Implementation and Clinical Impact of a Guideline for Standardized, Evidence-Based Induction of Labor.

OBJECTIVE: This study aimed to assess the impact of implementation of an induction of labor (IOL) guideline on IOL length and utilization of evidence-based practices. STUDY DESIGN: We conducted a quality improvement project to increase utilization of three evidence-based IOL practices: combined agent ripening, vaginal misoprostol, and early amniotomy. Singletons with intact membranes and cervical dilation ≤2 cm admitted for IOL were included. Primary outcome was IOL length. Secondary outcomes included cesarean delivery and practice utilization. We compared preimplementation (PRE; November 1, 2021 through January 31, 2022) to postimplementation (POST; March 1, 2022 through April 30, 2022) with sensitivity analyses by self-reported race and ethnicity. Cox proportional hazards models and logistic regression were used to test the association between period and outcomes. RESULTS: Among 495 birthing people (PRE, n = 293; POST, n = 202), IOL length was shorter POST (22.0 vs. 18.3 h, p = 0.003), with faster time to delivery (adjusted hazard ratio [aHR] 1.38, 95% CI 1.15-1.66), more birthing people delivered within 24 hours (57 vs. 68.8%, adjusted odds ratio [aOR] 1.90 [95% CI 1.25-2.89]), and no difference in cesarean. Utilization of combined agent ripening (31.1 vs. 42.6%, p = 0.009), vaginal misoprostol (34.5 vs. 68.3%, p < 0.001), and early amniotomy (19.1 vs. 31.7%, p = 0.001) increased POST. CONCLUSION: Implementation of an evidence-based IOL guideline is associated with shorter induction time. Additional implementation efforts to increase adoption of practices are needed to optimize outcomes after IOL. KEY POINTS: · Implementation of an IOL guideline is associated with faster time to delivery.. · Evidence-based induction practices were used more often after guideline implementation.. · Adoption of evidence-based induction practices is variable even with a guideline..

Prenatal Low-Dose Aspirin Use Associated with Reduced Incidence of Postpartum Hypertension among Women with Preeclampsia.

OBJECTIVE: Postpartum hypertension (PP-HTN), defined as systolic/diastolic blood pressure (SBP/DBP) ≥140/90, on two occasions at least 4 hours apart after delivery occurs in up to 50% of preeclamptic pregnancies, and is associated with adverse maternal outcomes. Excessive production of antiangiogenic factors (i.e., soluble fms-like tyrosine kinase 1 [sFLT1]) and reduced levels of proangiogenic factors (i.e., placental growth factor [PlGF]) are associated with preeclamptic pregnancies. The aim of this study was to identify clinical risk factors and/or serum biomarkers associated with PP-HTN in preeclampsia. STUDY DESIGN: Preeclamptic women (n = 82, aged ≥18 years) were prospectively enrolled in an observational study. Serial blood pressures were obtained through the labor course and until 48 hours postpartum, and serum was obtained within 24 hours postpartum. Statistical analysis was performed by using Student's two-tailed t-test and Fisher's exact test. RESULTS: Baseline comorbidities and antihypertensive use were similar among those who developed PP-HTN and those who did not. Among preeclamptic patients, 33% developed PP-HTN; these had significantly more severe preeclampsia features versus no PP-HTN (96 vs. 78%, p = 0.05). PP-HTN was associated with higher re-hospitalization rates (26 vs. 6%, p = 0.01). Among those taking low-dose aspirin (ASA) for preeclampsia prophylaxis (n = 12), PP-HTN was significantly less frequent versus those not taking low-dose ASA (0 vs. 22%, p = 0.007). Low-dose ASA use was associated with significantly lower peripartum sFLT1 levels (4,650 ± 2,335 vs. 7,870 ± 6,282 pg/mL, p = 0.03) and sFLT1/PlGF ratio (397 ± 196 vs. 1,527 ± 2,668, p = 0.03). CONCLUSION: One-third of women with preeclampsia develop PP-HTN; these patients have more severe preeclampsia and have higher re-hospitalization rates. Prenatal low-dose ASA use was associated with significantly lower incidence of PP-HTN, reduced levels of antiangiogenic factors, and lower 6-week re-hospitalization rates. These findings, if replicated, may have clinical implications on the use of low-dose ASA during pregnancy to reduce incidence of postpartum HTN. KEY POINTS: · Postpartum hypertension is common in preeclampsia.. · Prenatal aspirin may reduce postpartum hypertension.. · Prenatal aspirin may reduce sFLT1 levels..

The Impact of Group Prenatal Care on Interpregnancy Interval.

