July Effect in Obstetric Outcomes.

Objective: The July effect represents the month when interns begin residency and residents advance with increased responsibility. This has not been well studied in Obstetrics and Gynecology residencies and no study has been conducted evaluating obstetric outcomes. The purpose of this study was to evaluate the July effect on obstetric outcomes. Women who delivered between July and September (quarter 1) were compared to those delivering between April and June (quarter 4).

Methods: This retrospective cohort study compared outcomes of deliveries between quarter 1 and quarter 4 from 2017 to 2020. Outcomes evaluated were postpartum length of stay (LOS), postpartum readmission, wound complication, wound infection, blood transfusion, estimated blood loss, 3rd and 4th degree lacerations, 5 min APGAR scores, and cesarean delivery rates.

Results: There were 3693 deliveries in quarter 1 and 3107 deliveries in quarter 4. There was a higher incidence Of wound infection during the April-June period (N = 21; 0.68%) compared to July-September (N = 10; 0.27%; p = 0.0135). Although LOS for both periods were the same, the average postpartum LOS during July-September was slightly longer than April-June (1.7 days; SD = 1.1 vs 1.6 days; SD = 1.2; p = 0.0026). All other pregnancy outcomes were similar between the two groups.

Conclusion: Overall, the July effect is minimal on obstetric complications. However, LOS between July and September may differ because all residents are less experienced in quarter 1. Wound infection rates were higher in April-June, perhaps because new PGY-1s went from assisting to primary on cesarean surgeries starting in the 4th quarter of the year.