Recurrent miscarriage is defined as two or more consecutive, spontaneous pregnancy losses.
Approximately 20% of all pregnancies will end in a miscarriage, and this risk increases with maternal age. Most miscarriages occur within the first 10-12 weeks of gestation. Miscarriages most commonly occur because the fetus has a chromosomal abnormality that does not allow normal fetal development to occur beyond a certain point. These abnormalities can be due to an abnormal egg, an abnormal sperm, or an abnormality in cell division that occurs after fertilization. In each situation, the embryo ends up with an abnormal number of chromosomes. Too much or too little genetic information almost always results in abnormal development.
When a woman has had two or more miscarriages, there is an increased risk that something other than an abnormal embryo may be causing the losses. Abnormal blood levels of thyroid hormone or prolactin can result in miscarriage. Low production of progesterone from the ovary can also result in losses. Genital tract infections, blood clotting disorders, abnormalities within the uterus, and medical problems such as diabetes mellitus or immune system abnormalities can also significantly increase the risk of miscarriage.
The risk of miscarriage also increases with increasing maternal age, especially in women over the age of 35. Smoking, excess caffeine, and alcohol can each increase the risk of miscarriage. Medications, including some that can be purchased “over the counter”, may also increase the risk.
Testing for recurrent miscarriage
+ Karyotype – a blood test that looks for abnormal numbers or arrangements of chromosomes in one or both members of a couple
+ Hysterosalpingogram (HSG) or saline sonogram (SIS) to look for abnormalities of the uterus like a septum, fibroids or polyps
+ Blood work – to measure levels of prolactin, thyroid hormone, and other endocrine and immune factors
+ Ovarian reserve testing –blood tests to measure FSH and AMH levels
+ Glucose screening – a blood test to rule out the presence of diabetes
+ Acquired thrombophilia testing – blood testing to look for antibodies that cause blood clots to form in the microscopic blood vessels of the placenta. Examples include Antiphospholipid Antibody Syndrome, lupus anticoagulant, and Factor V Leiden deficiency.
Treatment of recurrent miscarriage
Treatment for recurrent miscarriage is based on the results of the testing. Surgery may be required to remove uterine fibroids, polyps, intrauterine adhesions (scar tissue), or a uterine septum. Hormonal issues such as abnormal production of thyroid hormone or prolactin can be corrected with medication. Antiphospholipid Antibody Syndrome or other clotting disorders are treated with blood thinners to prevent clotting. If a balanced translocation is discovered in one of the partners in the couple, then preimplantation genetic testing during an IVF cycle or using donor gametes (sperm or eggs) may be an option. All treatment is individualized based on any diagnosis(es) made during your evaluation.
