An ectopic pregnancy is one in which the fertilized ovum is implanted in any tissue other than the uterine wall. Most ectopic pregnancies occur in the Fallopian tube (so-called tubal pregnancies), but implantation can also occur in the cervix, ovaries, and abdomen.
In a normal pregnancy, the fertilized egg enters the uterus and settles into the uterine lining where it has plenty of room to divide and grow. In a typical ectopic pregnancy, the embryo does not reach the uterus, but instead adheres to the lining of the Fallopian tube. As the embryo implants and grows, the tube becomes stretched and inflamed, causing increasing pain in the pregnant woman. If left untreated, the affected Fallopian tube will likely burst, causing gynecologic hemorrhage and endangering the life of the woman. Only 2 % of ectopic pregnancies occur outside of the fallopian tubes. About 1% of pregancies are in an ectopic location.
Cilia damage and tube occlusion
Hair-like cilia located on the internal surface of the Fallopian tubes carry the fertilized egg to the uterus. Damage to the cilia, or blockage of the Fallopian tubes is likely to lead to an ectopic pregnancy.
Women with pelvic inflammatory disease (PID) have a high occurrence of ectopic pregnancy. This results from the build-up of scar tissue in the Fallopian tubes, causing damage to cilia and possibly tube occlusion.
Tubal surgery, such as tubal ligation (or the reversal thereof), is also likely to cause cilia damage. And because ectopic pregnancy is treated with tubal surgery, a history of ectopic pregnancy increases the risk of future occurrences.
Excessive estrogen and progesterone
High levels of estrogen and progesterone increase the risk of ectopic pregnancy because these hormones slow the movement of the fertilized egg through the Fallopian tube. The use of progesterone-secreting intrauterine devices (IUDs), the morning-after pill, and other hormonal methods of contraception often result in high estrogen and progesterone concentration and may increase the risk of ectopic pregnancy. Ectopic pregnancies are seen more commonly in patients undergoing infertility treatments.
Patients are at higher risk for ectopic pregnancy with advancing age. Also, it has been noted that smoking is associated with ectopic risk. Vaginal douching has been shown to increase ectopic pregnancies.
Patients with an ectopic pregnancy typically have lower back, abdominal, or pelvic pain. There may be cramping or even tenderness on one side of the pelvis. The pain is of recent onset, and often getting worse. In addition, vaginal bleeding may be present. Ectopic pregnancy is noted that it can mimic symptoms of other diseases such as appendicitis, other gastrointestinal disorder, problems of the urinary system, as well as pelvic infalmmatory disease and other gynecologic problems.
Ectopic pregnancy has to suspected in any woman with lower abdominal pain and/or unusal bleeding who is sexually active. A pregnancy test usually needs to be positive. An ultrasound examination may reveal the abnormal location of the pregnancy, show evidence of intraabdominal bleeding, or reveal an empty uterine cavity when normally the pregnancy should have been detectable within the uterus.
A laparoscopy or laparotomy can also be performed to visually confirm ( and then remove) an ectopic pregnancy within the abdominal or pelvic cavity.
Nontubal ectopic pregnancy
2% of ectopic pregnancies occur in the ovary, cervix, or intraabdominally. Transvaginal ultrasound examination is usually able to detect a cervical pregnancy. An ovarian pregnancy is differentiated from a tubal pregnancy by the criteria set by Spiegelberg. While a fetus of ectopic pregnancy cannot be salvaged, the case of an occasional abdominal pregnancy has been the very rare exception to this rule. In such a situation the placenta sits on the intraabdominal organs and the peritoneum and has found sufficient access to support a fetus to viability. Such a fetus will have to be delivered by laparotomy. However, the vast majority of abdominal pregnancies require intervention well before fetal viability because the risk of hemorrhage.
Early treatment of an ectopic pregnancy with the drug methotrexate has proven to be a viable alternative to surgical treatment since 1993. If administered early in the pregnancy, methotrexate can disrupt the growth of the developing embryo causing the cessation of pregnancy.
If hemorrhaging has already occurred, surgical intervention is necessary to halt blood loss and reduce the risk of shock. Surgeon use laparoscopy or laparotomy to gain access to the pelvis and can either incise the affected Fallopian and remove only the pregancy (salpingostomy) or remove the affected tube with the pregnancy (salpingectomy). The first successfull surgery for an ectopic pregnancy was performed by Robert Lawson Tait in 1883. The chance of future pregnancy depends on the status of the tube(s) that are left behind, but is increased. Often, patients may have to resort to IVF to achieve a successful pregnancy.
Last updated: 10-17-2005 19:56:14