percent while in the developing world it is between one and three percent. The first known description of an ectopic pregnancy is by Al-Zahrawi in the 11th century. The word "ectopic" means "out of place".
Signs and symptoms
Up to 10% of those with ectopic pregnancy have no symptoms, and one-third have no medical signs. In many cases the symptoms have low specificity, and can be similar to those of other genitourinary and gastrointestinal disorders, such as appendicitis, salpingitis, rupture of a corpus luteum cyst, miscarriage, ovarian torsion or urinary tract infection. Clinical presentation of ectopic pregnancy occurs at a mean of 7.2 weeks after the last normal menstrual period, with a range of four to eight weeks. Later presentations are more common in communities deprived of modern diagnostic ability.
Signs and symptoms of ectopic pregnancy include increased hCG, vaginal bleeding (in varying amounts), sudden lower abdominal pain, pelvic pain, a tender cervix, an adnexal mass, or adnexal tenderness. In the absence of ultrasound or hCG assessment, heavy vaginal bleeding may lead to a misdiagnosis of miscarriage. Nausea, vomiting and diarrhea are more rare symptoms of ectopic pregnancy.
Rupture of an ectopic pregnancy can lead to symptoms such as abdominal distension, tenderness, peritonism and hypovolemic shock. Someone with a ruptured ectopic pregnancy may experience pain when lying flat and may prefer to maintain upright posture as intrapelvic blood flow can lead to swelling of the abdominal cavity and cause additional pain.
Complications
The most common complication is rupture with internal bleeding which may lead to hypovolemic shock. Damage to the fallopian tubes can lead to difficulty becoming pregnant in the future. The woman's other fallopian tube may function sufficiently for pregnancy. After the removal of one damaged fallopian tube, pregnancy remains possible in the future. If both are removed, in-vitro fertilization remains an option for women hoping to become pregnant.