The effect of weigth increases during pregnancy on birthweight and preterm delivery

The effect of weight increases during pregnancy on birth weight and preterm delivery Manuela Chiavarini M Chiavarini1, L Minelli1, D Nucci1, L Salmasi2 1Department of Experimental Medicine, Public Health Section, University of Perugia, Italy 2Department of Political Science, University of Perugia, Italy Contact: manuela.chiavarini@unipg.it Introduction The high prevalence of unhealthy preconception body weight and inappropriate gestational weight gain among pregnant women is an important public health concern. The amount of weight gained during pregnancy can affect the immediate and future health of a woman and her infant. Low or high pre pregnancy body mass index (BMI) and weight increases during pregnancy are linked to an increased risk of adverse neonatal outcomes, especially regarding to low birth weight (LBW), high birth weight (HBW) and pre-term delivery (PTD). We studied the impact of weight increases in pregnancy on LBW, HBW and PTD. Methods Data were obtained from women interviewed at the Teaching Hospital of Perugia (Italy). We gathered a large sample of about 2,000 women, which were asked about weight increases during pregnancy, socio-demographic characteristics and newborns’ health. The revised classification proposed by Institute of Medicine (IOM 2009) was usedto identify women with weight increases considered as more or less than normal. Logistic regression models were adoptedto assess the effect of non-normal weight increases on LBW/HBW, defined as weighing less than 2,500 gr or more than 4,000 gr at birth respectively, and on PTD delivery. Results According to our estimates we find that women with a less than normal weight increase during pregnancy have a higher probability of LBW (O.R.=2.195, s.e.=0.524) and of PTD (O.R. 1.769, s.e.=0.323), whereas those with a more than normal weight increase have a higher probability of HBW (O.R. = 2.439, s.e. = 0.406). Conclusions We find that having a non-normal weight increase during pregnancy leads to undesired outcomes in terms of birth weight of newborns, increasing significantly the probabilities of LBW, HBW and PTD, implying negative consequences on newborns’ current and future health. Key messages Non-normal maternal weight increase rises the probability of LBW, HBW and PTD Unhealthy preconception BMI and inappropriate gestational weight gain is an important public health concern