Variations in cesarean delivery for fetal distress

Increases in cesarean section frequency may be dependent on institutional or individual practitioner characteristics. The purpose of this study was to examine whether the diagnosis of fetal distress was influenced by time of day or institutional factors.

Chart review was performed on a random sample of women stratified by month of delivery at each institution (N = 8647). All women who gave birth by elective cesarean section or whose labor was induced were excluded from analysis (n = 2207), leaving a total population of 6440 for study. Women were stratified based on risk status, and comparisons were made between the time of delivery, maternal socioeconomic factors, and obstetric variables for those who had a cesarean section for fetal distress compared with women who gave birth vaginally.

Large variations in rates of cesarean delivery for fetal distress were observed among the participating institutions (range 0.9% to 3.0% of all deliveries). Increased rates of cesarean delivery for fetal distress were observed in nonwhite women and those who had had a previous cesarean delivery. Also, a significant increase in rates of cesarean section for fetal distress was noted between the hours of 9:00 PM and 3:00 AM. When adjusted for risk status, previous cesarean delivery, race, use of pitocin augmentation, length of labor, and site, time of day was still a significant predictor (adjusted odds ratio = 1.56, 95% confidence interval 1.06 to 2.29) for cesarean delivery for fetal distress.

Cesarean delivery for the diagnosis of fetal distress appears to vary depending on institutional and other nonclinical factors. The observation that cesarean deliveries for fetal distress peak during nighttime hours raises the possibility that the interpretation of fetal monitor tracing is influenced by physician and patient fatigue or other clinical factors.