Ectopic pregnancy is one that develops outside the uterus. The egg (oocyte) and the sperm meet in the fallopian tube and fertilization occurs. The embryo is supposed to move back to the uterine cavity for implantation. However, in ectopic pregnancy this does not occur, and the embryo gets implanted elsewhere.
The most common location is in one of the narrow tubes that connect each ovary to the uterus (fallopian tube). As the fertilized egg enlarges, the fallopian tube stretches and ruptures, causing life-threatening internal bleeding. Other locations include the ovary, cervix, space beside the uterus (broad ligament space) or in the abdominal cavity. About 1 in 100 pregnancies is an ectopic.
CAUSES AND RISK FACTORS
The occurrence of ectopic pregnancy is usually associated with an abnormal function of the fallopian tubes. Hence, tubal pregnancy is the most common type. Hormonal imbalances or abnormal development of the fertilized egg might also play a role. Certain condition may predispose to a higher chance of ectopic pregnancy such as:
- Previous abdominal or pelvic infection
- Pelvic inflammatory disease (PID), involving the fallopian tubes
- Pregnancy after tubal ligation
- Assisted reproduction techniques such as in vitro fertilization.
- Adhesions (bands of scar tissue) from previous pelvic surgery.
- Previous tubal pregnancy.
- History of endometritis (infection of the inner uterine lining)
- Malformed (abnormal) uterus or fallopian tubes
- Pregnant with an intrauterine device (IUD) in place (failure of IUD)