New labor curves of dilation and station to improve the accuracy of predicting labor progress

BACKGROUND

The diagnosis of failure to progress, the most common indication for intrapartum cesarean delivery, is based on the assessment of cervical dilation and station over time. Labor curves serve as references for expected changes in dilation and fetal descent. The labor curves of Friedman, Zhang et al, and others are based on time alone and derived from mothers with spontaneous labor onset. However, labor induction is now common, and clinicians also consider other factors when assessing labor progress. Labor curves that consider the use of labor induction and other factors that influence labor progress have the potential to be more accurate and closer to clinical decision-making.

OBJECTIVE

This study aimed to compare the prediction errors of labor curves based on a single factor (time) or multiple clinically relevant factors using two modeling methods: mixed-effects regression, a standard statistical method, and Gaussian processes, a machine learning method.

STUDY DESIGN

This was a longitudinal cohort study of changes in dilation and station based on data from 8022 births in nulliparous women with a live, singleton, vertex-presenting fetus ≥35 weeks of gestation with a vaginal delivery. New labor curves of dilation and station were generated with 10-fold cross-validation. External validation was performed using a geographically independent group. Model variables included time from the first examination in the 20 hours before delivery; dilation, effacement, and station recorded at the previous examination; cumulative contraction counts; and use of epidural anesthesia and labor induction. To assess model accuracy, differences between each model's predicted value and its corresponding observed value were calculated. These prediction errors were summarized using mean absolute error and root mean squared error statistics.

RESULTS

Dilation curves based on multiple parameters were more accurate than those derived from time alone. The mean absolute error of the multifactor methods was better (lower) than those of the single-factor methods (0.826 cm [95% confidence interval, 0.820-0.832] for the multifactor machine learning and 0.893 cm [95% confidence interval, 0.885-0.901] for the multifactor mixed-effects method and 2.122 cm [95% confidence interval, 2.108-2.136] for the single-factor methods; P<.0001 for both comparisons). The root mean squared errors of the multifactor methods were also better (lower) than those of the single-factor methods (1.126 cm [95% confidence interval, 1.118-1.133] for the machine learning [P<.0001] and 1.172 cm [95% confidence interval, 1.164-1.181] for the mixed-effects methods and 2.504 cm [95% confidence interval, 2.487-2.521] for the single-factor [P<.0001 for both comparisons]). The multifactor machine learning dilation models showed small but statistically significant improvements in accuracy compared to the mixed-effects regression models (P<.0001). The multifactor machine learning method produced a curve of descent with a mean absolute error of 0.512 cm (95% confidence interval, 0.509-0.515) and a root mean squared error of 0.660 cm (95% confidence interval, 0.655-0.666). External validation using independent data produced similar findings.

CONCLUSION

Cervical dilation models based on multiple clinically relevant parameters showed improved (lower) prediction errors compared to models based on time alone. The mean prediction errors were reduced by more than 50%. A more accurate assessment of departure from expected dilation and station may help clinicians optimize intrapartum management.

Booster course of antenatal corticosteroids after preterm prelabor rupture of membranes: a double-blind randomized trial

BACKGROUND

Preterm prelabor rupture of membranes is a leading cause of preterm birth and is responsible for 18% to 20% of perinatal deaths in the United States. An initial course of antenatal corticosteroids has been shown to reduce morbidity and mortality in patients with preterm prelabor rupture of membranes. For patients who remain undelivered for 7 days or more after the initial course of antenatal corticosteroids, it is uncertain whether a booster course of antenatal corticosteroids reduces neonatal morbidity or increases the infection risk. The American College of Obstetricians and Gynecologists has concluded that the current evidence is insufficient to make a recommendation.

OBJECTIVE

This study aimed to evaluate if a single booster course of antenatal corticosteroids improves neonatal outcomes after preterm prelabor rupture of membranes.

STUDY DESIGN

We conducted a multicenter, placebo-controlled randomized clinical trial. The inclusion criteria were preterm prelabor rupture of membranes, gestational age of 24.0 to 32.9 weeks, singleton, initial antenatal corticosteroid course administered at least 7 days before randomization, and planned expectant management. Consenting patients were randomized in gestational age blocks to either receive booster antenatal corticosteroids (12 mg betamethasone every 24 hours for 2 days) or a saline placebo. The primary outcome was composite neonatal morbidity or death. A sample size of 194 patients was calculated to yield 80% power at P<.05 to detect a reduction in primary outcome from 60% in placebo group to 40% in antenatal corticosteroids group.

RESULTS

From April 2016 through August 2022, 194 patients consented and were randomized (47% of 411 eligible patients). Intent-to-treat analysis was performed on 192 patients (2 placebo patients left hospital, outcomes unknown). The groups had similar baseline characteristics. The primary outcome occurred in 64% of patients who received booster antenatal corticosteroids vs in 66% of patients who received the placebo (odds ratio, 0.82; 95% confidence interval, 0.43-1.57; gestational age-stratified Cochran-Mantel-Haenszel test). Individual components of the primary outcome and secondary neonatal and maternal outcomes were not significantly different between the antenatal corticosteroids and placebo groups. Specifically, chorioamnionitis (22% vs 20%), postpartum endometritis (1% vs 2%), wound infections (2% vs 0%), and proven neonatal sepsis (5% vs 3%) were not different between the groups.

CONCLUSION

A booster course of antenatal corticosteroids at least 7 days after the first antenatal corticosteroids course in patients with preterm prelabor rupture of membranes did not improve neonatal morbidity or any other outcome in this adequately-powered, double-blind randomized clinical trial. Booster antenatal corticosteroids did not increase maternal or neonatal infection.

Should case management be considered a component of obstetrical interventions for pregnancies at risk of preterm birth?

Preterm birth remains the leading cause of morbidity and mortality among nonanomalous neonates in the United States. Unfortunately, preterm birth rates remain high despite current medical interventions such as progestogen supplementation and cerclage placement. Case management, which encompasses coordinated care aimed at providing a more comprehensive and supportive environment, is a key component in improving health and reducing costs in other areas of medicine. However, it has not made its way into the general lexicon and practice of obstetrical care. Case management intended for decreasing prematurity or ameliorating its consequences may include specialty clinics, social services, coordination of specialty services such as nutrition counseling, home visits or frequent phone calls by specially trained personnel, and other elements described herein. It is not currently included in nor is it advocated for as a recommended prematurity prevention approach in the American College of Obstetricians and Gynecologists or Society for Maternal-Fetal Medicine guidelines for medically indicated or spontaneous preterm birth prevention. Our review of existing evidence finds consistent reductions or trends toward reductions in preterm birth with case management, particularly among individuals with high a priori risk of preterm birth across systematic reviews, metaanalyses, and randomized controlled studies. These findings suggest that case management has substantial potential to improve the environmental, behavioral, social, and psychological factors with patients at risk of preterm birth.

Better Estimation of Spontaneous Preterm Birth Prediction Performance through Improved Gestational Age Dating

The clinical management of pregnancy and spontaneous preterm birth (sPTB) relies on estimates of gestational age (GA). Our objective was to evaluate the effect of GA dating uncertainty on the observed performance of a validated proteomic biomarker risk predictor, and then to test the generalizability of that effect in a broader range of GA at blood draw. In a secondary analysis of a prospective clinical trial (PAPR; NCT01371019), we compared two GA dating categories: both ultrasound and dating by last menstrual period (LMP) (all subjects) and excluding dating by LMP (excluding LMP). The risk predictor's performance was observed at the validated risk predictor threshold both in weeks 19^1/7-20^6/7 and extended to weeks 18^0/7-20^6/7. Strict blinding and independent statistical analyses were employed. The validated biomarker risk predictor showed greater observed sensitivity of 88% at 75% specificity (increases of 17% and 1%) in more reliably dated (excluding-LMP) subjects, relative to all subjects. Excluding dating by LMP significantly improved the sensitivity in weeks 19^1/7-20^6/7. In the broader blood draw window, the previously validated risk predictor threshold significantly stratified higher and lower risk of sPTB, and the risk predictor again showed significantly greater observed sensitivity in excluding-LMP subjects. These findings have implications for testing the performance of models aimed at predicting PTB.