OBJECTIVE: To evaluate whether participation in CenteringPregnancy group prenatal care is associated with decreased risk of an interpregnancy interval (IPI) ≤6 months. STUDY DESIGN: We conducted a retrospective cohort study of women enrolled in Missouri Medicaid from 2007 to 2014 using maternal Medicaid data linked to infant birth certificate records. Inclusion criteria were women ≥11 years old, ≥1 viable singleton delivery during the study period, residency in St. Louis city or county, and ≥2 prenatal visits. The primary outcome was an IPI ≤6 months. Secondary outcomes included IPI ≤12 months, IPI ≤18 months, postpartum long-acting reversible contraception (LARC) uptake, and postpartum LARC or depot medroxyprogesterone acetate (DMPA) uptake. Data were analyzed using descriptive statistics and logistic regression. Backward stepwise logistic regression was used to adjust for potential confounders including maternal age, race, obesity, nulliparity, marital status, diabetes, hypertension, prior preterm birth, and maternal education. RESULTS: Of the 54,968 pregnancies meeting inclusion criteria, 1,550 (3%) participated in CenteringPregnancy. CenteringPregnancy participants were less likely to have an IPI ≤6 months (adjusted odds ratio [aOR]: 0.61; 95% confidence interval [CI]: 0.47-0.79) and an IPI ≤12 months (aOR: 0.74; 95% CI: 0.62-0.87). However, there was no difference for an IPI ≤18 months (aOR: 0.89; 95% CI: 0.77-1.13). Women in CenteringPregnancy were more likely to use LARC for postpartum contraception (aOR: 1.37; 95% CI: 1.20-1.57). CONCLUSION: Participation in CenteringPregnancy is associated with a significant decrease in an IPI ≤6 and ≤12 months and a significant increase in postpartum LARC uptake among women enrolled in Missouri Medicaid compared with women in traditional prenatal care. KEY POINTS: · CenteringPregnancy is associated with a significant decrease in interpregnancy intervals ≤6 and ≤12 months.. · LARC uptake is significantly higher among patients participating in CenteringPregnancy.. · CenteringPregnancy participation enhances self-efficacy in making contraception decisions and promotes healthy pregnancy spacing..

Obstetric Outcomes in Singleton Pregnancies with Abnormal Placental Cord Insertions.

OBJECTIVE: There is wide variation in the management of pregnancies complicated by abnormal placental cord insertion (PCI), which includes velamentous cord insertion (VCI) and marginal cord insertion (MCI). We tested the hypothesis that abnormal PCI is associated with small for gestational age (SGA) infants. STUDY DESIGN: This is a retrospective cohort study of all pregnant patients undergoing anatomic ultrasound at a single institution from 2010 to 2017. Patients with abnormal PCI were matched in a 1:2 ratio by race, parity, gestational age at the time of ultrasound, and obesity to patients with normal PCIs. The primary outcome was SGA at delivery. Secondary outcomes were cesarean delivery, preterm delivery, cesarean delivery for nonreassuring fetal status, 5-minute Apgar score < 7, umbilical artery pH < 7.1, and neonatal intensive care unit admission. These outcomes were compared using univariate and bivariate analyses. RESULTS: Abnormal PCI was associated with an increased risk of SGA (relative risk [RR]: 2.43; 95% confidence interval [CI]: 1.26-4.69), increased risk of preterm delivery <37 weeks (RR: 3.60; 95% CI: 1.74-7.46), and <34 weeks (RR: 3.50; 95% CI: 1.05-11.63) compared with patients with normal PCI. There was no difference in rates of cesarean delivery, Apgar score of <7 at 5 minutes, acidemia, or neonatal intensive care unit admission between normal and abnormal PCI groups. In a stratified analysis, the association between abnormal PCI and SGA did not differ by the type of abnormal PCI (p for interaction = 0.46). CONCLUSION: Abnormal PCI is associated with an increased risk of SGA and preterm delivery. These results suggest that serial fetal growth assessments in this population may be warranted. KEY POINTS: · Abnormal PCI is associated with SGA infants and preterm birth.. · If an abnormal PCI is identified, the provider should consider serial growth ultrasounds.. · There is no difference in obstetric outcomes between VCI and MCI..

Retrospective Use of Patients' Characteristics to Assess Variation in Prenatal Care Utilization.

