Macrosomia, top of the iceberg: The charm of underlying factors

Background: Macrosomia is associated with childhood obesity. Gestational diabetes mellitus (GDM) is a risk factor for macrosomia. The aim of this large-scale investigation was to determine the incidence, risk factors, characteristic features, and perinatal outcome of macrosomic infants. Methods: This prospective study was carried out on 6385 newborns. Demographic data included maternal age, paternal age, type of delivery, sex, parity and gestational age at delivery. Anthropometric measurements were recorded. ABO/Rh typing was performed and GDM was diagnosed. Results: Out of 6385 term deliveries, 477 infants (7.47%) were macrosomic. Incidence of GDM was 0.6% and 4.8% in the control group and in macrosomic births, respectively. Incidence of GDM(+) cases was 4% among macrosomic infants weighing 4000-4500 g. GDM(+) cases were densely populated (11%) in macrosomic infants weighing >= 4500 g (P < 0.05). Male/female ratio was significantly higher in macrosomic infants weighing >= 4500 g than those weighing 4000-4500 g (P < 0.05). High parental age was the risk factor for GDM. Blood group A was the most frequently observed type among mothers with macrosomic infants, however, blood group O was dominant in cases with GDM. In multivariate logistic regression analysis, the male infant was the most striking infant characteristic and GDM was the most striking maternal characteristic that were significantly associated with increased odds of macrosomic birth. Conclusions: This research reports the association between blood group system and macrosomia as well as parental age and GDM simultaneously. Our study reports a prevalence of GDM in both infants with normal birth weight and macrosomic newborns at the same time.