Researchers: U.S. birth weights decreasing

February 19, 2010 (CHICAGO) Researchers say between 1990 and 2005, birth weights decreased by nearly two ounces.

That leaves most babies still in the safe range, but further decline could have health consequences.

Babies weighing less than 5.5 lbs. at birth face increased risk of lower body temperatures, low blood sugar, and blood clots.

Researchers have not pinpointed the reasons for the decline in birth weights.

Results of the study are published in February's issue of Obstetrics and Gynecology.