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.
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| 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.
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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
