Our Virginia fertility clinic staff is familiar with the pain and disappointment that accompanies miscarriage. Our fertility specialists are highly trained to deal with the medical causes of miscarriage and can often help couples carry their baby to term.
The following information is provided as a summary of conditions
that may cause recurrent pregnancy loss and medical testing
that will be performed to rule them out. We have also provided
information on conditions that you may have heard of from the
lay press but are not recognized causes of recurrent pregnancy
loss.
This information will, in some cases, draw the important
distinction of whether a condition is recognized as a possible
cause of an occasional pregnancy loss versus recurrent pregnancy
loss. In other words, some pregnancy losses may have an identifiable
cause - such as an infection - but there is no evidence that
the condition will persist to cause future pregnancy losses.
After ovulation, the ovaries produce the hormone progesterone.
This hormone prepares the endometrium (the uterine lining)
for arrival of the early embryo and affects changes that promote
implantation and therefore pregnancy. After pregnancy is established,
the ovaries continue to produce progesterone. Progesterone
from the ovaries is important through the first 8-10 weeks
of pregnancy. If the amount of progesterone produced by the
ovaries is inadequate, infertility or pregnancy loss may result.
Testing for luteal phase defect (LPD) is performed by a timed
blood test for progesterone. The test is performed five to
nine days after ovulation (there is no advantage to perform
multiple tests). Luteal phase defect may be treated by clomiphene
citrate (an oral medication) or by progesterone vaginal suppositories
or pills (see separate information sheets on both of these
therapies). LPD is an infrequent cause of pregnancy loss.
Congenital or acquired abnormalities of the uterus may cause
recurrent pregnancy loss. A hysterosalpingogram will be performed
to evaluate the uterus in this regard. Conditions that may
be diagnosed include: uterine anomalies (abnormalities in
the formation of the uterus) - septate uterus or bicornuate
uterus; intrauterine adhesions; uterine myomas (fibroids);
in utero diethylstilbestrol (DES) exposure. With the exception
of in utero DES exposure anomalies, the management of uterine
abnormalities as a cause of recurrent pregnancy loss is surgical.
Septate uteri, intrauterine adhesions and some uterine fibroids
may be treated by hysteroscopy (endoscopic surgery) as an
outpatient procedure. Surgery for bicornuate uterus anomaly
or large uterine fibroids requires a major operation. The
prognosis for subsequent normal pregnancy after surgical treatment
of most conditions listed above is excellent.
Abnormalities of maternal or paternal chromosomes may cause
recurrent pregnancy loss. It is possible for men or women
to be physically normal in every way but carry a chromosomal
abnormality that will affect the risk of early pregnancy loss.
The incidence of chromosome abnormalities in couples with
at least two spontaneous miscarriages is approximately 5%.
A simple (but expensive) blood test may be performed to determine
maternal and paternal chromosome make up and diagnose this
condition. The test involves culturing cells obtained from
a blood sample and takes several weeks to complete. Occasionally,
the cells fail to grow and the test must be repeated.
A common and untreatable cause of early pregnancy loss is
a "spontaneous" chromosome imbalance in the early
embryo. In this situation, the chromosomes of the sperm and
the egg are normal however a problem develops during the early
process of egg fertilization leading to a chromosome make-up
in the early embryo that is not compatible with life -e.g.
too many chromosomes or too few chromosomes. Of all early
pregnancy losses, approximately half are due to this type
of genetic abnormality.
This is not a cause of recurrent pregnancy
loss but rather should be anticipated as occurring occasionally
during the reproductive years as a percentage of all pregnancies.
There is no treatment for this natural spontaneous event.
Couples, who experience an early pregnancy loss due to this
type of genetic error, will be expected to have a normal chance
to carry a subsequent pregnancy to full term. The risk of
this type of pregnancy loss increases with increasing maternal
age.
Bacteria, which may rarely cause a spontaneous abortion, include:
listeria monocytogenes, campylobacters, and brucella species
bacteria. These organisms have not been linked to recurrent
pregnancy loss.
One group of bacteria-like organisms - genital mycoplasmas
-has been linked to recurrent pregnancy loss. These organisms
are commonly present in the cervix or in the vagina in normal
women. Presence of mycoplasma within the uterine cavity is
abnormal. It is very difficult to culture the uterine cavity
to prove the presence of a mycoplasma infection. Due to this
difficulty with cultures, we have elected to treat all couples
with antibiotics, which are effective against mycoplasma.
This treatment is performed by taking two weeks of oral Doxycycline
or Erythromycin.
CMV infection may affect live born infants of term pregnancies.
Whether this virus causes early pregnancy loss or recurrent
pregnancy loss is not clear. Half or more of adult females
have been exposed to CMV. After initial exposure, the virus
enters a latent (or quiet) stage and may or may not affect
the woman or her offspring. Women with an active CMV infection
or reactivation of a previous infection may deliver infants
that are in some way affected. CMV infection may be responsible
for some early pregnancy losses - this is probably very rare.
There is no clear information that CMV infection is responsible
for recurrent pregnancy loss. There is no treatment for this
viral disease.
Rubella (German measles) when acquired during the first trimester
of pregnancy may cause early pregnancy loss or fetal developmental
abnormalities. This happens if the initial maternal infection
occurs during early pregnancy. After the initial infection,
reinfection is not possible (or is extremely rare) and therefore,
rubella is not a cause of recurrent pregnancy loss.
