Recurrent miscarriage, habitual abortion, or recurrent pregnancy loss (RPL) is three or more consecutive pregnancy losses.
What can cause recurrent miscarriages?
There are many causes of miscarriage, but they are usually divided into two groups: early and late
Recurrent early miscarriages (within the first trimester) are most commonly due to genetic or chromosomal problems of the embryo, with 50-80% of spontaneous losses having abnormal chromosomal number. Structural problems of the uterus can also play a role in early miscarriage.
Recurrent late miscarriage can be the result of uterine abnormalities, autoimmune problems, an incompetent cervix or premature labor.
What causes recurrent pregnancy loss?
While often the reasons for miscarriage are not obvious, many patients go on to have a successful third pregnancy. Even after two miscarriages, there’s a 65% chance your third pregnancy will end in live birth.
However, if a cause is discovered, it may be easy to fix, and finding the cause at this point may prevent further losses and emotional stress. After two miscarriages, you have what is known as recurrent pregnancy loss and you may benefit from the diagnostic testing noted above to see if there is a reason for why your are mis-carrying.
Genetic (embryo or parents)
Random chromosomal abnormalities of the embryo are common and comprise 50-80% of all first trimester losses. However, there are times when some chromosomal abnormalities are repeatedly passed on which can contribute to multiple pregnancy losses. If you have had two or more losses, you and your partner should consider a karyotype check.
About 15% of all repeated miscarriages are caused by a uterine structural problem. Abnormalities of the uterus can be something that you’re born with (congenital), like a double uterus, a uterus that is divided by a wall (septate uterus) or other less common congenital problems.
There are also problems with fibroids or polyps for some women. These are growths that can occur in any place within the uterus, which may have no effect on pregnancy or can cause problems. Intra-uterine scarring can also lead to miscarriages. The good news is that the majority of these problems can be dealt with prior to conception through surgery, thus increasing your chances of a health pregnancy.
Endocrine issues that warrant investigation include disease of the thyroid and pituitary glands, diabetes or polycystic ovarian syndrome.
An informed approach is always the best step in evaluating potential endocrine issues.
Autoimmune diseases: Antiphospholipid antibody syndrome
Immunological problems occur when the mother produces antibodies that indirectly cause clotting in blood vessels that lead to the developing fetus. The fetus is deprived of nutrients and dies in utero, causing a miscarriage.
A number of blood tests can be done to test for this problem if you have suffered 3 or more losses. There is a treatment for this condition, with the aid of aspirin or heparin (an anticoagulant).
Blood clotting disorders are no longer felt to cause recurrent pregnancy loss, however, patients with a personal or family history of blood clots (in their extremities or lungs for example) should undergo testing for certain clotting disorders.
Exposure to certain chemicals, drugs, x-rays, etc. may also increase the risk of miscarriage. Some of these factors are work-related, while others may be related to lifestyle. Excess use of alcohol or caffeine, and smoking (first- and second-hand) by either partner may impact pregnancy outcome. Obesity is associated with an increased risk of miscarriage.
Finding a cause
A history of recurrent miscarriage calls for evaluation and management. Tests may include:
• Anatomical testing / sonography (ultrasound test or HSG / X-ray)
• Testing for auto-immune disorders (in cases of 3 or more losses)
• Testing for insulin resistance, diabetes, and other endocrinopathies related to the thyroid and pituitary glands
• Chromosome testing of products of conception after losses
• Blood clotting studies
• Chromosome testing of parents looking for balanced translocations
Preventing Miscarriage: Is There Anything You Can Do?
• If you’re not already pregnant, schedule a pre-conception visit with your gynecologist.
• Eat a well-balanced diet.
• Exercise in moderation.
• Limit caffeine.
• Avoid drugs, smoking, and alcohol.
• Get a handle on stress.
• Get your blood sugar under control (if you have diabetes).
• Ask your gynaecologist if you should take low-dose aspirin.
Often, the reasons are unknown about multiple miscarriages. Despite extensive testing, in up to 50-60% cases, no cause can be deduced. However, even after two miscarriages, there’s a 65% chance that your third pregnancy will be fine. Seeking a gynaecologist who specializes in repeated miscarriages is important so that they can get to the root of the problem and help you achieve a full term pregnancy. Never give up hope. With the correct treatment and guidance, you will have a good chance to conceive and carry your baby to term.