OBJECTIVE: We used patients' medical and psychosocial risk factors to explore prenatal care utilization and health outcomes to inform prenatal care tailoring. STUDY DESIGN: This retrospective cohort study assessed patients who gave birth at an academic institution from January 1 to December 31, 2018, using electronic health record (EHR) data. Patients were categorized into four phenotypes based on medical/psychosocial risk factors available in the EHR: Completely low risk; High psychosocial risk only; High medical risk only; and Completely high risk. We examined patient characteristics, visit utilization, nonvisit utilization (e.g., phone calls), and outcomes (e.g., preterm birth, preeclampsia) across groups. RESULTS: Of 4,681 patients, the majority were age 18 to 35 (3,697, 79.0%), White (3,326, 70.9%), multiparous (3,263, 69.7%), and Completely high risk (2,752, 58.8%). More Black and Hispanic patients had psychosocial risk factors than White patients. Patients with psychosocial risk factors had fewer prenatal visits (10, interquartile range [IQR]: 8-12) than those without (11, IQR: 9-12). Patients with psychosocial risk factors experienced less time in prenatal care, more phone calls, and fewer EHR messages across the same medical risk group. Rates of preterm birth and gestational hypertension were incrementally higher with additional medical/psychosocial risk factors. CONCLUSION: Data readily available in the EHR can assess the compounding influence of medical/psychosocial risk factor on patients' care utilization and outcomes. KEY POINTS: · Medical and psychosocial needs in pregnancy can inform patient phenotypes and are associated with prenatal care use and outcomes.. · Patient phenotypes are associated with prenatal care use and outcomes.. · Patients with high psychosocial risk spent less time in prenatal care and had more phone calls in pregnancy.. · Tailored prenatal care models may proactively address differences in patient's needs..

Association between Maternal Serum Lipids and Intrapartum Oxytocin Requirements during Labor Induction and Augmentation.

OBJECTIVE: This study aimed to investigate the relationship between maternal serum lipid parameters and oxytocin requirements among women with term vaginal deliveries. STUDY DESIGN: In this secondary analysis of a prospective cohort study, women who presented for delivery at ≥37 weeks' gestation and received oxytocin during their labor were included. Maternal serum was collected intrapartum. The cohort was stratified into two groups based on maximum oxytocin infusion dose during labor. Primary outcomes were maternal total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels. Generalized linear regression models were used to assess the association between lipid parameters and maximum oxytocin dose requirements while controlling for potential confounders. For secondary analyses, the cohort was stratified by HDL-C into two groups. Multivariable logistic regression was used to evaluate the relationship between low maternal HDL-C and additional intrapartum oxytocin parameters. RESULTS: There were no differences in maternal total cholesterol, LDL-C, or triglyceride values between high and low maximum oxytocin groups. Median serum HDL-C was significantly lower among women in the high oxytocin group compared with those in the low oxytocin group (56 vs. 62 mg/dL, p < 0.01). For every 0.26 mg/dL lower HDL-C, women had 1 mU/min higher maximum oxytocin infusion dose during labor. Women with low serum HDL-C were also more likely to require maximum oxytocin doses above the 75th percentile (adjusted odds ratio [aOR]: 1.99, 95% confidence interval [CI]: 1.06-3.75) and above the 90th percentile (aOR: 2.47, 95% CI: 1.10-5.54). Among women undergoing induction of labor, low serum HDL-C was also associated with longer duration of oxytocin infusion (aOR: 2.07, 95% CI: 1.02-4.20). CONCLUSION: Low maternal HDL-C levels at term are associated with higher maximum oxytocin infusion doses among women undergoing labor induction or augmentation. Given the growing prevalence of metabolic syndrome in the United States and persistently high rates of cesarean delivery, HDL-C or its components may present a new target for predicting and improving labor outcomes. KEY POINTS: · Serum HDL-C at term is inversely correlated with oxytocin infusion doses at term.. · Low maternal serum HDL-C is associated with higher oxytocin requirements during labor induction or augmentation.. · No association between maternal serum total cholesterol, LDL-C, or triglyceride levels and oxytocin requirements in labor..

The Impact of a Multidisciplinary Opioid Use Disorder Prenatal Clinic on Breastfeeding Rates and Postpartum Care.

OBJECTIVE: To evaluate the hypothesis that patients with opioid use disorder (OUD), who receive prenatal care in a multidisciplinary, prenatal OUD clinic, have comparable postpartum breastfeeding rates, prenatal and postpartum visit compliance, and postpartum contraceptive use when compared with matched controls without a diagnosis of OUD. STUDY DESIGN: This was a retrospective, matched, cohort study that included all patients who received prenatal care in a multidisciplinary, prenatal OUD clinic-Clinic for Acceptance Recovery and Empowerment (CARE)-between September 2018 and August 2020. These patients were maintained on opioid agonist therapy (OAT) throughout their pregnancy. CARE patients were matched to controls without OUD in a 1:4 ratio for mode of delivery, race, gestational age ± 1 week, and delivery date ± 6 months. The primary outcome was rate of exclusive breastfeeding at maternal discharge. Secondary outcomes included adherence with prenatal care (≥4 prenatal visits), adherence with postpartum care (≥1 postpartum visit), postpartum contraception plan prior to delivery, and type of postpartum contraceptive use. Conditional multivariate logistic regression was used to account for possible confounders in adjusted calculations. RESULTS: A total of 210 patients were included (42 CARE and 168 matched controls). Despite having lower rates of adequate prenatal care, 40 CARE patients (95%) were exclusively breastfeeding at discharge resulting in CARE patients being significantly more likely to be breastfeeding at discharge (adjusted relative risk (aRR): 1.28, 95% confidence interval [CI]: 1.05-1.55). CARE patients and controls demonstrated no difference in postpartum visit compliance (86 vs. 81%, aRR: 1.03, 95% CI: 0.76-1.40) or effective, long-term contraception use (48 vs. 48%; aRR: 0.81, 95% CI: 0.36-1.84). CONCLUSION: In the setting of multidisciplinary OUD prenatal care during pregnancy, patients with OUD were more likely to be breastfeeding at the time of discharge than matched controls, with no difference in postpartum visit compliance or effective, long-term contraception. KEY POINTS: · Women with OUD are more likely to breastfeed when engaged in a multidisciplinary prenatal clinic.. · Women with OUD had no difference in LARC use when engaged in a multidisciplinary prenatal clinic.. · Women with OUD had no difference in postpartum visit rate in a multidisciplinary prenatal clinic..

