In addition, a cohort of women who had a positive result on the 50-g glucose loading test but a normal result on a subsequent oral glucose-tolerance testand who were matched with the study cohort according to race and body-mass
index (the weight in kilograms divided by the square of the height in meters), dichotomized as less than 27 or 27 or
more, were enrolled by the data coordinating center in the group that received usual prenatal care.