Baby weight more 9th mth. To baby?

Dear Sir, Thank you for your question regarding increased baby weight. The growth of the fetus in terms of anthropometry and biometric is usually measured by ultrasound done in the third trimester. Maximum increase in the baby weight occurs in the last 3 months.The weight of baby in kilograms is then plotted in terms of percentile in a standardized growth chart to give an indication of predicted Macrosomia ( Large for gestational age) baby. This weight measurement is accurate to within 16+/- percent. Definitions of Macrosomia differ in different ethnic subgroups but a calculated percentile above 90 percent is defined as Macrosomia. Sir, it is important for me to know whether your wife has a history of diabetes / obesity/ previous baby with LGA / excessive weight gain in pregnancy and what is your wife's height as they have a bearing upon mode of delivery. For babies with weight more than 3.5 kg with maternal diabetes or more than 4 kg. most Obstetricians prefer an abdominal mode of delivery by cesarean section. This is because vaginal delivery in increased fetal body weight beyond a certain point is associated with poor maternal outcome ( difficult delivery, prolonged labour, shoulder dystocia,  obstructed labor, instrumental delivery,  perineal injuries and post partum bleeding)  and poor fetal outcome as a result of difficult vaginal delivery especially if mother has a gestational diabetes. The risk to the mother and fetus with vaginal delivery versus an elective cesarean section will be elucidated by your treating Obstetrician to make an informed choice regarding delivery method to prevent the possible complications. Best Regards, Aditi