Changes in neonatal morbidity, neonatal care practices, and length of hospital stay of surviving infants born very preterm in the Netherlands in the 1980s and in the 2000s: a comparison analysis with identical characteristics definitions

Table 2 Comparison analysis between cohorts on maternal and infant characteristics

	LOLLIPOP (2002-03) N = 549		POPS (1983) N = 679
Maternal characteristics - Sociodemographic characteristics
	Mean	SD	Mean	SD	T-value (df)	P-value
Maternal age at birth, years	30.5	4.5	27.2	4.7	9.18 (363)	< 0.0001*
	N	%	N	%	Chi ² (df)
Parental education, high	227	41.9	158	25.4	64.8 (2)	< 0.0001*
Maternal characteristics - Prenatal characteristics
Previous birth	144	26.2	383	56.5	113.4 (1)	< 0.0001*
Maternal smoking during pregnancy	112	20.5	190	31.4	17.5 (1)	< 0.0001*
Infant characteristics
	Mean	SD	Mean	SD	T-value (df)
Gestational age, weeks	29.2	1.6	29.4	1.5	1.8 (1226)	0.07
Birth weight, grams	1298.2	367.4	1329.2	315.5	1.6 (1226)	0.11
	N	%	N	%	Chi ² (df)
SGA	104	18.9	110	16.2	1.6 (1)	0.21
Sex, male	265	48.3	363	53.9	0.6 (1)	0.55
Multiples	187	34.1	156	23.0	18.5 (1)	< 0.0001*
PPROM	95	17.9	163	24.0	6.6 (1)	0.010
Meconium stained amniotic fluid	12	2.3	33	5.0	6.1 (1)	0.014
Breech presentation	124	36.3	187	27.5	9.4 (1)	0.002
APGAR < 7 at 5 min	46	8.7	80	13.4	6.5 (1)	0.011
Born with cesarean section	282	53.1	242	35.6	37.0 (1)	< 0.0001*

* still significant after Bonferroni correction
In POPS, complete data ranged between N = 595 and N = 679 depending on characteristic. In LOLLIPOP, complete data ranged between N = 531 and N = 549, except for maternal age (N = 211) and breech presentation (N = 424)

ISSN: 1471-2431