Miscarriage, which occurs in an estimated 20% of all pregnancies, can spark a wave of overwhelmingly emotional upheaval for the couples who experience them. But medical experts stress that multiple miscarriages, defined as experiencing three or more successive losses, could be a sign of an underlying medical problem.
A Red Flag for Other Health Complications
Scientists at Repromedix, an infertility testing laboratory in the Boston area, say approximately seven out of every 1,000 women who become pregnant will experience recurrent miscarriages. And there is a range of associated conditions that could arise in women who experience them.
"Recurrent pregnancy loss should be viewed as a flag for possible underlying disease with implications for the rest of the woman's life, and independent of her failure or success in fighting her fertility issues," explained Benjamin Rivnay, PhD, vice-president of Research and Development at Repromedix.
Underlying Causes
"Some causes of recurrent miscarriage … include coagulation disorders and autoimmune or alloimmune disorders," Rivnay told Priority Healthcare. "Coagulation disorders are clearly linked to a number of broader health issues, such as heart disease and thrombosis (which has associated organ-specific complications, such as stroke, heart attack, eye problems, kidney problems, etc.)."
Thrombophilia is a condition characterized by the abnormal formation of blood clots.1 It may be a contributing factor in up to 60% of unexplained multiple miscarriages, Rivney said, including cases of anti-phospholipid antibody disorders related to thrombophilia. He advises tests for women with consecutive, unexplained pregnancy losses or a history of coagulation disorder.
Thrombophilia can boost the risk of miscarriage because abnormal blood clotting can also occur in the blood vessels of the placenta, jeopardizing the normal flow of blood, in addition to the well-being of the fetus. In addition, some components of acquired thrombophilia like antiphospholipid antibodies can have a negative impact on the placenta exclusive of blood clotting complications, Rivnay explained.
Thrombophilia-Related Tests
Tests used to check for these complications include the following:
• Factor V Leiden—A genetic test to look for gene abnormalities that predisposes a person to blood clotting.
• Prothrombin mutation—A genetic test to search for abnormalities in the prothrombin gene which controls proteins that play a role in blood clotting.
• Antithrombin—A test that searches for levels of natural clotting inhibitors in the blood. (Incidentally, a blood thinner known as heparin targets these inhibitors).
• Lupus anticoagulant (LAC)—A test that looks for a group of antiphospholipid antibodies that play a role in clotting processes.
Do You Have an Autoimmune Disorder?
Rivnay says there are a number of other potential health implications to consider. Autoimmune diseases like lupus and thyroid conditions are linked with repeat miscarriage and infertility. Autoimmune disorders can affect many aspects of health, from the thyroid to the digestive system. Women who have a history of autoimmune disease and unexplained multiple miscarriage might consider tests like ACA/APA (anti-cardiolipin antibodies/anti-phospholipid antibodies), which detect antibodies associated with a possible autoimmune disorder, and LAC (lupus anti-coagulant), a test that looks for factors associated with possible abnormal blood clotting. This is not a lupus test.2
Abnormal Hormones
Hormonal disorders, such as polycystic ovary syndrome (PCOS), can be linked with a higher incidence of miscarriage, as well as gestational diabetes and preeclampsia (pregnancy-induced high blood pressure). Women diagnosed with PCOS also face a greater risk of developing heart disease. If you have experienced recurrent miscarriage and symptoms such as certain menstrual disorders, skin disorders, or high blood pressure, tests that may be helpful include those that involve specialty glucose, insulin, and testosterone, Rivnay advises.
PCOS is characterized by a hormone imbalance that includes symptoms such as irregular periods, acne, excess body hair, and obesity. Higher-than-normal levels of insulin secreted by the pancreas may also be involved. The disease happens when luteinizing hormone (LH), which plays a role in ovulation, or insulin levels are too high. The result is additional testosterone production in the ovaries.
The condition may also be characterized by tiny cysts, or bumps, on the inside of the ovaries, though not every woman with PCOS has these cysts. Most often, the cysts are not harmful. It's estimated that nearly one out of every ten women of reproductive age has PCOS.3
"It is very likely that abnormal levels of hormones are linked to recurrent pregnancy loss," Rivnay told Priority Healthcare.
Another Factor to Consider
While immune, coagulation, and endocrine disorders should not be overlooked in recurrent miscarriage, he adds that "the quality of the genetic material of the gametes (sperm and egg), or the embryo, are of paramount significance."
"Hence, testing for parental or embryonic chromosomal abnormalities, and for the functional integrity of the male partner's sperm should not be underestimated," Rivnay said.
1. University of Illinois-Urbana/Champaign. Carle Cancer Center. Available at: http://www-admin.med.uiuc.edu/hematology/Glossary.htm. Accessed August 9, 2005.
2. American Association for Clinical Chemistry. Lupus Anticoagulant. Available at: http://www.labtestsonline.org/understanding/
analytes/lupus_anticoagulant/glance.html. Accessed August 2, 2005.
3. Center for Young Women's Health. Children's Hospital Boston. A Guide to Polycystic Ovary Syndrome (PCOS). Available at: http://www.youngwomenshealth.org/pcosinfo.html. Accessed August 2, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
