Intrapartum electronic fetal monitoring features associated with a clinical diagnosis of nonreassuring fetal status.

BACKGROUND: Nonreassuring fetal status detected by continuous electronic fetal monitoring accounts for almost 1 in 4 primary cesarean deliveries. However, given the subjective nature of the diagnosis, there is a need to identify the electronic fetal monitoring patterns that are clinically considered nonreassuring. OBJECTIVE: This study aimed to describe which electronic fetal monitoring features are most commonly associated with first-stage cesarean delivery for nonreassuring fetal status, and to evaluate the risk of neonatal acidemia following cesarean delivery for nonreassuring fetal status. STUDY DESIGN: This was a nested case-control study in a prospectively collected cohort of patients with singleton pregnancies at ≥37 weeks' gestation, admitted in spontaneous labor or for induction of labor from 2010 to 2014 at a single tertiary care center. Patients with preterm pregnancies, multiple gestations, planned cesarean delivery, or nonreassuring fetal status in the second stage of labor were excluded. Cases were identified as having nonreassuring fetal status on the basis of what was documented in the operative note by the delivering physician. Controls were patients without nonreassuring fetal status within 1 hour of delivery. Cases were matched to controls in a 1:2 ratio by parity, obesity, and history of cesarean delivery. Electronic fetal monitoring data were abstracted by credentialed obstetrical research nurses for the 60 minutes before delivery. The primary exposure of interest was the incidence of high-risk category II electronic fetal monitoring features in the 60 minutes before delivery; in particular, the incidence of minimal variability, recurrent late decelerations, recurrent variable decelerations, tachycardia, and >1 prolonged deceleration were compared between groups. We also compared neonatal outcomes between cases and controls, including fetal acidemia (umbilical artery pH <7.1), other umbilical artery gas analytes, and neonatal and maternal outcomes. RESULTS: Of the 8580 patients in the parent study, 714 (8.3%) underwent cesarean delivery for nonreassuring fetal status in the first stage of labor. Patients diagnosed with nonreassuring fetal status requiring cesarean delivery were more likely to have recurrent late decelerations, >1 prolonged deceleration, and recurrent variable decelerations compared with controls. More than 1 prolonged deceleration was associated with 6 times increased rate of nonreassuring fetal status diagnosis resulting in cesarean delivery (adjusted odds ratio, 6.73 [95% confidence interval, 2.47-8.33]). Rates of fetal tachycardia were similar between groups. Minimal variability was less common in the nonreassuring fetal status group compared with controls (adjusted odds ratio, 0.36 [95% confidence interval, 0.25-0.54]). Compared with control deliveries, cesarean delivery for nonreassuring fetal status was associated with nearly 7 times higher risk of neonatal acidemia (7.2% vs 1.1%; adjusted odds ratio, 6.93 [95% confidence interval, 3.83-12.54]). Composite neonatal morbidity and composite maternal morbidity were more likely among patients delivered for nonreassuring fetal status in the first stage (3.9% vs 1.1%; adjusted odds ratio, 5.70 [2.60-12.49]; and 13.3% vs 8.0%; adjusted odds ratio, 1.99 [1.41-2.80]). CONCLUSION: Although multiple category II electronic fetal monitoring features have been traditionally linked to acidemia, the presence of recurrent late decelerations, recurrent variable decelerations, and prolonged decelerations seemed to concern obstetricians enough to surgically intervene for nonreassuring fetal status. A clinical intrapartum diagnosis of nonreassuring fetal status in the setting of these electronic fetal monitoring features is also associated with increased risk of acidemia, suggesting clinical validity to the diagnosis of nonreassuring fetal status.

The Impact of Cervical Effacement at Time of Amniotomy in Patients Undergoing Induction of Labor.

