Recurrent Miscarriage
The diagnosis of recurrent pregnancy loss is made when a couple has two or more miscarriages. Miscarriage also becomes more common as the age of the female partner rises with more than one-third of all pregnancies in women over 40 ending in miscarriage. The underlying problem in patients with recurrent miscarriage is often different from cases of isolated miscarriage which can be due to random chromosomal abnormalities in that particular embryo. Couples who experience recurrent miscarriage may benefit from psychological support and a thorough medical evaluation as listed below:
- Anatomic factors – These account for the cause in 10-15% of patients. This problem includes a uterine septum, scar tissue, polyps or fibroids. The problem is diagnosed by a test known as a hysterosalpingogram (HSG) or by a sonohysterogram (SHG). If an abnormality is found, it may be surgically correctable as an outpatient.
- Antiphospholipid Syndrome – This accounts for the cause in about 3-15% of patients. Blood tests for anticardiolipin antibodies and lupus anticoagulant may identify women with antiphospholipid syndrome. A second blood test performed at least 6 weeks later confirms the diagnosis. Antiphospholipid syndrome may result in microscopic clots forming in the small blood vessels in the placenta preventing adequate blood flow to the fetus. If the diagnosis of antiphospholipid syndrome is made, then pregnancy outcomes are improved by the use of a daily baby aspirin either alone or with a blood thinner called heparin or Lovenox.
- Thrombophilias - Inherited disorders that raise a woman's risk of serious blood clots (thrombosis) may also increase the risk of fetal death in the second half of pregnancy. However, there is no proven benefit for testing or treatment of women with thrombophilias and recurrent miscarriage in the first half of pregnancy.
- Chromosomal disorders – Chromosome disorders account for 3-5% of the causes of recurrent miscarriage and include translocations, inversions and ring chromosomes. Chromosome disorders are 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 3-4 weeks to return. Many insurance companies will not pay for this test which can cost up to $1800.00 each. The risk of subsequent miscarriage varies with the type of disorder and the sex of the carrier. In general, carriers of chromosomal disorders that are identified after the birth of an abnormal child have a 5-30% risk for another abnormal child in the future, whereas those with just miscarriages have a risk for an abnormal child in the future of 0-5%. If a chromosomal abnormality is found, consultation with a genetic counselor is advised to more accurately determine the specific problems and risks associated with that particular disorder. Treatment options include amniocentesis or chrorionic villus sampling when pregnant to identify a problem or the use of Preimplantation Genetic Diagnosis (PGD) at time of In Vitro Fertilization (IVF) which can screen embryos prior to implantation.
- 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 whose significance remains controversial. The test for thyroid and prolactin are simple blood tests. While several tests have been used in the past to diagnose the luteal phase defect such as blood progesterone levels and an endometrial biopsy, none have been shown to be accurate. For this reason, supplemental progesterone therapy is started in all recurrent miscarriage patients beginning 3 days after ovulation. Waiting until a positive pregnancy test to start the progesterone may decrease its effectiveness. Progesterone supplementation is continued until the 12th week of pregnancy.
- Metabolic Abnormalities - Poorly controlled diabetes increases the risk of miscarriage. Women with diabetes improve pregnancy outcomes if blood sugars are controlled before conception. Women who have insulin resistance, such as obese women and many who have polycystic ovarian syndrome (PCOS), also have higher rates of miscarriage. There is still not enough evidence to know if medications that improve insulin sensitivity lower miscarriage risks in women with PCOS.
- Male Factor - Increasing evidence suggests that abnormal integrity (intactness) of sperm DNA may affect embryo development and possibly increase miscarriage risk. However, these data are still very preliminary, and it is not known how often sperm defects contribute to recurrent miscarriage.
- 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 regardless of treatment.
- Tests with no proven benefit for recurrent miscarriage include cultures for bacteria or viruses, tests for insulin resistance, antinuclear antibodies, antithyroid antibodies, maternal antipaternal antibodies, antibodies to infectious agents, and embryotoxic factors.
- Treatments with no proven benefit include leukocyte (white blood cell) immunization and intravenous immunoglobulin (IVIG) therapy.
Conclusion:
A healthy lifestyle and folic acid supplementation is recommended before attempting another pregnancy. Smoking cessation, reduced alcohol and caffeine consumption, moderate exercise, and weight control may all be of benefit. Counseling may provide comfort and help cope with the grief, anger, isolation, fear, and helplessness that many individuals experience after repeated miscarriages.