Why do miscarriages happen? Why do some women miscarry again and again?
As a gynaecologist, I see that miscarriages are becoming increasingly common. WIth hectic and stressful lifestyles, about 10-15% of all natural pregnancies end up in a miscarriage.
There are several reasons for a miscarriage. The commonest reason is probably Nature’s selection. It is believed that as many as 75% of all pregnancies result in miscarriage, though most go unrecognised as they happen so early that it feels like that of a normal period, though slightly delayed.
A miscarriage is often a result of Nature’s selection process (Nature tries to allow only the best embryos to thrive and embryos which are below the mark are rejected ....meaning thrown out by the process of abortion). Hence most doctors would not ask for a battery of tests after a single abortion.
For any early embryo to survive and grow in the uterus, the first step after fertilization is implantation i.e. the baby latches on to the inner lining of the uterus. Early in the second month of pregnancy, an organ called placenta starts forming. The placenta is a collection of blood vessels and the blood flows from the uterus, via the placenta to the fetus through the umbilical cord. The hormone progesterone plays an important part in the maintenance of the pregnancy in the earlier stages till the placenta is completely formed (usually by the end of the 3rd month).
Miscarriage may occur early in pregnancy as a result of defective implantation if some problem occurs at that early stage (usually just before or about the time of expected menses); or from reduced blood supply to the developing baby.
Why some embryos (even if normal) fail to implant or secure adequate blood supply is as yet a mystery even to medical science.
The known causes are as follows:
- Genetic defects
- Immunological causes (antibodies)
- Defects of the uterus
- Hormonal disturbances
- Environmental causes (lifestyle, drugs, exposure to damaging material)
About 50% of all miscarriages are a result of genetic causes. The fetus is genetically or chromosomally defective and is thus not able to survive. This usually occurs as a random event and a vast majority of these couples have no problem with conception next time. However, to diagnose a chromosomal defect, one would need to perform advanced tests on the abortus, which is not recommended after a first miscarriage. Hence, for most of the time, the miscarriage goes unexplained.
Some of these couples may be unfortunate in that they may suffer a repeat miscarriage due to genetic defect in the abortus. Occasionally one of the parents may carry abnormal genetic material which may result in an abnormal offspring. Therefore, couples who suffer repeated miscarriages may opt for genetic testing of the abortus.
Some women carry antibodies in their blood which may attack their own cells. Some of these antibodies may attack the placenta or promote formation of clots in the blood supply to the developing foetus. This may lead to slower growth foetal growth and eventual demise.
Auto-antibodies, as described above, usually cause foetal loss towards the third month of pregnancy or later.
Defects of the uterus:
Some women may have, from birth, a septum (wall) within the uterus or even “double” or “half” uterine cavity or a similar defect. Miscarriage may result from that (though it is not necessary). Rarely, after repeated D&Cs from miscarriage or wilful abortion, or uterine infection (such as tuberculosis), ‘bands’(adhesions) may form within the uterus, not allowing the baby to grow or get proper blood flow. Very large fibroids, especially those which enter into the uterine cavity may also interfere with a norma pregnancy.
Sometimes the cervix (the mouth of the uterus) opens up early in the second trimester causing miscarriage. This may be prevented by a simple stitch to ‘hold’ the pregnancy, in selected cases.
Infections can interfere with early pregnancy development and many bacteria, viruses or parasites are known to cause pregnancy loss, though that is not very common.
Various hormones which work in balance to provide the ideal environment to the developing embryo. Women with hormonal imbalance, menstrual disturbances and PCOS have a higher risk of early miscarriage.
Women with uncontrolled diabetes or uncontrolled thyroid disorder are also at a higher risk than others.
A pregnant woman needs to be especially watchful in the first three months as what she ingests through her mouth or lungs may reach her unborn baby whose organs are forming. Harmful substances such as certain drugs, alcohol, smoking or excessive caffeine intake and stress may harm the foetus and may eventually cause miscarriage. Pregnant women should not undergo Xray or CT scan, unless recommended by the doctor (under compelling conditions and with adequate precautions).
Finally, let us understand that a majority of the miscarriages go unexplained and are random occurrences.
I am afraid that I may miscarry again or may not conceive again. Is that true?
Having had a miscarriage does not mean that you cannot be a mother again. You have only a 15% chance of suffering another one. However, after two losses, the risk rises to 30%, and after three miscarriages, you have a 45% chance of another miscarriage.
It is wise to consult a specialist if you are having difficulty retaining your pregnancy. You would need specialised tests and treatment for the same.
When can one try to conceive after a miscarriage?
There is no one single answer to this question. However, most doctors would agree that you as a couple should complete the basic investigations (and treat the cause whenever possible) and you should recover your physical and mental health sufficiently before you are ready again. Usually 3 months is a good time for this process, however, it may vary vastly. Ask your doctor the recommendations for you.
What are the treatments available to prevent a miscarriage?
All women planning a pregnancy should be taking folic acid supplement. Once you get pregnant, visit your gynaecologist immediately. She/he would start progesterone capsules or gel(oral or vaginal) to support your pregnancy or give you Inj HCG weekly or twice a week. You should avoid exertion, emotional stress and travel.
In case, the specialist detects a specific causes for miscarriage, the same would be treated. For example if you have a uterine septum, surgery would help. Similarly, if you would benefit from heparin injections throughout pregnancy if your placenta is not allowing adequate blood flow to the baby.
How does a miscarriage take a physical and emotional toll on a woman?
Pregnancy is an event which brings joy and hope. So you as a couple are looking at a new horizon together. Miscarriage is not just the death of an as yet unborn entity, it is the shattering of a dream.
You may feel angry and helpless… “Why me!?” You may feel that you have let down yourself, your partner and family. Often in our society, the woman gets blamed for the miscarriage, for ‘things’ which she ‘did’ or ‘did not do’. You may feel guilty and a failure. Feelings of fatigue, loss of interest in everything, body pains, lack of sleep or excess sleep, loss of appetite, mood swings and wanting to be alone, can signal depression.
The above emotional turmoil is often compounded by anxiety about the outcome of a future pregnancy, as well as a dip in hormonal levels immediately post miscarriage.
Your partner, though not as expressive, is likely to be grieving in his own way. He may, in addition, feel out of control, at being unable to set things right and may frequently seek work as a way out. Most men do not seek support and would rather procure more information on the subject and try to prevent a future mishap.
How do I cope with a miscarriage?
Every woman is different and as such her ability to cope with a stressful situation differs.
You need to give yourself time and space to grieve. Grieving is a most natural reaction and your family should honour your feelings. You may decide to take time off from work or involve yourself in prayer or spiritual practices, or revive an old hobby or take up a new one.
You seek solace your husband and family.
Most partners do support each other unconditionally and miscarriage brings them closer. However, you may perceive your husband as ‘cold’ or your husband may feel that you are not trying to get over it soon enough and this may strain your relationship.
Family support (especially from mother and sister) is invaluable. Sometimes insensitive, though well-meaning relatives may unintentionally hurt your emotions and make you feel that you are over-reacting.
You may seek professional help from counsellors if things are beyond your control.
Meet your gynaecologist and ask her all the questions you need to. Your doctor will give you all the relevant information for future conception. Follow your gynaecologist's advice and perform all the requisite tests.
Hope for the future is the best coping mechanism for miscarriage. Life goes on!
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