Normally, conception occurs not in the uterus but in the fallopian tubes. The fertilized egg then moves into the uterus where it should implant in the lining of the uterus. When the embryo implants anywhere other than the uterine lining it is called an ectopic pregnancy. "This type of pregnancy is estimated to happen in two percent of all pregnancies," explains Dr. Mark P. Trolice, MD, director of Fertility C.A.R.E., in Winter Park, Florida. "Ninety percent of all ectopics occur in the fallopian tube. More infrequently they can occur in the cervix, ovary, or abdomen. Ectopic pregnancies can also occur with in vitro fertilization (IVF), about three to five percent of the time," he says.
As the embryo grows outside of the uterus it is usually in a confined space, such as the fallopian tube. Eventually, the embryo enlarges the tube to the point of rupturing it, which causes hemorrhaging and loss of the fetus. This hemorrhaging can be so severe as to cause shock and death. Thankfully, diagnosis can occur before something so drastic occurs.
Ectopic pregnancies are more common than people often think, according to Dr. Susan Klugman, MD, an OB-GYN and reproductive geneticist at Montefiore Medical Center, Bronx, New York.
Because ectopic pregnancy is potentially a life-threatening situation, women need to be aware of the signs and symptoms. These include lower abdominal pain and bleeding in early pregnancy. "These are very common symptoms so it is important to have an obstetric provider prior to conceiving. It is also important to get early prenatal care, and if there are any issues at all, an early sonogram to check for the location and viability of the pregnancy," Dr. Klugman advises.
Women most at risk include those who have had sexually transmitted diseases, women who have had pelvic inflammatory disease, those who use an intrauterine device (IUD), and women who have had surgery, such as tubal ligation and reversal. These situations can all leave a scarred path that the fertilized egg may get hung up on while trying to navigate its way to the uterus for implantation. "Women who have had a previous ectopic are at the greatest risk, with about 10 to 15 percent recurrence," Dr. Klugman says. Dr. Trolice emphasizes that it is important for women who have had a prior ectopic to have close monitoring in the first trimester of any subsequent pregnancies.