Clinical and economic evaluation of a proteomic biomarker preterm birth risk predictor: cost-effectiveness modeling of prenatal interventions applied to predicted higher-risk pregnancies within a large and diverse cohort

OBJECTIVES

Preterm birth occurs in more than 10% of U.S. births and is the leading cause of U.S. neonatal deaths, with estimated annual costs exceeding $25 billion USD. Using real-world data, we modeled the potential clinical and economic utility of a prematurity-reduction program comprising screening in a racially and ethnically diverse population with a validated proteomic biomarker risk predictor, followed by case management with or without pharmacological treatment.

METHODS

The ACCORDANT microsimulation model used individual patient data from a prespecified, randomly selected sub-cohort (N = 847) of a multicenter, observational study of U.S. subjects receiving standard obstetric care with masked risk predictor assessment (TREETOP; NCT02787213). All subjects were included in three arms across 500 simulated trials: standard of care (SoC, control); risk predictor/case management comprising increased outreach, education and specialist care (RP-CM, active); and multimodal management (risk predictor/case management with pharmacological treatment) (RP-MM, active). In the active arms, only subjects stratified as higher risk by the predictor were modeled as receiving the intervention, whereas lower-risk subjects received standard care. Higher-risk subjects' gestational ages at birth were shifted based on published efficacies, and dependent outcomes, calibrated using national datasets, were changed accordingly. Subjects otherwise retained their original TREETOP outcomes. Arms were compared using survival analysis for neonatal and maternal hospital length of stay, bootstrap intervals for neonatal cost, and Fisher's exact test for neonatal morbidity/mortality (significance, p < .05).

RESULTS

The model predicted improvements for all outcomes. RP-CM decreased neonatal and maternal hospital stay by 19% (p = .029) and 8.5% (p = .001), respectively; neonatal costs' point estimate by 16% (p = .098); and moderate-to-severe neonatal morbidity/mortality by 29% (p = .025). RP-MM strengthened observed reductions and significance. Point estimates of benefit did not differ by race/ethnicity.

CONCLUSIONS

Modeled evaluation of a biomarker-based test-and-treat strategy in a diverse population predicts clinically and economically meaningful improvements in neonatal and maternal outcomes.

Clinical Validation of a Proteomic Biomarker Threshold for Increased Risk of Spontaneous Preterm Birth and Associated Clinical Outcomes: A Replication Study

Preterm births are the leading cause of neonatal death in the United States. Previously, a spontaneous preterm birth (sPTB) predictor based on the ratio of two proteins, IBP4/SHBG, was validated as a predictor of sPTB in the Proteomic Assessment of Preterm Risk (PAPR) study. In particular, a proteomic biomarker threshold of -1.37, corresponding to a ~two-fold increase or ~15% risk of sPTB, significantly stratified earlier deliveries. Guidelines for molecular tests advise replication in a second independent study. Here we tested whether the significant association between proteomic biomarker scores above the threshold and sPTB, and associated adverse outcomes, was replicated in a second independent study, the Multicenter Assessment of a Spontaneous Preterm Birth Risk Predictor (TREETOP). The threshold significantly stratified subjects in PAPR and TREETOP for sPTB (p = 0.041, p = 0.041, respectively). Application of the threshold in a Kaplan-Meier analysis demonstrated significant stratification in each study, respectively, for gestational age at birth (p < 001, p = 0.0016) and rate of hospital discharge for both neonate (p < 0.001, p = 0.005) and mother (p < 0.001, p < 0.001). Above the threshold, severe neonatal morbidity/mortality and mortality alone were 2.2 (p = 0.0083,) and 7.4-fold higher (p = 0.018), respectively, in both studies combined. Thus, higher predictor scores were associated with multiple adverse pregnancy outcomes.

Is Exposure to Intrapartum Prostaglandins for Labor Induction Associated with a Lower Incidence of Neonatal Respiratory Distress Syndrome?

OBJECTIVE

Respiratory distress syndrome (RDS) is implicated in 30% of neonatal deaths. Since prostaglandins promote surfactant secretion and labor is associated with a lower risk of RDS in term neonates, it is plausible that synthetic prostaglandin (sPG) exposure is associated with a lower risk of RDS. Thus, we evaluated the association between sPG exposure and RDS in neonates born after the induction of labor (IOL).

STUDY DESIGN

Secondary analysis of women with singleton pregnancies undergoing IOL at 34^0/7 to 42^0/7 weeks in the nuMoM2b study, a multicenter prospective cohort of nulliparous women. RDS rates and secondary neonatal outcomes in neonates with intrapartum sPG exposure were compared with those who had IOL with non-sPG methods (e.g., balloon catheter, amniotomy, oxytocin, and laminaria). Logistic regression models estimated the association of sPG with RDS and with secondary outcomes after adjustment for clinical and demographic factors (including gestational age). A sensitivity analysis was performed in which analysis was restricted to those with an admission cervical dilation ≤2 cm.

RESULTS

Of 10,038 women in the total cohort, 3,071 met inclusion criteria; 1,444 were exposed and 1,627 were unexposed to sPGs. Antenatal corticosteroid exposure rates were low (3.0%) and similar between groups. In univariable analysis, neonates with sPG exposure had higher rates of RDS (3.2 vs. 2.0%, odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.01-2.50). This relationship was similar by gestational age at delivery (term vs. preterm, interaction p = 0.14). After adjustment, the association between sPG and RDS was no longer significant (adjusted odds ratio: 1.4, 95% CI: 0.9-2.3). When analysis was restricted to subjects with admission cervical dilation of ≤2 cm, there was also no association between sPG exposure and RDS.

CONCLUSION

In pregnancies between 34 and 42 weeks of gestation, exposure to sPG for cervical ripening or labor induction was not associated with newborn RDS.

KEY POINTS

· RDS is implicated in 30% of neonatal deaths.. · sPG exposure was not associated with RDS.. · Avoiding preterm birth remains crucial in RDS prevention..

Evaluation of a novel screening method for fetal aneuploidy using cell-free DNA in maternal plasma

Objective

To evaluate the test performance of a novel sequencing technology using molecular inversion probes applied to cell-free DNA screening for fetal aneuploidy.

Methods

Two cohorts were included in the evaluation; a risk-based cohort of women receiving diagnostic testing in the first and second trimesters was combined with stored samples from pregnancies with fetuses known to be aneuploid or euploid. All samples were blinded to testing personnel before being analyzed, and validation occurred after the study closed and results were merged.

Results

Using the new sequencing technology, 1414 samples were analyzed. The findings showed sensitivities and specificities for the common trisomies and the sex chromosome aneuploidies at >99% (Trisomy 21 sensitivity 99.2 CI 95.6–99.2; specificity 99.9 CI 99.6–99.9). Positive predictive values among the trisomies varied from 85.2% (Trisomy 18) to 99.0% (Trisomy 21), reflecting their prevalence rates in the study. Comparisons with a meta-analysis of recent cell-free DNA screening publications demonstrated equivalent test performance.

Conclusion

This new technology demonstrates equivalent test performance compared with alternative sequencing approaches, and demonstrates that each chromosome can be successfully interrogated using a single probe.

