Maternal pre-pregnancy weight and infant spontaneous movement: is there an association?

Abstract Introduction Maternal pre-pregnancy overweight status might create a chronic systemic inflammatory environment for the foetus, impairing neurons development. The Motor Optimality Score-Revised (MOS-R) is an established tool to assess infant spontaneous movement at 3-5 months helping predict later neurodevelopmental outcomes in infants, including language, minor neurological dysfunction or learning difficulties at school age. The aim of our study was to investigate if maternal BMI together with other characteristics were potentially associated with MOS-R score at 3-5 months in a sample of newborns representative of physiologic full-term pregnancies. Methods 128 mother-children couples were enrolled in the Hospital of Modena, Italy. Mothers’ socio-demographic characteristics and BMI pre and during pregnancy were collected. MOS-R was assessed in infants within 9-18 weeks post term age (Median 13, IQR 12-14). Descriptive statistics, bivariate associations and multivariate analysis were performed. Results In our sample, 94.5% of infants (44% females) had a MOS-R≥25 (optimal score), 3.9% a MOS-R between 23-24 and 1.6% a MOS-R<23. In bivariate analyses pre-pregnancy BMI≥25 and weight gain higher than recommended during pregnancy were associated with MOS-R<25 (p < 0.05); being unemployed before and during pregnancy and having pregnancy during COVID lockdown were associated with reduced “age adequate movement repertoire” subcategory (p < 0.05). In multivariate analysis, pre-pregnancy BMI≥25 remained the only factor significantly associated with lower scores (p < 0.05). Discussion Our sample of healthy infants showed a typical range of spontaneous movements reflecting neural integrity. However, lower MOS-R scores were associated with pre-pregnancy overweight. This finding reinforce the importance of enhancing public health actions targeted at keeping a weight in the normal range to protect from a large number of unhealthy conditions both the mother and the offspring. Key messages • Pre-pregnancy weight appears associated with infant spontaneous movement in 3-5 months infants. • Public health actions targeted at keeping female weight in the normal range must be strengthen.