| from
the book How to Have a Baby: Overcoming Infertility
by Dr. Aniruddha Malpani, MD and Dr. Anjali Malpani,
MD.
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Endometriosis -- The Silent Invader
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Infertility
Table of Contents
What
is an ectopic pregnancy ?
How
is ectopic pregnancy diagnosed ?
How
is ectopic pregnancy treated ?
How
does an ectopic pregnancy affect future fertility ?
What
is an ectopic pregnancy ?
An ectopic pregnancy is one which develops
outside the uterus. Most ectopics are found in the fallopian
tube and these are called tubal pregnancies. However,
they can also occur at other pelvic sites and these
include: the ovary; the abdomen; and the cervix.
Fertilisation normally occurs in the
outer half of the fallopian tube which is called the
ampulla. The embryo is then propelled along the fallopian
tube, by the coordinated beating of the cilia which
line the tube, towards the uterus. An ectopic pregnancy
occurs when the embryo gets stuck in the fallopian tube
and implants here, instead of moving on to the uterus.

Fig 1. Schematic of unruptured ectopic pregnancy in
right fallopian tube

Fig 2. Ruptured ectopic pregnancy in ampulla of left
fallopian tube. Observe the blood collected in the pelvis.
Ectopic pregnancy occurs once in every
one hundred pregnancies. The commonest cause of a tubal
pregnancy is tubal damage, which is most often due to
pelvic inflammatory disease. If tubal damage is severe,
the tube gets totally blocked, as a result of which
the patient is infertile. However, with less severe
infection, the tube remains open, but the tubal lining
is damaged, as a result of which the cilia can no longer
function effectively. Other reasons for tubal damage
include: tubal surgery, infection following IUCD insertion;
and previous tubal pregnancy.
Infertile patients are at increased
risk for ectopic pregnancies, for unclear reasons. Perhaps
the cause of their infertility is subtle tubal damage.
There is also an increased risk for tubal pregnancy
after IVF, since the embryo may sometimes migrate after
embryo transfer from the uterine cavity to the fallopian
tube. The risk of ectopics after GIFT is greater than
with IVF.
How is ectopic pregnancy
diagnosed ?
Initially an ectopic pregnancy may appear
just as a normal pregnancy - with a missed menstrual
period and symptoms such as sore breasts and nausea.
However, there is often abnormal vaginal bleeding which
may occur at the time of, a little later than, the expected
period. Often, this bleeding is mistaken for a period.
Pain on the side of the ectopic occurs commonly and
may be associated with a feeling of light-headedness.
If the tube ruptures, this usually results in severe
abdominal pain, fainting and shock. Making the diagnosis
on clinical examination is difficult, and the only suspicious
finding may be pain on internal examination.
A tubal pregnancy used to be a catastrophe.
Diagnosis was usually made only after the tube had ruptured
- and emergency surgery was required to stop the bleeding
and save the mother's life. Often this meant removing
the whole tube, which was often completely damaged.
Consequently, the chances of a patient's conceiving
after this was markedly reduced.
Today, an ectopic pregnancy can be diagnosed
very early using blood tests for HCG ; and vaginal ultrasound.
Both these tests need to be done simultaneously in order
to interpret them correctly. Beta HCG is a very specific
"marker" for pregnancy. This blood test is very sensitive
and if negative, virtually excludes any risk of a significant
ectopic pregnancy. A positive HCG level confirms that
the patient is pregnant, but does not provide information
about the site of the pregnancy. A vaginal ultrasound
allows the doctor to locate the gestational sac of the
early pregnancy. Occasionally, the sac may be seen outside
the uterus, making a positive diagnosis of ectopic on
sonography. Often, however, the sac cannot be seen clearly
in ectopic pregnancies, especially if it is in an early
stage. Then, both the scan and HCG levels need to be
studied. In a normal intrauterine pregnancy, the doctor
should be able to see a gestational sac in the uterine
cavity on vaginal ultrasound, if the HCG level is more
than 2000 mIU/ml ( this is called the discriminatory
zone). However, if the level is more than 2000 mIU/ml
and the doctor cannot see a gestational sac , this means
that the diagnosis is an ectopic pregnancy.
Another blood test which can be helpful
is a serum progesterone level, which is low ( less than
15 ng/ml) in patients with ectopic pregnancies, as compared
to normal pregnancies.
Sometimes, differentiating between an
ectopic pregnancy and an early miscarriage can be difficult.
In these cases, if a curettage shows that there is no
pregnancy tissue in the uterus (as tested by histopathologic
examination) then an ectopic is suspected. The diagnosis
can be confirmed by laparoscopy, if needed, which shows
that the pregnancy is in the tubes, where it appears
as a dark bluish bulge.
How is ectopic pregnancy treated
?
The major benefit of early diagnosis
is that with early treatment it is possible to save
the tube, thus preserving fertility and increasing the
chances of a normal pregnancy in the future. If the
ectopic is very early and the HCG levels low, one can
choose to simply wait and watch. Often, the HCG levels
will fall, meaning that the pregnancy is being reabsorbed
by the body on its own and no treatment is needed. Medical
treatment is also possible. This involves the use of
the anti-cancer drug, methotrexate, which acts on the
rapidly dividing cells of the tubal pregnancy and kills
them, thus preventing the pregnancy from growing further.
After giving an intramuscular injection of methotrexate,
the beta HCG levels need to be monitored regularly,
to ensure they are falling, till they decline to zero.
This confirms that the pregnancy has been successfully
destroyed. If the diagnosis is made early, methotrexate
treatment of ectopic pregnancies is very successful.
Ultrasound - guided treatment is also
useful for treating tubal pregnancies which have not
ruptured. This involves the injection of the toxic chemical,
potassium chloride , into the fetus in the tube under
ultrasound - guidance. This kills the pregnancy tissue,
allowing the body to reabsorb it.
Surgical treatment for early tubal pregnancies
can be done through the laparoscope as well; with salpingotomy,
the pregnancy can be selectively removed and the tube
saved.
If the tube has ruptured, and blood
has collected in the abdomen, then emergency surgery
is needed. In these cases the tube is often so badly
damaged, that it has to be removed entirely. When this
occurs, a couple not only mourns the loss of a pregnancy,
but also the possible loss or reduction in their fertility.
This sense of loss is accompanied by the discomfort
and anxiety of having had an emergency operation.
How does
an ectopic pregnancy affect future fertility ?
What about the chances of getting pregnant
after an ectopic pregnancy? Because tubal disease usually
damages both sides, the chances of being infertile are
increased. Also, the risk of a repeat ectopic pregnancy
are increased even if the other tube seems normal. However,
about 60% of women who have had a tubal pregnancy the
first time will have a normal pregnancy the next time
without further treatment. Early testing during pregnancy
to rule out a repeat ectopic is essential!
If pregnancy does not occur within about
a year of trying, then treatment is needed. Treatment
options for fertility will depend upon what surgery
was done for the ectopic pregnancy; and what the condition
of the other tube is. Often, a second look laparoscopy
is needed, to assess tubal status. Options may include:
ovulation induction; tubal surgery; laparoscopic surgery;
and often IVF.
Having had an unsuccessful outcome the
first time makes getting pregnant very stressful - especially
if the tubal pregnancy ended in a rupture. However,
with the right treatment, chances of having a baby are
quite good - after all, the fact an ectopic pregnancy
occurred means that the eggs and sperms are good!
Next page: Unexplained
Infertility
Previous page:
Endometriosis -- The Silent Invader
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