Intravenous versus Oral Iron for Iron-Deficiency Anemia in Pregnancy (IVIDA): A Randomized Controlled Trial.

OBJECTIVE: Iron-deficiency anemia (IDA) can have serious consequences for mothers and babies. Iron supplementation is recommended, but the administration route is controversial. We sought to conduct a randomized controlled trial (RCT) testing the effectiveness and safety of intravenous (IV) iron compared with oral iron on perinatal outcomes in pregnant women with IDA. STUDY DESIGN: This open-label RCT randomized patients with IDA (hemoglobin [hgb] <10 g/dL and ferritin <30 ng/mL) at 24 to 34 weeks' to oral iron or single 1,000-mg dose of IV low-molecular weight iron dextran over one hour. The primary outcome was maternal anemia at delivery (hgb < 11 g/dL). Secondary outcomes were mild/moderate or severe adverse reactions, maternal hgb and ferritin at delivery, blood transfusion, gestational age at delivery, birth weight, neonatal hgb and ferritin, and composite neonatal morbidity. Analysis was as per protocol. RESULTS: The trial was stopped early for logistical reasons, and the data analyzed as preliminary data to inform a larger, potentially externally funded, definitive trial. Of 55 patients approached, 38 consented. Of these, 15 were withdrawn: 5 received IV iron from their primary obstetrician after being randomized to oral iron and 10 declined to receive IV iron. Of the remaining 23 patients, who were included in the analytic population, 13 received oral iron and 10 received IV iron. The rate of maternal anemia at delivery (hgb < 11 g/dL) was high overall but significantly reduced with IV iron (40 vs. 85%, p = 0.039). Rates of maternal hgb < 10 g/dL were significantly lower in the IV iron group (10 vs. 54%, p = 0.029). There were no severe adverse reactions and similar rates of mild/moderate reactions between groups. CONCLUSION: IV iron reduces rates of anemia at the time of admission for delivery, supporting a larger RCT comparing IV versus oral iron for the treatment of IDA of pregnancy powered for definitive clinical outcomes. However, issues uncovered in this RCT suggest that patient, clinician, and systems-level barriers associated with different IDA treatment modalities must be considered prior to conducting a larger RCT. This study is registered with clinicaltrials.gov with identifier no.: NCT03438227. KEY POINTS: · IV iron decreases rates of anemia on admission for delivery compared with oral iron.. · In an unblinded randomized trial, a significant proportion of patients preferred alternate therapy.. · Future RCTs should incorporate double-blinded technique to reduce risk of patient crossover.. · Results from feasibility trial support a larger RCT comparing IV to oral iron for IDA in pregnancy..

Obesity, Second Stage Duration, and Labor Outcomes in Nulliparous Women.

OBJECTIVE: This study aimed to estimate second stage duration and its effects on labor outcomes in obese versus nonobese nulliparous women. STUDY DESIGN: This was a secondary analysis of a cohort of nulliparous women who presented for labor at term and reached complete cervical dilation. Adjusted relative risks (aRR) were used to estimate the association between obesity and second stage characteristics, composite neonatal morbidity, and composite maternal morbidity. Effect modification of prolonged second stage on the association between obesity and morbidity was assessed by including an interaction term in the regression model. RESULTS: Compared with nonobese, obese women were more likely to have a prolonged second stage (aRR: 1.48, 95% CI: 1.18-1.85 for ≥3 hours; aRR: 1.65, 95% CI: 1.18-2.30 for ≥4 hours). Obesity was associated with a higher rate of second stage cesarean (aRR: 1.78, 95% CI: 1.34-2.34) and cesarean delivery for fetal distress (aRR: 2.67, 95% CI: 1.18-3.58). Obesity was also associated with increased rates of neonatal (aRR: 1.38, 95% CI: 1.05-1.80), but not maternal morbidity (aRR: 1.06, 95% CI: 0.90-1.25). Neonatal morbidity risk was not modified by prolonged second stage. CONCLUSION: Obesity is associated with increased risk of neonatal morbidity, which is not modified by prolonged second stage of labor.

