Maternal characteristics: Significance tests for age, parity, and gestational age are based on t tests; the rest are based on χ2 tests.
| CHARACTERISTIC | TOTAL PREGNANCIES N = 1206 | EXPOSED PREGNANCIES N = 300 | P VALUE |
|---|---|---|---|
| Mean (SD) age, y | 24.6 (5.9) | 24.2 (4.7) | .088 |
| Mean (SD) parity | 2.8 (1.8) | 2.9 (1.7) | .152 |
| Mean (SD) gestational age, wk | 38.9 (1.5) | 38.9 (1.3) | .825 |
| Smoking, n (%) | 672 (55.7) | 250 (83.3) | < .001* |
| Alcohol consumption, n (%) | 225 (18.7) | 39 (13.0) | .003* |
| Hypertension, n (%) | 70 (5.8) | 19 (6.3) | .657 |
| Type 2 diabetes mellitus, n (%) | 38 (3.2) | 13 (4.3) | .184 |
| Gestational diabetes, n (%) | 90 (7.5) | 20 (6.7) | .533 |
| Cesarean section, n (%) | 305 (25.3) | 74 (24.7) | .774 |
| Nonelective cesarean section, n (%) | 193 (16.0) | 51 (17.0) | .497 |
| Out-of-hospital delivery, n (%) | 36 (3.0) | 4 (1.3) | .052 |
| Postpartum hemorrhage, n (%) | 112 (9.3) | 28 (9.3) | .978 |
↵* Statistically significant difference between exposed and nonexposed pregnancies.