Cervical Pessary versus Expectant Management for the Prevention of Delivery Prior to 36 Weeks in Women with Placenta Previa: A Randomized Controlled Trial

Objective  This multicenter randomized controlled trial compared cervical pessary (CP) versus expectant management (EM) in women with placenta previa between 22.0 and 32.0 in prolonging gestation until ≥ 36.0 weeks' gestation. Study Design  This study took place from November 2016 to June 2018. Women were randomized to receive either the Bioteque CP or EM. The pessary was removed at ≥ 36.0 weeks unless indicated. The primary outcome was gestational age (GA) at delivery, with secondary outcomes including need for transfusion, number and duration of antepartum admissions, type of delivery, and neonatal outcomes. A total of 140 patients were needed to show a 3-week prolongation of pregnancy in the pessary group; however, the trial was stopped early due to budgetary issues. Results  Of the 33 eligible women, 17 were enrolled. Although not statistically significant, the mean GA at delivery in the CP group was greater than women in the EM group (36.5 ± 1.23 vs. 36.0 ± 2.0; p  = 0.1673). The number and duration of antepartum admissions was greater in the EM group (2.7 ± 0.58 vs. 16.0 ± 22.76 days; p  = 0.1264) as well. Conclusion  Although the study was underpowered to determine the primary outcome, safety and feasibility of CP in pregnancies complicated with previa were demonstrated.

Effects of repeat prenatal corticosteroids given to women at risk of preterm birth: An individual participant data meta-analysis

BACKGROUND

Infants born preterm compared with infants born at term are at an increased risk of dying and of serious morbidities in early life, and those who survive have higher rates of neurological impairments. It remains unclear whether exposure to repeat courses of prenatal corticosteroids can reduce these risks. This individual participant data (IPD) meta-analysis (MA) assessed whether repeat prenatal corticosteroid treatment given to women at ongoing risk of preterm birth in order to benefit their infants is modified by participant or treatment factors.

METHODS AND FINDINGS

Trials were eligible for inclusion if they randomised women considered at risk of preterm birth who had already received an initial, single course of prenatal corticosteroid seven or more days previously and in which corticosteroids were compared with either placebo or no placebo. The primary outcomes for the infants were serious outcome, use of respiratory support, and birth weight z-scores; for the children, they were death or any neurosensory disability; and for the women, maternal sepsis. Studies were identified using the Cochrane Pregnancy and Childbirth search strategy. Date of last search was 20 January 2015. IPD were sought from investigators with eligible trials. Risk of bias was assessed using criteria from the Cochrane Collaboration. IPD were analysed using a one-stage approach. Eleven trials, conducted between 2002 and 2010, were identified as eligible, with five trials being from the United States, two from Canada, and one each from Australia and New Zealand, Finland, India, and the United Kingdom. All 11 trials were included, with 4,857 women and 5,915 infants contributing data. The mean gestational age at trial entry for the trials was between 27.4 weeks and 30.2 weeks. There was no significant difference in the proportion of infants with a serious outcome (relative risk [RR] 0.92, 95% confidence interval [CI] 0.82 to 1.04, 5,893 infants, 11 trials, p = 0.33 for heterogeneity). There was a reduction in the use of respiratory support in infants exposed to repeat prenatal corticosteroids compared with infants not exposed (RR 0.91, 95% CI 0.85 to 0.97, 5,791 infants, 10 trials, p = 0.64 for heterogeneity). The number needed to treat (NNT) to benefit was 21 (95% CI 14 to 41) women/fetus to prevent one infant from needing respiratory support. Birth weight z-scores were lower in the repeat corticosteroid group (mean difference -0.12, 95%CI -0.18 to -0.06, 5,902 infants, 11 trials, p = 0.80 for heterogeneity). No statistically significant differences were seen for any of the primary outcomes for the child (death or any neurosensory disability) or for the woman (maternal sepsis). The treatment effect varied little by reason the woman was considered to be at risk of preterm birth, the number of fetuses in utero, the gestational age when first trial treatment course was given, or the time prior to birth that the last dose was given. Infants exposed to between 2-5 courses of repeat corticosteroids showed a reduction in both serious outcome and the use of respiratory support compared with infants exposed to only a single repeat course. However, increasing numbers of repeat courses of corticosteroids were associated with larger reductions in birth z-scores for weight, length, and head circumference. Not all trials could provide data for all of the prespecified subgroups, so this limited the power to detect differences because event rates are low for some important maternal, infant, and childhood outcomes.

CONCLUSIONS

In this study, we found that repeat prenatal corticosteroids given to women at ongoing risk of preterm birth after an initial course reduced the likelihood of their infant needing respiratory support after birth and led to neonatal benefits. Body size measures at birth were lower in infants exposed to repeat prenatal corticosteroids. Our findings suggest that to provide clinical benefit with the least effect on growth, the number of repeat treatment courses should be limited to a maximum of three and the total dose to between 24 mg and 48 mg.

"Doing something" about the cesarean delivery rate

There is a general consensus that the cesarean delivery rate in the United States is too high, and that practice patterns of obstetricians are largely to blame for this situation. In reality, the US cesarean delivery rate is the result of 3 forces largely beyond the control of the practicing clinician: patient expectations and misconceptions regarding the safety of labor, the medical-legal system, and limitations in technology. Efforts to "do something" about the cesarean delivery rate by promulgating practice directives that are marginally evidence-based or influenced by social pressures are both ineffective and potentially harmful. We examine both the recent American Congress of Obstetricians and Gynecologists (ACOG)/Society for Maternal-Fetal Medicine Care Consensus Statement "Safe Prevention of Primary Cesarean Delivery" document and the various iterations of the ACOG guidelines for vaginal birth after cesarean delivery in this context. Adherence to arbitrary time limits for active phase or second-stage arrest without incorporating other clinical factors into the decision-making process is unwise. In a similar manner, ever-changing practice standards for vaginal birth after cesarean driven by factors other than changing data are unlikely to be effective in lowering the cesarean delivery rate. Whether too high or too low, the current US cesarean delivery rate is the expected result of the unique demographic, geographic, and social forces driving it and is unlikely to change significantly given the limitations of current technology to otherwise satisfy the demands of these forces.

Estimating risk of severe neonatal morbidity in preterm births under 32 weeks of gestation

Background: A large recent study analyzed the relationship between multiple factors and neonatal outcome and in preterm births. Study variables included the reason for admission, indication for delivery, optimal steroid use, gestational age, and other potential prognostic factors. Using stepwise multivariable analysis, the only two variables independently associated with serious neonatal morbidity were gestational age and the presence of suspected intrauterine growth restriction as a reason for admission. This finding was surprising given the beneficial effects of antenatal steroids and hazards associated with some causes of preterm birth. Multivariable logistic regression techniques have limitations. Without testing for multiple interactions, linear regression will identify only individual factors with the strongest independent relationship to the outcome for the entire study group. There may not be a single "best set" of risk factors or one set that applies equally well to all subgroups. In contrast, machine learning techniques find the most predictive groupings of factors based on their frequency and strength of association, with no attempt to identify independence and no assumptions about linear relationships.Objective: To determine if machine learning techniques would identify specific clusters of conditions with different probability estimates for severe neonatal morbidity and to compare these findings to those based on the original multivariable analysis.Materials and methods: This was a secondary analysis of data collected in a multicenter, prospective study on all admissions to the neonatal intensive care unit between 2013 and 2015 in 10 hospitals. We included all patients with a singleton, stillborn, or live newborns, with a gestational age between 23 0/7 and 31 6/7 week. The composite endpoint, severe neonatal morbidity, defined by the presence of any of five outcomes: death, grade 3 or 4 intraventricular hemorrhage (IVH), and ≥28 days on ventilator, periventricular leukomalacia (PVL), or stage III necrotizing enterocolitis (NEC), was present in 238 of the 1039 study patients. We studied five explanatory variables: maternal age, parity, gestational age, admission reason, and status with respect to antenatal steroid administration. We concentrated on Classification and Regression Trees because the resulting structure defines clusters of risk factors that often bear resemblance to clinical reasoning. Model performance was measured using area under the receiver-operator characteristic curves (AUC) based on 10 repetitions of 10-fold cross-validation.Results: A hybrid technique using a combination of logistic regression and Classification and Regression Trees had a mean cross-validated AUC of 0.853. A selected point on its receiver-operator characteristic (ROC) curve corresponding to a sensitivity of 81% was associated with a specificity of 76%. Rather than a single curve representing the general relationship between gestational age and severe morbidity, this technique found seven clusters with distinct curves. Abnormal fetal testing as a reason for admission with or without growth restriction and incomplete steroid administration would place a 20-year-old patient on the highest risk curve.Conclusions: Using a relatively small database and a few simple factors known before birth it is possible to produce a more tailored estimate of the risk for severe neonatal morbidity on which clinicians can superimpose their medical judgment, experience, and intuition.