The effect of intrapartum oxygen supplementation on category II fetal monitoring.

BACKGROUND: Maternal oxygen administration is a widely used intrauterine resuscitation technique for fetuses with category II electronic fetal monitoring patterns, despite a paucity of evidence on its ability to improve electronic fetal monitoring patterns. OBJECTIVE: This study investigated the effect of intrapartum oxygen administration on Category II electronic fetal monitoring patterns. STUDY DESIGN: This is a secondary analysis of a randomized trial conducted in 2016-2017, in which patients with fetuses at ≥37 weeks' gestation in active labor with category II electronic fetal monitoring patterns were assigned to 10 L/min of oxygen by face mask or room air until delivery. Trained obstetrical research nurses blinded to allocation extracted electronic fetal monitoring data. The primary outcome was a composite of high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, or minimal variability 60 minutes after randomization to room air or oxygen. Secondary outcomes included individual components of the composite high-risk category II features, resolution of recurrent decelerations within 60 minutes of randomization, and total deceleration area. The outcomes between the room air and oxygen groups were compared using univariable statistics. Time-to-event analysis was used to compare time to resolution of recurrent decelerations between the groups. Paired analysis was used to compare the pre- and postrandomization outcomes within each group. RESULTS: All 114 randomized patients (57 room air and 57 oxygen) were included in this analysis. There was no difference in resolution of recurrent decelerations within 60 minutes between the oxygen and room air groups (75.4% vs 86.0%; P=.15). The room air and oxygen groups had similar rates of composite high-risk category II features including recurrent variable decelerations, recurrent late decelerations, prolonged decelerations, tachycardia, and minimal variability 60 minutes after randomization. Time to resolution of recurrent decelerations and total deceleration area were similar between the room air and oxygen groups. Among patients who received oxygen, there was no difference in the electronic fetal monitoring patterns pre- and postrandomization. Similar findings were observed in the electronic fetal monitoring patterns pre- and postrandomization in room air patients. CONCLUSION: Intrapartum maternal oxygen administration for category II electronic fetal monitoring patterns did not resolve high-risk category II features or hasten the resolution of recurrent decelerations. These results suggest that oxygen administration has no impact on improving category II electronic fetal monitoring patterns.

A new definition of gestational hypertension? New-onset blood pressures of 130 to 139/80 to 89 mm Hg after 20 weeks of gestation.

BACKGROUND: Diagnostic criteria for hypertensive disorders in pregnancy have historically been based on the American Heart Association and American College of Cardiology's definition of hypertension, previously defined as a blood pressure of ≥140/90 mm Hg. With the recent redefinition of hypertension, blood pressures of 130 to 139/80 to 89 mm Hg are now considered abnormal. OBJECTIVE: In this study, we aimed to test whether the new-onset blood pressure elevations of 130 to 139/80 to 89 mm Hg after 20 weeks of gestation in previously normotensive women are associated with increased risk for adverse pregnancy outcomes, specifically the development of hypertensive disorders in pregnancy. STUDY DESIGN: We performed a retrospective cohort study at a single tertiary care center of all women who delivered singleton gestations after 20 weeks of gestation from January 01, 2014, to June 08, 2016. Normotensive patients were defined as having maximum blood pressure of <130/80 mm Hg before 20 weeks of gestation and no previous diagnosis of chronic hypertension. Patients who remained normotensive for the remainder of pregnancy were then compared with patients who developed new-onset blood pressure elevations of 130 to 139/80 to 89 mm Hg after 20 weeks of gestation before delivery admission. The primary outcome was the development of a hypertensive disorder in pregnancy at hospital admission or during delivery. Clinical outcomes were assessed using χ2 test and multivariable logistic regression. RESULTS: Of the 2090 normotensive women from our cohort who were analyzed, 1318 (63.0%) remained normotensive for their entire antenatal course before delivery admission and 772 (37.0%) had new-onset blood pressure elevations between 130 and 139/80 and 89 mm Hg. Women with new-onset blood pressure elevations between 130 and 139/80 and 89 mm Hg after 20 weeks of gestation have a significantly increased risk for developing a hypertensive disorder in pregnancy at admission or during delivery (adjusted relative risk, 2.41; 95% confidence interval, 2.02-2.85) including an almost 3-fold increased risk for preeclampsia with severe features, even after adjusting for confounders. There were no differences in other secondary obstetrical outcomes. CONCLUSION: Normotensive women with new-onset blood pressures elevations between 130 and 139/80 and 89 mm Hg after 20 weeks of gestation are more likely to experience hypertensive disorders in pregnancy and preeclampsia with severe features at or during their delivery hospitalization. These more modest blood pressure elevations may be an early indicator of disease and call into question our current blood pressure threshold for diagnosis of hypertensive disorders in pregnancy.