HSV is a sexually transmitted virus that may affect babies
born to mothers with an initial (or primary) infection. Babies
affected by HSV may suffer serious or fatal complications.
Women who contract an initial HSV infection during early pregnancy
may have an increased risk of early pregnancy loss. There
is no recognized link between HSV infection and recurrent
pregnancy loss. Although reactivation of maternal Herpes lesions
may occur, this type of infection is not thought to cause
early pregnancy loss.
Several diseases are caused by apparent confusion within the
body's normal mechanisms that respond to disease. Normally,
the human body makes antibodies against infection or any foreign
tissue (as in rejection of organ transplants). In some disease
states, the body becomes confused and apparently makes antibodies
against its own normal tissue. Some of these disease states
are associated with recurrent pregnancy loss.
Recent information suggests that high levels of either anti-cardiolipin
antibodies or the 'lupus' anticoagulant antibody may be linked
to early pregnancy loss. Some women with normal reproductive
histories have low levels of these antibodies. The reason
for early pregnancy loss due to APA is unclear. There are
several theories - the most widely accepted explanation links
the presence of these antibodies to damage of the small blood
vessels which link the mother to the fetus resulting in inadequate
blood flow to the baby.
There are several medical studies
suggesting that treatment with heparin, lovenox and/or aspirin
improves the successful pregnancy rate when APA is proven
to exist in women experiencing recurrent pregnancy loss. It
should be emphasized that pregnancy loss may occur in spite
of treatment. In addition, there are risks associated with
treatment - an effect on the pregnancy or fetus due to the
medications. The overall "state of the art" related
to APA-linked pregnancy loss supports the treatment of these
conditions as noted above. Testing for APA will be part of
your evaluation (anticardiolipin antibody levels and a PT/PTT
blood test).
SLE is sometimes diagnosed in young women. SLE classically
causes vague, intermittently recurring symptoms such as facial
rashes, joint pain, psychological disturbances, and muscle
aches among others. Because these symptoms can be very mild
and only occur occasionally, true cases of SLE often may go
on for quite awhile before being diagnosed. SLE has been linked
to an increase in early pregnancy loss and pregnancy loss
through 20 weeks gestation. A simple blood test to screen
for high levels of anti-nucleic acid or anti-nuclear antibodies
(ANA) can be done to help establish the diagnosis of SLE.
If SLE is diagnosed, there is no recognized treatment that
effectively lowers pregnancy loss associated with this condition.
Several other maternal autoimmune diseases may cause early
pregnancy loss: rheumatoid arthritis; systemic scleroderma;
polymyositis; polyarteritis nodosa, mixed connective tissue
disease. The link between these unusual autoimmune diseases
and recurrent pregnancy loss is not clear. The "state-of-the-art"
of recurrent pregnancy loss work ups at this time does not
include screening tests for these diseases.
Some mild forms of blood clotting disorders can cause recurrent
early pregnancy losses (and/or problems with later stages of
pregnancy) even if the mother does not have a known problem
with blood clotting herself. As a cause for recurrent pregnancy
loss these particular disorders are relatively rare. A screening
test for these disorders is part of your evaluation.
Poorly controlled diabetes mellitus has been linked to early
pregnancy loss. Although it is very unlikely that unrecognized
diabetes causes recurrent pregnancy loss, screening for diabetes
will be performed by a blood test.
Thyroid dysfunction may be a cause of early pregnancy loss
- either under activity (hypothyroidism) or over activity
(hyperthyroidism). Thyroid disease is a very rare cause of
recurrent miscarriage. Your thyroid function will be tested.
Several environmental factors may increase the risk of early
pregnancy loss. The use of alcohol or cigarettes has been
associated with a higher than normal incidence of spontaneous
pregnancy loss. Most women who smoke or drink alcohol carry
pregnancies successfully and therefore there may be an unusual
susceptibility on the part of some pregnancies or mothers.
There is also likely to be a dose related effect. In other
words, excessive smoking or alcohol consumption, in some women
(it is not possible to identify which women) may cause early
pregnancy loss.
Many chemicals have been implicated in early pregnancy loss.
Women with occupational exposure to anesthetic gases, lead,
or mercury may suffer increased pregnancy loss. The wives
of men exposed to vinyl chloride, chloroprene, or DBCP have
also suffered an increased rate of early pregnancy loss.
Maternal exercise is often a matter of concern. There is
no substantial evidence that strenuous maternal exercise causes
pregnancy loss. Even so, "taking it easy" or even
bed rest are often recommended in cases of threatened miscarriage.
These measures may or may not help - they certainly do not
do any harm.
Lastly, in terms of general prognosis, two of the largest
studies that have investigated the problem of recurrent pregnancy
loss have shown that women experiencing even 3 or 4 early
spontaneous pregnancy losses with no known cause and no medical
intervention have a fairly high chance of having a normal
term delivery with their next pregnancy. The table below shows
various data on the chance of subsequent pregnancy loss.
- <35 3 - 4 miscarriages, (+) previous live birth 70%
- <35 3 - 4 miscarriages, (-) previous live birth 60%
- 35 - 40 3 - 4 miscarriages, regardless of previous history
> 60%
- >40 > 2 miscarriages, regardless of previous history 50%
