Table 1. Demographics of study populations.
| Term birth | Spontaneous preterm birth | ||
| n = 140 | n = 140 | p | |
| Maternal age (years)* | 27.4±0.5 | 26.0±0.7 | 0.036 |
| Primigravida (%) | 15.7 (22/140) | 42.9 (60/140) | <0.001 |
| Nulliparous (%) | 17.9 (25/140) | 47.9 (67/140) | <0.001 |
| Gestational age at delivery (weeks)* | 39.5±0.1 | 34.0±0.2 | <0.001 |
| Cesarean delivery (%) | 50.0 (70/140) | 22.1 (31/140) | <0.001 |
| Birth weight (g)* | 3416.7±26.7 | 2377.4±47.5 | <0.001 |
| Baby gender (male sex) (%) | 55.0 (77/140) | 67.1 (94/140) | 0.037 |
| Placental pathology | |||
| Acute chorioamnionitis (%) | 12.9 (18/140) | 18.6 (26/140) | NS |
| Maternal underperfusion (%) | 2.1 (3/140) | 12.9 (18/140) | 0.001 |
| Fetal vascular thrombo-occlusive disease (%) | 6.4 (9/140) | 6.4 (9/140) | NS |
| Villitis of unknown etiology (%) | 15.7 (22/140) | 22.1 (31/140) | NS |
| Chronic chorioamnionitis (%) | 13.6 (19/140) | 40.7 (57/140) | <0.001 |
*Mean±SEM.