Recurrent Miscarriage

The definition of recurrent miscarriage is made when a couple has two miscarriages. Miscarriage becomes more common as the age of the female partner rises. The underlying problem in patients with recurrent miscarriage is often different from cases of isolated miscarriage prompting a thorough evaluation for the cause and treatment as listed below.

1. Anatomic factors – These account for the cause in 10-15% of patients. This problem is typically a uterine anomaly such as a uterine septum. The problem is diagnosed by a test known as a hysterosalpingogram (HSG) or by a sonohysterogram (SHG). If a septum is found, it can be surgically treated as an outpatient.

2. Thrombophilias – These account for the cause in about 3-15% of patients. Thrombophilias can be acquired or hereditary. The thrombophilia causes microscopic clots to form in the small blood vessels in the placenta preventing adequate blood flow to the fetus. This problem is diagnosed by several blood tests which take about 2 weeks to return. If a problem is found the treatment sometimes is a baby aspirin either alone or with a blood thinner called heparin.
3. Chromosomal abnormalities – This problem accounts for about 2-4% of the cases seen and usually is an abnormality called a balanced translocation. It is also as likely to be a male problem as a female one so a blood test called a karyotype is drawn on both partners. These tests take 3 weeks to return. If a problem is found, it is not treatable but most couples with this problem will have a healthy child if they are persistent.
4. Hormonal abnormalities – Hormone problems account for 25-40% of the causes of recurrent miscarriage. This category includes hypothyroidism, hyperprolactinemia and a progesterone problem called a luteal phase defect. The test for thyroid and prolactin are simple blood tests. The gold standard testing for a luteal phase defect is an endometrial biopsy a few days before a period starts which if it is abnormal (out of phase) must be repeated a second time. Blood tests for progesterone levels are frequently inaccurate due to wide variations and overlapping of normal and abnormal values. Also, many of the luteal phase defects are due to a progesterone receptor problem which a blood test will not check for. Supplemental progesterone treatment is very easy and cheap, so we usually empirically treat with 100 mg of vaginal progesterone suppositories starting 3 days after ovulation and continuing until the period starts or the 12th week of pregnancy.
5. Unexplained Recurrent Miscarriage – This category accounts for about 50%. This diagnosis is made when everything else returns as normal. Of couples with unexplained recurrent miscarriage, 60-70% will have a successful pregnancy with their next attempt.