Predictive Value of Midtrimester Universal Cervical Length Screening Based on Parity.

OBJECTIVES: To evaluate the effect of parity on performance characteristics of midtrimester cervical length (CL) in predicting spontaneous preterm birth (sPTB) before 37 weeks. METHODS: This was a retrospective cohort study of 13,508 women with no history of sPTB undergoing universal transvaginal CL screening at 17 to 23 weeks' gestation from 2011 to 2016. Patients who declined screening or with unknown delivery outcomes were excluded. Areas under the receiver operator characteristic curves were used to assess and compare the predictive ability of CL screening for sPTB. The sensitivity, specificity, and positive and negative predictive values were estimated for specific CL cutoffs for prediction of sPTB. RESULTS: There were 20,100 patients, of whom 2087 (10%) declined screening and 4505 (22%) did not meet inclusion criteria. Of the remaining 13,508 patients, 43% were nulliparous. The incidence rates of sPTB were 6.5% in nulliparas and 4.9% in multiparas (P < .001). The mean CLs were 39.9 mm in nulliparas and 41.8 mm in multiparas (P < .001), and those of the first percentiles were 19.0 mm in nulliparas and 24.0 mm in multiparas. Cervical length was significantly more predictive of sPTB in nulliparas (area under the curve, 0.67; 95% confidence interval, 0.63-0.70; versus 0.61, 95% confidence interval, 0.57-0.63; P = .008). At CL cutoffs of 10, 15, 20, and 25 mm or less, the sensitivity was lower in multiparas, and the specificity was comparable between the groups. CONCLUSIONS: Midtrimester CL is less predictive of sPTB in multiparas compared to nulliparas. The poor predictive ability, especially in multiparas, calls into question the value of universal CL screening in this population.

Acidemia Can Occur Despite Category I Tracing.

OBJECTIVE: Electronic fetal monitoring (EFM) is intended to assess fetal well-being during labor. Our objective was to test the hypothesis that findings of a category I tracing at any time in the 60 minutes prior to delivery would rule out neonatal acidemia. STUDY DESIGN: This was a planned secondary analysis of a single-center prospective cohort study of 8,580 singleton pregnancies undergoing labor with nonanomalous infants at term. Monitoring was reviewed by obstetric research nurses at 10-minute intervals in the 60 minutes prior to delivery. The primary outcome was acidemia, defined as an umbilical cord arterial pH of 7.10 or less. RESULTS: Of the 4,274 patients included, 42 (0.98%) infants had acidemia at birth. Of the 42 infants with acidemia, 13 (31%) had category I tracings in the 30 minutes prior to delivery. Three (7%) infants had neonatal acidemia despite category I tracing for >40 minutes in the 60 minutes prior to delivery. CONCLUSION: Even in the presence of category I tracing in the 60 minutes prior to delivery, neonatal acidemia can still occur. Periods of category I should be interpreted within the clinical context of a priori risk for acidemia, knowing that it does not completely rule out acidemia.

A Randomized Trial Comparing Skin Antiseptic Agents at Cesarean Delivery.

BACKGROUND: Preoperative skin antisepsis has the potential to decrease the risk of surgical-site infection. However, evidence is limited to guide the choice of antiseptic agent at cesarean delivery, which is the most common major surgical procedure among women in the United States. METHODS: In this single-center, randomized, controlled trial, we evaluated whether the use of chlorhexidine-alcohol for preoperative skin antisepsis was superior to the use of iodine-alcohol for the prevention of surgical-site infection after cesarean delivery. We randomly assigned patients undergoing cesarean delivery to skin preparation with either chlorhexidine-alcohol or iodine-alcohol. The primary outcome was superficial or deep surgical-site infection within 30 days after cesarean delivery, on the basis of definitions from the Centers for Disease Control and Prevention. RESULTS: From September 2011 through June 2015, a total of 1147 patients were enrolled; 572 patients were assigned to chlorhexidine-alcohol and 575 to iodine-alcohol. In an intention-to-treat analysis, surgical-site infection was diagnosed in 23 patients (4.0%) in the chlorhexidine-alcohol group and in 42 (7.3%) in the iodine-alcohol group (relative risk, 0.55; 95% confidence interval, 0.34 to 0.90; P=0.02). The rate of superficial surgical-site infection was 3.0% in the chlorhexidine-alcohol group and 4.9% in the iodine-alcohol group (P=0.10); the rate of deep infection was 1.0% and 2.4%, respectively (P=0.07). The frequency of adverse skin reactions was similar in the two groups. CONCLUSIONS: The use of chlorhexidine-alcohol for preoperative skin antisepsis resulted in a significantly lower risk of surgical-site infection after cesarean delivery than did the use of iodine-alcohol. (Funded by the National Institutes of Health and Washington University School of Medicine in St. Louis; ClinicalTrials.gov number, NCT01472549.).

