This week's New Yorker features a fascinating piece on preeclampsia, a fairly common but little understood complication of pregnancy.
Preeclampsia, for those fortunate enough to have been spared it, is marked by high blood pressure and protein in the urine (swelling, weight gain, problems with vision and dizziness are also common symptoms). Women who suffer from it are often prescribed bed rest, but the only real cure is delivering the baby. It affects about 5 percent of pregnant women, and though most women in the United States and Europe receive appropriate treatment, contributing writer Jerome Groopman notes that the disorder "is among the most common causes of premature birth in the U.S." and "is one of the leading causes of maternal death in the developing world."
In the piece, Groopman, who's a professor of medicine at Harvard, follows medical researcher Ananth Karumanchi's quest to determine what causes preeclampsia. (Preeclampsia is known as "the disease of theories," a prominent OB-GYN tells Groopman, because its cause is unknown.) Karumanchi discovers that women suffering from preeclampsia have elevated levels of the proteins soluble FLT and endolgin in their bloodstreams. These proteins bind to other proteins and prevent nourishment from reaching the endothelial cells that line the mother's blood vessels. Bad for the mother, but good for the fetus; researchers theorize that "the fetus, by releasing soluble FLT into the mother's bloodstream, causes her vessels to constrict, diverting blood to the placenta at the expense of her organs." Karumanchi's reasearch seems to indicate that an influx of certain other proteins can repair the damage done by soluble FLT and endolgin, and a commercial drug to treat preeclampsia using this method is in development.
That's the quick and dirty version, and the full article is well worth reading. But some of Groopman's and Karumanchi's side observations about maternity and the medical industry deserve special note. Groopman observes that "among medical researchers, obstetrics is often regarded as a dead end," because "when a pregnant woman takes a drug or undergoes a medical procedure, her fetus may be affected in ways that are difficult to measure or to predict ... [and] a fetus cannot consent to participate in a study." He notes that "pregnant women are understandably reluctant to volunteer to test new drugs and therapies," and the medical community can also be reluctant. Karumanchi had trouble getting his research funded by the National Institutes of Health when his proposals dealt with pregnancy, but when he described his work as "focused on the effects of hypertension on the kidneys and made no mention of placentas or pregnant women," he immediately got funding from the National Institute of Diabetes and Digestive and Kidney Diseases. It's a knotty problem; no one wants to risk damaging fetuses, but that understandable reluctance may wind up compromising maternal health.
A similar conflict of interests plays out during pregnancy. If Karumanchi's theory is correct, preeclampsia may be viewed as "an extreme version of maternal-fetal conflict," Groopman writes. Evolutionary biology professor David Haig has written that "an infant's prospects may be bleak if a mother dies, but children have survived without mothers. Thus, if childbirth threatens the lives of the baby and its mother, the baby may struggle for its own survival, even if that increases risk to the mother." All the more reason for women to be able to choose whether to carry their pregnancies to term, I say.
Particularly since all pregnancies aren't created equal. Research like Karumanchi's will probably help doctors diagnose, monitor and treat preeclampsia, and that's great news. But though doctors still aren't entirely sure why some mothers get preeclampsia and some don't, Karumanchi believes that "the underlying health of the mother's blood vessels" likely plays a role. Women with diabetes, hypertension, kidney disease or abnormal clotting proteins, as well as women with genetic predispositions, may be more likely to get preeclampsia, and as of now, there's no cure beyond bed rest. Here's hoping researchers heed Karumanchi's call for more testing: "Now is the moment; we've got to grab it and run with it," he told Groopman. "My feeling is that it would be almost a crime not to try it."