What
is a miscarriage?
A
miscarriage is the spontaneous loss of a pregnancy from conception to 20 weeks’
gestation. The term stillbirth refers to the death of a foetus after 20 weeks’
gestation. Miscarriage is sometimes referred to as spontaneous abortion,
because the medical term abortion means the ending of a pregnancy, whether
intentional or unintentional. Most miscarriages occur in the first three months
of pregnancy, between the 7th and 12th weeks of pregnancy.
How
common is miscarriage?
Miscarriage
is very common. Because many or even most miscarriages occur so early in
pregnancy that a woman might not have known that she was pregnant, it is
difficult to estimate how many miscarriages occur. Some experts believe that
about half of all fertilized eggs die before implantation or are miscarried. Of
known pregnancies (in which a woman misses a period or has a positive pregnancy
test), about 10% to 20% end in miscarriage.
What
causes miscarriage?
The
majority of miscarriages are believed to be caused by genetic problems in the
embryo that would prevent a baby from developing normally and surviving. These
fatal genetic errors typically are not related to genetic problems in the
mother.
In
other cases, certain illnesses or medical conditions can cause miscarriage and
may increase the risk of miscarriage. Mothers who have diabetes or thyroid
disease are at increased risk of miscarriage. Infections that spread to the
placenta, including some viral infections, can also increase the risk of
miscarriage.
Causes
of Miscarriage
Most
early miscarriages (as many as 60% of first trimester ones) will remain
unexplained. It is usually assumed these losses are genetic, where the
chromosomes simply did not replicate correctly. Many people will assume that
something that happened recently, such as an illness, fall, or exposure to
something will have caused the miscarriage. This is rarely true, since by the
time a miscarriage is diagnosed or begins, the baby has been lost for quite
some time. Hopefully this section will help you understand the causes
There
are several categories of miscarriage causes:
Sexually
transmitted infections
Hormones
Chromosome
Defects
Physical
Problem with the Uterus or Cervix
Immune
Disorders
Premature
Rupture of Membranes and Early Labor
Other
Unknown
Blighted
Ovum, Ectopic Pregnancy, Molar Pregnancy, and Stillbirth
There
are a number of things that are not on the list above, even if you heard they
cause miscarriage, because they are not documented causes of a loss.
Hormones
When
we talk about a hormone problem, you have likely miscarried in less than 10
weeks. After that, the placenta has taken over hormone production and any
normal deficiency you have is not a factor. Low progesterone, the most common
problem, is not as easy to treat as you might hope. Progesterone suppositories,
while frequently prescribed, are not proven to be helpful and often actually
cause a nonviable pregnancy to last longer than it should.
The
only situation where progesterone is a sure solution is with a luteal phase
defect, where the corpus luteum, which is formed along with egg at ovulation,
does not produce the hormones needed to sustain a pregnancy. For most women,
however, this is usually not an every-month problem. Usually the situation
rights itself with the next egg and the next corpus luteum. This problem, if it
is a permanent one, can be diagnosed through two separate endometrial biopsies.
Progesterone must be started 48 hours after ovulation to work. By the time you
have missed a period, it is too late to save a pregnancy with a luteal phase
defect. 5
Low
progesterone, however, is usually a symptom of a nonviable pregnancy, and not
the cause. Doctors often prescribe progesterone suppositories out of patient
pressure when the hormone levels are low, but their use is controversial and
usually completely ineffective. A common treatment for a suspected progesterone
problem is Clomid, a pill taken for five days early in your cycle to rev up
your hormone production. Not everyone is a candidate for Clomid, and 25% of
women will have decreased cervical mucus, which can actually make you less
fertile. See the Sperm Meets Egg Plan for more information.
Other
hormone problems may be created when you have an untreated thyroid disorder.
Your thyroid function can easily be tested, and this problem is very treatable.
