A Simple Approach to Adjust for Case-Mix When Comparing Institutional Cesarean Birth Rates.

OBJECTIVE: This study aimed to develop a validated model to predict intrapartum cesarean in nulliparous women and to use it to adjust for case-mix when comparing institutional laboring cesarean birth (CB) rates. STUDY DESIGN: This multicenter retrospective study used chart-abstracted data on nulliparous, singleton, term births over a 7-year period. Prelabor cesareans were excluded. Logistic regression was used to predict the probability of CB for individual pregnancies. Thirty-five potential predictive variables were evaluated including maternal demographics, prepregnancy health, pregnancy characteristics, and newborn weight and gender. Models were trained on 21,017 births during 2011 to 2015 (training cohort), and accuracy assessed by prediction on 15,045 births during 2016 to 2017 (test cohort). RESULTS: Six variables delivered predictive success equivalent to the full set of 35 variables: maternal weight, height, and age, gestation at birth, medically-indicated induction, and birth weight. Internal validation within the training cohort gave a receiver operator curve with area under the curve (ROC-AUC) of 0.722. External validation using the test cohort gave ROC-AUC of 0.722 (0.713-0.731 confidence interval). When comparing observed and predicted CB rates at 16 institutions in the test cohort, five had significantly lower than predicted rates and three had significantly higher than predicted rates. CONCLUSION: Six routine clinical variables used to adjust for case-mix can identify outliers when comparing institutional CB rates.

Assessing the potential impact of extending antenatal steroids to the late preterm period.

BACKGROUND: In 2016, guidance statements were issued by the Society for Maternal-Fetal Medicine and the American Congress of Obstetricians and Gynecologists about extending antenatal steroid use to selected late preterm singleton pregnancies. OBJECTIVE: We sought to review antenatal steroid use prior to the 2016 guidance statements and assess the potential impact of these. STUDY DESIGN: This cohort study used chart-abstracted data from singleton deliveries from Jan. 1, 2012, through March 31, 2016, at 12 centers participating in the Obstetrics Clinical Outcomes Assessment Program, a quality initiative in Washington State. Pregnancies with missing gestation at delivery, fetal anomalies, or antepartum demise were excluded. Antenatal steroid use prior to the 2016 guidance was evaluated based on the percentage of early preterm deliveries (23+0-33+6 weeks) and the percentage of all pregnancies that received antenatal steroids. Newborn complication rates were calculated for late preterm deliveries (34+0+0-36+6 weeks), grouped by whether they would be potentially eligible or ineligible for antenatal steroids based on the 2016 guidance statements. RESULTS: The opportunity for antenatal steroids was missed in 21.8% (226/1034) of early preterm deliveries and of all those who received antenatal steroids, 32.2% (614/1908) delivered at term. Of preterm deliveries, 74% (n = 2942) were in the late preterm period. In all, 80% (n = 2363) of late preterm deliveries were potentially eligible for antenatal steroids and 60% of these (n = 1411) delivered at 36 weeks. The rate of respiratory complications in newborns delivering at 34 and 35 weeks was higher in the group potentially eligible for late preterm antenatal steroids compared to those in the ineligible group. Of those delivering at 36 weeks, no differences were detected in prevalence of respiratory complications by potential eligibility for antenatal steroids; however, compared with the ineligible group, those potentially eligible had a lower risk of neonatal intensive care unit admission (P < .001). More than two thirds (69%; 171/248) of newborn respiratory complications among late preterm deliveries potentially eligible for antenatal steroids occurred in those delivering at 34-35 weeks. The highest rate of respiratory complications was in those ineligible for antenatal steroids due to prepregnancy diabetes or chorioamnionitis, regardless of gestational age at delivery. CONCLUSION: Careful consideration of which pregnancies should receive late preterm antenatal steroids and how to identify these pregnancies is important to optimize benefits and mitigate potential risks of this intervention.

Cervical Dilation on Admission in Term Spontaneous Labor and Maternal and Newborn Outcomes.

OBJECTIVE: To examine associations between cervical dilation on admission and maternal and newborn outcomes in term spontaneous labor. METHODS: This is a retrospective cohort study of 11,368 singleton, term (37-43 6/7 weeks of gestation) spontaneously laboring women delivering in 14 hospitals in Washington State between 2012 and 2014 using chart abstracted data from the Obstetrics Clinical Outcomes Assessment Program. Women with prior cesarean delivery or ruptured membranes on admission were excluded. Pregnancy history, cervical dilation on admission, and outcomes were analyzed. Associations between early (less than 4 cm cervical dilation) and late (4 cm or greater cervical dilation) admission and outcomes were examined using general linear models with a log-link stratifying by parity. Results were reported as adjusted relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: Early admission compared with late admission was associated with increased epidural use of 84.8% compared with 71.8% in nulliparous women and 66.3% compared with 53.1% in multiparous women (nulliparous RR 1.18, 95% CI 1.13-1.24; multiparous RR 1.25, 95% CI 1.18-1.32); oxytocin augmentation in 58.5% compared with 36.6% in nulliparous women and 45.9% compared with 20.7% in multiparous women (nulliparous RR 1.56, 95% CI 1.50-1.63; multiparous RR 2.14, 95% CI 1.87-2.44); and cesarean delivery of 21.8% compared with 14.5% in nulliparous women and 3.7% compared with 1.9% in multiparous women (nulliparous RR 1.50, 95% CI 1.32-1.70; multiparous women RR 1.95, 95% CI 1.47-2.57). Early admission was associated with increased neonatal intensive care unit admission for newborns of nulliparous women only (RR 1.38, 95% CI 1.01-1.89). Between 2012 and 2014, late admission increased 14.6% for nulliparous patients and 10.1% for multiparous patients, and the cesarean delivery rate decreased from 10.5% to 7.9% (P<.001) for all. CONCLUSION: Early admission (less than 4 cm cervical dilation) is a risk factor for increased medical intervention and cesarean delivery.