Today I’m going to talk about ectopic pregnancy. An ectopic pregnancy really means any pregnancy not in the uterus. Mostly this refers to pregnancy in the fallopian tube or tubal pregnancy.
The uterus has a fallopian tube attached to each side. At the end of each fallopian tube are delicate fingerlike projections called fimbriae. These fimbriae function to catch ova (eggs) released from the ovary and help transport the egg(s) down the tube and into the uterus. Sperm actually meet the ovum (egg) in the tube. The resulting early embryo is then wafted down to the uterus where implantation normally occurs. Tiny little hair-like structures inside the fallopian tube called cilia beat rhythmically, also moving the embryo along the tube. If the embryo gets stuck along the way then an ectopic/tubal pregnancy occurs. The embryo grows in the narrow tube until the tube can no longer accommodate it. The tube then ruptures, causing bleeding into the abdomen.
|An opened oviduct with an ectopic pregnancy at about 7 weeks gestational age. Wikipedia
Symptoms of tubal pregnancy include missed period (which may be a short irregular one), spotting, and pelvic/abdominal pain. The pregnancy test will be positive. OB/GYN’s specifically look at the blood (serum) pregnancy test result called a beta HCG. This result is typically abnormally low compared to a healthy pregnancy in the uterus. Normally this value, early in pregnancy, should double every 48 hours. If these values do not double appropriately, then a tubal pregnancy is suspected.
If a woman presents with a positive pregnancy test, a tender distended belly, low blood pressure, and rapid pulse, then she must be taken for emergency surgery as blood from the ruptured tube is spilling into the abdomen resulting in shock.
Most of the time, this scenario is not that dramatic. There may be blood leaking from the end of the tube, or the tube may not have ruptured. If caught early enough by pelvic ultrasound, and if the tube hasn’t ruptured, then the tubal pregnancy can be treated medically with Methotrexate. This is an anti-neoplastic medicine (meaning killing growing cells) that is injected into a muscle (ie usually buttock/hip). This hopefully should kill (dissolve) the ectopic pregnancy. Given the appropriate conditions, Methotrexate works well. The pregnancy hormone levels must be watched carefully until they decline to zero. Occasionally a second dose is needed. Sometimes Methotrexate fails and surgery to remove the tubal pregnancy is necessary.
Surgery for tubal pregnancy can involve removing the part of the tube affected if it is ruptured (salpingectomy). If the rupture is slight or not at all, then the tube may be surgically slit open, the ectopic pregnancy scooped out, and the tube heals over time (salpingostomy). These surgeries are usually done laparascopically.
Any woman having a tubal pregnancy is at risk to have another tubal pregnancy in the future. We tell these women to be checked out early the minute they know they are pregnant.
Risk factors for tubal pregnancy are previous tubal pregnancy, scarred tubes from tubal infections, endometriosis (also can scar tubes), smoking (causes the cilia to not beat properly, and previous tubal ligation (sterilization by tying tubes, burning them, or placing special clips/rings on tubes). Tubes can re-cannulize or grow back together. Also assisted reproduction such as in vitro fertilization (IVF) can increase the risk that the embryo can migrate up into the tube.
More rare and extremely dangerous ectopic pregnancies include cornual ectopics (getting stuck in the junction where the tube inserts into the uterus), cervical ectopics (in cervix), and pregnancies inside the abdomen. These pregnancies can get very large and when rupture occurs it can cause extensive blood loss.
Tanya Goodwin is an obstetrician/gynecologist and a novelist of romantic suspense with slice of medicine. She enjoys sprinkling unusual medical conditions in her writing. A character in one of her novels has the misfortune of contracting necrotizing fasciitis, and in her debut novel, If Memory Serves, due for release in November by Knight Romance Publishing, her main character, Dr. Tara Ross has dissociative fugue, a rare disorder as well. You can find out more about Tanya at www.tanyagoodwin.com