///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

Scheduled cesarean deliveries at ≥39 weeks compared to ≥37 weeks does not significantly impact obstetric and anesthetic workflow

Abstract Number: S-56
Abstract Type: Original Research

Yuri Cho M.D.1 ; Brendan Carvalho M.D.2; Alex Butwick M.D. 3; Yair Blumenfeld M.D.4; Edward Riley M.D.5


Delivery of infants before 39 weeks gestation increases the risk of adverse neonatal outcomes, including increased mechanical ventilation, newborn sepsis, hypoglycemia and admission to NICU. [1] Current guidelines now recommend a minimum gestational age of 39 weeks for elective cesarean deliveries (CD). However, scheduling CDs at ≥39 weeks gestation (compared to ≥37 weeks) may increase unscheduled and after-hours CDs, requiring delivery prior to their scheduled CD. [2] The aim of this study was to determine the impact of waiting until 39 weeks gestation on the timing of CDs.


After IRB approval, we conducted a retrospective, single center study of all women who underwent a CD between January 2010 and September 2013. On April 1, 2011, an institutional policy was implemented to eliminate non-medically indicated deliveries before 39 weeks gestation. The timing of CDs before (01/01/2010 to 03/30/2011) and after (06/01/2011 to 09/30/2013) the policy change was determined; April and May 2011 were omitted to account for an adjustment period. Data were extracted from an institutional database. Extracted data included date and time of admission and type of delivery. Shifts were divided into daytime shifts (7am-5pm) and nighttime shifts (5pm-7am) in accordance with our institution’s current anesthesia shift times.


On average 4214 deliveries per year occurred at our hospital during the study period. The overall CD rate changed slightly between the two study periods (41.5% vs. 39.4%; before vs. after the policy change; P=0.012). Figure 1 shows the average percentage of CDs that occurred each hour before and after the policy change. There was a very slight increase in the percentage of CDs performed in the daytime shifts (55.4% before and 58.7% after the change; P = 0.014). There was also a small increase in the CD percentage occurring during the weekend shifts (17.6% vs. 21.6% before vs. after the change, P=0.002).


Our analysis suggests that scheduling CDs at ≥39 weeks compared to ≥37 weeks does not impact the temporal pattern of CDs. The most significant change was an increase in CDs during the weekend shifts. This change amounted to one more CD during the weekend shift on average, which does not impact the workflow enough to warrant a change in staffing patterns.


1. Tita ATN, et al. N Engl J Med 2009;360:111-20

2. Suzuki S. Int J Gynaecol Obstet 2012;116:177-8

SOAP 2014