Chromosome
Defects
There
are many factors that come in to play when the egg and sperm unite and form
that first cell. Even if both the egg and sperm come with perfect chromosomes,
the first few cell divisions can see an abnormality crop up that would
certainly be devastating. Chromosome defects that cause a newly fertilized egg
to die can account for as much as 60 percent of early miscarriages.
You
can usually find out if you had a baby with a chromosome problem through
testing tissue from the miscarriage. This must be done RIGHT AWAY when the
tissue comes out or the cells cannot grow and the test won’t work. If this is
your first miscarriage, however, do not go to great lengths to save tissue.
Very few doctors will test it, and a chromosomal cause for the miscarriage will
be assumed without testing.
Even
when you have a D&C and the doctor sends the tissue immediately, the test
still might not work. (Mine didn’t.) But if you do find your baby had a
chromosome defect, find a small measure of comfort in knowing that although you
lost this one precious baby, the chances of it happening again are extremely
small. Another threshold will be crossed, however, at age 35. At that point,
your eggs will begin to age, and your odds of a chromosomal miscarriage will
begin increasing dramatically.
After
the 2nd trimester begins, the number of miscarriages caused by genetic factors
drops to less than 10 percent. if you have had several miscarriages in a row,
then your odds of this being your problem are quite low, about 7%.42
Physical
Problem with the womb or neck of the womb
Some
women have a uterus that does not have the usual shape. Others have a cervix
that may be weakened by a number of causes, including multiple D&C
procedures or their mother taking DES when she was pregnant (although note that
DES was discontinued in 1971 and most DES daughters are leaving their
childbirth years behind.) Both of these problems can cause early labor, usually
during a critical period from 12-24 weeks. This cause is responsible for 12
percent of miscarriages during this time period. As the baby grows, especially
during the very rapid growth spurt during this time frame, the irregularly
shaped uterus may not be able to expand or the weak cervix may start to open up
and let the baby out. There are treatments for both of these that are quite
effective—corrective surgery on the uterus and a cervical stitch that holds the
cervix closed. This problem WILL REOCCUR if not treated.
A
uterine abnormality often causes a miscarriage due to early labour, but it can
also cause foetal demise, which is what happened to our Casey. Sixteen weeks
into my pregnancy with Emily, we had an abnormal AFP screening. Since we were
near the point of the pregnancy when Casey died, naturally we were frantic. We
saw a primatologist, who discovered I had a septate uterus.
There
is a huge wall going down the middle of my uterus. When Casey implanted, he
chose the middle wall. This section, however, has little blood flow. As Casey
grew and required more and more blood and nutrition, this area could not
support him. Although Emily chose a better implantation spot, this problem
caused her to be breech and required a C-section. While I did have the surgery
to correct this problem, my next pregnancy still had complications, and I was
not allowed a vaginal delivery.
Be
aware that there are varying levels of septum’s. Some are paper-thin and simply
move out of the way for the baby, causing no problems. Others, like mine,
increase your chance of miscarriage significantly. Only a high-level sonogram
or an HSG dye test can uncover this problem.
Others
-- Infections, Age, Chronic Disease
Many
infections can cause miscarriage, but they are the big ones like syphilis,
mycoplasma, toxoplasmosis, and malaria. An upper respiratory infection is NOT
going to cause a miscarriage, even though it may worry you to death. Viruses
are the same. Normal illnesses like the common cold will not cause a problem,
but AIDS and German measles can. Infections that directly affect the uterus are
bigger risk. This does NOT include yeast infections, which are extremely common
in pregnancy. See the section on Premature Rupture of Membranes for more
information on these infections.
There
are a few common illnesses that can cause a miscarriage or fetal malformation
if you get them for the FIRST TIME during pregnancy, including Chicken Pox and
Fifth Disease. The vast majority of women already have immunity to these
diseases, however, and should not be concerned about exposure to them during
pregnancy. If you think you may not have immunity, ask your doctor to run an
antibody titter to see if you have a live antibody, or only an old antibody to
the disease in your blood. Only the live antibody without the old antibody
present is a danger.
