Table 5.

Characteristics of singleton and multiple birth preterm infants

	Preterm (≤30 weeks gestation)		Very low birth weight (< 1,500 g)
	Singleton n = 2277 (73%)	Multiple n = 841 (27%)	Singleton n = 2424 (71%)	Multiple n = 975 (29%)
Demographics
Mean birth weight (grams)	1071	1072	1031	1066
Mean gestational age (weeks)	27.3	27.6*	27.9	28.4*
Small for gestational age (%)	15.0	13.8	26.3	25.7
5-minute Apgar score (mean)	7.2	7.4*	7.2	7.5*
Outborn (%)	22.5	18.9*	21.9	17.6*
Antenatal Steroids (%)	68.2	75.4*	65.7	73.2*
SNAP-II (mean)	27.1	26.2	26.3	24.1*
Outcomes
Survival (%)	86.1	85.7	87.1	87.4
Necrotizing enterocolitis (%)	6.9	6.3	6.8	5.6
Patent ductus arteriosus (%)	29.6	30.9	28.1	28.0
Seizures (%)	5.3	3.2*	4.8	3.2*
Chronic lung disease (%)	24.4	21.7	23.4	20.2
Primary infection (%)	2.2	0.8*	1.9	0.9*
Nosocomial infection (%)	22.1	21.6	22.0	20.0
Intraventricular hemorrhage (≥grade 3) (%)	9.2	7.3	8.4	6.5
Retinopathy of prematurity (≥stage 3) (%)	12.1	7.4*	11.3	7.2*
Resource use
Caesarean section (%)	43.0	52.4*	48.7	57.7*
NTISS (mean)	17.3	17.3	16.8	16.1*
Assisted ventilation (%)	87.6	88.6	82.8	79.6*
Number of ventilated days (mean)	18.2	15.9*	17.1	14.1*
Surgery (%)	18.8	17.1	18.4	15.3*
Length of NICU stay (mean) (days)	48.8	47.6	47.9	43.9*

* denotes p < 0.05 level of significance