Gestational Age, Health, and Educational Outcomes in Adolescents.

Background And Objectives: As outcomes for extremely premature infants improve, up-to-date, large-scale studies are needed to provide accurate, contemporary information for clinicians, families, and policy makers. We used nationwide New Zealand data to explore the impact of gestational age on health and educational outcomes through to adolescence.

Methods: We performed a retrospective cohort study of all births in New Zealand appearing in 2 independent national data sets at 23 weeks' gestation or more. We report on 2 separate cohorts: cohort 1, born January 1, 2005 to December 31, 2015 (613 521 individuals), used to study survival and midterm health and educational outcomes; and cohort 2, born January 1, 1998 to December 31, 2000, and surviving to age 15 years (146 169 individuals), used to study high school educational outcomes. Outcomes described by gestational age include survival, hospitalization rates, national well-being assessment outcomes at age 4 years, rates of special education support needs in primary school, and national high school examination results.

Results: Ten-year survival increased with gestational age from 66% at 23 to 24 weeks to >99% at term. All outcomes measured were strongly related to gestational age. However, most extremely preterm children did not require special educational support and were able to sit for their national high school examinations.

Conclusions: Within a publicly funded health system, high-quality survival is achievable for most infants born at periviable gestations. Outcomes show improvement with gestational ages to term. Outcomes at early-term gestation are poorer than for children born at full term.