Is Diabetes Born in the Womb?

Undersized infant girls at risk of gestational diabetes later in life

TUESDAY, May 14, 2002 (HealthDayNews) -- Underweight baby girls are significantly more likely than their normal-sized and even heavier crib mates to develop diabetes when they become pregnant later in life.

A new study of first-time mothers has found that women who weighed less than about 4.5 pounds at birth were far more likely than heavier infants to go on to have gestational diabetes. Their odds of developing the condition -- which can lead to oversized infants and potentially complicated labor and recovery -- are even greater if they have other risk factors for the blood sugar disorder.

The findings appear in tomorrow's issue of the Journal of the American Medical Association, which this week is devoted to diabetes. They also point to the possibility that some cases of diabetes may have their origin in the womb.

Diabetes affects an estimated 17 million Americans, most of whom have the Type II, or adult-onset, form of the disease.

Roughly 3 percent to 5 percent of pregnant women in the United States develop a gestational form of diabetes, in which their blood sugar levels rise to dangerous levels. If untreated, their babies are more likely to be large upon delivery, upping the need for cesarean section surgery and increasing the odds of shoulder dislocations and other complications large babies face.

After birth, they're prone to respiratory distress, are more likely to be overweight or obese as they age, and face an elevated risk of Type II diabetes.

Mothers who develop diabetes during pregnancy are also at an increased risk of having Type II diabetes in the future. The condition can lead to blindness, kidney failure and cardiovascular trouble like heart attacks and strokes.

Earlier research has revealed an inverse relationship between birth weight and future risk of Type II diabetes. In other words, the lower a person's weight at birth, the greater her risk of developing the condition.

Being slight in the womb may damage the beta cells in the pancreas that produce insulin, the hormone that helps the body convert sugar into energy. It also appears to make cells insensitive to insulin and scrambles the healthy balance of blood fats. Taken together, these effects may undermine a woman's ability to handle the increased metabolic demands of pregnancy, and increase her risk of developing diabetes.

In the latest study, scientists at the University of Colorado in Denver and the University of Virginia in Charlottesville used medical records to explore the connection between birth weight and gestational diabetes in 440 New York women with the sugar condition and almost 23,000 others without the problem.

The pattern was "striking," the researchers say. They found that the lightest infants -- those born weighing less than 2,000 grams -- had the greatest risk of developing diabetes during pregnancy, 60 percent higher than those twice as heavy or larger at birth.

After considering other known risk factors, including a woman's weight before conception and whether her own mother had the condition, the odds of gestational diabetes associated with low birth weight more than quadrupled.

"The results of this study are consistent with the hypothesis that susceptibility to diabetes and related insulin resistance conditions may be programmed in utero," the researchers write.

Dr. Luigi Meneghini, director of the Eleanor and Joseph Kosow Diabetes Treatment Center at the Diabetes Research Institute in Miami, says the latest findings aren't surprising given similar results from earlier studies. And he says it's unlikely that doctors would use a pregnant woman's birth weight to predict her risk of gestational diabetes over conventional markers like pre-pregnancy weight.

However, Meneghini says, the research is important because it helps shed light on the origins of diabetes. "It opens up another field of study that can get us closer to the source of the problem."

What to Do: For more on gestational diabetes, try the National Institute of Child Health and Human Development, or the University of Michigan.

SOURCES: Luigi Meneghini, M.D., director, Eleanor and Joseph Kosow Diabetes Treatment Center, Diabetes Research Institute, Miami; May 15, 2002, Journal of the American Medical Association
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