Page 17 - Sample Moderate prematurity, socioeconomic status, and neurodevelopment in early childhood

INTRODUCTION
Worldwide, one in ten live births ends before 37 weeks of gestational age (GA).1
Although children born at less than 32 weeks of gestation face the greatest risk
of mortality and morbidity, more than 85% of preterm children are born beyond
32 weeks’ of gestation.2 Every week, therefore, that a child is born closer to term, 2 decreases the risk of mortality and morbidity,3 but it increases the impact on public
health due to the much larger number of children involved.4
In the long-term, moderately preterm-born children (MP; 32 to 36 weeks’
gestation) face significantly more developmental problems than term-born children (38 to 42 weeks’ gestation).5-8 In MP children aged four, the risk of developmental delay is twice the risk of term-born children and half the risk of very preterm children (< 32 weeks’ gestation).6 Huddy et al. reported that up to one third of MP children will have difficulties functioning at school.7 Specifically fine motor skills and handwriting seem to be affected.6,7-9
Recent evidence indicated that differences in socioeconomic status (SES) may (partially) explain the association of moderate prematurity with developmental delay.5,10 Additionally, low SES may further increase the effects of moderate prematurity on development. Nevertheless, the role of SES in the relationship between moderate prematurity and developmental delay is unclear. Our aim was, therefore, to assess the separate and joint effects of moderate prematurity and low SES on developmental delay in early childhood.
METHODS
Study design
Data used for this study are from the Longitudinal Preterm Outcome Project (Lollipop): a large prospective cohort study, designed to investigate growth, development, and general health of preterm-born children, with a special focus on MP children (320 to 356 weeks of gestation) in the Netherlands.6 Lollipop consists of a community-based sample of preterm children and a random sample of term-born controls (380 to 416 weeks of gestation). At the stage in which the study was designed, MP children concerned those children born at 32-35 weeks gestation and therefore children born at 360-366 weeks gestation were not included. Participants were recruited from thirteen randomly selected Preventive
Developmental outcomes: risks multiply
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