Table 1

Characteristics of moderately preterm and term-born children

Mean gestational age (weeks)Preterm (n=916) 34.0 (SD 1.0)Term (n=543) 39.6 (SD 1.0)
Mean birth weight (g)2244 (SD 465) % (n)3553 (SD 488) % (n)p Value
Gestational age (weeks)
 3211.5 (105)
 3320.1 (184)
 3427.8 (255)
 3540.6 (372)
 3817.1 (93)
 3926.2 (142)
 4035.9 (195)
 4120.8 (113)
SGA*9.2 (84/916)7.7 (42/543)0.4
Gender (male)57.2 (524/916)49.2 (267/543)0.003
Age of child (months)0.6
 <430.9 (7/768)0.6 (3/467)
 43–4789.6 (688/768)91.4 (427/467)
 >479.5 (73/768)7.9 (37/467)
Family composition0.005
 Two-parent family92.7 (845/912)96.3 (517/537)
 One-parent family7.3 (67/912)3.7 (20/537)
Number of siblings0.006
 018.6 (170/916)12.5 (68/543)
 154.5 (499/916)55.2 (300/543)
 220.7 (190/916)23.2 (126/543)
 ≥36.2 (57/916)9.0 (49/543)
Maternal age (years)0.05
 <258.5 (75/885)6.1 (32/526)
 25–3473.6 (651/885)71.5 (376/526)
 >3418.0 (159/885)22.4 (118/526)
Maternal educational level0.08
 Low30.5 (278/912)25.6 (138/539)
 Medium43.0 (392/912)43.6 (235/539)
 High26.5 (242/912)30.8 (166/539)
Maternal ethnicity0.6
 Netherlands94.2 (856/909)95.1 (507/533)
 Europe1.8 (16/909)1.9 (10/533)
 Outside Europe4.1 (37/909)3.0 (16/533)
  • * SGA, small for gestational age, that is, birth weight below the 10th percentile of the Dutch Kloosterman growth charts.

  • Age at completing the Child Behavior Checklist.

  • Low, primary school or less and/or low-level technical and vocational training; medium, high school or medium-level technical and vocational training for 12–16 years; high, university or high-level technical and vocational training for >16 years.