Doctor’s Room: Miscarriage (II)

By Dr Noah O. Olaomo

Causes of Miscarriage
The known causes of miscarriage can be grouped under the following;
1. Genetic (chromosomal)
2. Toxic.
3. Infections
4. Structural/anatomical
5. Hormonal
6. Chronic Diseases
7. Immune abnormalities
8. Unknown

• Genetic/chromosomal
The commonest cause of miscarriage in the first trimester of pregnancy is genetic. Genetic cause has to do with abnormalities with the sperm and or the egg (ovum). A genetic/chromosomal defect will result in abnormal embryo/ fetus that usually results in a miscarriage. It is also a natural way of preventing deliveries of abnormal babies.

Toxic causes of miscarriage arise from exposure to poisonous substances during pregnancy. Prominent among toxins that can result in miscarriage are drugs, herbal mixtures, unregulated supplements, radiations among others.
Therefore, a pregnant woman must be careful to avoid unwholesome exposure to these agents.

Different types of infections can predispose to a miscarriage. Infections produce unfavorable environment for the growing baby which may result in a miscarriage. A lot of infections also cause fever. And, fever produces an unfavorable environment for embryo/fetus.
Common example of infections/infestations that can cause miscarriage include, malaria, urinary tract infection, bacterial vaginosis etc

For a pregnancy to be successfully carried to term (9months), the womb (uterus) and the cervix (neck of womb) must be strong and structurally intact to carry the pregnancy.
The cervix can be weak from previous injuries or naturally (structural weakness) This leads to cervical incompetence/insufficiency which causes miscarriage from above 13weeks. It can also cause a preterm birth.
There may also be congenital (inborn) abnormalities with the womb. Some of the abnormalities cause reduced capacity of the womb to carry pregnancy to term thus causing miscarriages.
Also uterine fibroids can distort the structure and functions of the womb and then promote miscarriage

Progesterone is an hormone that is particularly needed to sustain the pregnancy. The placenta produces this hormone in adequate quantity.
However, placenta only becomes fully functional at about 3months. Earlier, progesterone is produced by a cyst in the ovary (corpus luteum cyst). In some women, this cyst
does not produce enough progesterone thus resulting in repeated miscarriages.

Chronic Diseases
Many chronic diseases in the pregnant woman can predispose to miscarriage. These include uncontrolled diabetes and hypertension, sicklers, connective tissue diseases and other chronic diseases.

Immune abnormality
Some immune problems as occur in antiphospholipid syndrome can lead to repeated miscarriages

The causes for a lot of other miscarriages will not be known.

The common symptoms women have when miscarriage happens are vaginal bleeding and abdominal pain.
If the pregnancy is advanced beyond 5months, some may experience drainage of water vaginally especially in cervical incompetence.
Miscarriage in cervical incompetence is usually initially painless and starts with drainage of liquor.
If bleeding is extensive, the woman may feel dizzy and faint.
In case of missed abortion, the earlier pregnancy symptoms might have stopped.
At the hospital, it may be found that the cervix has opened and part of the products of conception are already being expelled. In missed abortion, the size of the abdomen will also not be in keeping with the duration of pregnancy.

A detailed evaluation by a doctor and investigations like ultrasound will be needed to make a diagnosis.


The following steps will help in preventing or minimizing the occurrence of miscarriage.
• All women intending to be pregnant should go for a detailed preconception care. This will allow proper evaluation, detection and treatment of preexisting diseases. This will make all women to become pregnant when they are in their best state of health.

• Preexisting diseases like diabetes, hypertension and others should be properly treated before and during pregnancy.

• A woman with a cervical incompetence will always need to have a cervical cerclage at about 12-14weeks to prevent recurrent miscarriage

•Every woman should seek expert care in pregnancy as much as is possible and available.

* Some couple with recurrent miscarriage may need genetic testing (karyotyping) to ascertain the possible genetic cause of the miscarriage.

*Surgery might be needed to solve the problem of recurrent miscarriage. Some women will need surgery to remove fibroids (myomectomy). Others with congenital problem with the womb might need corrective surgery.

When there is a case of miscarriage treatment depends on the type and mode of presentation.
If it is complete miscarriage without any complication, no further treatment may be necessary.
Surgical evacuation and treatment with drugs will be used as necessary. Antibiotics, blood transfusion, hematinics etc are given as necessary.

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