The Impact of cfDNA Screening on the Frequency of Invasive Procedures in a Geographically Diverse Private Network

Objective Cell-free fetal DNA (cfDNA) screening has had a dramatic impact in obstetrics. We examined the impact of cfDNA screening in a network of geographically diverse referral maternal–fetal medicine (MFM) private practices.

Study Design Data were derived from the genetic clinics of 16 testing centers from a wide geographic area and included all women undergoing either amniocentesis or chorionic villus sampling (CVS) during a 6-month control period versus a 30-month study period.

Results During the control period, there were 193 amniocenteses and 47 CVS/month. During the last 6 months of the study, amniocenteses dropped to 52/month and CVS to 18/month. Positive aneuploid test results per procedure increased from 6.9% during the control period to 15.0% during the last 6 months of the study period. However, the overall number of aneuploidy results decreased from 16.7/month to of 10.5/month.

Conclusion Our study demonstrates the dramatic changes in the era of cfDNA screening on reducing the frequency of amniocentesis and CVS associated with a higher percentage of positive results per procedure. There was an unexpected decrease in aneuploid fetuses diagnosed over the study period, which could reflect decisions regarding genetically abnormal fetuses being made without a definitive diagnostic procedure.

A randomized, double-blinded, controlled trial of the effects of fluid rate and/or presence of dextrose in intravenous fluids on the labor course of nulliparas

BACKGROUND

Prolonged labor has been demonstrated to increase adverse maternal and neonatal outcome. A practice that may decrease the risk of prolonged labor is the modification of fluid intake during labor.

OBJECTIVE

Several studies demonstrated that increased hydration in labor as well as addition of dextrose-containing fluids may be associated with a decrease in length of labor. The purpose of our study was to characterize whether high-dose intravenous fluids, standard-dose fluids with dextrose, or high-dose fluids with dextrose show a difference in the duration of labor in nulliparas.

STUDY DESIGN

Nulliparous subjects with singletons who presented in active labor were randomized to 1 of 3 groups of intravenous fluids: 250 mL/h of normal saline, 125 mL/h of 5% dextrose in normal saline, or 250 mL/h of 2.5% dextrose in normal saline. The primary outcome was total length of labor from initiation of intravenous fluid in vaginally delivered subjects. Secondary outcomes included cesarean delivery rate and length of second stage of labor, among other maternal and neonatal outcomes.

RESULTS

In all, 274 subjects who met inclusion criteria were enrolled. There were no differences in baseline characteristics among the 3 groups. There was no difference in the primary outcome of total length of labor in vaginally delivered subjects among the 3 groups. First stage of labor duration, second stage of labor duration, and cesarean delivery rates were also equivalent. There were no differences identified in other secondary outcomes including clinical chorioamnionitis, postpartum hemorrhage, blood loss, Apgar scores, or neonatal intensive care admission.

CONCLUSION

There is no difference in length of labor or delivery outcomes when comparing high-dose intravenous fluids, addition of dextrose, or use of high-dose intravenous fluids with dextrose in nulliparous women who present in active labor.

A multicenter prospective study of neonatal outcomes at less than 32 weeks associated with indications for maternal admission and delivery

BACKGROUND

Counseling for patients with impending premature delivery traditionally has been based primarily on the projected gestational age at delivery. There are limited data regarding how the indications for the preterm birth affect the neonatal outcome and whether this issue should be taken into account in decisions regarding management and patient counseling.

OBJECTIVE

We performed a prospective study of pregnancies resulting in premature delivery at less than 32 weeks to determine the influence of both the indications for admission and their associated indications for delivery on neonatal mortality and complications of prematurity.

STUDY DESIGN

This is a multicenter, prospective study in 10 hospitals where all data from the neonatal intensive care unit routinely was imported to a deidentified data warehouse. Maternal data were collected prospectively at or near the time of delivery. Eligible subjects included singleton deliveries in these hospitals between 23 0/7 and 31 6/7 weeks. The primary hypothesis of the study was to determine whether there was a difference in the primary outcome, which was defined as neonatal composite morbidity, between those neonates delivered after admission for premature labor vs premature rupture of membranes, because these were expected to be the 2 most frequent diagnoses leading to premature birth. The sample size was calculated based on a 10% difference in outcomes for these 2 entities. We based this hypothesis on the knowledge that premature rupture of membranes has a greater incidence of intra-amniotic infection and inflammation than premature labor and that outcomes for premature neonates are worse when delivery is associated with intra-amniotic infection. Additional outcomes were analyzed for all other indications for admission and delivery. Composite morbidity was defined as ≥1 of the following: respiratory distress syndrome (oxygen requirement, clinical diagnosis, and consistent chest radiograph), bronchopulmonary dysplasia (requirement for oxygen support at 28 days of life), severe intraventricular hemorrhage (grades 3 or 4), periventricular leukomalacia, blood culture-proven sepsis present within 72 hours of birth, necrotizing enterocolitis, or neonatal death before discharge from the hospital. A secondary composite of serious neonatal morbidity also was defined prospectively.

RESULTS

The study included 1089 mother/baby pairs. Composite morbidity between those with premature labor (77.2%) and premature rupture of membranes (73.2%) was not significantly different (P = .29). A few neonatal complications were associated with indications for admission and delivery, but on logistic regression adjusting for gestational age and other confounders, suspected intrauterine growth restriction was the only indication for admission or delivery associated with an increase in serious morbidity (odds ratio 4.5, [2.1 to 9.8], P < .003). Other factors not related to the indications for admission including cesarean delivery, and low 5-minute Apgar were associated with an increase in morbidity.

CONCLUSION

Studies of many single factors related to the indications for preterm delivery have been shown to be associated with adverse neonatal outcome. In this study evaluating all of the most frequent indications, however, we found only suspected intrauterine growth restriction as an indication for admission and delivery was found to be so. Thus, it seems that in almost all situations counseling patients can be based primarily on gestational age along with other factors including estimated fetal weight, sex, race, plurality, and completion of a course of antenatal corticosteroids.

