Articles
Register for Recurrent Miscarriage (Pregnancy Loss)
by Eric Daiter, MD
(part 1 of 2)
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Recurrent Pregnancy Loss: grieving process |
As soon as a pregnancy becomes recognized, each (prospective) parent generally
starts to accept and plan for their new arrival. If the pregnancy is lost, this is often considered a "death
within the family" and the couple will go through an intense grieving process. The loss of a pregnancy can
be devastating for a couple, regardless of the number of children in the family or the cause for the loss.
Components of the grieving process may be easier to accept and cope with if they are consciously understood. Therefore,
I have outlined major issues. Interested couples can either read the original sources or consult a professional
psychologist specializing in this area.
The grieving process often includes sequential periods of
- denial, beginning with the shock of learning that there has been a death
- anger, often inappropriately directed at anyone the person thinks about or sees
- bargaining, often involving charitable acts or attempts to reconcile damaged relationships
- depression, often associated with feelings of helplessness and hopelessness
- acceptance, enjoying the time spent with family and social groups "more than ever."
There may also be changes in one's self image. The changes that have been described in the context of the loss of a body part may be relevant, including
- impact, beginning at the point of awareness that there is a problem requiring the loss of a body part (or here essentially a "family part")
- retreat, where denial of the importance of the loss may occur (a second opinion at this point is often important in allowing movement toward closure)
- acknowledgment, with acceptance of the need for treatment generating an attempt to place the treatment and loss into an appropriate context
- reconstruction, a redefinition of self image without the presence of the lost part (or family member)
In this grieving process, if the "redefined self images" of each member of the family can not be accepted by the other members then there is often a long lasting impact possibly resulting in depression. If a couple can "not get over the loss" then professional counseling is often quite powerful and should be recommended.
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Recurrent Pregnancy Loss: Incidence Rates |
No one really knows how often human pregnancies are lost. Investigation of the "rates of loss" are inherently difficult due to the inaccessibility of information.
- Many pregnancies are lost "at home" without the aid of medical facilities. These losses may go unreported.
- In the USA, there is no formal reporting of previable pregnancy losses to a centralized agency (as there is with live birth statistics).
Most of the research on incidence rates of pregnancy loss incorporate their own
unique methodologies for identifying these losses. Consequently, the rates reported between studies vary tremendously.
This situation has led to the apparent discrepancy often noted between doctors in their discussions on the rates
of miscarriage.
The most widely accepted rate of loss for a "single spontaneous abortion" in an unselected population of couples (that is, regardless of characteristics associated
with pregnancy loss) is about 15-20% (1 in 6) of "clinically detected" pregnancies (where the woman missed
a menses or otherwise knew that she was pregnant).
Many pregnancies are lost prior to clinical detection but the incidence of these very early losses is not clear.
A number of studies checked for pregnancy each month with a highly sensitive immunoassay from blood drawn or urine
collected in sexually active women not using contraception. This research consistently demonstrates a high rate
of "unrecognized pregnancy" in woman who are just "a little late for the menstrual flow." Some
studies report a total pregnancy loss rate (nonclinical plus clinical) of more than 50% (1 in 2).
The chance of having a second spontaneous abortion with a history of only one isolated spontaneous abortion is
generally considered to remain at 15-20% (for clinically recognized pregnancy). The incidence does not decrease
(as if you used up your 1 in 6 and now must have 5 normal pregnancies) or increase significantly.
If there have been 2 spontaneous
abortions in a row, then the most
reliable information suggests that there is about a 35% chance (1 in 3) that the next pregnancy will be lost. Therefore,
the loss rate is approximately doubled.
If there have been 3 spontaneous
abortions in a row, then it appears
that the couple has a roughly 45-50% chance of a loss with the next pregnancy. There are reports indicating improvement
in future pregnancy success for couples with recurrent pregnancy loss after there has been at least one prior live
born for the couple (that is, a 40-45% loss rate if no live borns and only a 30% loss rate with a history of a
prior live born). Therefore, the couple's prior reproductive history is also important.
The spontaneous abortion rate rises as the woman's age increases, with a gradual increase starting about age 30,
more rapid increases after age 35, and much more rapid increases after age 40. The age related increases in spontaneous
abortion rates appear to be predominantly due to chromosomal accidents around the time of fertilization, where
the egg is given one too many or one too few chromosomes so that the resulting fertilized egg (embryo) has a lethal
genetic abnormality. When women over 40 or 45 years age are recipients of donor eggs from younger women they do
not have this increased spontaneous abortion rate. This suggests that the cause of this increase in loss rate is
related to egg rather than uterine factors.
