The Association of High Birth Weight with Pregnancy Outcomes: a Longitudinal Study

Abstract

To explore the adverse perinatal results associated with high birth weight (HBW) and analyse other risk factors associated with these events. This was a retrospective longitudinal study of all childbirths occurring in our maternity centre during the period of 2010–2016. A comparative analysis was performed between pregnancy outcomes of newborns with weights above the 95th percentile and newborns with normal weight. In addition, a multivariate logistic regression analysis was performed to evaluate the risk factors associated with the identified adverse perinatal events. The perinatal results of 31,576 deliveries were analysed. When the two groups were compared, the group of pregnancies with HBW newborns showed higher frequencies of maternal diabetes, induction of labour, stalled labour caesarean section, severe perineal tears, and type 3 or greater neonatal resuscitation and a higher maternal age (p < 0.05). The multivariate regression analysis identified HBW as an important risk factor for stalled labour caesarean section and severe perineal tears, with odds ratios (ORs) of 3.6 (95% confidence interval (CI), 3.08–4.2) and 2.06 (95% CI, 1.33–3.19), respectively. Other risk factors such as induction of labour, gestational diabetes and instrument-assisted delivery (p < 0.001) were identified. Deliveries of newborns with weights above the 95th percentile presented poorer perinatal results compared to deliveries of normal weight newborns. This study identified additional relevant risk factors associated with stalled labour caesarean section and severe perineal tears. These findings could be useful to provide adequate advice to pregnant women.