Obstetric and neonatal characteristics of pregnancy and delivery for infant birthweight ≥5.0 kg

Aim: Infant birthweight >5.0 kg represents a significant risk factor for mother and neonate. The objective of this study was to examine the obstetric and neonatal outcome measures in a large cohort of such deliveries. Methods: The data used for this study were prospectively entered into an obstetric computerized database during the period 1989-2013. All pregnancies where the delivery resulted in an infant weighing >= 5.0 kg were identified. The results were retrospectively analyzed separately for parity, and a separate analysis was performed comparing the outcome measures observed in the earlier years of the study with those of the later years. Results: There were 73,796 deliveries in the time period of which there were n = 201 (0.3%) infants with birth weight >= 5.0 kg. The mean maternal body mass index (BMI) was in the obese category range (30.9 kg/m(2)) and the median gestation at delivery was 40.8 weeks. The cesarean delivery rate for nulliparous women was 56.3% and for parous women 30.8%. The overall rate of third degree perineal tears was 3.8%, the rate of shoulder dystocia was 4.6% and the rate of Erb's Palsy was 1.5%. There was a significant increase in cesarean delivery in the latter of the study (26.7% versus 43.0%, p = 0.02), due to an increase in the planned pre-labor cesarean deliveries (30.0 versus 12.9%, p = 0.005). There was no difference in adverse outcomes in both groups. Conclusion: These findings describe the features of pregnancy associated with infant birthweight >= 5.0 kg, and outline reliable maternal and neonatal morbidity data for these pregnancies. In this cohort, there was no apparent benefit from increased planned pre-labor cesarean delivery rates.