Evaluation of an Initiative to Decrease the Use of Oxygen Supplementation for Category II Fetal Heart Rate Tracings.

OBJECTIVE: To examine compliance with a guideline to reduce exposure to supplemental oxygen for category II fetal heart rate (FHR) tracings in normally oxygenated laboring patients. METHODS: All patients in labor in an urban academic medical center from January 1 to July 31, 2020 were assessed. The preintervention group included those who delivered from January 1 to March 19, 2020. On March 20, 2020, a new guideline took effect that recommended no maternal supplemental oxygen for category II FHR tracings. The postintervention group delivered from March 20 to July 31, 2020. Exclusion criteria were planned cesarean delivery, multiple gestations, delivery at less than 24 weeks of gestation, intrauterine fetal death, and patients who received supplemental oxygen for an oxygen saturation lower than 95%. The primary outcome was the percentage of patients who received oxygen in labor analyzed by control charts and the rules of special cause variation. Chi-squared and t tests were used for secondary outcome assessment. P<.05 was considered significant. RESULTS: A total of 1,333 patients were included, 474 patients in the preintervention group and 859 in the postintervention group. Oxygen was administered to 22.6% of patients before guideline implementation, compared with 0.6% after the guideline. Special cause variation was detected with an 8-point shift starting the month that the guideline was implemented, indicating statistical significance. There were no differences in any studied secondary maternal or fetal outcomes, although our statistical power to detect differences in infrequent outcomes was limited. CONCLUSION: This quality-improvement study demonstrated significant adherence to the guideline that supplemental oxygen would no longer be given to patients with category II FHR tracings in the absence of maternal hypoxemia, with no significant change in maternal or perinatal outcomes.

Blood type and postpartum hemorrhage by mode of delivery: A retrospective cohort study.

OBJECTIVE: To assess the relationship between postpartum hemorrhage and ABO blood type for vaginal delivery and cesarean delivery. STUDY DESIGN: This is a retrospective cohort study of data abstracted from the PeriBank database regarding demographics and delivery outcomes. All live singleton deliveries from January 2011 until March 2018 were included in this study. Exclusion criteria were sickle cell disease and multiple gestations. Analyses were conducted separately for cesarean delivery and vaginal delivery. Quantitative variables were analyzed with analysis of variance testing and categorical variables with chi square testing. Significant demographic differences between groups were controlled for using multivariate logistical regression. The primary outcome was the rate of postpartum hemorrhage by blood type (A, B, AB, and O), defined as blood loss >500 mL in vaginal delivery and >1000 mL in cesarean delivery. 43,437 patients were screened and 32,023 women met inclusion criteria (22,484 vaginal deliveries (70.2%) and 9539 cesarean deliveries (29.8%)). RESULTS: In the vaginal delivery group there were differences in age, parity, race, use of regional anesthesia, rate of induction of labor, and thrombocytopenia between blood types. In the cesarean delivery group, age, parity, and race were significantly different between blood types. There was no observed difference in the rate of postpartum hemorrhage by blood type for those who delivered via vaginal delivery when controlling for demographic differences (p = 0.2). In the cesarean delivery group, there was a significantly higher rate of postpartum hemorrhage in women with type O blood (5.2% type O vs 3.8% type A vs 4.4% type B vs 4.2% type AB, p = 0.035), including when controlling for demographic differences (p = 0.02). In both vaginal and cesarean delivery groups, there was no difference in rates of any of the secondary outcomes, including blood transfusion, hysterectomy, intrapartum dilation and curettage, and intensive care unit admission. CONCLUSION: Although this study found no statistically significant difference in clinical outcomes between blood types, type O blood may be an additional risk factor to consider for postpartum hemorrhage at the time of cesarean delivery.