Table 1.
Descriptive Statistics: Necrotizing Enterocolitis and Categorical Predictors.
| Variable | n | % |
|---|---|---|
| Necrotizing enterocolitis | 704 | 6.8 |
| Gestational age < 28 weeks | 3902 | 37.7 |
| Gestational age < 26 weeks | 1874 | 18.1 |
| Birthweight < 1000 g | 3900 | 37.7 |
| Birthweight < 750 g | 1611 | 15.6 |
| Small-for-gestational-age | 2224 | 21.6 |
| Sex: male | 5115 | 49.4 |
| Birth-Year | ||
| 2013 | 1392 | 13.4 |
| 2014 | 2119 | 20.5 |
| 2015 | 2380 | 23.0 |
| 2016 | 2346 | 22.7 |
| 2017 | 2116 | 20.4 |
| Birth-Season: Spring | 2513 | 24.3 |
| Birth-Season: Summer | 2608 | 25.2 |
| Birth-Season: Autumn | 2738 | 26.4 |
| Birth-Season: Winter | 2494 | 24.1 |
| Multiple pregnancy | 3637 | 35.1 |
| Multipara | 6448 | 62.3 |
| In vitro fertilization | 2389 | 23.1 |
| Gestational DM | 826 | 8.0 |
| Overt DM | 114 | 1.1 |
| Pregnancy-induced hypertension | 1976 | 19.1 |
| Chronic hypertension | 221 | 2.1 |
| Chorioamnionitis | 2989/8612 | 34.7 |
| PROM > 18 h | 2455/10,266 | 23.9 |
| Antenatal steroid | 8071/10,162 | 79.4 |
| Cesarean section | 8052 | 77.8 |
| Oligohydramnios | 1399/9442 | 14.8 |
| Polyhydramnios | 153/9442 | 1.6 |
| Congenital infection | 127 | 1.2 |
| 1-min Apgar score ≤ 3 | 2975/10,278 | 28.9 |
| 5-min Apgar score < 7 | 3488/10,283 | 33.9 |
| Neonatal resuscitation program | 9169/10,281 | 89.2 |
| Neonatal resuscitation program intensive | 6466/10,281 | 62.9 |
| Blood gas pH < 7.0 | 503/7792 | 6.5 |
| Blood gas base excess < -15 | 235/7768 | 3.0 |
| Pulmonary hemorrhage | 636 | 6.1 |
| Respiratory distress syndrome | 8058 | 77.8 |
| Surfactant count ≥ 2 | 2081 | 20.1 |
| Patent ductus arteriosus treatment | 3705/10,044 | 36.9 |
| Patent ductus arteriosus ligation | 1099/7296 | 15.1 |
| Air leak syndrome | 569 | 5.5 |
| Sepsis | 2177 | 21.1 |
Abbreviations: DM, Diabetes mellitus; PROM, Pre-labor rupture of membrane.