Table 1.

Characteristics of the Study Population.^*

Variable	Treatment Group (N = 485)	Control Group (N = 473)
Age — yr	29.2±5.7	28.9±5.6
Primigravida — no. (%)	104 (21.4)	123 (26.0)
Race or ethnic group — no. (%)†
Black	56 (11.5)	54 (11.4)
White	123 (25.4)	119 (25.2)
Asian	22 (4.5)	28 (5.9)
Hispanic	281 (57.9)	265 (56.0)
Other	3 (0.6)	7 (1.5)
Smoking — no. (%)	38 (7.8)	31 (6.6)
Alcohol use — no. (%)	23 (4.7)	11 (2.3)
Body-mass index at entry‡	30.1±5.0	30.2±5.1
Glucose level after 50-g glucose-loading test — mg/dl§	159.0±15.3	159.7±15.5
Duration of gestation randomization — wk	28.8±1.6	28.9±1.5
Glucose levels in 3-hr OGTT — mg/dl§
Fasting	86.6±5.7	86.3±5.7
1-hr	191.8±21.9	193.4±19.3
2-hr	173.7±21.8	173.3±19.6
3-hr	137.3±29.0	134.1±31.5

^*Plus–minus values are means ± SD. Only alcohol use was significantly different between study groups (P=0.04). OGTT denotes oral glucose-tolerance test.

^†Race or ethnic group was self-reported.

^‡The body-mass index is the weight in kilograms divided by the square of the height in meters.

^§To convert the values for glucose to millimoles per liter, multiply by 0.05551.