Greater Maternal Weight Gain Advocated for Twins. (Lowers Perinatal Mortality).

STANFORD, CALIF. - The time has come to seriously consider encouraging weight gains of 45-50 pounds or more as "best practice" in twin pregnancies, Judith E. Brown, Ph.D., said at a conference on perinatal and pediatric nutrition.

"In talking about weight gains of 50 pounds or more, I know I might get nasty stuff thrown at me at any moment. There's a huge sentiment out there, particularly among obstetricians but also some nutritionists, that women are gaining far too much weight now under the Institute of Medicine recommendations" calling for weight gains of 35-45 pounds in twin pregnancies, noted Dr. Brown, professor of public health nutrition at the University of Minnesota, Minneapolis.

She argued that the optimal birth weight of twins is 3,000-3,500 g, as that's what is associated with the lowest perinatal mortality. Those birth weights, however, are far above the current national average for twins, which is roughly 2,400 g. Fifty-four percent of twins are low birth weight, defined as less than 2,500 g.

"We have a long way to go to improve the health of infants in this country. We still have 7.8% low birth weight, 11.9% preterm delivery, and although average birth weights are increasing we're being beaten down by lower gestational age. If we don't do something to shift this distribution we're going to stay right where we are. One of those things would be to optimize the rate of weight gain and total gain in women who have multifetal pregnancies. And that might mean talking about a 45-to 50-pound gain," she said at the conference, which was jointly sponsored by Symposia Medicus and Stanford University.

Dr. Brown cited new data from the University of Minnesota's Diana II Project, a study of 570 twin pregnancies, 48% of which ended with optimal neonatal outcome, defined as both babies having birth weights in excess of 2,500 g. In that study, the highest rate of optimal pregnancy outcome-57%--occurred in women having a pregnancy weight gain in excess of 45 pounds.

In contrast, only 48% of women who gained 35-45 pounds had two babies weighing more than 2,500 g each, as did 35% of women who gained less than 35 pounds.

In a multiple regression analysis looking at quartiles of total pregnancy weight gain, the average birth weight of twin pairs whose mother gained 50 pounds or more was 2,699 g, compared with 2,599 g for women who gained 41-50 pounds, 2,410 g for those who ...