Labor Intervention and Outcomes in Women Who Are Nulliparous and Obese: Comparison of Nurse‐Midwife to Obstetrician Intrapartum Care

Abstract

Background Women who are obese have slower labors than women of normal weight, and show reduced response to interventions designed to speed labor progress like oxytocin augmentation and artificial rupture of membranes. The optimal labor management for these women has not been described. Methods This retrospective cohort study compared 2 propensity score-matched groups of women (N = 360) who were healthy, nulliparous, spontaneously laboring, and obese (body mass index 30 kg/m2). Labors were managed by either a certified nurse-midwife (CNM) or an obstetrician at one hospital from 2005 through 2012. Comparisons were made on a range of labor processes and outcomes. Results Women who were obese and cared for in labor by CNMs were 87.0% less likely to have operative vaginal birth (adjusted odds ratio [aOR], 0.15; 95% confidence interval [CI], 0.06–0.41) and 76.3% less likely to have third- or fourth-degree perineal lacerations (aOR, 0.31; 95% CI, 0.13–0.79) compared to a matched group of women who were obese and had similarly sized neonates but who were cared for by obstetricians. The rates of unplanned cesarean birth, postpartum hemorrhage, maternal intrapartum fever, and neonatal intensive care unit admission were similar between groups. CNM patients were significantly less likely than patients of obstetricians to have labor anesthesia, synthetic oxytocin augmentation, or intrauterine pressure catheters. By contrast, CNM patients were significantly more likely than patients of obstetricians to use physiologic labor interventions, including intermittent fetal monitoring, ambulation, and hydrotherapy. Discussion In women with spontaneous labor onset who were healthy, obese, and nulliparous, watchful waiting and use of physiologic labor interventions, characterizing CNM intrapartum care, were associated with outcomes that were similar to, or better than, those of women who were obese and exposed to more high-technology interventions characterizing intrapartum care by obstetricians. In women who were obese, physiologic labor interventions were safe for both mothers and neonates.

Influence of midwifery presence in United States centers on labor care and outcomes of low‐risk parous women: A Consortium on Safe Labor study

“…2,3 Evidence suggests that the hospital in which an otherwise healthy woman gives birth is a factor independently affecting maternal and neonatal outcomes. 6 Whereas research suggests that the presence of midwives within a hospital system improves patient care outcomes, previous analyses have focused on a single site 7,8 or a single state. 6 Whereas research suggests that the presence of midwives within a hospital system improves patient care outcomes, previous analyses have focused on a single site 7,8 or a single state.…”

Preventing Cesarean Birth in Women with Obesity: Influence of Unit‐Level Midwifery Presence on Use of Cesarean among Women in the Consortium on Safe Labor Data Set

“…Despite evidence that obesity has a profound influence on labor, few research teams have examined whether and to what extent the intrapartum caregiving environment might be optimized to reduce poor birth outcomes for these women. In a previous analysis by members of our team, decreased use of oxytocin augmentation among nulliparous women with obesity and spontaneous labor was associated with intrapartum care by a midwife compared with obstetrician‐led care in matched comparison groups . In a related investigation conducted at the same institution, midwife‐led intrapartum care was associated with a decrease in cesarean birth in low‐risk nulliparous women compared with obstetrician‐led care, even after adjusting for the influence of maternal obesity .…”

“…In a previous analysis by members of our team, decreased use of oxytocin augmentation among nulliparous women with obesity and spontaneous labor was associated with intrapartum care by a midwife compared with obstetrician-led care in matched comparison groups. 30 In a related investigation conducted at the same institution, midwife-led intrapartum care was associated with a decrease in cesarean birth in low-risk nulliparous women compared with obstetrician-led care, even after adjusting for the influence of maternal obesity. 49 In 2 studies that used data from the CSL, conducted by members of this team, decreases in cesarean birth in both nulliparous 32 and parous 33 women were shown in units with midwifery presence.…”

“…[24][25][26][27][28][29] However, few previous studies have examined the influence of midwifery care on birth outcomes among women with higher risks of complications, such as women with obesity. 30,31 Previous analysis by this research group using the Consortium on Safe Labor (CSL) data set showed an association between the hospital unit-level presence of midwives and fewer labor interventions and cesarean births in both nulliparous 32 and multiparous women. 33 However, it is unknown if CSL institutions with intrapartum care provider teams that include midwives had similar benefits for pregnant women who were at higher risk of cesarean because of obesity.…”

Assessing the Value of the ARRIVE Trial for Clinical Practice: Sea Change or Just a Splash?

“…New and advanced statistical techniques estimate relationships among events and outcomes with greater precision . This Journal has featured some of these techniques in previous issues, including Carlson et al's use of propensity‐score matching and Bovbjerg et al's study using Cox proportional‐hazards models . In this issue, Ellen Tilden, CNM, PhD, and Jon Snowden, PhD, explain some new statistical approaches to study maternity care in a 3‐part series .…”