Ectopic Pregnancy Risk
All Procedures Have Risks
For many couples, the dream of becoming parents can only come true through fertility treatments. Overall, in vitro fertilization (IVF) is a very safe way to ensure pregnancy. It does have risks, of course, as does any type of medical or surgical procedure. Some of the possible side effects or complications that can arise from IVF include failure of the treatment, problems resulting from ovarian stimulation, risk of multiple pregnancy and risks associated with egg collection from the ovaries. Another risk associated with IVF is ectopic pregnancy.
What Causes Ectopic Pregnancy?
According to the medical dictionary, an ectopic pregnancy is any pregnancy that occurs outside the cavity of the womb. It is potentially life threatening to the woman and usually ends in abortion of the pregnancy.
While there does not seem to be a consistent opinion as to what, exactly, causes ectopic pregnancies, the most common cause is a problem with the fallopian tubes. They are either too narrow or misshapen, perhaps a consequence of PID (pelvic inflammatory disease), infection or surgery, endometriosis or a previous ectopic pregnancy. Congenital defects can be a cause as well. The theory has been posited that perhaps the damaged tube is unable to expel or push the embryo back down into the uterus after it has found its way into the tube.
Incidence Of Ectopic Pregnancy Greater With IVF Treatment
The incidence of ectopic pregnancy in connection with IVF is considerably higher than it is with natural conception. Reported incidences after IVF treatment varies between 2-11 percent of all pregnancies while the occurrence after natural conception is one in 100-300 pregnancies. After an ectopic pregnancy has been experienced, the risk for another one is between 10 to 20 percent. Additionally, a combined normal and ectopic pregnancy, called heterotopic pregnancy, after IVF is about one percent of all pregnancies as compared with two in 30,000 after natural conception.
Why is the risk so high? It may be due to the technique used in the transference of the embryo to the uterus. If the embryo is placed too high into the uterine cavity, it may be forced up into the fallopian tube and, since the tube may be damaged, it is caught and unable to return to the uterus. Another possibility is injecting too much volume of the culture medium or injecting the embryo at a pressure that is too high. In most cases of ectopic pregnancy because of IVF, the cause is not known.
At one time tubal occlusion, closing off the fallopian tubes, was advocated by IVF practitioners. This practice is no longer used. Even though it was helpful in the reduction of incidence of ectopic pregnancies, it did nothing to prevent interstitial pregnancies-an ectopic pregnancy which implants in the inner part of the tube within the muscle of the uterus.