OBJECTIVE: There is evidence to suggest that early amniotomy during induction of labor is advantageous. However, following cervical ripening balloon removal, the cervix remains less effaced and the utility of amniotomy in this setting is less clear. We investigated whether cervical effacement at the time of amniotomy impacts outcomes among nulliparas undergoing induction of labor. STUDY DESIGN: This was a secondary analysis of a prospective cohort of singleton, term, nulliparous patients at a tertiary care center undergoing induction of labor and amniotomy. The primary outcome was completion of the first stage of labor. Secondary outcomes were vaginal delivery and postpartum hemorrhage. Outcomes were compared between patients with cervical effacement ≤50% (low effacement) and >50% (high effacement) at time of amniotomy. Multivariable logistic regression was used calculate risk ratios (RR) to adjust for confounders including cervical dilation. Stratified analysis was performed in patients with cervical ripening balloon use. A post hoc sensitivity analysis was performed to further control for cervical dilation. RESULTS: Of 1,256 patients, 365 (29%) underwent amniotomy at low effacement. Amniotomy at low effacement was associated with reduced likelihood of completing the first stage (aRR: 0.87 [95% confidence interval, CI: 0.78-0.95]) and vaginal delivery (aRR: 0.87 [95% CI: 0.77-0.96]). Although amniotomy at low effacement was associated with lower likelihood of completing the first stage in all-comers, those who had amniotomy performed at low effacement following cervical ripening balloon expulsion were at the highest risk (aRR: 0.84 [95% CI: 0.69-0.98], p for interaction = 0.04) In the post hoc sensitivity analysis, including patients who underwent amniotomy at 3- or 4-cm dilation, low cervical effacement remained associated with a lower likelihood of completing the first stage of labor. CONCLUSION: Low cervical effacement at time of amniotomy, particularly following cervical ripening balloon expulsion, is associated with a lower likelihood of successful induction. KEY POINTS: · Low cervical effacement at amniotomy was associated with lower rates of complete dilation.. · Effacement at amniotomy is especially important for patients who had a cervical ripening balloon.. · Providers should consider cervical effacement when timing amniotomy for nulliparous term patients..

Video Instruction for Pushing in the Second Stage: a randomized controlled trial.

BACKGROUND: The second stage of labor requires active patient engagement. Previous studies suggest that coaching can influence the second stage of labor duration. However, a standardized education tool has not been established, and patients face many barriers to accessing childbirth education before delivery. OBJECTIVE: This study aimed to investigate the effect of an intrapartum video pushing education tool on the second stage of labor duration. STUDY DESIGN: This was a randomized controlled trial of nulliparous patients with singleton pregnancies ≥37 weeks of gestation admitted for induction of labor or spontaneous labor with neuraxial anesthesia. Patients were consented on admission and block randomized in active labor to 1 of 2 arms in a 1:1 ratio. The study arm viewed a 4-minute video before the second stage of labor on what to anticipate in the second stage of labor and pushing techniques. The control arm received the standard of care: bedside coaching at 10 cm dilation from a nurse or physician. The primary outcome was second stage of labor duration. The secondary outcomes were birth satisfaction (using the Modified Mackey Childbirth Satisfaction Rating Scale), mode of delivery, postpartum hemorrhage, clinical chorioamnionitis, neonatal intensive care unit admission, and umbilical artery gases. Of note, 156 patients were needed to detect a 20% decrease in the second stage of labor duration with 80% power, 2-sided alpha level of .05, and 10% loss after randomization. Funding was provided by the Lucy Anarcha Betsy award from the division of clinical research at Washington University. RESULTS: Of 161 patients, 81 were randomized to standard of care, and 80 were randomized to intrapartum video education. Among these patients, 149 progressed to the second stage of labor and were included in the intention-to-treat analysis: 69 in the video group and 78 in the control group. Maternal demographics and labor characteristics were similar between groups. The second stage of labor duration was statistically similar between the video arm (61 minutes [interquartile range, 20-140]) and the control arm (49 minutes [interquartile range, 27-131]) (P=.77). There was no difference in mode of delivery, postpartum hemorrhage, clinical chorioamnionitis, neonatal intensive care unit admission, or umbilical artery gases between groups. Although the overall birth satisfaction score on the Modified Mackey Childbirth Satisfaction Rating Scale was similar between groups, patients in the video group rated their "level of comfort during birth" and "attitude of the doctors in birth" significantly higher or more positively than patients in the control group (P<.05 for both). CONCLUSION: Intrapartum video education was not associated with a shorter second stage of labor duration. However, patients who received video education reported a higher level of comfort and a more favorable perception of their physician, suggesting that video education may be a helpful tool to improve the birth experience.

Association between Elevated Intrauterine Resting Tone during Labor and Neonatal Morbidity.