Exposure to any antenatal corticosteroids and outcomes in preterm infants by gestational age: prospective cohort study

Objective To determine whether exposure to any antenatal corticosteroids is associated with a lower rate of death at each gestational age at which administration is currently recommended.Design Prospective cohort study.Settings 300 participating neonatal intensive care units of the Pediatrix Medical Group in the United States.Participants 117 941 infants 23 0/7 to 34 6/7 weeks' gestational age born between 1 January 2009 and 31 December 2013.Exposure Any antenatal corticosteroids.Main outcomes measures Death or major hospital morbidities analyzed by gestational age and exposure to antenatal corticosteroids with models adjusted for birth weight, sex, mode of delivery, and multiple births.Results Infants exposed to antenatal corticosteroids (n=81 832) had a significantly lower rate of death before discharge at each gestation 29 weeks or less, 31 weeks, and 33-34 weeks compared with infants without exposure (range of adjusted odds ratios 0.32 to 0.55). The number needed to treat with antenatal corticosteroids to prevent one death before discharge increased from six at 23 and 24 weeks' gestation to 798 at 34 weeks' gestation. The rate of survival without major hospital morbidity was higher among infants exposed to antenatal corticosteroids at the lowest gestations. Infants exposed to antenatal corticosteroids had lower rates of severe intracranial hemorrhage or death, necrotizing enterocolitis stage 2 or above or death, and severe retinopathy of prematurity or death compared with infants without exposure at all gestations less than 30 weeks and most gestations for infants born at 30 weeks' gestation or later.Conclusion Among infants born from 23 to 34 weeks' gestation, antenatal exposure to corticosteroids compared with no exposure was associated with lower mortality and morbidity at most gestations. The effect size of exposure to antenatal corticosteroids on mortality seems to be larger in infants born at the lowest gestations.

The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia

BACKGROUND

Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive.

OBJECTIVE

The purpose of this study was to validate a recently published algorithm for the management of category II fetal heart rate tracings, to examine reasons for the birth of infants with significant metabolic acidemia despite the use of electronic fetal heart rate monitoring, and to examine critically the limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia.

STUDY DESIGN

The potential performance of electronic fetal heart rate monitoring under ideal circumstances was evaluated in an outcomes-blinded examination fetal heart rate tracing of infants with metabolic acidemia at birth (base deficit, >12) and matched control infants (base deficit, <8) under the following conditions: (1) expert primary interpretation, (2) use of a published algorithm that was developed and endorsed by a large group of national experts, (3) assumption of a 30-minute period of evaluation for noncritical category II fetal heart rate tracings, followed by delivery within 30 minutes, (4) evaluation without the need to provide patient care simultaneously, and (5) comparison of results under these circumstances with those achieved in actual clinical practice.

RESULTS

During the study period, 120 infants were identified with an arterial cord blood base deficit of >12 mM/L. Matched control infants were not demographically different from subjects. In actual practice, operative intervention on the basis of an abnormal fetal heart rate tracings occurred in 36 of 120 fetuses (30.0%) with metabolic acidemia. Based on expert, algorithm-assisted reviews, 55 of 120 patients with acidemia (45.8%) were judged to need operative intervention for abnormal fetal heart rate tracings. This difference was significant (P=.016). In infants who were born with a base deficit of >12 mM/L in which blinded, algorithm-assisted expert review indicated the need for operative delivery, the decision for delivery would have been made an average of 131 minutes before the actual delivery. The rate of expert intervention for fetal heart rate concerns in the nonacidemic control group (22/120; 18.3%) was similar to the actual intervention rate (23/120; 19.2%; P=1.0) Expert review did not mandate earlier delivery in 65 of 120 patients with metabolic acidemia. The primary features of these 65 cases included the occurrence of sentinel events with prolonged deceleration just before delivery, the rapid deterioration of nonemergent category II fetal heart rate tracings before realistic time frames for recognition and intervention, and the failure of recognized fetal heart rate patterns such as variability to identify metabolic acidemia.

CONCLUSIONS

Expert, algorithm-assisted fetal heart rate interpretation has the potential to improve standard clinical performance by facilitating significantly earlier recognition of some tracings that are associated with metabolic acidemia without increasing the rate of operative intervention. However, this improvement is modest. Of infants who are born with metabolic acidemia, only approximately one-half potentially could be identified and have delivery expedited even under ideal circumstances, which are probably not realistic in current US practice. This represents the limits of electronic fetal heart rate monitoring performance. Additional technologies will be necessary if the goal of the prevention of neonatal metabolic acidemia is to be realized.

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

OBJECTIVE

To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and Cochrane databases (until December 2015).

REVIEW METHODS

Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks' gestation.

RESULTS

32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks' gestation (risk difference 1.2/1000, 95% confidence interval -1.3 to 3.6; I(2)=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I(2)=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (-12.4 to 17.4/1000; I(2)=0%). The rates of neonatal morbidity showed a consistent reduction with increasing gestational age in monochorionic and dichorionic pregnancies, and admission to the neonatal intensive care unit was the commonest neonatal complication. The actual risk of stillbirth near term might be higher than reported estimates because of the policy of planned delivery in twin pregnancies.

CONCLUSIONS

To minimise perinatal deaths, in uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks' gestation; in monochorionic pregnancies delivery should be considered at 36 weeks.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014007538.

Assessing first-stage labor progression and its relationship to complications

BACKGROUND

New labor curves have challenged the traditional understanding of the general pattern of dilation and descent in labor. They also revealed wide variation in the time to advance in dilation. An interval of arrest such as 4 hours did not fall beyond normal limits until dilation had reached 6 cm. Thus, the American College of Obstetricians and Gynecologists/Society for Maternal-Fetal Medicine first-stage arrest criteria, based in part on these findings, are applicable only in late labor. The wide range of time to dilate is unavoidable because cervical dilation has neither a precise nor direct relationship to time. Newer statistical techniques (multifactorial models) can improve precision by incorporating several factors that are related directly to labor progress. At each examination, the calculations adapt to the mother's current labor conditions. They produce a quantitative assessment that is expressed in percentiles. Low percentiles indicate potentially problematic labor progression.

OBJECTIVE

The purpose of this study was to assess the relationship between first-stage labor progress- and labor-related complications with the use of 2 different assessment methods. The first method was based on arrest of dilation definitions. The other method used percentile rankings of dilation or station based on adaptive multifactorial models.

STUDY DESIGN

We included all 4703 cephalic-presenting, term, singleton births with electronic fetal monitoring and cord gases at 2 academic community referral hospitals in 2012 and 2013. We assessed electronic data for route of delivery, all dilation and station examinations, newborn infant status, electronic fetal monitoring tracings, and cord blood gases. The labor-related complication groups included 272 women with cesarean delivery for first-stage arrest, 558 with cesarean delivery for fetal heart rate concerns, 178 with obstetric hemorrhage, and 237 with neonatal depression, which left 3004 women in the spontaneous vaginal birth group. Receiver operating characteristic curves were constructed for each assessment method by measurement of the sensitivity for each complication vs the false-positive rate in the normal reference group.

RESULTS

The duration of arrest at ≥6 cm dilation showed poor levels of discrimination for the cesarean delivery interventions (area under the curve, 0.55-0.65; P < .01) and no significant relationship to hemorrhage or neonatal depression. The dilation and station percentiles showed high discrimination for the cesarean delivery-related outcomes (area under the curve, 0.78-0.93; P < .01) and low discrimination for the clinical outcomes of hemorrhage and neonatal depression (area under the curve, 0.58-0.61; P < .01).

CONCLUSIONS

Duration of arrest of dilation at ≥6 cm showed little or no discrimination for any of the complications. In comparison, percentile rankings that were based on the adaptive multifactorial models showed much higher discrimination for cesarean delivery interventions and better, but low discrimination for hemorrhage. Adaptive multifactorial models present a different method to assess labor progress. Rather than "pass/fail" criteria that are applicable only to dilation in late labor, they produce percentile rankings, assess 2 essential processes for vaginal birth (dilation and descent), and can be applied from 3 cm onward. Given the limitations of labor-progress assessment based solely on the passage of time and because of the extreme variation in decision-making for cesarean delivery for labor disorders, the types of mathematic analyses that are described in this article are logical and promising steps to help standardize labor assessment.

