Beta J, et al. - The risks of maternal and neonatal complications in pregnancies with macrosomia [birth weight (BW) > 4000 g] were determined via performing a retrospective cohort study at a large maternity unit in the UK between January 2009 and December 2016. The study population was comprised of 35,548 pregnancies; of these 4,522 (12.7%) were with macrosomia. Severe macrosomia was noted in 643 (1.8%) pregnancies and normal BW was reported for 31,026 (87.3%) pregnancies. Serious adverse perinatal outcomes—a cesarean section for failure to progress (adjusted OR 3.1), severe postpartum hemorrhage (adjusted OR 2.4), obstetric anal sphincter injury (adjusted OR 2.3), shoulder dystocia (adjusted OR 10.4), obstetric brachial plexus injury (adjusted OR 28.5), birth fractures(adjusted OR 32.3), hypoxic-ischemic encephalopathy (adjusted OR 4.4)—were observed in correlation to macrosomia. Accurate estimates of risks provided in this study may assist in pregnancy management.