Maternal body mass index and oxytocin exposure in nulliparous women: is there an interaction associated with maternal and neonatal morbidities?

OBJECTIVE: Increasing body mass index (BMI) and administered doses of oxytocin are related to maternal and neonatal morbidities. We evaluated the effect of oxytocin dosage, BMI, and their interaction on select perinatal outcomes. STUDY DESIGN: We retrospectively studied nulliparas with singletons ≥36 weeks' gestation who received oxytocin and reached the second stage of labor. Oxytocin dosage was defined by the oxytocin product ([maximum oxytocin dose] × [duration of oxytocin infusion]/100 (milliunits)). Outcomes included cesarean, postpartum hemorrhage, puerperal infection, and a composite of neonatal morbidities. Logistic regression produced odds ratios (OR) for BMI and oxytocin product. The final model included a BMI-oxytocin product interaction term. RESULTS: One thousand two hundred and four women met enrollment criteria. Increasing BMI was associated with longer duration from first exam to delivery and higher rates of cesarean. Oxytocin dosage increased linearly with BMI (p < .001). There were increasing odds of all four outcomes as both BMI and oxytocin dosage increased (except cesarean with oxytocin). However, there was no significant interaction between BMI and oxytocin for any outcome. CONCLUSIONS: BMI and oxytocin dosage are associated with select maternal and neonatal outcomes. However, the lack of interaction between BMI and oxytocin product suggests that the higher administered dose of oxytocin associated with increasing BMI does not synergistically potentiate maternal and neonatal morbidities.

Effect of mesh width on apical support after sacrocolpopexy.

INTRODUCTION AND HYPOTHESIS: We evaluated the effect of polypropylene mesh width on vaginal apical support, mesh elongation, and mesh tensile strength for abdominal sacrocolpopexy. METHODS: Abdominal sacrocolpopexy was performed on ten cadavers using pieces of polypropylene mesh of width 1, 2, and 3 cm. Weights of 1, 2, 3, and 4 kg were sequentially applied to the vagina. The total distance moved by the vaginal apex, and the amount of stretch of the intervening mesh segment between the sacrum and the vagina were recorded for each width. The failure strengths of additional single and double layer sets of each width were also tested using a tensiometer. Data were analyzed with analysis of variance using a random effects model. RESULTS: The mean (standard error of the mean) maximum distance moved by the vaginal apex was 4.63 cm (0.37 cm) for the 1 cm mesh compared to 3.67 cm (0.26 cm) and 2.73 cm (0.14 cm) for the 2 and 3 cm meshes, respectively (P < 0.0001). The 1 cm width ruptured during testing in four of the ten cadavers. The results were similar for mesh elongation, with the 1 cm mesh stretching the most and the 3 cm mesh stretching the least. Mesh failure loads for double-layer mesh were 52.9 N (2.5 N), 124.4 N (2.7 N), and 201.2 N (4.5 N) for the 1, 2, and 3 cm meshes, respectively, and were higher than the failure loads for single mesh (P < 0.001). CONCLUSIONS: In a cadaver model, increasing mesh width is associated with better vaginal apical support, less mesh elongation, and higher failure loads. Mesh widths of 2-3 cm provide sufficient repair strength for sacrocolpopexy.

Wound morbidity with staples compared with suture for cesarean skin closure by diabetic status.

OBJECTIVE: To determine if the risk of post-cesarean wound morbidity in patients undergoing staple versus suture closure is modified by diabetic status. METHODS: Secondary analysis of a randomized trial of skin closure with subcuticular 4-0 monocryl suture or surgical staples after cesarean delivery. The primary outcome was a composite of wound disruption or infection within 4-6 weeks. We compared the association between this outcome and skin closure method by diabetic status (also stratified by gestational or pregestational) using the Breslow-Day test for interaction. RESULTS: Of 350 patients, 179 were randomized to staples and 171 to suture. Of the 67 (19.1%) diabetic patients, 35 were gestational and 32 pregestational. The incidence of composite wound morbidity in non-diabetics was 16.7% for staples and 3.6% for suture (p ≤ 0.001, RR: 4.6, 95% CI: 1.8-11.8); it was 5.7% for staples and 15.6% for sutures in diabetics (p = 0.25, RR: 0.4, 95% CI: 0.1-1.7). The corresponding Breslow-Day p value indicated a significant difference between diabetics and non-diabetics (p = 0.002). Stratified further by gestational and pregestational diabetes, the RRs were 0.3 (95% CI: 0.03-2.4) and 0.5 (95% CI: 0.05-5.0) compared to non-diabetics, respectively. Each diabetic sub-group was significantly different from non-diabetics (Breslow-Day p values for homogeneity p = 0.005 and p = 0.045, respectively). CONCLUSIONS: The use of staples compared with subcuticular suture for cesarean skin closure is associated with increased wound morbidity. While this is true for non-diabetics, further studies of diabetics are needed to evaluate for a null or opposite effect of closure type.