Role of the Hospitalist and Maternal Fetal Medicine Physician in Obstetrical Inpatient Care

OBJECTIVE

The objective of this study was to evaluate the role of hospitalists and Maternal Fetal Medicine (MFM) subspecialists in obstetrical inpatient care.

STUDY DESIGN

This electronic survey study was offered to members of the American College of Obstetrics & Gynecology (ACOG; n = 1,039) and the Society for Maternal-Fetal Medicine (SMFM; n = 1,813).

RESULTS

Overall, 607 (21%) respondents completed the survey. Overall, 35% reported that hospitalists provided care in at least one of their hospitals. Compared with ACOG respondents, a higher frequency of SMFM respondents reported comfort with hospitalists providing care for all women on labor and delivery (74.4 vs. 43.5%, p = 0.005) and women with complex issues (56.4 vs. 43.5%, p = 0.004). The majority of ACOG respondents somewhat/completely agreed that hospitalists were associated with decreased adverse events (69%) and improved safety/safety culture (70%). Overall, 35% of ACOG respondents have MFM consultation available with 53% having inpatient coverage. Of these, 85% were satisfied with MFM availability.

CONCLUSION

Over one-third of respondents work in units staffed with hospitalists and more than half have inpatient MFM coverage. It is important to evaluate if and how hospitalists can improve maternal and perinatal outcomes, and the types of hospitals that are best served by them.

17-Hydroxyprogesterone caproate in triplet pregnancy: an individual patient data meta-analysis

BACKGROUND

Preterm birth complicates almost all triplet pregnancies and no preventive strategy has proven effective.

OBJECTIVE

To determine, using individual patient data (IPD) meta-analysis, whether the outcome of triplet pregnancy is affected by prophylactic administration of 17-hydroxyprogesterone caproate (17OHPc).

SEARCH STRATEGY

We searched literature databases, trial registries and references in published articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of progestogens versus control that included women with triplet pregnancies.

DATA COLLECTION AND ANALYSIS

Investigators from identified RCTs collaborated on the protocol and contributed their IPD. The primary outcome was a composite measure of adverse perinatal outcome. The secondary outcome was the rate of birth before 32 weeks of gestation. Other pre-specified outcomes included randomisation-to-delivery interval and rates of birth at <24, <28 and <34 weeks of gestation.

MAIN RESULTS

Three RCTs of 17OHPc versus placebo included 232 mothers with triplet pregnancies and their 696 offspring. Risk-of-bias scores and between-study heterogeneity were low. Baseline characteristics were comparable between 17OHPc and placebo groups. The rate of the composite adverse perinatal outcome was similar among those treated with 17OHPc and those treated with placebo (34 and 35%, respectively; risk ratio [RR] 0.98, 95% confidence interval [95% CI] 0.79-1.2). The rate of birth at <32 weeks was also similar in the two groups (35 and 38%, respectively; RR 0.92, 95% CI 0.55-1.56). There were no significant between-group differences in perinatal mortality rate, randomisation-to-delivery interval, or other specified outcomes.

CONCLUSION

Prophylactic 17OHPc given to mothers with triplet pregnancies had no significant impact on perinatal outcome or pregnancy duration.

TWEETABLE ABSTRACT

17-Hydroxyprogesterone caproate had no significant impact on the outcome or duration of triplet pregnancy.

Business and Organizational Models of Obstetric and Gynecologic Hospitalist Groups

The growth of obstetric and gynecologic (OB/GYN) hospitalists throughout the United States has led to different organizational approaches, depending on the perception of what an OB/GYN hospitalist is. There are advantages of OB/GYN hospitalist practices; however, practitioners who do this as just 1 piece of their practice are not fulfilling the promise of what this new specialty can deliver. Because those with office practices have their own business models, this article is devoted to the organizational and business models of OB/GYN hospitalists for physicians whose practice is devoted to inpatient obstetrics with or without emergency room and/or inpatient gynecology coverage.

17-hydroxyprogesterone caproate for preterm rupture of the membranes: a multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVE

Preterm rupture of membranes (PROM) is associated with an increased risk of preterm birth and neonatal morbidity. Prophylactic 17-hydroxyprogesterone caproate (17OHP-C) reduces the risk of preterm birth in some women who are at risk for preterm birth. We sought to test whether 17OHP-C would prolong pregnancy or improve perinatal outcome when given to mothers with preterm rupture of the membranes.

STUDY DESIGN

This is a multicenter, double-blind, placebo-controlled, randomized clinical trial. The study included singleton pregnancies with gestational ages from 23(0/7) to 30(6/7) weeks at enrollment, documented PROM, and no contraindication to expectant management. Consenting women were assigned randomly to receive weekly intramuscular injections of 17OHP-C (250 mg) or placebo. The primary outcome was continuation of pregnancy until a favorable gestational age, which was defined as either 34(0/7) weeks of gestation or documentation of fetal lung maturity at 32(0/7) to 33(6/7) weeks of gestation. The 2 prespecified secondary outcomes were interval from randomization to delivery and composite adverse perinatal outcome. The planned sample size was 222 total women.

RESULTS

From October 2011 to April 2014, 152 women were enrolled; 74 women were allocated randomly to 17OHP-C, and 78 were allocated randomly to placebo. The trial was stopped when results of a planned interim analysis suggested that continuation was futile. The primary outcome was achieved in 3% of the 17OHP-C group and 8% of the placebo group (P = .18). There was no significant between-group difference in the prespecified secondary outcomes, randomization-to-delivery interval (17.1 ± 16.1 vs 17.0 ± 15.8 days, respectively; P = .76) or composite adverse perinatal outcome (63% vs 61%, respectively; P = .93). No significant differences were found in other outcomes, which included rates of chorioamnionitis, postpartum endometritis, cesarean delivery, individual components of the composite outcome, or prolonged neonatal length of stay.

CONCLUSION

Compared with placebo, weekly 17OHP-C injections did not prolong pregnancy or reduce perinatal morbidity in patients with PROM in this trial.

Detection of microbial invasion of the amniotic cavity by analysis of cervicovaginal proteins in women with preterm labor and intact membranes

OBJECTIVE

Microbial invasion of the amniotic cavity (MIAC) is common in early preterm labor and is associated with maternal and neonatal infectious morbidity. MIAC is usually occult and is reliably detected only with amniocentesis. We sought to develop a noninvasive test to predict MIAC based on protein biomarkers in cervicovaginal fluid (CVF) in a cohort of women with preterm labor (phase 1) and to validate the test in an independent cohort (phase 2).

STUDY DESIGN

This was a prospective study of women with preterm labor who had amniocentesis to screen for MIAC. MIAC was defined by positive culture and/or 16S ribosomal DNA results. Nine candidate CVF proteins were analyzed by enzyme-linked immunosorbent assay. Logistic regression was used to identify combinations of up to 3 proteins that could accurately classify the phase 1 cohort (N = 108) into those with or without MIAC. The best models, selected by area under the curve (AUC) of the receiver operating characteristic curve in phase 1, included various combinations of interleukin (IL)-6, chemokine (C-X-C motif) ligand 1 (CXCL1), alpha fetoprotein, and insulin-like growth factor binding protein-1. Model performance was then tested in the phase 2 cohort (N = 306).

RESULTS

MIAC was present in 15% of cases in phase 1 and 9% in phase 2. A 3-marker CVF model using IL-6 plus CXCL1 plus insulin-like growth factor binding protein-1 had AUC 0.87 in phase 1 and 0.78 in phase 2. Two-marker models using IL-6 plus CXCL1 or alpha fetoprotein plus CXCL1 performed similarly in phase 2 (AUC 0.78 and 0.75, respectively), but were not superior to CVF IL-6 alone (AUC 0.80). A cutoff value of CVF IL-6 ≥463 pg/mL (which had 81% sensitivity in phase 1) predicted MIAC in phase 2 with sensitivity 79%, specificity 78%, positive predictive value 38%, and negative predictive value 97%.

