Table 1.
Characteristics of the study population according to the etiology of preterm birth
| Indicated preterm birth group ( n=110 ) |
Spontaneous preterm birth group ( n=147 ) |
P value | |
|---|---|---|---|
| Maternal age (mean±SD) | 32.0±4.5 | 31.3±4.4 | NS |
| Parity (nulliparity) (%) | 47.3 (52/110) | 47.6 (70/147) | NS |
| Gestational age at delivery (weeks) (mean±SD) |
29.3±1.8 | 28.5±2.3 | .005 |
| Antenatal steroid use* (%) | 73.4 (80/109) | 76.9 (113/147) | NS |
| Cesarean delivery (%) | 91.8 (101/110) | 51 (75/147) | <.001 |
| Sex (Male) (%) | 40.9 (45/110) | 64.6 (95/147) | <.001 |
| Birth weight (g) (mean±SD) | 1069.7±401.7 | 1286.9±408.0 | <.001 |
| 1-min Apgar score of < 7 (%) | 84.5 (93/110) | 76.9 (113/147) | NS |
| 5-min Apgar score of < 7 (%) | 64.5 (71/110) | 49.7 (73/147) | .017 |
| Umbilical arterial pH of < 7.15† (%) | 25.3 (25/99) | 10.1 (13/129) | .002 |
| Hypertensive disorders (%) | 74.5 (82/110) | 2.7 (4/147) | <.001 |
| Histological chorioamnionitis‡ (%) | 9.3 (9/97) | 59.9 (82/137) | <.001 |
| Funisitis§ (%) | 1.0 (1/98) | 33.8 (47/139) | <.001 |
| RDS¶ (%) | 58.1 (61/105) | 38.4 (53/138) | .002 |
| Neonatal mortality (%) | 16.4 (18/110) | 11.6 (17/147) | NS |
NS, not significant; RDS, respiratory distress syndrome.
*
One case was excluded from the analysis because of unavailable data for the use of antenatal corticosteroid.
†
Twenty-nine cases that did not have the results of the umbilical arterial blood gas analysis were excluded from the analysis.
‡
Twenty-three cases that did not have histopathologic examinations of the placenta were excluded from the analysis.
§
Twenty cases that had unavailable placental histological results for funisitis were excluded from the analysis.
¶
Fourteen cases that died immediately at the delivery room regardless of resuscitation were excluded from the analysis.