Maternal glucose levels influence birthweight and 'catch-up' and 'catch-down' growth in a large contemporary cohort

Aim To explore the effects of maternal glucose on birthweight, infant and childhood growth in non-diabetic pregnant women using routinely collected data. Methods Routinely collected data were extracted retrospectively from two clinical databases. These data comprised measurements of maternal random plasma glucose, infant birthweight, infant and child weight and height at 6-8 weeks, 24-36 weeks and 96-120 weeks in 6263 cases. After data cleaning, 4681 were analysed. Results When the data were analysed in thirds, a positive association between birthweight standard deviation scores (SDS), weight SDS and height SDS with maternal random plasma glucose (RPG) was observed. Regression analysis of birthweight SDS and RPG was significant (P < 0.001). Babies were similar to 48 g heavier at birth for each 1 mmol/l increase of mother's RPG. Infants who showed 'catch-up' growth (as shown by change in weight SDS) at 2 years were born to mothers with lower glucose levels than infants who showed 'catch-down' growth (P < 0.001). Conclusions Random maternal glucose concentrations (taken at 28 weeks' gestation) in the normal range are positively related to birthweight. Glucose concentrations also predict greater weight and length in infancy. Despite this, babies born to mothers with higher glucose concentrations within the normal range show significant 'catch-down' growth in infancy as shown by a fall in weight SDS.