Unexplained Recurrent Pregnancy Loss
In some women, there's no difficulty conceiving a child. However, holding on to the pregnancy is difficult. When a woman miscarries three or more times in a row, she is deemed as having recurrent or repeated pregnancy loss.
One-fifth of all pregnancies end in miscarriage. The rate of miscarriage rises with the age of the woman who conceives. For women younger than 24, the rate for miscarriage is 9.5%, 11% in women in their 30's, and 33% in women in their 40's. In women over the age of 44, there is a dramatic rise in the rate of miscarriage, which goes up to 53%.
While repeated pregnancy loss can have a serious emotional impact on a woman, 60% of women with this condition do finally manage to sustain a successful pregnancy with only minimal treatment. Where the cause of pregnancy loss can be identified, the success rate rises to more than 75% in women receiving appropriate treatment.
Once the condition is diagnosed, the focus is on trying to identify the cause of repeated pregnancy loss. The physician will look at immunological, infectious, genetic, anatomical, and endocrine factors.
There may be uterine abnormalities causing the recurrent pregnancy loss. To this end, your physician may order a saline-ultrasound, or an x-ray with dye to get a picture of the uterus. In general, surgery to correct such abnormalities is effective and often involves low-risk outpatient procedures.
Some 70% of all early miscarriages are linked to abnormalities of the fetal chromosomes. Also, 30% of miscarriages occurring in the second trimester as well as 3% of all stillbirths are due to chromosomal abnormalities. Usually, this is a random event related to the fetus, and the couple's chromosomes are just fine. In women with undergoing IVF who have a history for repeated pregnancy loss, pre-implantation genetic diagnosis (PGD) can be performed before embryo transfer to screen for chromosomal abnormalities.
While serious maternal infections are known to lead to miscarriage, experts still don't know how such bacterial infections work to cause recurrent miscarriages.
A link between recurrent miscarriage and a class of proteins known as antiphospholipid antibodies (aPL) has been firmly established. These proteins seem to attack an early pregnancy, leading to miscarriages caused by immune factors. In women with aPL issues, the live birth rate is sometimes only 10%. But the rate can go up to 70% when the condition is treated with low doses of aspirin and heparin.
Endocrine disorders like thyroid disease and diabetes have been linked to miscarriage, but where these conditions are receiving proper supervision and treatment, there is no risk factor for pregnancy loss. Sometimes there is not enough progesterone secreted during menstruation and early pregnancy and this can be the cause of recurrent miscarriage. Another endocrine factor that may be responsible for repeated miscarriages is polycystic ovarian syndrome (PCOS) in which the ovaries are covered with an abundance of follicles.
Alas, sometimes there is no apparent reason for repeated miscarriage, though counseling often leads to a future pregnancy success rate of around 75%.