First stage of labor progression in women with large-for-gestational age infants.

BACKGROUND: Women with suspected large-for-gestational age fetuses have higher rates of dysfunctional labor and labor arrest diagnoses and, consequently, higher rates of cesarean deliveries. The identification of the factors that significantly affect labor progression of women with large-for-gestational age infants may better inform expected duration of labor for certain subgroups of this population. OBJECTIVE: Because the standards for the first stage of labor when large-for-gestational age is present have not been defined clearly, the present study aims to evaluate labor progress of women with large-for-gestational age infants who complete the first stage of labor after 3-cm cervical dilation. STUDY DESIGN: We conducted a retrospective cohort study of patients who were admitted for labor from 2004-2014 with a term vertex singleton who achieved 10-cm cervical dilation. Labor curves were constructed with repeated measures regression and were compared between patients who delivered large-for-gestational age infants (actual birthweight, >90th percentile for gestational age) and those who delivered appropriate-for-gestational age infants (actual birthweight, 10-90th percentile for gestational age). Interval-censored regression estimated median duration of labor after 3-cm cervical dilation stratified by actual infant birthweight and further stratified by parity (nulliparity vs multiparity), labor onset (spontaneous [augmented and not augmented] and induced labor), pregestational diabetes mellitus or gestational diabetes mellitus status, and maternal body mass index (obese, ≥30 kg/m2 vs not obese, <30 kg/m2). Multivariate analysis adjusted for confounding factors that were identified by bivariate analysis. RESULTS: Among all 17,097 women who were included, 15,843 women (92.7%) had appropriate-for-gestational age infants; 1254 women (7.3%) had large-for-gestational age infants, of whom 387 (30.9%) were nulliparous; 464 women (37.0%) underwent induction of labor; 863 women (68.8%) were obese, and 158 women (12.6%) had diabetes mellitus or gestational diabetes mellitus. Women with large-for-gestational age infants had a slower progression from 3- to 10-cm cervical dilation compared with those with appropriate-for-gestational age infants (median, 8.57 hours [5th, 95th percentile, 2.95, 24.86] vs 6.46 hours [5th, 95th percentile, 2.23, 18.74]; P<.01). In the large-for-gestational age group, dilation from 6-10 cm progressed slower in nulliparous compared with multiparous women (3.28 hours [5th, 95th percentile, 0.71, 15.16] vs 2.03 hours [5th, 95th percentile, 0.44, 9.39]; P<.01) and in obese compared with not obese women (2.36 hours [5th, 95th percentile, 0.51, 10.91] vs 1.79 hours [5th, 95th percentile, 0.39, 8.31]; P<.01). Labor curves did not differ between large-for-gestational age and appropriate-for-gestational age groups when stratified by labor onset (nonaugmented spontaneous labor vs induced labor) or the presence of diabetes mellitus or gestational diabetes mellitus. CONCLUSION: After 3-cm cervical dilation, the time required to reach the second stage of labor is greater in women with large-for-gestational age infants compared with those with appropriate-for-gestational age infants; these differences are most pronounced in nulliparous and obese women with large-for-gestational age infants in the active phase of labor (6-10 cm). Among women with large-for-gestational age infants, labor onset and presence of diabetes mellitus or gestational diabetes mellitus have no apparent effect on the duration of the first stage of labor after 3-cm cervical dilation.

The transition from latent to active labor and adverse obstetrical outcomes.