An
infection that causes a fever of over 101 degrees Fahrenheit should be treated
immediately, however. There is a small risk that prolonged fever can affect
your baby. Take Tylenol to keep your fever down and stay in touch with your
doctor.
Age
is only a factor in miscarriage when you consider what aging can do to your
body. The first and most common is with chromosomes. It is not YOU who have a
problem; it is likely your egg or sperm, which have also aged. Age can,
however, bring other problems such as poor health, disease, or hormonal
imbalance that can make a pregnancy harder to sustain. You don’t start seeing
these problems in great numbers, however, until after 40.
Health
problems in the mother can create problems with the pregnancy. Diabetes, heart
problems, and thyroid disorders are just a few that may complicate the
pregnancy. Having these does NOT mean you will certainly have a miscarriage.
You will simply have to be more careful and make sure your treatments are
adapted if needed during pregnancy.
The
Unknown
Typically
do not cause a miscarriage. The baby is well protected in its amniotic sac,
surrounded by fluid, and even a hard blow to the abdomen will likely only rock
it. Most women who have a car accident, even with a certain amount of trauma,
have their babies’ just fine.
The
hardest thing to accept is no reason at all. You live in fear, wondering if the
same terrible cause of your first baby’s death will cause another one to die.
You scarcely dare to try again. I have been in this situation and I tossed my
doctor’s statistics aside. I had already been on the wrong side of the
statistics; I didn’t care for anymore. But I do know this. One miscarriage
hardly raises your chances to miscarry again at all. You are simply back at
square one. Try to put the risk as far back in your mind as possible and enjoy
another pregnancy. But I understand if you can’t.
Ectopic
Pregnancy (pregnancy outside the womb)
Is
a normal fertilized egg that gets stuck in the fallopian tube (although
occasionally it will fall into the abdominal cavity) and implants there. This
type of pregnancy cannot survive and puts the mother at great risk for severe
hemorrhaging and possibly even death as the baby grows and eventually bursts
the tube. When the ectopic is discovered based on pain and symptoms rather than
an early ultrasound, the mother will immediately have surgery to remove the baby.
Things will happen very fast, and most likely if this has happened to you, you
are reading this after it is all over. If you are afraid you have an ectopic,
the symptoms that you really want to watch for are: sharp, intense pain in your
abdomen or possibly in your shoulder; a pregnancy test that is positive, then
turns negative a few days later; and spotty red bleeding that continues day
after day. Ectopics that are caught early can be treated with a cancer drug
called Methotrexate, which will end the pregnancy safely and without surgery.
Ectopic
are usually caused by scar tissue in the fallopian tubes that could have been
caused by: previous surgery in the pelvic region, uterus, or tubes; a pelvic
infection such as chlamydia or pelvic inflammatory
Stillbirth
is technically any pregnancy that ends after the 20th week and the baby does
not survive. Some babies die in uteri and are discovered when the heartbeat is
not found. The most common causes of this are: uterine abnormalities, a knot or
other umbilical cord accident, infections of the lining of the gestational sac
or cord, and placental abrupt ions that cause the placenta to pull away from
the uterine wall. These babies are usually born through the induction of
labour, although some babies are small enough to be taken by D&C or D&E
procedures.
Other
babies are lost through early labour. The causes of early labor are Premature
Rupture of Membranes, uterine abnormalities that make the uterus too small to
hold the baby, and an incompetent, which opens up and lets the baby out.
Sometimes a stillbirth occurs during the birth, by an umbilical cord that gets
pinched between the baby’s head and the cervix, or the cord wraps around the
baby’s neck. Repeat stillbirths are extremely rare and are almost all related
to uterine or cervix problems, which can be fixed or treated once found
What
are the types of miscarriage?
