April 12, 2002

Asimple blood test conducted during the first trimester of pregnancy may be able to identify women at risk for preeclampsia, a common and dangerous complication of late pregnancy. A study from the MGH Renal Unit has found that women who eventually developed preeclampsia, also called toxemia, were more likely early in pregnancy to have had reduced blood levels of a protein called SHBG, a known marker for insulin resistance. The report appears in the April issue of The Journal of Clinical Endocrinology and Metabolism.

"This study showed that a risk factor that can be detected many weeks before symptoms appear may be able to predict who will develop preeclampsia," says Myles Wolf, MD, of the MGH Renal Unit, the paper's first author. In preeclampsia, a pregnant woman develops high blood pressure and other metabolic abnormalities. If not appropriately managed, preeclampsia can proceed to eclampsia — characterized by seizures — or liver or kidney failure. The complications can prove fatal to the mother; and the baby is at increased risk of premature birth, because delivery is the only way to stop the condition.

Although overweight women are known to be at an increased risk for both preeclampsia and insulin resistance, the study linked reduced SHBG levels with the risk of preeclampsia in both lean and overweight women. "The fact that lean women with reduced first-trimester SHBG have a greater risk of preeclampsia suggests that insulin resistance may be the true risk factor," says Wolf. "It also may provide the only clue that a lean woman is at elevated risk."

"Preeclampsia can be devastating, and unfortunately we do not have a way to treat women with this condition," says Ravi Thadhani, MD, MPH, of the MGH Renal Unit, the study's senior author. "Finding a way to predict who will develop preeclampsia is a necessary first step to testing new therapies." Other co-authors are Laura Sandler, Kristine Munoz and Karen Hsu of the Renal Unit, and Jeffrey Ecker, MD, of the MGH Vincent Obstetrics and Gynecology Service.