Effects of Perinatal Factors on Body Mass Index and Exercise Capacity of School-age Children

Objective: To identify the possible long term effects of perinatal factors on child’s body mass index (BMI) and fitness capacity.

Methods: Data from two registries, the SLOFIT database and NPIS, were linked to evaluate the potential effects of perinatal factors on children’s body mass index (BMI) and exercise capacity (PFI). We analyzed SLOFIT data of 2929 children from 2016 and linked them to data of 6894 born infants (90 stillbirths and neonatal deaths excluded) at our institution in 2008. Our subjects were thus 8 (SD) years old on average. Linear regression analysis was used to assess the potential relationship between child’s BMI or child’s physical fitness index (PFI) and perinatal factors.

Results: We identified 2929 (43%) of children in the SLOFIT database born in our institution in 2008. Child’s BMI at school-age was positively associated with maternal pre-pregnancy BMI (p<0.001), and inversely associated with term birth (p=0.02) and mother’s education level (p<0.001). Child’s PFI at school-age was positively associated with school grade (p<0.001), birth weight (p=0.006), and maternal education (p<0.001). PFI was inversely associated with nuliparity (p<0.001), lower maternal education (p=0.003), maternal pre-pregnancy BMI (p<0.001), and Neonatal Intensive Care Unit (NICU) admission (p=0.020).

Conlusions: Maternal pre-pregnancy BMI and education level are associated with BMI and fitness capacity at the age of 8 years. Firstborns and those admitted to NICU had lower fitness capacity. Being born very preterm had no significant impact neither on BMI or PFI.