Miscarriages
are sometimes referred to by specific names to reflect the clinical findings or
the type of miscarriage. Examples include:
·
Threatened abortion: a woman may experience vaginal bleeding or others signs of
miscarriage (see below), but miscarriage has not occurred
·
Incomplete abortion: some of the products of conception (foetal and placental
tissues) have been expelled from the uterus, but some remain within the uterus
·
Complete abortion: all of the tissue from the pregnancy has been expelled
·
Missed abortion: the foetus has not developed, so there is no viable pregnancy,
but there is placental tissue contained within the uterus
·
Septic abortion: a miscarriage in which there is infection in the foetal and
pregnancy material before or after a miscarriage
How
is miscarriage diagnosed?
An
ultrasound examination is typically performed if a woman has symptoms of a
miscarriage. The ultrasound can determine if the pregnancy is intact and if a
fatal heartbeat is present. Ultrasound examination can also reveal whether the
pregnancy is an ectopic pregnancy (located outside of the uterus, typically in
the Fallopian tube), which may have similar symptoms and signs as miscarriage.
Other tests that may be performed include blood tests for pregnancy hormones,
blood counts to determine the degree of blood loss or to see whether infection
is present, and a pelvic examination. The mother’s blood type will also be
checked at the time of a miscarriage, so that Rh-negative women can receive an
injection of rho-D immune globulin (RhoGam) to prevent problems in future
pregnancies.
What
happens after a miscarriage?
There
are no specific treatments that can stop a miscarriage, although women who are
at risk and have not yet miscarried may be advised to rest in bed, abstain from
sexual activity, and restrict all activity until any warning signs are no
longer present. Once a miscarriage occurs, there is no treatment available. In
many cases, the miscarriage will take its course, and unless there is severe
pain and cramping or severe blood loss, no treatment is required. If a
miscarriage does not completely clear the pregnancy tissue from the uterus, a
procedure known as a dilatation and curettage (D&C) can be performed to
remove the remaining pregnancy material. This treatment is used in the case of
a missed abortion, for example, when the pregnancy material is not expelled
from the uterus.
As
mentioned above, women who are Rh-negative will receive a dose of rho-D immune
globulin to prevent complications in future pregnancies.
If
a miscarriage is due to infection, antibiotic treatment will be given.
Miscarriage
is such a common occurrence that typically, unless known risk factors are
present, no special testing is performed. For couples who have experienced more
than two miscarriages, diagnostic studies to detect genetic, hormonal, or
anatomical problems may be recommended. Some doctors recommend evaluation of
the couple after the second miscarriage, particularly if the woman is over 35
years of age.
What
is the outlook for future pregnancies after a miscarriage?
Most
women who miscarry go on to have a successful pregnancy. The likelihood of a
miscarriage in a future pregnancy increases with the number of miscarriages a
woman has had. In general, the risk of a second miscarriage in women who have
had a previous miscarriage is about 15%. The risk is about 30% in women who
have had two miscarriages. Most women will have their menstrual within 4 to 6
weeks after a miscarriage. Your doctor can advise you when you may start
conceive again. While it is possible to conceive again after your menstrual
period has returned, some doctors advise waiting a bit longer, such as another
menstrual cycle or more, to provide enough time for physical and emotional
recovery.
Can
miscarriage be prevented?
There
is no evidence that bed rest can help prevent miscarriage, but women who have
vaginal bleeding during pregnancy are often advised to rest and limit sexual
activity until there are no more potential signs of miscarriage. It is possible
that some risk factors for miscarriage can be minimized by maintaining a
healthy weight and avoiding the use of alcohol, illicit drugs, or tobacco.
Screening for and treatment of any sexually-transmitted diseases (STDs) can
also reduce the risk of a miscarriage. Avoidance of sports such as horseback
riding or skiing can reduce your risk of trauma to the uterus. In most
instances, however, the cause of a miscarriage is outside of the woman’s
control.
For
further information visit the EFSTH, number of government clinics throughout
the country, number of NGO and private clinics E mail drh_azadehmd@yahoo.com
Text only to 002207774469/3774469
Author
DR AZADEH Senior Lecturer in Obstetrics and Gynaecology at the University of
the Gambia, Senior Consultant in Obst/Gynaecology, Clinical Director of Medicare Clinic Health
services.