BACKGROUND: Recommendations on preventing primary cesarean delivery removed the previously defined time limits for latent labor (defined as ending at 6 cm) and urged clinicians to avoid cesarean delivery for labor abnormalities in the latent phase. However, relatively little is known about the implications of labor curve abnormalities from 4 to 6 cm and subsequent outcomes. OBJECTIVE: To examine the association between length of time for dilation from 4 to 6 cm, delivery outcomes, and maternal and neonatal morbidity. STUDY DESIGN: This is a secondary analysis of a prospective cohort study of patients at ≥37 weeks presenting in spontaneous or induced labor with a nonanomalous living singleton in vertex presentation. Patients with a history of cesarean delivery or who did not achieve 6-cm dilation were excluded. We used interval censored regression to determine the 90th percentile for dilation time from 4 to 6 cm and used logistic regression to estimate the odds ratios and 95% confidence intervals for adverse outcomes for patients above this cutoff percentile compared with those at or below. Analyses were adjusted for obesity, nulliparity, race, hypertension, diabetes, and type of labor (induced vs spontaneous/augmented). Outcomes included cesarean delivery, maternal morbidity (composite of postpartum fever, wound infection, hemorrhage), and neonatal morbidity (composite of neonatal death, hypothermic therapy, mechanical ventilation, respiratory distress, meconium aspiration syndrome, seizure, or treatment of sepsis). In addition, we created receiver operator characteristic curves to predict cesarean delivery, and maternal and neonatal morbidity based on time to dilate from 4 to 6 cm. The cutoff for time for each outcome was identified using the Youden index to maximize sensitivity and specificity, and test characteristics were computed. RESULTS: There were 7355 patients eligible for analysis, 728 (10%) had dilation times from 4 to 6 cm >10.3 hours, which was the 90th percentile, and 6627 (90%) had dilation times ≤10.3 hours. Having dilation time from 4 to 6 cm above the 90th percentile (10.3 hours) was associated with cesarean delivery (adjusted odds ratio, 2.05; 95% confidence interval, 1.67-2.52), composite maternal morbidity (adjusted odds ratio, 1.48; 95% confidence interval, 1.10-2.00), and composite neonatal morbidity (adjusted odds ratio 1.92; 95% confidence interval 1.52-2.4). The area under the receiver operator characteristic curve for predicting cesarean delivery was 0.73 (95% confidence interval, 0.71-0.75). The test characteristics for the cutoff of 9.75 hours were sensitivity 68.3% (95% confidence interval, 64.8%-71.7%), specificity 66.2% (95% confidence interval, 55.0%-67.3%), positive predictive value 18.5% (95% confidence interval, 17.1%-20.0%), and negative predictive value 94.9% (95% confidence interval, 94.2%-95.5%). For composite maternal morbidity, the cutoff was 6.98 hours and the area under the curve was 0.62 (95% confidence interval, 0.59-0.65), whereas for composite neonatal morbidity it was 5.5 hours (area under the curve 0.69; 95% confidence interval, 0.67-0.71). CONCLUSIONS: Patients whose dilation time from 4 to 6 cm exceeds the 90th percentile have increased odds of cesarean delivery and postpartum complications. Prolonged dilation time has moderate predictive ability for adverse outcomes. Future studies should investigate at what point, if any, intervention is warranted during this period to reduce these risks.

Effect of Oligohydramnios on Fetal Heart Rate Patterns during Term Labor Induction.

OBJECTIVE: To estimate the effect of oligohydramnios on fetal heart rate (FHR) patterns in patients undergoing induction of labor (IOL) at term. STUDY DESIGN: Secondary analysis of a prospective cohort study of consecutive term, singleton deliveries from 2010 to 2015. We included all patients who underwent IOL. Our primary outcomes were electronic fetal monitoring (EFM) characteristics in the 2 hours preceding delivery. Outcomes were compared between those induced with oligohydramnios and those induced without a diagnosis of oligohydramnios. Our secondary outcome was composite neonatal morbidity. Logistic regression was used to control for confounders. RESULTS: Of 3,787 patients who underwent IOL, 147 had a diagnosis of oligohydramnios and 3,640 were included in the no oligohydramnios group. There was no significant difference in EFM characteristics between the two groups. There was no difference in composite neonatal morbidity. In patients with oligohydramnios, EFM patterns with baseline tachycardia for 30 minutes or greater were significantly associated with composite neonatal morbidity (31.3 vs. 5.3% adjusted odds ratio 8.63, 95% confidence interval 2.18, 34.1]). CONCLUSION: Term patients undergoing IOL with oligohydramnios had EFM patterns that did not differ from their induced peers.

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.

Clinical Diagnosis of Placenta Accreta and Clinicopathological Outcomes.

OBJECTIVE: To investigate the association between the intraoperative diagnosis of placenta accreta at the time of cesarean hysterectomy and pathological diagnosis. STUDY DESIGN: This is a retrospective cohort study of all patients undergoing cesarean hysterectomy for suspected placenta accreta from 2000 to 2016 at Barnes-Jewish Hospital. The primary outcome was the presence of invasive placentation on the pathology report. We estimated predictive characteristics of clinical diagnosis of placenta accreta using pathological diagnosis as the correct diagnosis. RESULTS: There were 50 cesarean hysterectomies performed for suspected abnormal placentation from 2000 to 2016. Of these, 34 (68%) had a diagnosis of accreta preoperatively and 16 (32%) were diagnosed intraoperatively at the time of cesarean delivery. Two patients had no pathological evidence of invasion, corresponding to a false-positive rate of 4% (95% confidence interval [CI]: 0.5%, 13.8%) and a positive predictive value of 96% (95% CI: 86.3%, 99.5%). There were no differences in complications among patients diagnosed intraoperatively compared with those diagnosed preoperatively. CONCLUSION: Most patients undergoing cesarean hysterectomy for placenta accreta do have this diagnosis confirmed on pathology. However, since the diagnosis of placenta accreta was made intraoperatively in nearly a third of cesarean hysterectomies, intraoperative vigilance is required as the need for cesarean hysterectomy may not be anticipated preoperatively.