Objective To test the hypothesis that umbilical cord arterial lactate is superior to pH for predicting short-term neonatal morbidity at term. Methods We conducted a prospective cohort study of all consecutive, nonanomalous, singleton, vertex, term births from 2009 to 2012 at Washington University Medical Center. Umbilical arterial lactate and pH were measured immediately after delivery, prior to knowledge of neonatal outcomes. The primary outcome was a composite neonatal morbidity consisting of neonatal death, intubation, mechanical ventilation, meconium aspiration syndrome, hypoxic encephalopathy, and need for hypothermic therapy. The predictive ability of lactate and pH were compared using receiver-operating characteristics curves. Optimal cut-off values of lactate and pH were estimated based on the maximal Youden index. Results Of 4,997 term deliveries during the study period, 4,910 met inclusion criteria. The composite neonatal morbidity occurred in 56 neonates (1.1%). The mean lactate level was nearly two-fold higher in neonates with the composite morbidity (6.49 vs 3.26 mmol/L, p<0.001), while mean pH values were less distinct (7.19 vs 7.29, p<0.001). Lactate was significantly more predictive of neonatal morbidity than pH (ROC curve area: 0.84 vs 0.78, p=0.03). The optimal cut-off value for prediciting neonatal morbidity was 3.90 mmol/L for lactate and 7.25 for pH. Corresponding sensitivities and specificities were also higher for lactate (83.9% and 74.1% vs 75.0% and 70.6%, respectively). Conclusion Results of this large prospective cohort study show that umbilical cord arterial lactate is a more discriminating measure of neonatal morbidity at term than pH.

Objective-To test the hypothesis that umbilical cord arterial lactate is superior to pH for predicting short-term neonatal morbidity at term. Methods-We conducted a prospective cohort study of all consecutive, nonanomalous, singleton, vertex, term births from 2009 to 2012 at Washington University Medical Center. Umbilical arterial lactate and pH were measured immediately after delivery, prior to knowledge of neonatal outcomes. The primary outcome was a composite neonatal morbidity consisting of neonatal death, intubation, mechanical ventilation, meconium aspiration syndrome, hypoxic encephalopathy, and need for hypothermic therapy. The predictive ability of lactate and pH were compared using receiver-operating characteristics curves. Optimal cutoff values of lactate and pH were estimated based on the maximal Youden index. Results-Of 4,997 term deliveries during the study period, 4,910 met inclusion criteria. The composite neonatal morbidity occurred in 56 neonates (1.1%). The mean lactate level was nearly twofold higher in neonates with the composite morbidity (6.49 vs 3.26 mmol/L, p<0.001), while mean pH values were less distinct (7.19 vs 7.29, p<0.001). Lactate was significantly more predictive of neonatal morbidity than pH (ROC curve area: 0.84 vs 0.78, p=0.03). The optimal cutoff value for prediciting neonatal morbidity was 3.90 mmol/L for lactate and 7.25 for pH. Corresponding sensitivities and specificities were also higher for lactate (83.9% and 74.1% vs 75.0% and 70.6%, respectively). Conclusion-Results of this large prospective cohort study show that umbilical cord arterial lactate is a more discriminating measure of neonatal morbidity at term than pH.

IMPORTANCE Obesity increases the risk of both cesarean delivery and surgical-site infection. Despite widespread use, it is unclear whether prophylactic negative pressure wound therapy reduces surgical-site infection after cesarean delivery in obese women.OBJECTIVE To evaluate whether prophylactic negative pressure wound therapy, initiated immediately after cesarean delivery, lowers the risk of surgical-site infections compared with standard wound dressing in obese women. DESIGN, SETTING, AND PARTICIPANTSMulticenter randomized trial conducted from February 8, 2017, through November 13, 2019, at 4 academic and 2 community hospitals across the United States. Obese women undergoing planned or unplanned cesarean delivery were eligible. The study was terminated after 1624 of 2850 participants were recruited when a planned interim analysis showed increased adverse events in the negative pressure group and futility for the primary outcome. Final follow-up was December 18, 2019.INTERVENTIONS Participants were randomly assigned to either undergo prophylactic negative pressure wound therapy, with application of the negative pressure device immediately after repair of the surgical incision (n = 816), or receive standard wound dressing (n = 808). MAIN OUTCOMES AND MEASURESThe primary outcome was superficial or deep surgical-site infection according to the Centers for Disease Control and Prevention definitions. Secondary outcomes included other wound complications, composite of surgical-site infections and other wound complications, and adverse skin reactions. RESULTSOf the 1624 women randomized (mean age, 30.4 years, mean body mass index, 39.5), 1608 (99%) completed the study: 806 in the negative pressure group (median duration of negative pressure, 4 days) and 802 in the standard dressing group. Superficial or deep surgical-site infection was diagnosed in 29 participants (3.6%) in the negative pressure group and 27 (3.4%) in the standard dressing group (difference, 0.36%; 95% CI, −1.46% to 2.19%, P = .70). Of 30 prespecified secondary end points, 25 showed no significant differences, including other wound complications (2.6% vs 3.1%; difference, −0.53%; 95% CI, −1.93% to 0.88%; P = .46) and composite of surgical-site infections and other wound complications (6.5% vs 6.7%; difference, −0.27%; 95% CI, −2.71% to 2.25%; P = .83). Adverse skin reactions were significantly more frequent in the negative pressure group (7.0% vs 0.6%; difference, 6.95%; 95% CI, 1.86% to 12.03%; P < .001).CONCLUSIONS AND RELEVANCE Among obese women undergoing cesarean delivery, prophylactic negative pressure wound therapy, compared with standard wound dressing, did not significantly reduce the risk of surgical-site infection. These findings do not support routine use of prophylactic negative pressure wound therapy in obese women after cesarean delivery.

(Abstracted from JAMA 2020;324:1180–1189) Surgical-site infection is a significant cause of morbidity, lengthening hospital stays and contributing to health care costs. Cesarean delivery increases the risk of surgical site infection, and obesity contributes to this risk because obese pregnant women are more likely to have cesarean deliveries.