Abstract
Inadequate pre-pregnancy BMI and gestational weight gain (GWG) have been associated with sub-optimal child development. We used data from the 2015 Pelotas (Brazil) Birth Cohort Study. Maternal anthropometry was extracted from antenatal/hospital records. BMI (kg/m2) and GWG (kg) adequacy were classified according to WHO and IOM, respectively. Development was evaluated using the INTER-NDA assessment tool for 3,776 children aged 24 months. Suspected developmental delay (SDD) was defined as <10th percentile. Associations between maternal exposures and child development were tested using linear and logistic regressions. Mediation for the association between BMI and child development through GWG was tested using G-formula. Sex differences were observed for all child development domains, except motor. Maternal pre-pregnancy underweight increased the odds of SDD in language (OR: 2.75; 95%CI: 1.30–5.80), motor (OR: 2.28; 95%CI: 1.20–4.33), and global (OR: 2.14; 95% CI: 1.05–4.33) domains for girls; among boys, excessive GWG was associated with SDD in language (OR: 1.59; 95%CI: 1.13–2.24) and cognition (OR: 1.59; 95%CI: 1.15–2.22). Total GWG suppressed the association of pre-pregnancy BMI with percentiles of global development in the entire sample. Maternal underweight and excessive GWG were negatively associated with development of girls and boys, respectively. The association of pre-pregnancy BMI with global child development was not mediated by GWG, irrespective of child’s sex.
Highlights
Optimal child development is critical to health, and adult capacity to contribute effectively to society and the economy[1]
Two studies carried out in rural China found that average pre-pregnancy body mass index (BMI) and weekly gestational weight gain (GWG) were directly associated with neuro and intellectual development measured throughout childhood; in the same study, maternal pre-pregnancy underweight was negatively associated with verbal comprehension[12,13]
Despite the growing body of evidence, few studies investigated sex differences, with regards to child development differences between boys and girls, linked with maternal nutritional status[15,16], finding that preconception maternal overweight and obesity was associated with lower mental and psychomotor scores only among boys at ages of 3 and 7 years in a low-income cohort in the U.S The results were partially explained by a sex difference in growth rate in utero, which is more accelerated in boys than girls, leaving males more susceptible to adverse exposures in womb than females[16], or due to still under investigation pathways involving placenta[15]
Summary
Optimal child development is critical to health, and adult capacity to contribute effectively to society and the economy[1]. Most evidence on adverse consequences of maternal poor nutritional status, concerning pre-pregnancy body mass index (BMI) and gestational weight gain (GWG), on offspring intelligence and neurodevelopment from childhood to early adolescence, come from high-resource settings. These studies showed that both exposures present a non-linear relationship with scores for intelligence and neurodevelopment from 4 to 14 years of age, www.nature.com/scientificreports highlighting the hazardous effects of maternal pre-pregnancy underweight or overweight/obesity, as well as insufficient or excessive GWG6–11. Additional studies are lacking, and the mechanisms underpinning such associations remain unclear and are likely to be complex[15,16,17]
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