CONCLUSION

High levels of IL-6 in CVF are strongly associated with MIAC. If developed into a bedside test or rapid laboratory assay, cervicovaginal IL-6 might be useful in selecting patients in whom the probability of MIAC is high enough to warrant amniocentesis or transfer to a higher level of care. Such a test might also guide selection of potential subjects for treatment trials.

Fetal fibronectin versus cervical length as predictors of preterm birth in twin pregnancy with or without 17-hydroxyprogesterone caproate

OBJECTIVE

The objective of this study was to compare cervicovaginal fetal fibronectin (FFN) versus transvaginal sonographic cervical length as predictors of preterm birth in twin pregnancy and to test whether 17-hydroxyprogesterone caproate (17OHPc) modifies the predictive value of FFN.

STUDY DESIGN

Secondary analysis of a randomized trial of 17OHPc versus placebo in dichorionic-diamniotic twins, analyzing the subset with screening FFN (N = 198) and/or cervical length (N = 214) at 24 to 26 weeks of gestation.

RESULTS

Positive FFN was found in 7%, cervical length ≤ 25 mm in 8%, and both positive FFN and cervical length ≤ 25 mm in 3%. Birth < 32, < 34, and < 37 weeks occurred in 8, 30, and 67%, respectively. In logistic regression analysis controlling for FFN, cervical length, prior preterm birth, and treatment group, positive FFN was significantly associated with birth < 30 and < 32 weeks (odds ratio 55.0 [95% confidence interval 5.2-582], 18.1 [3.3-99], respectively, p < 0.001 for both) but cervical length ≤ 25 mm was not (odds ratio 0.1 [0.002-1.6], 0.6 [0.1-4.3]).

CONCLUSION

Positive FFN was stronger than cervical length ≤ 25 mm in predicting early preterm birth in twins, regardless of 17OHPc use. Treatment with 17OHPc did not appear to alter the predictive value of FFN.

Noninvasive prenatal screening for fetal trisomies 21, 18, 13 and the common sex chromosome aneuploidies from maternal blood using massively parallel genomic sequencing of DNA

OBJECTIVE

The objective of this study was to validate the clinical performance of massively parallel genomic sequencing of cell-free deoxyribonucleic acid contained in specimens from pregnant women at high risk for fetal aneuploidy to test fetuses for trisomies 21, 18, and 13; fetal sex; and the common sex chromosome aneuploidies (45, X; 47, XXX; 47, XXY; 47, XYY).

STUDY DESIGN

This was a prospective multicenter observational study of pregnant women at high risk for fetal aneuploidy who had made the decision to pursue invasive testing for prenatal diagnosis. Massively parallel single-read multiplexed sequencing of cell-free deoxyribonucleic acid was performed in maternal blood for aneuploidy detection. Data analysis was completed using sequence reads unique to the chromosomes of interest.

RESULTS

A total of 3430 patients were analyzed for demographic characteristics and medical history. There were 137 fetuses with trisomy 21, 39 with trisomy 18, and 16 with trisomy 13 for a prevalence rate of the common autosomal trisomies of 5.8%. There were no false-negative results for trisomy 21, 3 for trisomy 18, and 2 for trisomy 13; all 3 false-positive results were for trisomy 21. The positive predictive values for trisomies 18 and 13 were 100% and 97.9% for trisomy 21. A total of 8.6% of the pregnancies were 21 weeks or beyond; there were no aneuploid fetuses in this group. All 15 of the common sex chromosome aneuploidies in this population were identified, although there were 11 false-positive results for 45,X. Taken together, the positive predictive value for the sex chromosome aneuploidies was 48.4% and the negative predictive value was 100%.

CONCLUSION

Our prospective study demonstrates that noninvasive prenatal analysis of cell-free deoxyribonucleic acid from maternal plasma is an accurate advanced screening test with extremely high sensitivity and specificity for trisomy 21 (>99%) but with less sensitivity for trisomies 18 and 13. Despite high sensitivity, there was modest positive predictive value for the small number of common sex chromosome aneuploidies because of their very low prevalence rate.

Removal versus retention of cerclage in preterm premature rupture of membranes: a randomized controlled trial

OBJECTIVE

The decision of whether to retain or remove a previously placed cervical cerclage in women who subsequently rupture fetal membranes in a premature gestation is controversial and all studies to date are retrospective. We performed a multicenter randomized controlled trial of removal vs retention of cerclage in these patients to determine whether leaving the cerclage in place prolonged gestation and/or increased the risk of maternal or fetal infection.

STUDY DESIGN

A prospective randomized multicenter trial of 27 hospitals was performed. Patients included were those with cerclage placement at ≤23 weeks 6 days in singleton or twin pregnancies, with subsequent spontaneous rupture of membranes between 22 weeks 0 days and 32 weeks 6 days. Patients were randomized to retention or removal of cerclage. Patients were then expectantly managed and delivered only for evidence of labor, chorioamnionitis, fetal distress, or other medical or obstetrical indications. Management after 34 weeks was at the clinician's discretion.

RESULTS

The initial sample size calculation determined that a total of 142 patients should be included but after a second interim analysis, futility calculations determined that the conditional power for showing statistical significance after randomizing 142 patients for the primary outcome of prolonging pregnancy was 22.8%. Thus the study was terminated after a total of 56 subjects were randomized with complete data available for analysis, 32 to removal and 24 to retention of cerclage. There was no statistical significance in primary outcome of prolonging pregnancy by 1 week comparing the 2 groups (removal 18/32, 56.3%; retention 11/24, 45.8%) P = .59; or chorioamnionitis (removal 8/32, 25.0%; retention 10/24, 41.7%) P = .25, respectively. There was no statistical difference in composite neonatal outcomes (removal 16/33, 50%; retention 17/30, 56%), fetal/neonatal death (removal 4/33, 12%; retention 5/30, 16%); or gestational age at delivery (removal mean 200 days; retention mean 198 days).

CONCLUSION

Statistically significant differences were not seen in prolongation of latency, infection, or composite neonatal outcomes. However, there was a numerical trend in the direction of less infectious morbidity, with immediate removal of cerclage. These findings may not have met statistical significance if the original sample size of 142 was obtained, however they provide valuable data suggesting that there may be no advantage to retaining a cerclage after preterm premature rupture of membranes and a possibility of increased infection with cerclage retention.

Advancing research transdisciplinarity within our discipline

Advancing biomedical knowledge is crucial to the understanding of disease pathophysiology, diagnosis, treatment, and the maintenance of health. Whereas collaborative pursuits among basic and translational scientists, clinical researchers, and clinicians should advance biomedical progress and its translation to better medicine. The field of obstetrics and gynecology and its subspecialties has not escaped this problem. Obstetrics and gynecology specialists and subspecialists have limited opportunities to interact with translational or basic investigators, and cross-fertilization and collaborations are further challenged by the current healthcare and funding climate. This opinion manuscript focuses on the field of maternal-fetal medicine, serving as an example that illustrates the risks and opportunities that might exist within our obstetrics and gynecology academic community. A Pregnancy Task Force recently sought to identify ways to overcome hurdles related to research training, and ensure a sufficient pool of physician-scientists pursuing pertinent questions in the field. The group discussed strategies to promote a culture of intellectual curiosity and research excellence, securing additional resources for trainees, and attracting current and next generation basic, translational, and clinical scholars to our field. Recommendations encompassed activities within annual academic meetings, training initiatives, and additional funding opportunities. Inferences from these discussions can be made to all obstetrics and gynecology subspecialty areas.

