Candice Woolfolk

Weight Control Program and Gestational Weight Gain in Disadvantaged Women with Overweight or Obesity: A Randomized Clinical Trial

This study aimed to evaluate the efficacy of a home‐based lifestyle intervention delivered through Parents as Teachers (PAT) to reduce excessive gestational weight gain (GWG).

New Labor Management Guidelines and Changes in Cesarean Delivery Patterns

Background In 2010 the Consortium on Safe Labor published labor curves. It was proposed that the rate of cesarean delivery could be lowered by avoiding the diagnosis of arrest of dilation before 6 cm. However, there is little information on the uptake of the guidelines and on changes in cesarean delivery rates that may have occurred. Objective The objective of the study was to test the following hypotheses: (1) among patients laboring at term, rates of arrest of dilation disorders have decreased, leading to a decrease in the rate of cesarean delivery; (2) in the second stage, pushing duration prior to diagnosis of arrest of descent has increased, also leading to a reduction in the rate of cesarean delivery for this indication. As a secondary aim, we investigated changes in maternal and neonatal morbidity. Study Design This was a secondary analysis of a prospective cohort study of all patients presenting at ≥37 weeks’ gestation from 2010 through 2014 with a nonanomalous vertex singleton and no prior history of cesarean delivery. Rates of cesarean delivery, arrest of dilation, and changes in rates of maternal and neonatal morbidity were calculated in crude and adjusted models. Cervical dilation at diagnosis of the arrest of dilation, time spent at the maximal dilation prior to diagnosis of arrest of dilation, and time in the second stage prior to the diagnosis of arrest of descent were compared over the study period. Results There were 7845 eligible patients. The cesarean delivery rate in 2010 was 15.8% and, in 2014, 17.7% (P trend = .51). In patients undergoing cesarean delivery for the arrest of dilation, the median cervical dilation at the time of cesarean delivery was at 5.5 cm in 2010 and 6.0 cm in 2014 (P trend = .94). In these patients, there was an increase in the time spent at last dilation: 3.8 hours in 2010 to 5.2 hours in 2014 (P trend = .02). There was no change in the frequency of patients diagnosed with the arrest of dilation at <6 cm: 51.4% in 2010 and 48.6% in 2014 (P trend = .56). However, in these patients, the median time spent at the last cervical dilation was 4.0 hours in 2010 and 6.7 hours in 2014 (P trend = .046). There were 206 cesarean deliveries for the arrest of descent. The median pushing time in these patients increased in multiparous patients from 1.1 hours in 2010 to 3.4 hours in 2014 (P trend = .009); in nulliparous patients these times were 2.7 hours in 2010 and 3.8 hours in 2014 (P trend = .09). There was a significant trend toward increasing adverse neonatal and maternal outcomes (P < .001 for each). The adjusted odds ratio for adverse maternal outcome for 2014 compared with 2010 was 1.66 (95% confidence interval, 1.27–2.17); however, considering only transfusion, hemorrhage, or infection, there was no difference (P trend = .96). The adjusted odds ratio of adverse neonatal outcome in 2014 compared with 2010 was 1.80 (95% confidence interval, 1.36–2.36). Conclusion Despite significant changes in labor management that have occurred over the initial years since publication of the new labor curves and associated guidelines, the primary cesarean delivery rate was not reduced and there has been an increase in maternal and neonatal morbidity in our institution. A randomized controlled trial is needed.

Effect of Oxygen vs Room Air on Intrauterine Fetal Resuscitation: A Randomized Noninferiority Clinical Trial

