To determine if adverse perinatal outcomes are impacted by variations in delivery volumes.METHODS:
From a 3-year observational cohort, including 101,120 pregnancies in 24 hospitals, we evaluated the number of deliveries each day for each hospital. Each day was assigned a percentile [%ile] rank according to the total range of daily deliveries for that hospital. Days with higher (76–90th %ile, above [GT] the 90th %ile) and lower (less than [LT] the 10th %ile, 10–24th %ile) volumes were compared with days having intermediate volumes (25–75th %ile) for associations with adverse perinatal outcomes: Postpartum hemorrhage [PPH], 5-minute Apgar below 4 [LoAp5], hypoxic ischemic encephalopathy [HIE], shoulder dystocia [SD], fetal trauma [FT], and cord pH below 7.0 [LopH]. Multivariable regression models adjusted for maternal age, obstetric history, smoking, diabetes, hypertension, anticoagulants, BMI, multiple gestation, pPROM, presentation, weekday, and delivery gestation. Scheduled cesareans, those delivering outside L&D, non-presenting newborns in multiple gestations, and neonatal deaths without resuscitation were excluded.RESULTS:
We found a wide range in daily delivery volumes (range 0–56). After controlling for other factors, no consistent pattern of more or less frequent morbidities was seen on higher or lower delivery volume days, presented as OR (95% CI) for LT10th %ile, 10–24th %ile, 76–90th %ile, GT90th %ile: PPH: 0.89 (0.70–1.1), 1.1 (0.90–1.2), 1.0 (0.89–1.1), 0.86 (0.74–0.99); LoAp5: 1.2 (0.69–2.1), 1.4 (0.95–1.9), 0.85 (0.62–1.2), 0.91 (0.64–1.3); HIE: 1.1 (0.79–1.6), 1.1 (0.86–1.4), 1.0 (0.84–1.2), 0.91 (0.73–1.1); SD: 0.88 (0.68–1.1), 1.1 (0.92–1.3), 1.2 (1.0–1.3), 1.1 (0.92–1.2); FT: 1.3 (0.84–2.1), 1.1 (0.77–1.5), 0.95 (0.72–1.3), 1.1 (0.84–1.5); LopH: 1.3 (0.79–2.0), 0.94 (0.65–1.3), 0.92 (0.70–1.2), 0.87 (0.64–1.2).CONCLUSION:
We found no consistent association between and higher or lower delivery volume days and adverse perinatal outcomes. These encouraging results suggest that these Units were able to accommodate surges in patient delivery volume.