Table 3. Delivery outcome.
| Characteristics | Period 1 (1995–2000) (n=371) | Period 2 (2001–2006) (n=608) | Period 3 (2007–2012) (n=599) | Period 4 (2013–2018) (n=555) | P-valuea) | |
|---|---|---|---|---|---|---|
| Gestational age at delivery (wk) | 35.2±2.7 | 34.7±3.2 | 34.7±3.7 | 34.9±3.7 | 0.002 | |
| Early-preterm | 82 (22.1) | 172 (28.3) | 169 (28.2) | 151 (27.2) | <0.001 | |
| Late-preterm | 205 (55.3) | 284 (46.7) | 187 (31.2) | 159 (28.6) | ||
| Term | 84 (22.6) | 152 (25.0) | 243 (40.6) | 245 (44.1) | ||
| Mode of delivery | <0.001 | |||||
| Both vaginal delivery | 8 (2.2) | 58 (9.5) | 87 (14.5) | 60 (10.8) | ||
| Both cesarean section | 361 (97.3) | 549 (90.3) | 507 (84.6) | 490 (88.3) | ||
| First twin vaginal delivery-second twin cesarean | 2 (0.5) | 1 (0.2) | 5 (0.8) | 5 (0.9) | ||
Data expressed as mean±standard deviation or number (%).
a)Jonckheere-Terpstra test for continuous variables and linear-by-linear regression for categorical variables.