Fetal growth does not modify the relationship of infant weight gain with childhood adiposity and blood pressure in the Southampton women’s survey

<p></p><p><b>Background</b>: Rapid infant weight gain is a risk factor for childhood obesity. This relationship may depend on whether infant weight gain is preceded by in-utero growth restriction.</p> <p><b>Aim</b>: Examine whether fetal growth modifies the relationship between infant weight gain and childhood adiposity and blood pressure.</p> <p><b>Subjects and methods</b>: 786 children in the Southampton Women’s Survey. We related infant weight gain (weight at 2 years-birth weight) to body mass index (BMI), %body fat, trunk fat (kg), systolic (SBP) and diastolic blood pressure (DBP) at age 6-7 years. Mean estimated fetal weight (EFW) between 19-34 weeks and change in EFW (19-34 weeks) were added to models as effect modifiers.</p> <p><b>Results</b>: Infant weight gain was positively associated with all childhood outcomes. We found no evidence that these effects were modified by fetal growth (p>0.1 for all interaction terms). For example, a 1 standard deviation (SD) increase in infant weight gain was associated with an increase in BMI z-score of 0.51 (95% CI 0.37;0.64) when EFW-change was set at -2 SD-scores compared with an increase of 0.41 (95% CI 0.27;0.54,p_{(interaction)}=0.48) when set at 2 SD-scores.</p> <p><b>Conclusion</b>: The documented adverse consequences of rapid infant weight gain may occur regardless of whether growth was constrained in-utero.</p><br><p></p>