Page 12 - Sample Moderate prematurity, socioeconomic status, and neurodevelopment in early childhood

Chapter 1
In foetal life and in early childhood, rapid developmental processes in the central nervous system1 enable a child to adapt to the demands of the environment. However, if children are exposed to early adversities, such as preterm birth and low socioeconomic status (SES), the normal neurodevelopmental processes may come under threat. Early adversities may cause permanent changes in brain and body functions, potentially affecting the foundations of mental and physical health. The main aim of this thesis was to determine the associations between moderate to late prematurity, SES, and pre-school neurodevelopmental problems, and to consider the underlying neurodevelopmental processes from a life course perspective.
BACKGROUND
Moderate prematurity
Worldwide, approximately 10% of live births are preterm, that is birth before 37 weeks of gestation.2 Of the 12.9 million children concerned,2, 3 up to 85% are born between 32 and 37 weeks of gestation. Children born within this gestational age-range are referred to as moderately preterm (MP) and late preterm. In the Netherlands, approximately 10,000 births per year are within this age range.4 Due to the large number of children involved, MP and late preterm-born children contribute substantially to the societal burden associated with preterm birth.5, 6 By contrast, the individual burden is higher in very preterm children (born before 32 weeks’ gestation), as the risks of mortality and morbidity are much higher.7 Therefore, up to fifteen years ago researchers were particularly interested in outcomes following very preterm birth, but we now know that MP children too face significantly more neonatal and developmental problems than full-term children do.8 Examples of neonatal morbidities occurring in MP and late preterm-born children are temperature instability and hyperbilirubinemia, which often lead to a longer stay in hospital.9-11 Furthermore, in the longer term, MP and late preterm- born children have an increased risk of developmental and neurobehavioral problems, such as developmental delay,12 and social and functional difficulties at school age.13-15 In the following paragraphs, we describe what is currently known about developmental outcomes, as well as behavioural and emotional outcomes in MP children.
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