Table 1. Maternal demographic, prenatal, and perinatal characteristics.
| RDS (n = 78) | Non-RDS (n = 1989) |
P value | |
|---|---|---|---|
| Age (years) | 32.9±4.3 | 32.2±4.5 | 0.191 |
| Height (cm) | 160.0±5.4 | 160.4±5.3 | 0.491 |
| Weight (kg) | 65.4±12.5 | 66.8±12.9 | 0.332 |
| Body mass index (kg/m2) | 25.5±4.5 | 26.0±4.8 | 0.372 |
| Parity | 0.6±0.7 | 0.7±0.8 | 0.406 |
| Hypertension, n (%) | 6 (7.7) | 99 (5.0) | 0.29 |
| Diabetes mellitus, n (%) | 17 (22.2) | 276 (13.9) | 0.116 |
| Thyroid dysfunction, n (%) | 0.058 | ||
| Hyperthyroidism | 4 (5.1) | 30 (1.5) | |
| Hypothyroidism | 3 (3.8) | 66 (3.3) | |
| Prior cesarean delivery, n (%) | 21 (26.9) | 467 (23.5) | 0.497 |
| Prior conization of the uterine cervix, n (%) | 2 (2.6) | 16 (0.8) | 0.143 |
| History of pelvic inflammatory disease, n (%) | 1 (1.3) | 20 (1.0) | 0.424 |
| Serum glucose† (mg/dL) | 124.2±31.1 | 117.0±29.0 | 0.092 |
| Second trimester ultrasonography | |||
| Gestational age (weeks) | 22.8±3.5 | 22.2±3.4 | 0.177 |
| Fetal body weight (kg) | 0.62±0.4 | 0.6±0.4 | 0.323 |
| Fetal presentation | |||
| Breech presentation, n (%) | 16 (20.0) | 545 (27.4) | 0.365 |
| Transverse lie, n (%) | 6 (7.5) | 88 (4.4) | |
| Ultrasonography just before delivery | |||
| Gestational age (weeks) | 28.7±2.2 | 37.4±9.7 | <0.001* |
| Fetal body weight (kg) | 1.2±0.3 | 3.0±0.5 | <0.001* |
| Fetal presentation | 0.443 | ||
| Breech presentation, n (%) | 11 (14.3) | 95 (4.8) | |
| Transverse lie, n (%) | 7 (8.6) | 8 (0.4) | |
| Gestational age at delivery (weeks) | 30.9±4.1 | 38.4±2.0 | <0.001* |
| Preterm birth <37 weeks, n (%) | 67 (85.9) | 219 (11.7) | <0.001* |
| Use of antenatal corticosteroid, n (%) | 6 (7.1) | 41 (2.1) | 0.007 |
| Fetal body weight at delivery (kg) | 1.6±0.8 | 3.2±0.5 | <0.001* |
| Small-for-gestational age <10th percentile, n (%) | 15 (19.1) | 229 (11.5) | 0.058 |
| Low birth weight‡, n (%) | 61 (78.2) | 305 (15.3) | <0.001* |
| Female sex of infant, n (%) | 39 (49.4) | 963 (48.4) | 0.908 |
| Cesarean delivery, n (%) | 68 (87.5) | 1002 (50.4) | <0.001* |
| Indications for cesarean delivery | |||
| Placenta previa | 10 (15.0) | 34 (3.4) | <0.001* |
| Previous cesarean section | 17 (25.0) | 352 (35.0) | 0.037 |
| Dystocia | 4 (5.9) | 232 (23.2) | 0.38 |
| Abnormal presentation | 4 (5.9) | 91 (9.1) | 0.307 |
| Fetal distress | 20 (30.0) | 88 (8.8) | <0.001* |
| Fetal growth restriction | 0 (0) | 10 (1.0) | 0.86 |
| Oligohydramnios | 0 (0) | 24 (2.4) | 0.788 |
| Multiple pregnancy | 0 (0) | 13 (1.3) | 0.839 |
| Large-for-gestational age | 0 (0) | 20 (2.0) | 0.803 |
| Preeclampsia | 7 (10.0) | 17 (1.7) | <0.001* |
| Maternal disease | 3 (5.0) | 57 (5.7) | 0.203 |
| Fetal anomaly | 0 (0) | 17 (1.7) | 0.82 |
| Maternal request | 0 (0) | 3 (0.3) | 0.919 |
| Othersδ | 3 (5.0) | 44 (4.4) | 0.171 |
RDS, respiratory distress syndrome; NA, not applicable.
Data are presented as mean±standard deviation.
†In the 50-g oral glucose tolerance test.
‡Birth weight <2500 g.
δIncluded previous uterine surgeries, severe vulvar vascular congestion, and older primigravida.
*Statistically significant.