Table 1.
Characteristics of mother–infant pairs [n (%) or mean ± SD].
| Characteristic | Included participants (n = 622)a | Excluded participants (n = 91)b |
|---|---|---|
| Maternal | ||
| Age at delivery (years) | 24.5 ± 5.5 | 24.5 ± 5.2 |
| Prepregnancy BMI (kg/m2) | 26.9 ± 6.4 | 28.8 ± 7.0 |
| Weight gain during pregnancy (kg) | 13.1 ± 7.2 | 13.6 ± 7.7 |
| Marital status | ||
| Married or living with partner | 391 (64.1) | 64 (73.6) |
| Never married/separated/divorced | 219 (35.9) | 23 (26.4) |
| Race/ethnicity | ||
| White | 408 (67.2) | 58 (67.4) |
| Native American | 143 (23.6) | 24 (27.9) |
| Other (including Hispanic) | 56 (9.2) | 4 (4.7) |
| Education | ||
| < 12th grade | 159 (25.6) | 25 (28.1) |
| ≥ 12th grade | 462 (74.4) | 64 (71.9) |
| Annual household income | ||
| < $20,000 | 188 (47.5) | 45 (60.0) |
| $20,000–$40,000 | 134 (33.8) | 19 (25.3) |
| $40,000–$70,000 | 61 (15.4) | 7 (9.3) |
| > $70,000 | 13 (3.3) | 4 (5.3) |
| Impaired glucose tolerance, 24–28 weeks gestation | ||
| < 140 mg/dL | 508 (87.1) | 65 (84.4) |
| ≥ 140 mg/dL | 75 (12.9) | 12 (15.6) |
| Primiparous | ||
| Yes | 243 (39.1) | 32 (35.6) |
| No | 378 (60.9) | 58 (64.4) |
| Smoked during pregnancy* | ||
| Yes | 224 (36.0) | 22 (24.4) |
| No | 398 (64.0) | 68 (75.6) |
| Any smokers in household | ||
| Yes | 134 (38.0) | 32 (40.5) |
| No | 219 (62.0) | 47 (59.5) |
| Prenatal vitamin use* | ||
| Yes | 397 (63.8) | 32 (35.2) |
| No | 225 (36.2) | 59 (64.8) |
| Anemia at deliveryc | ||
| Yes | 156 (25.3) | 19 (22.4) |
| No | 460 (74.7) | 66 (77.6) |
| Hemoglobin at delivery (g/dL) | 11.8 ± 1.4 | 11.7 ± 1.2 |
| Infant | ||
| Birth weight (g) | 3370.2 ± 474.5 | 3245.6 ± 462.3 |
| Gestational age at birth (week) | 39.1 ± 1.3 | 38.7 ± 1.9 |
| Length at birth (cm) | 50.0 ± 2.6 | 50.8 ± 2.4 |
| Head circumference at birth (cm) | 34.5 ± 1.8 | 34.1 ± 1.3 |
| Male sex | 340 (54.7) | 46 (51.7) |
| aOf included participants, data were missing for prepregnancy BMI (n = 63), weight gain during pregnancy (n = 63), marital status (n = 12), race/ethnicity (n = 15), education (n = 1), household income (n = 226), impaired glucose tolerance (n = 39), primiparous (n = 1), any smokers in household (n = 269), anemia at delivery (n = 6), hemoglobin at delivery (n = 6), length at birth (n = 10), and head circumference at birth (n = 24). bOf excluded participants, data were missing for age at delivery (n = 3), prepregnancy BMI (n = 6), weight gain during pregnancy (n = 5), marital status (n = 4), race/ethnicity (n = 5), education (n = 2), household income (n = 16), impaired glucose tolerance (n = 14), primiparous (n = 1), smoked during pregnancy (n = 1), any smokers in household (n = 12), anemia (n = 6), hemoglobin at delivery (n = 6), birth weight (n = 3), gestational age at birth (n = 6), length at birth (n = 6), head circumference at birth (n = 7), and male sex (n = 2). cAnemia is defined as hemoglobin < 11.0 g/dL at delivery, which is based on definition from CDC (1998; during 3rd trimester), WHO (1968; during pregnancy), and the American Congress of Obstetricians and Gynecologists (2008; in 1st and 3rd trimesters). *Participants differed from nonparticipants, p < 0.05 in chi-square test. | ||