Table 1. Maternal and antenatal characteristics.
| USE (N = 74) | Control (N = 75) | p | RR (95% CI) | |
|---|---|---|---|---|
| Age | 25.6 ± 5.4 | 26.5 ± 5.3 | ||
| Ethnicity | ||||
| Afro-American | 40 (54%) | 24 (32%) | 0.009 | |
| Caucasian | 31 (42%) | 48 (64%) | ||
| Hispanic | 0 (0%) | 1 (1%) | ||
| Other | 3 (4%) | 2 (3%) | ||
| Nulliparous | 39 (53%) | 38 (51%) | 0.86 | |
| Prior preterm birth at 34–36 wk | 2 (3%) | 2 (3%) | 1.00 | |
| BMI at first visit (kg/m2) | 25.0 ± 5.3 | 25.6 ± 5.8 | 0.78 | |
| BMI at delivery (kg/m2) | 28.9 ± 5.1 | 29.1 ± 3.9 | 0.89 | |
| First ultrasound examination at (wk) | 14.4 ± 3.2 | 15.0 ± 3.2 | 0.88 | |
| Gestational age at randomization | 28.3 ± 2.0 | 28 ± 2.1 | 0.84 | |
| Complication after randomization | 20 (27%) | 19 (25%) | 0.85 | |
| Hypertension | 6 (8%) | 10 (13%) | ||
| Preterm labor | 4 (5%) | 1 (1%) | ||
| PPROM | 0 | 0 | ||
| Decreased fetal movement | 4 (5%) | 5 (7%) | ||
| Other | 6 (8%) | 3 (4%) | ||
| USE for EFW after randomization | 141 | 16 | – | – |
| 1st (32–34 wk) | 72 (97%) | 6(8%) | ||
| 2nd (36–37 wk) | 69 (93%) | 10 (13%) | ||
| US/EFW for other reasons | 1 (1%) | 16 (21%) | 0.001 | 0.11 (0.006–0.56) |
Abbreviations: BMI, body mass index; EFW, estimated fetal weight; PPROM, preterm premature rupture of membranes; USE, ultrasound examination.
Note: Data presented as mean ± standard deviation or N (%).