Implementation of a laborist program and evaluation of the effect upon cesarean delivery

OBJECTIVE

Laborist programs have expanded throughout the United States in the last decade. Meanwhile, there has been no published research examining their effect on patient outcomes. Cesarean delivery is a key performance metric with maternal health implications and significant financial impact. Our hypothesis is that the initiation of a full-time dedicated laborist staff decreases cesarean delivery.

STUDY DESIGN

In a tertiary hospital staffed with private practice physicians, data were retrospectively reviewed for 3 time periods from 2006 through 2011. The first period (16 months) there were no laborists (traditional model), followed by 14 months of continuous in-hospital laborist coverage provided by community staff (community laborist), and finally a 24-month period with full-time laborists providing continuous in-hospital coverage. The primary hypothesis was that full-time laborists would decrease cesarean delivery rates.

RESULTS

Data from 6206 term nulliparous patients were retrospectively reviewed. The cesarean delivery rate for no laborist care was 39.2%, for community physician laborist care was 38.7%, and for full-time laborists was 33.2%. With adjustment via logistic regression, full-time laborist presence was associated with a significant reduction in cesarean delivery when contrasted with no laborist (odds ratio, 0.73; 95% confidence interval, 0.64-0.83; P < .0001) or community laborist care (odds ratio, 0.77; 95% confidence interval, 0.67-0.87; P < .001). The community laborist model was not associated with an effect upon cesarean delivery.

CONCLUSION

A dedicated full-time laborist staff model is associated with lower rates of cesarean delivery. These findings may be used as part of a strategy to reduce cesarean delivery, lower maternal morbidity and mortality, and decrease health care costs.

Intrapartum management of category II fetal heart rate tracings: towards standardization of care

There is currently no standard national approach to the management of category II fetal heart rate (FHR) patterns, yet such patterns occur in the majority of fetuses in labor. Under such circumstances, it would be difficult to demonstrate the clinical efficacy of FHR monitoring even if this technique had immense intrinsic value, since there has never been a standard hypothesis to test dealing with interpretation and management of these abnormal patterns. We present an algorithm for the management of category II FHR patterns that reflects a synthesis of available evidence and current scientific thought. Use of this algorithm represents one way for the clinician to comply with the standard of care, and may enhance our overall ability to define the benefits of intrapartum FHR monitoring.

Putting the "M" back in maternal-fetal medicine

Although maternal death remains rare in the United States, the rate has not decreased for 3 decades. The rate of severe maternal morbidity, a more prevalent problem, is also rising. Rise in maternal age, in rates of obesity, and in cesarean deliveries as well as more pregnant women with chronic medical conditions all contribute to maternal mortality and morbidity in the United States. We believe it is the responsibility of maternal-fetal medicine (MFM) subspecialists to lead a national effort to decrease maternal mortality and morbidity. In doing so, we hope to reestablish the vital role of MFM subspecialists to take the lead in the performance and coordination of care in complicated obstetrical cases. This article will summarize our initial recommendations to enhance MFM education and training, to establish national standards to improve maternal care and management, and to address critical research gaps in maternal medicine.

Repeat prenatal corticosteroid prior to preterm birth: a systematic review and individual participant data meta-analysis for the PRECISE study group (prenatal repeat corticosteroid international IPD study group: assessing the effects using the best level of evidence) - study protocol

BACKGROUND

The aim of this individual participant data (IPD) meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol.

METHODS/DESIGN

The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE) Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants are eligible for the PRECISE IPD meta-analysis. The primary study outcomes for the infants will be serious neonatal outcome (defined by the PRECISE International IPD Study Group as one of death (foetal, neonatal or infant); severe respiratory disease; severe intraventricular haemorrhage (grade 3 and 4); chronic lung disease; necrotising enterocolitis; serious retinopathy of prematurity; and cystic periventricular leukomalacia); use of respiratory support (defined as mechanical ventilation or continuous positive airways pressure or other respiratory support); and birth weight (Z-scores). For the children, the primary study outcomes will be death or any neurological disability (however defined by trialists at childhood follow up and may include developmental delay or intellectual impairment (developmental quotient or intelligence quotient more than one standard deviation below the mean), cerebral palsy (abnormality of tone with motor dysfunction), blindness (for example, corrected visual acuity worse than 6/60 in the better eye) or deafness (for example, hearing loss requiring amplification or worse)). For the women, the primary outcome will be maternal sepsis (defined as chorioamnionitis; pyrexia after trial entry requiring the use of antibiotics; puerperal sepsis; intrapartum fever requiring the use of antibiotics; or postnatal pyrexia).

DISCUSSION

Data analyses are expected to commence in 2011 with results publicly available in 2012.

17-Hydroxyprogesterone caproate to prolong pregnancy after preterm rupture of the membranes: early termination of a double-blind, randomized clinical trial

Background

Progestational agents may reduce the risk of preterm birth in women with various risk factors. We sought to test the hypothesis that a weekly dose of 17-hydroxyprogesterone caproate (17P) given to women with preterm rupture of the membranes (PROM) will prolong pregnancy and thereby reduce neonatal morbidity.

Methods

Double-blind, placebo-controlled randomized clinical trial. Women with PROM at 23.0 to 31.9 weeks of gestation were randomly assigned to receive a weekly intramuscular injection of 17P (250 mg in 1 mL castor oil) or placebo (1 mL castor oil). The primary outcome was the rate of continuing the pregnancy until 34.0 weeks of gestation or until documentation of fetal lung maturity at 32.0 to 33.9 weeks of gestation. Planned secondary outcomes were duration of latency period and rate of composite neonatal morbidity. Enrollment of 111 participants per group, 222 total, was planned to yield 80% power to detect an increase in the primary outcome from 30% with placebo to 50% with 17P.

Results

Twelve women were enrolled of whom 4 were randomly assigned to receive 17P and 8 to receive placebo. The trial was terminated prematurely because of two separate issues related to the supply of 17P. No adverse events attributable to 17P were identified.

Conclusion

Because of premature termination, the trial does not have adequate statistical power to evaluate efficacy or safety of 17P in women with PROM. Nonetheless, ethical principles dictate that we report the results, which may contribute to possible future metaanalyses and systematic reviews.

Trial Registration

ClinicalTrials.gov: NCT01119963

Supported by a research grant from the Center for Research, Education, and Quality, Pediatrix Medical Group, Sunrise, FL

A randomized, double-masked trial of prophylactic indomethacin tocolysis versus placebo in women with premature rupture of membranes

Preterm premature rupture of membranes (PPROM) complicates 3% of pregnancies and frequently results in preterm birth, often within 48 hours of membrane rupture. Our objective was to determine if subjects with PPROM between 24 and 31 (6)/ (7) weeks' gestation benefit from a 48-hour course of prophylactic indomethacin tocolysis. This was a double-masked randomized controlled trial. Subjects with PPROM between 24 and 31 (6)/ (7) weeks' gestation were randomized to receive indomethacin or placebo for 48 hours in addition to corticosteroids and latency antibiotics. The primary outcome of the study was delivery within 48 hours. Maternal and neonatal outcomes were also compared. This study was concluded prematurely due to slow accrual after a total of 50 subjects were enrolled. A total of 23/25 (92%) subjects in the indomethacin group remained pregnant beyond 48 hours compared with 20/22 (90.9%) in the placebo group (relative risk, 1.01; 95% confidence interval, 0.84 to 1.21). The latency period medians and interquartile ranges were similar between the two groups [indomethacin 193 (92 to 376.5) hours versus placebo 199 (77.5 to 459) hours, P = 0.91], and no differences were noted in any maternal or neonatal secondary outcomes. This limited study demonstrates no benefit with the use of prophylactic indomethacin tocolysis for women with PPROM.