A few other factors cause miscarriages, and as I spent time at St. Mary's Hospital and two other clinics devoted to pregnancy loss, I quickly realized that karyotyping losses remain the exception to the rule: The field has few good tests to detect other problems that lead to miscarriage. And without good diagnostic tools, it becomes exceedingly difficult to assess whether an intervention works, much less whether to recommend one for clinical use.
Besides chromosomal abnormalities, women miscarry because they have immune responses that disrupt implantation, blood-clotting problems, physical abnormalities with the uterus or cervix, or hormonal imbalances. (Infections also can cause miscarriages, but they do not explain repeated losses.) But until researchers can distinguish among these possible causes, knowing which interventions to use is more art than science.
Transcript: Dr. John Larsen, a specialist at George Washington University Medical Center, answered questions about high-risk pregnancies.
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For instance, many clinicians routinely stitch shut a pregnant woman's cervix if they deem it "insufficient" (or "incompetent") and thus likely to release a fetus prematurely. But they do not have a test that can clearly predict whose cervix will malfunction, so they rely instead on fuzzier parameters like the length of the cervix and previous second- or third-term losses.
Although studies have shown that the procedure, called cerclage, may well help women who previously have had late-term losses, there's no convincing evidence that it does anything for women who have had previous first-trimester losses. One recent article in the journal Obstetrics & Gynecology called cerclage a "crude, archaic procedure."
Similarly, doctors prescribe progesterone to correct hormonal imbalances, even though the main test to detect the problem is outdated and can only crudely gauge whether a woman's hormones are out of whack. What's more, there is no conclusive evidence that progesterone treatment prevents miscarriages.
Ditto for blood-clotting problems, which some doctors attempt to treat by prescribing low-dose aspirin and even heparin, which work as blood thinners. Convincing studies show that those treatments are very effective for women with abnormal levels of so-called antiphospholipid antibodies. But it's not known how effective these treatments are for others.
When Shannon and I were trying to navigate the stormy seas of miscarriage, no one sat us down and explained the knowns and unknowns. She never received a test for antiphospholipid antibodies, even though a proven intervention exists for that particular problem, which affects roughly 15 percent of women who recurrently miscarry.
And we saw the best specialists at a renowned university hospital. In fact, they encouraged us to consider in vitro fertilization (IVF). Although IVF may have speeded up the act of conception, which normally requires at least four months of trying for a young woman, I found this recommendation odd given that our main problem was not getting pregnant but staying pregnant.
A Lack of Focus
All of this speaks to a deeper truth about miscarriage that I only came to realize after we had our second child: Miscarriage is a sub-sub-specialty that doesn't attract the attention, funding or research talent that it deserves.
Few OB/GYNs specialize in miscarriage, and though a small number of clinics in the United States are devoted to miscarriage, they remain a rarity. No miscarriage journal exists, and there are no medical conferences devoted solely to the subject. Financially, treating miscarriage pales in comparison with the lucrative business of IVF, which predictably enough has lured many of the best and brightest OB/GYNs.