Is there an obstetric July phenomenon?

OBJECTIVE

To estimate whether variations in intrapartum management and complications exist with regard to the time of delivery within the academic year.

METHODS

The delivery records of 7814 patients were separated by both term half year and quarter. Statistical comparisons were made using chi2 tests of association (P < .05) with respect to the academic time of the year and perineal trauma (third- or fourth-degree tear), episiotomy usage, cesarean delivery, postpartum hemorrhage, chorioamnionitis, shoulder dystocia, neonatal intensive care unit admission, 1- or 5-minute Apgar scores less than 7, and low umbilical cord pH.

RESULTS

There were 4082 deliveries in the first half and 3732 in the second half of the year from April 1996 through March 1999. The first half-year overall cesarean rate was higher (15.8% versus 14.3%, P < .03). Primary cesarean rates were similar. No other differences were found by term half year. More perineal trauma was noted in the fourth quarter (first 3.3%, second 4.5%, third 3.7%, fourth 5.5%, P < .037). Episiotomy usage was higher in both the first and fourth quarters (13.0%, 11.3%, 10.6%, and 14.8%, P < .002). More cases of chorioamnionitis occurred in the fourth quarter (first 3.4%, second 3.1%, third 2.6%, fourth 4.0%, P < .038, third versus fourth quarter). Chorioamnionitis occurred more frequently in July (July 5.0% versus August-June 3.1%, P < .005). There were no other clinically significant differences. Neonatal outcomes were not affected by academic time of year.

CONCLUSION

Although small differences in outcome exist with respect to the academic time of the year, the timing of these differences indicates that there is not a "July phenomenon" in obstetrics at our institution.