In
approximately one pregnancy in seventy, the embryo implants
in a location outside of the uterus. Almost all ectopic
pregnancies are confined to the fallopian
tubes (96%). Approximately 2% are found in the portion
of the fallopian tube that goes through the wall of the
uterus. The remaining ectopic pregnancies can be found in
the cervix, ovary and abdomen.
Ectopic pregnancies are best treated when they are diagnosed
early. In our practice, a quantitative beta hCG level (blood
pregnancy test) is drawn on the day of a missed period.
This level should be approximately 100 mIU/mL, and should
double every forty-eight hours. Women with ectopic pregnancies
typically have lower hCG levels that rise slowly. They are
often associated with vaginal bleeding and pelvic pain.
Women with a history of prior ectopic
pregnancy, tubal or pelvic surgery, pelvic
inflammatory disease and the use of intrauterine devises
have a higher risk of ectopic pregnancy. Women treated with
ovulation
induction medicine such as clomiphene
citrate and especially injectable FSH
also have a higher risk of having an ectopic pregnancy.
The likelihood that the fallopian tube will remain functional
after an ectopic pregnancy is primarily determined by how
severely the tube is damaged. Early diagnosis of ectopic
pregnancies can lead to better tubal function afterwards.
When hCG levels are between 1,000 and 1,500, transvaginal
ultrasonography should demonstrate a pregnancy located in
the uterus. An ectopic pregnancy has to be suspected in
a woman with an hCG level greater than 1,500, and no intrauterine
pregnancy is seen on transvaginal ultrasound.
Ectopic pregnancies can either be treated by laparoscopic
surgery, or with medication. Women with larger ectopic pregnancies,
higher hCG levels, and significant pelvic pain are best
treated by laparoscopy.
In this out-patient surgical procedure, an incision is made
in the fallopian tube overlaying the ectopic pregnancy.
The ectopic pregnancy is then completely removed and the
fallopian tube subsequently heals on its own. In 80% of
cases, the fallopian tube will be patent (remain open) post-operatively.
Occasionally, when the fallopian tube has been severely
damaged by the ectopic pregnancy, the tube must be removed
laparoscopically.
Some women with early small ectopic pregnancies and hCG
levels under
5,000 mIU/mL can be treated with a chemotherapy medication,
methotrexate. Methotrexate works by blocking the action
of folic
acid. Rapidly dividing cells in placental tissue, are
dependent on the presence of folic acid. We have had extensive
experience using methotrexate in treating several hundred
patients with ectopic pergnancies. We use the single dose
methotrexate protocol that was initially popularized by
Dr. Stovall in the early 1990's (American Journal of Obstetrics
and Gynecology 168: 1759 - 65, 1993). Prior to methotrexate
administration, blood is drawn to measure the hCG titer,
liver function tests, complete blood count, electrolytes,
blood type, and Rh factor. An hCG level is drawn four days
after the methotrexate is given and then again three days
later. A drop of 15% between the two hCG levels on days
four and seven after administration of methotrexate is expected.
Should hCG levels not be falling appropriately a second
dose of methotrexate can be given. It is important that
women receiving methotrexate therapy not take folic acid
or multi- vitamins containing folic acid. In cases of early
ectopic pregnancies treated with methotrexate, the fallopian
tube remains patent 80% of the time.
Methotrexate therapy is extremely safe, though complications
do rarely occur. These include mouth ulcers, transient
abnormalities in liver function tests, and bone marrow
suppression. In approximately 70% of women treated with
methotrexate abdominal pain develops five to twelve days
after methotrexate administration. This pain is due to
the fallopian tube expelling the ectopic pregnancy, or
when the placental tissue in the fallopian tube disintegrates.
All of our patients treated with methotrexate are instructed
to call with any abdominal pain so that they can be rapidly
evaluated. In almost all cases reassurance is all that
is required.
Fifteen percent of women with a prior ectopic pregnancy
will have another ectopic. The recurrence risk for ectopic
pregnancy rises to approximately 30% after two ectopic pregnancies
and nearly 50% after three ectopic pregnancies. In women
who are at risk for ectopic pregnancy, or those with a prior
ectopic pregnancy, it is important to notify your physician
with a late or abnormal period. At that time blood will
be drawn for hCG and progesterone
levels. The pregnancy should be monitored closely, so that
an ectopic pregnancy, if present, can be treated optimally
and early.
