Table 2

Characteristics of the cohort children, weighted per cent unless otherwise stated

AllVery pretermModerately pretermLate pretermEarly termTermPost-term
Gestational age (weeks)23–42<3232–3334–3637–3839–4142
Cohort birth is twin or triplet1.511.617.410.
Timing of interview (mean, months after birth)†
Birth weight, mean, kg3.
Labour complications (any)34.862.058.338.130.534.937.7
Health problems at birth or in first week (any)25.789.181.659.228.720.723.0
Baby sent to special care‡19.498.297.360.119.510.312.0
Age at discharge from hospital, in weeks (median, p25–p75)§0.1 (0.3, 0.6)8.6 (5.0, 12.9)3.0 (2.0, 4.0)1.0 (0.4, 1.7)0.4 (0.1, 0.7)0.3 (0.1, 0.6)0.3 (0.1, 0.6)
Subsequent hospital admissions (any)13.346.823.
Subsequent hospital admissions (3 or more)
  • *Child's chronological age, not corrected age.

  • †Sex of first child where cohort families have twins or triplets.

  • ‡Proportion of babies for whom data are available (because they reported health problems at birth or in first week).

  • §Age in weeks the baby came home from hospital, longest stay reported for multiples.