About 80% (4 in 5) of spontaneous abortions occur in the first trimester of pregnancy (in the initial 13 weeks
gestation). In couples without a history of recurrent losses if a fetal heart beat (FH) is seen by ultrasonography
at 6 weeks gestational age then there is a reduced loss rate to about 5% (1 in 20). There is a further reduction
if an FH is seen at 8 weeks gestation to about 3% (1 in 33). Unfortunately, in couples with recurrent losses the
loss rate is still about 4-5 times greater (about 20% or 1 in 5) even after seeing an FH. Of course, seeing the
fetal heart beating is reassuring but not as encouraging as if seen in an unselected population.
The high level of uncertainty involving any pregnancy seems to warrant that couples remain "cautiously optimistic"
when they recognize a pregnancy. Many couples do not announce that they are "expecting" until seeing
the FH or the completion of the first trimester.
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Recurrent Pregnancy Loss: Overview of Causes |
Many couples blame themselves (often harshly) for their pregnancy losses. In fact,
it is rare that either member of the couple has done anything that would result in a pregnancy loss. Additionally,
the actual incidence of pregnancy loss in the United States is much higher than typically thought. The result is
that many couples might benefit from knowledge of the recognized causes for pregnancy loss.
There is a major difference in both "incidence rates" and "causes" for single spontaneous abortions
and recurrent spontaneous abortions. Recurrent abortion is typically defined as three or more consecutive (in a
row) pregnancy losses that occur prior to fetal viability (usually 20 weeks gestation or a fetal weight of 500
grams). The reason for this criteria is the reports of a significantly higher chance for further pregnancy loss
following the loss of "three in a row."
The two major clinically important categories of causes for spontaneous abortion (miscarriage) are fetal and maternal.
Fetal causes include the genetic
composition of the fetus.
- human live borns have a very low percentage of chromosomal abnormalities (about 0.6% or 1 in 170). This low percentage indicates that almost all chromosomal abnormalities are lethal and aborted early in pregnancy.
- The only chromosomal abnormalities (other than those involving the X and Y sex chromosomes) that might result in a human live born are trisomy 21 (three of the 21 chromosome, known as "Down's syndrome"), trisomy 18 (three of the 18 chromosome, known as "Edward's syndrome" and all die during infancy) and trisomy 13 (three of the 13 chromosome, known as "Patau syndrome" and all die during infancy).
Maternal causes include abnormalities in the "environment" in which the embryo and fetus develops. Known maternal causes related to an action of the mother are uncommon, but can include
- heavy smoking (uncommon for this to result in a loss)
- alcohol abuse (uncommon for this to result in a loss)
- irradiation or exposure to chemical toxins
- medications known to be teratogenic (cause fetal malformation)
Other maternal causes which are not related to any conscious activity of the mother or couple include
- anatomic abnormalities (typically uterine)
- hormonal imbalances (typically in progesterone)
- immunologic system errors (autoimmune and alloimmune)
- serious or life threatening maternal disease
By far the most common causes for spontaneous pregnancy loss are fetal not maternal.
It is difficult for a woman with an undesired pregnancy to consciously create an unfavorable environment for the
pregnancy to successfully force a miscarriage.
Often couples blame themselves for "doing something" that must have resulted in the pregnancy loss. Focusing
on themselves (often harshly) for doing something wrong is unfortunate since
- it adds guilt on top of an existing emotionally charged situation, which is counterproductive and may delay or arrest recovery from the event
- it is misdirected since very few losses are related to conscious maternal actions
- it often assumes that such losses are rare events when in fact they are common (but not commonly discussed)
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Recurrent Pregnancy Loss: clinical evaluation |
An evaluation for known causes of recurrent pregnancy loss is usually initiated after 2 or 3 consecutive pregnancy losses. The tremendous emotional impact of each loss may encourage an evaluation sooner than later. A full evaluation includes
- demonstration of a normally shaped uterine cavity (by either hysterosalpingogram or hysteroscopy)
- evaluation for a hormonal deficiency in progesterone production (by either endometrial biopsy or bloodwork)
- analysis of both the maternal and paternal chromosomes (by bloodwork)
- laboratory testing for immunologic causes of pregnancy loss (by bloodwork)
- taking a history for maternal disease states, environmental or other toxin exposure
If a full evaluation is completed on couples with either 2 or 3 consecutive losses there will still be about 50% (1 of 2) of couples with "unexplained" recurrent pregnancy loss. That is, roughly half of couples seem to have a reason for recurrent loss that is beyond modern medicine's ability to diagnose this cause. This can be frustrating for both the couple and the physician. In this situation, the couple will at least know that potentially repairable pathology has been ruled out. The couple can then elect to enroll in experimental protocols designed to further our knowledge of recurrent pregnancy loss. In my experience, these experimental treatments often result in reproductive success despite limited knowledge on why they work.
Visit Dr. Daiter's website: InfertilityTutorials.com
