Brian Pierce

Observations on labor epidural analgesia and operative delivery rates

OBJECTIVE Our purpose was to compare operative vaginal and abdominal delivery rates in a large population before and after on-demand labor epidural analgesia became available. STUDY DESIGN We retrospectively compared patients who gave birth during a 20-month period immediately before the introduction of an on-demand labor epidural analgesia service with those who gave birth during a 20-month period after the epidural usage rate had reached a plateau at approximately 60%. Operative vaginal and cesarean delivery rates were stratified according to parity and history of prior cesarean delivery. RESULTS A total of 4859 women gave birth during the study period when on-demand epidural analgesia was available, and 4778 women gave birth in the study period before the availability of on-demand epidural analgesia. Comparisons between the women with and those without on-demand availability of epidural analgesia demonstrated no statistically significant differences in the rate of spontaneous vaginal delivery (69.5% vs 68.3%), the overall cesarean delivery rate (19.0% vs 19.4%), the primary cesarean delivery rate (13.2% vs 13.4%), or the operative vaginal delivery rate (11.1% vs 11.9%) between the 2 periods. There were no statistically significant differences in mean gestational age at the time of delivery between the 2 groups, whereas there were statistically significant increases in the proportion of nulliparous women and in mean birth weight during the on-demand epidural period. Analysis after substratification of the study groups according to parity also revealed no statistically significant differences in the primary cesarean delivery rate or the proportion of women undergoing vaginal delivery. The sample size was adequate to exclude a 2% increase in the primary cesarean delivery rate between the 2 periods with 80% power. Subgroup analysis of the population of women who gave birth while epidural analgesia was available on request demonstrated that nulliparous parturient women who requested epidural analgesia were almost twice as likely to require operative vaginal or cesarean delivery as women who did not request epidural analgesia, a finding suggesting that women who request labor epidural analgesia have an inherent propensity toward operative delivery. CONCLUSION The introduction of an on-demand labor epidural analgesia service does not increase the rate of cesarean delivery or operative vaginal delivery.

Relationship Between the Extent of Histologic Villous Mineralization and Stillbirth in Aneuploid and Euploid Fetuses

Objective: To describe the relationship between the degree of placental histologic villous mineralization (VM) and stillbirth in anueploid and euploid fetuses. Methods: The extent of VM for aneuploid and gestational age-matched euploid placentas was graded semiquantitatively on a 0 to 3 scale based on the number of terminal or stem villi containing mineralizations in forty × 10 fields of view. The extent of VM was analyzed in relation to fetal status at delivery (liveborn or stillborn) for both aneuploid and euploid fetuses. Results: For 14 available aneuploid placentas, grade 0 or 1 VM was recorded for seven aneuploid specimens, of which two were stillborn. Grade 2 or 3 VM was recorded for seven aneuploid specimens, of which six were stillborn. Fourteen gestational age-matched euploid placentas served as controls. Grade 0 or 1 VM was observed in nine euploid specimens, of which four were stillborn. Grade 2 or 3 VM was observed in five euploid specimens, of which four were stillborn. For aneuploid fetuses, stillbirth was significantly more frequent with grade 2 or 3 VM compared with grade 0 or 1 VM (χ2 = 4.667, P < .05). This relationship did not exist for euploid fetuses (χ2 = 1.659, P > .05). Conclusion: Histologic VM is not a universal finding in, or exclusive to, stillbirths. Aneuploid but not euploid stillbirths show increased histologic VM compared with livebirths. This may implicate impaired placental or circulatory function as a mechanism for death in aneuploid fetuses.