Table 1.
Baseline maternal characteristics. Values are means (standard deviation) or absolute frequency (relative frequency)
| Variable | Singleton (N = 161) | Twin (N = 77) | p |
|---|---|---|---|
| Maternal age (years) | 33.2 (5.82) | 35.6 (5.81) | 0.016 |
| BMI (kg/m2) | 27.8 (6.44) | 25.6 (5.0) | 0.003 |
| Ethnicity | |||
| Black | 5 (3.1%) | 3 (3.9%) | 0.620 |
| Oriental | 1 (0.6%) | 1 (1.3%) | |
| Caucasian | 155 (96.3%) | 73 (94.8%) | |
| Smoke | 19 (11.8%) | 8 (10.4%) | 0.830 |
| Conception | |||
| Spontaneous | 148 (91.9%) | 35 (45.5%) | < 0.001 |
| ART | 13 (8.1%) | 42 (54.5%) | |
| Nulliparity | 93 (57.8%) | 48 (62.3%) | 0.573 |
| Chronic Hypertension | 22 (13.7%) | 5 (6.5%) | 0.123 |
| Diabetes Mellitus | |||
| Type 1 | 2 (1.2%) | 0 (0%) | < 0.001 |
| Type 2 | 23 (14.3%) | 1 (1.3%) | |
| APL Syndrome | 2 (1.2%) | 0(0%) | 1 |
| Gestational age at PE onset | |||
| Preterm PE | 78 (48.5%) | 61 (79.2%) | < 0.001 |
| At term PE | 83 (51.6%) | 16 (20.7%) | |
| Gestational age at delivery (weeks)* | 37.0 (3.9) | 35.9 (2.1) | 0.001 |
| < 28 weeks | 6 (3.7%) | 1 (1.3%) | < 0.001 |
| 28–32 weeks | 24 (14.9%) | 4 (5.2%) | |
| 32–34 weeks | 9 (5.6%) | 9 (11.7%) | |
| 34–37 weeks | 43 (26.7%) | 53 (68.8%) | |
| > 37 weeks | 79 (49.1%) | 10 (13.0%) | |
| Labor onset | |||
| Spontaneous | 28 (17.4%) | 13 (16.9%) | 0.032 |
| Induced | 96 (59.6%) | 34 (44.2%) | |
| No labor onset | 37 (23.0%) | 30 (39.0%) | |
| Type of delivery | |||
| Vaginal | 57 (35.4%) | 26 (33.8%) | 0.885 |
| Cesarean section | 104 (64.6%) | 51 (66.2%) | |
| Steroids | 43 (26.7%) | 29 (37.7%) | 0.085 |
| Gestational age at steroids administration, weeks* | 31.6 (5.4) | 33.0 (3.7) | 0.207 |
Statistically significant comparisons are represented in bold
BMI Body Mass Index, ART Assisted Reproductive Techniques, APL Antiphospholipid syndrome. * Variables reported as median (Interquartile range)