In utero factors shape responses to stress, sugar.

Abnormal conditions during pregnancy can lead in unexpected ways to physiological problems in children once they reach adulthood, two new studies suggest.

In the 1960s, British obstetricians encouraged pregnant women to eat a meat-heavy, low-carbohydrate diet. At the time, it was thought that this diet might prevent preeclampsia, a complication of pregnancy that limits the supply of oxygen and nutrients to the fetus.

Hundreds of mothers' meticulous records, preserved by one such obstetrician in Motherwell, Scotland, contain detailed data about what kinds and quantities of food they ate during pregnancy.

Rebecca M. Reynolds of the University of Edinburgh and her colleagues tracked down dozens of "Motherwell babies" who were born in 1967 and 1968 and are now in their late 30s. Eighty-six of them volunteered to undergo stress testing, in which they did arithmetic and dealt with a staged, confrontational interview.

Researchers measured blood pressure, heart rate, and blood and sputum concentrations of the stress hormone cortisol before and after each test. They then compared those data with the recorded dietary information.

Stress responses were most exaggerated in the children of women who, during pregnancy, had made the most extreme shifts toward a meat-heavy diet. That shows that a mother's "unbalanced" diet can have adverse, lifelong effects on her children, Reynolds says.

In a separate study, J. Nina Ham of the Children's Hospital of Philadelphia and her colleagues conclude that babies born to mothers with preeclampsia may be at risk of diabetes even if they are of normal weight at birth. Low birth weight, which is sometimes a consequence of preeclampsia, is linked to diabetes risk in people.

The researchers simulated preeclampsia in mice by placing pregnant animals in a low-oxygen chamber. The pregnancies appeared normal, as did the newborn mice, Ham says. But, she adds, "even though their birth weight was normal, these mice did get diabetes as they got older."--B.H.