Around one out of a hundred pregnancies is ectopic, which means it is growing outside of the uterus. While ectopic pregnancy occasionally occurs in the pelvis, the most common site for ectopic pregnancy is in the fallopian tube. Pregnancy in the tube can be life threatening.
Causes of Ectopic Tubal Pregnancy
Ectopic pregnancy is becoming more common. Tubal pregnancies are more common in women who:
- Have dilated fallopian tubes, known as hydrosalpinx, often from untreated sexually transmitted disease.
- Have had previous tubal surgery. Reversal of tubal ligation gives a risk for ectopic of 5-10%
- Have an IUD in place when they get pregnant. There’s a 20% risk of ectopic in these pregnancies.
- Smoke. Smoking raises the risk of ectopic pregnancy by 1.5 to 4 times.
- Use birth control pills that are progestin only, and get pregnant on the pill.
- Undergo infertility treatments such as in vitro fertilization.
Symptoms of Ruptured Ectopic Pregnancy
Women with an early ectopic pregnancy may not realize the pregnancy is in the tube. If they do a pregnancy test, the test may be negative, or the hormone levels may be very low. An ultrasound done at five weeks or so will show nothing in the uterus. If the pregnancy test is positive, this should be an immediate warning sign of an ectopic.
A ruptured ectopic pregnancy is a true medical emergency. The following symptoms should send a woman with a suspected ectopic, or one who missed a period, immediately to the emergency room.
- severe lower abdominal pain
- severe shoulder pain
- dizziness or lightheadedness
- passing out
- unexplained weakness
A ruptured tubal pregnancy, or a tube that’s about to rupture, needs immediate emergency surgery. The fallopian tube will need to be removed or repaired. The embryo can’t be saved in an ectopic pregnancy, because the placenta will have grown into the tube and can’t be removed and implanted in the uterus.
Methotrexate for Treating Early Ectopic Pregnancy
If an ectopic is discovered very early in the pregnancy, it may be able to be dissolved by giving a drug called methotrexate. Methotrexate, a drug sometimes used for cancer treatment, stops the cell growth of the embryo. It must be given when the embryo is still small, less than an inch long. Methotrexate is most effective for treating ectopic pregnancy when given by injection. Frequent ultrasounds monitor the effectiveness of methotrexate.
Giving methotrexate to treat ectopic pregnancy is successful 90% of the time in early pregnancy, but can cause side of effects of diarrhea, mouth sores and stomach irritation in a small number of women. Women who have had one tubal pregnancy have a 20% chance of having a second. If one tube was removed, the chance of future pregnancy is reduced but still quite possible.
Ectopic Pregnancy and Future Pregnancy Planning
Any woman who has had an ectopic pregnancy should be very aware of the risk of another tubal pregnancy. Seeing a doctor very early in the pregnancy is essential for early diagnosis and treatment to preserve the fallopian tube and prevent future infertility.