Importance Two-thirds of women in labor receive supplemental oxygen to reverse perceived fetal hypoxemia and prevent acidemia. Oxygen is routinely administered for category II fetal heart tracings, a class of fetal tracing used to designate intermediate risk for acidemia. This liberal use of oxygen may not be beneficial, particularly because neonatal hyperoxygenation is harmful. Objective To test the hypothesis that room air is noninferior to oxygen in improving fetal metabolic status among patients with category II fetal heart tracings. Design, Setting, and Participants This was a randomized, unblinded noninferiority clinical trial conducted between June 2016 and July 2017 in the labor and delivery ward of a single tertiary care center. Women with singleton pregnancies at 37 weeks’ gestational age or more who were admitted for delivery were eligible. Of those who met inclusion criteria, the patients who developed category II tracings in labor that necessitated intrauterine resuscitation were randomized in a 1:1 ratio to room air or oxygen. Analyses were intention-to-treat. Interventions The oxygen group received 10 L of oxygen per minute by nonrebreather facemask until delivery. The room air group was exposed to room air only without a facemask. Main Outcomes and Measures The primary outcome was umbilical artery lactate, a marker of metabolic acidosis and neonatal morbidity. Noninferiority was defined as a mean difference between groups of less than 9.0 mg/dL (1.0 mmol/L). Secondary outcomes were other umbilical artery gases, cesarean delivery for nonreassuring fetal status, and operative vaginal delivery. Results Of the 705 patients who met inclusion criteria, 277 (39.3%) were enrolled on admission. During labor, 114 patients (41.2% of the enrolled patients) developed category II tracings and were randomized to room air (57 patients; 50.0% of the randomized patients) or oxygen (57 patients; 50.0% of the randomized patients). A total of 99 patients (86.8% of the randomized patients) with paired cord gases were included in the modified intention-to-treat analysis. The 99 patients included 76 African American women (77%); mean (SD) age was 27.3 (6.3) years in the oxygen group and 27.8 (5.3) years in the room air group. There was no difference in umbilical artery lactate between the group on oxygen and the group on room air (mean, 30.6 mg/dL [95% CI, 27.0 to 34.2 mg/dL] vs 31.5 mg/dL [95% CI, 27.9 to 36.0 mg/dL]); P = .69). The mean difference in lactate was 0.9 mg/dL (95% CI, −4.5 to 6.3 mg/dL), which was within the noninferiority margin. There was no difference in other umbilical artery gas components or mode of delivery between groups. Conclusions and Relevance Among patients with category II fetal heart tracings, intrauterine resuscitation with room air is noninferior to oxygen in improving umbilical artery lactate. The results of this trial challenge the efficacy of a ubiquitous obstetric practice and suggest that room air may be an acceptable alternative. Trial Registration ClinicalTrials.gov Identifier: NCT02741284

Effect of Immediate vs Delayed Pushing on Rates of Spontaneous Vaginal Delivery Among Nulliparous Women Receiving Neuraxial Analgesia: A Randomized Clinical Trial

Importance It is unclear whether the timing of second stage pushing efforts affects spontaneous vaginal delivery rates and reduces morbidities. Objective To evaluate whether immediate or delayed pushing results in higher rates of spontaneous vaginal delivery and lower rates of maternal and neonatal morbidities. Design, Setting, and Participants Pragmatic randomized clinical trial of nulliparous women at or beyond 37 weeks’ gestation admitted for spontaneous or induced labor with neuraxial analgesia between May 2014 and December 2017 at 6 US medical centers. The interim analysis suggested futility for the primary outcome and recruitment was terminated with 2414 of 3184 planned participants. Follow-up ended January 4, 2018. Interventions Randomization occurred when participants reached complete cervical dilation. Immediate group participants (n = 1200) began pushing immediately. Delayed group participants (n = 1204) were instructed to wait 60 minutes. Main Outcomes and Measures The primary outcome was spontaneous vaginal delivery. Secondary outcomes included total duration of the second stage, duration of active pushing, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, chorioamnionitis, endometritis, perineal lacerations (≥second degree), and a composite outcome of neonatal morbidity that included neonatal death and 9 other adverse outcomes. Results Among 2414 women randomized (mean age, 26.5 years), 2404 (99.6%) completed the trial. The rate of spontaneous vaginal delivery was 85.9% in the immediate group vs 86.5% in the delayed group, and was not significantly different (absolute difference, −0.6% [95% CI, −3.4% to 2.1%]; relative risk, 0.99 [95% CI, 0.96 to 1.03]). There was no significant difference in 5 of the 9 prespecified secondary outcomes reported, including the composite outcome of neonatal morbidity (7.3% for the immediate group vs 8.9% for the delayed group; between-group difference, −1.6% [95% CI, −3.8% to 0.5%]) and perineal lacerations (45.9% vs 46.4%, respectively; between-group difference, −0.4% [95% CI, −4.4% to 3.6%]). The immediate group had significantly shorter mean duration of the second stage compared with the delayed group (102.4 vs 134.2 minutes, respectively; mean difference, −31.8 minutes [95% CI, −36.7 to −26.9], P < .001), despite a significantly longer mean duration of active pushing (83.7 vs 74.5 minutes; mean difference, 9.2 minutes [95% CI, 5.8 to 12.6], P < .001), lower rates of chorioamnionitis (6.7% vs 9.1%; between-group difference, −2.5% [95% CI, −4.6% to −0.3%], P = .005), and fewer postpartum hemorrhages (2.3% vs 4.0%; between-group difference, −1.7% [95% CI, −3.1% to −0.4%], P = .03). Conclusions and Relevance Among nulliparous women receiving neuraxial anesthesia, the timing of second stage pushing efforts did not affect the rate of spontaneous vaginal delivery. These findings may help inform decisions about the preferred timing of second stage pushing efforts, when considered with other maternal and neonatal outcomes. Trial Registration ClinicalTrials.gov Identifier: NCT02137200

Spontaneous Labor Onset and Outcomes in Obese Women at Term.

