Table 1.
Characteristics of women with familiar and sporadic sPTB and controls.
| Cases (N = 292) |
Controls (N = 281) |
p | ||
|---|---|---|---|---|
| Familiar sPTB (N = 44) |
Sporadic sPTB (N = 248) |
|||
| Maternal characteristics | ||||
| Mean age at delivery/median (range) | 31 (22–40) | 31 (16–44) | 30 (19–43) | 0.128 1 |
| Prepregnancy BMI/median (range) | 23 (17–32) | 25 (19–39) | 24 (16–39) | 0.202 2 |
| Gestational age at delivery/median (range) | 34 (24–36) | 35 (21–36) | 40 (37–41) | 0.000 2 |
| Extremely preterm < 28 weeks/N (%) | 5 (11.4) | 20 (8.3) | ||
| Very preterm 32–28 weeks/N (%) | 6 (13.6) | 37 (15.2) | ||
| Moderate to late preterm 32–36 weeks/N (%) | 33 (75.0) | 186 (76.5) | ||
|
Smoking during pregnancy Yes/N (%) No/N (%) |
6 (13.6) 38 (86.4) |
46 (18.9) 197 (81.1) |
40 (18.4) 177 (81.6) |
0.702 3 |
|
Parity Nulliparous/N (%) Multiparous/N (%) |
15 (35.7) 27 (64.3) |
46 (20.1) 183 (79.9) |
33 (15.2) 184 (84.8) |
0.008 3 |
|
Previous sPTB Yes/N (%) No/N (%) |
11 (25.0) 33 (75.0) |
24 (9.9) 218 (90.1) |
0.005 3 | |
| Fetal characteristics | ||||
| Birth weight (grams)/median (range) | 2170 (650–3400) | 2269 (576–3550) | 3460 (2380–4740) | 0.000 2 |
Bold denotes statistical significance; epidemiological data about smoking during pregnancy and parity were available for familiar 42/44 (95.5%) and 229/248 (92.3%) sporadic sPTB, and 217/281 (77.2%) controls; data about previous sPTB were available for woman with familiar 44/44 (100.0%) and 242/248 (97.6%) sporadic sPTB. 1 One-way ANOVA. 2 Kruskal–Wallis. 3 χ2 test.