Nulliparous Women in the Second Stage of Labor: Changes in Delivery Outcomes Between Two Cohorts From 2000 and 2011.

OBJECTIVE: To evaluate changes over the past decade in the mode of delivery and second-stage duration in nulliparous women. METHODS: We conducted a retrospective cohort study at a single institution of nulliparous women reaching complete cervical dilation with singleton gestations 36 weeks or greater from January 1, 2011, to December 31, 2012, and compared these with a prior cohort prospectively collected from July 28, 2000, to February 28, 2003. We excluded pregnancies with prenatally diagnosed fetal anomalies. The primary outcome was cesarean delivery. Secondary outcomes included second-stage duration, rates of operative vaginal delivery (forceps and vacuum collectively), and indications for cesarean delivery and operative vaginal delivery. RESULTS: There were 1,023 mother-neonate pairs in the prior cohort and 1,476 in the current cohort. In the prior and current cohorts, respectively, 2% compared with 6% underwent cesarean delivery, 21% compared with 10% underwent operative vaginal delivery, and 77% compared with 84% had spontaneous vaginal delivery (all P<.01). Compared with the prior cohort, the adjusted odds (OR) of cesarean delivery (compared with any vaginal birth) for current patients was 1.74 (95% confidence interval [CI] 1.04-2.91), and in a separate regression model, the adjusted OR of operative vaginal delivery (compared with spontaneous vaginal delivery or cesarean delivery) was 0.42 (95% CI 0.33-0.54). Median (25th, 75th percentile) second-stage duration significantly increased from 38 (20, 71) to 42 (22, 87) minutes (P<.01), but this difference was nullified after adjusting for confounders. CONCLUSION: Comparing cohorts from 2000 and 2011, although the second-stage duration has not changed appreciably, nulliparous women in the second stage of labor at our institution are twice as likely to undergo cesarean delivery and half as likely to undergo operative vaginal delivery. LEVEL OF EVIDENCE: II.

Effect of myogenic stem cells on the integrity and histomorphology of repaired transected external anal sphincter.

INTRODUCTION AND HYPOTHESIS: The objective was to evaluate the effect of myogenic stem cells on histological properties and the volume of striated muscle of the external anal sphincter after transection and repair. METHODS: Histological analysis was performed on the external anal sphincters of 40 young female rats euthanized at 7 or 90 days after transection and repair and randomization to injection of either phosphate buffered solution (PBS) or myogenic stem cells (SC) at the transection site. Sphincter complexes, previously evaluated for neurophysiological function, were processed for histology and analyzed for possible disruption, amount of inflammation, and volume of striated muscle. The relationship between the muscular disruption and contractile force of sphincters was evaluated. RESULTS: Disruption was seen in 100 % of sphincters 7 days after repair for both SC and control animals. Eighty-nine percent of controls and 78% of SC-administered animals had intact sphincters at 90 days. Significant inflammatory infiltrate was seen in repaired anal sphincters for both the PBS and the SC groups at 7 days, and persisted at 90 days, with no difference between treatment groups. Striated muscle volume increased from 7 to 90 days for both control and SC-administered animals. Although there was no difference in volume between treatments, there was substantial temporal improvement in contractile force generation of the sphincters receiving SC compared with those receiving PBS. CONCLUSION: In this animal model, administration of myogenic stem cells to transected/repaired anal sphincters did not alter the amount of inflammation nor the volume of striated muscle, suggesting that stem cells might improve contractile function through other cellular processes.

Prevention and management of cesarean wound infection.

Cesarean wound infections represent a significant health and economic burden. Several modifiable risk factors have been identified for their development. Understanding these risks and techniques to manage cesarean wounds is essential for providers. In this article, these factors and prophylactic and therapeutic interventions are reviewed.