Table 4.
Male/Female characteristics of preterm (≤30 weeks gestation) and very low birth weight Infant (< 1,500 g) groups
| Preterm (≤30 weeks gestation) | Very low birth weight (< 1,500 g) | |||
| Male n = 1741 (56%) | Female n = 1376 (44%) | Male n = 1797 (53%) | Female n = 1601 (47%) | |
| Demographics | ||||
| Mean birth weight (grams) | 1102 | 1032* | 1050 | 1031* |
| Mean gestational age (weeks) | 27.4 | 27.4 | 27.9 | 28.3* |
| Small for gestational age (%) | 13.6 | 16.1* | 24.4 | 28.2* |
| 5-minute Apgar score (mean) | 7.2 | 7.3 | 7.2 | 7.4* |
| Outborn (%) | 21.4 | 21.7 | 21.4 | 19.9 |
| Antenatal steroids (%) | 69.3 | 71.3 | 66.2 | 69.4* |
| SNAP-II (mean) | 26.6 | 27.2 | 26.5 | 24.8* |
| Outcomes | ||||
| Survival (%) | 85.2 | 86.9 | 85.6 | 88.9* |
| Necrotizing enterocolitis (%) | 6.5 | 7.0 | 6.6 | 6.3 |
| Patent ductus arteriosus (%) | 28.0 | 32.3* | 27.3 | 28.8 |
| Seizures (%) | 4.6 | 4.9 | 4.5 | 4.2 |
| Chronic lung disease (%) | 25.1 | 21.7* | 25.7 | 18.9* |
| Primary infection (%) | 1.8 | 2.0 | 1.6 | 1.6 |
| Nosocomial infection (%) | 21.2 | 22.1 | 21.9 | 20.9 |
| Intraventricular hemorrhage (≥grade 3) (%) | 9.6 | 7.5* | 9.1 | 6.4* |
| Retinopathy of prematurity (≥stage 3) (%) | 10.9 | 10.8 | 10.5 | 9.7 |
| Resource use | ||||
| NTISS (mean) | 17.5 | 17.1 | 17.1 | 16.0* |
| Assisted ventilation (%) | 88.7 | 86.7 | 83.9 | 79.6* |
| Number of ventilated days (mean) | 18.0 | 17.1 | 17.5 | 14.9* |
| Surgery (%) | 21.2 | 14.5* | 21.6 | 12.9* |
| Length of NICU stay (mean) (days) | 48.1 | 48.9 | 47.6 | 45.7 |
* significant (p < 0.05) difference between male and female infants