Does emigration by itself improve birth weight? Study in European newborns of Indo-Pakistan origin.

Objective: Our aim was to evaluate the effect of emigration on fetal birth weight (BW) in a group of pregnant women coming from the Indian subcontinent. Methods: This was a retrospective study in a mixed population of pregnant women from the Indian subcontinent that either moved to Europe or stayed in their original countries. The influence of emigration along with several pregnancy characteristics: GA at delivery, fetal gender, maternal age, height, weight, body mass index (BMI) and parity on BW was evaluated by means of multivariable linear regression analysis. Results: According to European standards, babies born to Indo-Pakistan emigrants and babies born to women staying in the Indian subcontinent were similarly small (BW centile 30± 29 and 30.1 ± 28, p<0.68). Multivariable regression demonstrated that emigration by itself did not exert a direct influence on BW (p  = 0.27), being BMI and gestational age at delivery the true determinants of BW (p<0.0001). Conclusions: Maternal BMI is the most relevant parameter affecting fetal growth regardless of the place of residence.