Objective The objective of this study was to compare the rates of spontaneous labor onset and its progression in obese and nonobese women after 37 weeks. Study Design We performed a secondary analysis of a retrospective cohort of all women who were admitted for delivery at ≥ 37 weeks of gestation at a university‐based tertiary care center between 2004 and 2010. The cohort was stratified by weeks of gestation at which the patient presented for delivery. The rates of spontaneous labor, vaginal delivery, and augmentation with oxytocin were compared between obese (body mass index [BMI] ≥ 30) and nonobese (BMI < 30) women. Results Obese women had lower rates of spontaneous labor than nonobese women at every gestational week (37 weeks, 6.1 vs. 9.3%, p < 0.001; 38 weeks, 12.8 vs. 19.2%, p < 0.001; 39 weeks 26.0 vs. 37.0%, p < 0.001; 40 weeks, 39.6 vs. 50.2%, p < 0.001; 41 weeks, 30.8 vs. 38.0%, p < 0.012). Among women who presented in spontaneous labor, obesity was associated with higher rates of augmentation with oxytocin and lower rates of vaginal delivery. Conclusion Obese women at or beyond 37 weeks are less likely to experience spontaneous labor compared with nonobese women. In addition, obese women presenting in spontaneous labor are less likely that nonobese women to have a vaginal delivery at 37 to 40 weeks, even after oxytocin augmentation.

Normal Cervical Effacement in Term Labor

Objective To estimate the natural history of cervical effacement in labor. Study Design This is a retrospective cohort study of term, vertex, singletons who reached 10 cm of cervical dilation from 2010 to 2014. Interval‐censored regression was used to estimate the median number of hours between changes in effacement (measured in centimeters of the residual cervix) and to estimate the median effacement at a given cervical dilation. Analysis was stratified by parity and labor type. Results In total, 7,319 patients were included. Multiparas had faster effacement from 1 cm to complete effacement than nulliparas, but nulliparas were significantly more effaced at each cervical dilation. Patients in spontaneous labor had faster effacement and were significantly more effaced at each centimeter of cervical dilation than those who were induced or augmented. Once active labor was established (>6 cm of cervical dilation), 95% of patients had an effacement of 1 cm or less. By 8 cm of cervical dilation, 50% of all patients were completely effaced. Conclusion There is a wide range in the normal length of time for the progression of cervical effacement. However, once a patient is in active labor, 95% of patients have effaced to 1 cm or less.

A Prediction Model for Severe Maternal Morbidity in Laboring Patients at Term

Objective To determine the factors associated with severe maternal morbidity in a modern cohort of women laboring at term and to create a prediction model. Study Design This is a retrospective cohort study of all term, laboring patients with live births at a single tertiary care center from 2004 to 2014. The primary outcome was composite maternal morbidity including organ failure, amniotic fluid embolism, anesthesia complications, sepsis, shock, thrombotic events, transfusion, or hysterectomy. Multivariable logistic regression was used to identify independent risk factors. Antepartum, intrapartum, and combined risk scores were created and test characteristics were analyzed. Results Among 19,249 women delivering during the study period, 323 (1.68%) patients experienced severe morbidity, with blood transfusion the most common complication (286, 1.49%). Factors in the antepartum model included advanced maternal age, race, hypertension, nulliparity, history of cesarean delivery, smoking, and unfavorable Bishop score. Intrapartum factors included mode of delivery, use of cervical ripening agents or oxytocin, prolonged second stage, and macrosomia. The combined model had an area under the curve of 0.76 (95% confidence interval [CI], 0.73, 0.79). Conclusion This three‐part risk scoring system can help clinicians counsel patients and guide clinical decision making for anticipating severe maternal morbidity and necessary resources.

Epidurals and the Modern Labor Curve: How Epidural Timing Impacts Fetal Station during Active Labor

Objective The objective of this study was to estimate epidural timings impact on fetal station during active labor. Study Design This secondary analysis of a single‐institution prospective cohort study included all term singleton pregnancies, stratified by parity. Those with early epidurals (placed at <6 cm) were compared with those with late epidurals (placed at ≥6 cm). The primary outcome was median fetal station from 6 to 10 cm. Secondary outcomes included rate of prolonged first or second stage of labor (>95%). Multivariable logistic regression adjusted for labor type. Results Among 7,647 women, 3,434 were nulliparous (2,983 with early epidurals and 451 with late epidurals) and 4,213 multiparous (3,141 with early epidurals and 1,072 with late epidurals). Interquartile ranges (IQRs) suggested fetal station at 6 cm was likely lower among those with early epidurals (nulliparous: median head station −1 [IQR: −1 to 0] for early epidural vs. −1 [IQR: −2 to 0] for late epidural, p < 0.01; multiparous: −1 (IQR: −2 to 0] for early epidural vs. −1 [IQR: −3 to −1] for late epidural, p < 0.01). Early epidurals were not associated with increased risk of prolonged first stage, but among nulliparous were associated with decreased risk of prolonged second stage (adjusted odds ratio: 0.66 [95% confidence interval: 0.44–0.99]). Conclusion Early epidurals were associated with lower fetal station in active labor but not prolonged first stage.