OBJECTIVE: Internal contraction monitoring provides a quantitative assessment of intrauterine resting tone. During the course of labor, elevated intrauterine resting tone may be identified. We hypothesized that elevated intrauterine resting tone could lead to compression of the spiral arteries, thus limiting uterine blood flow and resulting in neonatal compromise. Therefore, our objective was to assess the association between elevated resting tone during labor and neonatal morbidity. STUDY DESIGN: This was a secondary analysis of a prospective cohort study of singleton deliveries at ≥37 weeks of gestation. Patients with ruptured membranes and an intrauterine pressure catheter in place for at least 30 minutes prior to delivery were included. Intrauterine resting tone was calculated as the average baseline pressure between contractions during the 30 minutes prior to delivery. The study group had elevated intrauterine resting tone, defined as intrauterine resting tone ≥75th percentile (≥12.3 mm Hg). Primary outcome was composite neonatal morbidity: hypoxic-ischemic encephalopathy, hypothermia treatment, intubation, seizures, umbilical arterial pH ≤7.1, oxygen requirement, or death. Secondary outcomes included umbilical artery pH <7.2, lactate ≥4 mmol/L, and rates of neonatal intensive care unit admission. RESULTS: Of the 8,580 patients in the cohort, 2,210 (25.8%) met the inclusion criteria. The median intrauterine resting tone was 9.7 mm Hg (interquartile range: 7.3-12.3 mm Hg). Elevated resting tone was associated with a shorter median duration of the first stage of labor (10.0 vs. 11.0 hours, p < 0.01) and lower rates of labor induction and oxytocin augmentation (p < 0.01). Neonatal composite morbidity was higher among patients with elevated intrauterine resting tone (5.1 vs. 2.9%, p = 0.01). After adjusting for chorioamnionitis and amnioinfusion, elevated intrauterine resting tone was associated with increased risk of neonatal morbidity (adjusted odds ratio: 1.70, 95% confidence interval: 1.06-2.74). CONCLUSION: Our findings suggest that elevated intrauterine resting tone is associated with increased risk of neonatal composite morbidity. KEY POINTS: · Higher intrauterine resting tone is associated with increased risk of neonatal morbidity.. · Elevated intrauterine tone can negatively impact umbilical artery pH and lactate levels.. · If elevated intrauterine pressure is noted, we recommend close monitoring of fetal status..

The association of fetal acidemia with adverse neonatal outcomes at time of scheduled cesarean delivery.

BACKGROUND: Fetal acidemia at the time of a scheduled cesarean delivery is generally unexpected. In the setting of reassuring preoperative monitoring, the duration of fetal acidemia in this scenario is presumably brief. The neonatal sequelae and risks associated with brief fetal acidemia in this setting are unknown. OBJECTIVE: We aimed to assess whether fetal acidemia at the time of a scheduled prelabor cesarean delivery is associated with adverse neonatal outcomes. STUDY DESIGN: This was a retrospective cohort study of singleton, term, nonanomalous, liveborn neonates delivered by scheduled cesarean delivery that was performed under regional anesthesia from 2004 to 2014 at a single tertiary care center with a universal umbilical cord gas policy. Neonates born to laboring gravidas and those whose cesarean delivery was performed for nonreassuring fetal status were excluded. All included patients had reassuring preoperative fetal monitoring. The primary outcome was a composite adverse neonatal outcome that included neonatal death, encephalopathy, therapeutic hypothermia, seizures, intubation, and respiratory distress. This outcome was compared between patients with and those without fetal acidemia (umbilical artery pH <7.2). A multivariable logistic regression was used to adjust for confounders. Cases of fetal acidemia were further characterized as respiratory, metabolic, or mixed acidemia based on additional umbilical cord gas values. Secondary analyses examining the association between the type of acidemia and neonatal outcomes were also performed. RESULTS: Of 2081 neonates delivered via scheduled cesarean delivery, 252 (12.1%) had fetal acidemia at the time of delivery. Acidemia was more common in breech neonates and in neonates born to gravidas with obesity and gestational diabetes mellitus. Compared with fetuses with normal umbilical artery pH, those with fetal acidemia were at a significantly increased risk for adverse neonatal outcome (adjusted relative risk, 2.95; 95% confidence interval, 2.03-4.12). This increased risk was similar regardless of the type of acidemia. CONCLUSION: Even a brief period of mild acidemia is associated with adverse neonatal outcomes at the time of a scheduled cesarean delivery despite reassuring preoperative monitoring. Addressing modifiable intraoperative factors that may contribute to fetal acidemia at the time of a scheduled cesarean delivery, such as maternal hypotension and prolonged operative time, is an important priority to potentially decrease neonatal morbidity in full-term gestations.

Reduction of opioid utilization after vaginal delivery with an electronic health record intervention.

BACKGROUND: The national epidemic of opioid misuse has focused its attention on postpartum analgesic usage. Adequate pain control achieved with nonopioid pain medications and conservative measures could reduce the number of opioid pain medications available for misuse and diversion. Interventions that decrease inpatient opioid use after delivery could reduce the potential for chronic dependence in postpartum women. Modification of preloaded electronic order sets to decrease opioid administration has successfully reduced opioid use following a major abdominal surgery, including cesarean delivery. However, interventions to reduce opioid use following vaginal delivery are not well described. OBJECTIVE: We aimed to evaluate the effect of removing opioid medications from postpartum order sets on medication usage following vaginal delivery. STUDY DESIGN: We performed a retrospective cohort study of women undergoing a singleton vaginal delivery at an academic tertiary care center. Our institution removed opioid medications from postpartum order sets in April 2018. We compared the following 2 delivery cohorts: the "preintervention" cohort (April 2016-March 2018) and the "postintervention" cohort (June 2018-July 2018). The primary outcome was postpartum opioid use. The secondary outcomes were nonopioid analgesic use and discharge with an opioid prescription. We compared the demographic and obstetrical data, self-reported pain scores, and postpartum analgesic usage between groups. We determined that a minimum of 138 patients would be needed in each group to identify a 20% decrease in opioid usage (α=.05; ß=.2). RESULTS: We analyzed 276 subjects: 138 in the preintervention group and 138 in the postintervention group. The postintervention group was older and more likely to have an operative vaginal delivery. Otherwise, groups had similar demographic and obstetrical characteristics. Postpartum opioid use decreased from 56% in the preintervention group to 16% in the postintervention group, a 71% reduction (P<.001). The incidence of severe pain score (>7) was similar between groups with a median occurrence of 1 (interquartile range, 0-4) for both (P=.7). The number of opioid discharge prescriptions among those receiving inpatient opioids was significantly lower in the postintervention group than in the preintervention group (18% vs 38%, respectively), a 53% decrease (P<.001). CONCLUSION: Removal of opioids from the postpartum order set was associated with lower rates of opiate usage following vaginal delivery in a single center without changing the frequency of severe pain scores. This simple intervention has the potential to reduce opioid exposure.

Time from neuraxial anesthesia placement to delivery is inversely proportional to umbilical arterial cord pH at scheduled cesarean delivery.

BACKGROUND: Neuraxial block-related hypotension and maternal obesity contribute to uterine hypoperfusion and decreased umbilical arterial pH at cesarean delivery. Between the time of anesthesia placement and delivery, the fetus may be exposed to a hypoperfused uterine environment without surgeon awareness of fetal compromise. OBJECTIVE: We sought to evaluate neonatal umbilical arterial pH according to predelivery time intervals at scheduled term cesarean. STUDY DESIGN: We performed a retrospective cohort study of cesarean deliveries between September 2014 and February 2017. Singleton gestations undergoing scheduled cesarean delivery under spinal anesthesia between 37 and 41 weeks with a reassuring preoperative nonstress test were included. Time intervals between operative room entry, spinal anesthesia placement, skin incision, uterine incision, and delivery were calculated. The primary outcome was umbilical arterial pH. Demographic data, maternal blood pressures, predelivery time intervals, and delivery outcomes were analyzed according to umbilical arterial pH intervals of <7.0, 7.01-7.10, 7.11-7.20, 7.21-7.30, and >7.30. Umbilical cord gas analytes and neonatal outcomes were analyzed by spinal to delivery time. Stepwise linear regression was performed to identify predictors of decreasing umbilical arterial pH. Receiver-operator characteristic curves were calculated for spinal to delivery time and umbilical arterial pH <7.0 and 7.1. RESULTS: Among 527 included participants, median umbilical arterial pH was 7.27 [interquartile range, 7.23-7.29] and body mass index was 35 kg/m2 [interquartile range, 30-41]. Both maternal body mass index and hypotensive episodes increased with decreasing umbilical arterial pH (P <.001, P ≤ .02). All predelivery time intervals (operative room to delivery, spinal to skin, spinal to delivery, and uterine incision to delivery) increased as umbilical arterial pH interval decreased (P < .05 for all). In a stepwise linear regression, maternal body mass index, noncephalic presentation, spinal start to delivery interval, uterine incision to delivery interval, and maximum reduction in blood pressure from baseline were predictive of decreasing umbilical arterial pH after controlling for confounding variables (F [5,442] = 17.7, P = .0001], adjusted R2 of 0.157. When evaluated by spinal to delivery time, both umbilical arterial and venous pH and partial pressure of carbon dioxide decreased (P < .001 for all), but base deficit and neonatal outcomes were similar (P ≥ .7 for all). There were 2 cases of hypoxic-ischemic encephalopathy (0.38%). A receiver-operating characteristic curve demonstrated that a spinal start to delivery time greater than 27 minutes was associated with an umbilical arterial pH <7.1 (area under the curve, 0.74, 100% sensitivity, 21% specificity), and an interval greater than 30 minutes was associated with an umbilical arterial pH <7.0 (area under the curve, 0.80, 100% sensitivity, 33% specificity). CONCLUSION: Longer spinal-to-delivery and uterine incision-to-delivery time intervals were associated with decreasing umbilical arterial pH at scheduled term cesarean delivery. Efforts to minimize predelivery time following spinal placement could reduce the frequency of unanticipated neonatal acidemia.