Effects of Antihypertensive Therapy During Pregnancy on Postpartum Blood Pressure Control.

OBJECTIVE: To compare differences in postpartum blood pressure (BP) control (BP below 140/90 mm Hg) for participants with hypertension randomized to receive antihypertensive treatment compared with no treatment during pregnancy. METHODS: This study was a planned secondary analysis of a multicenter, open-label, randomized controlled trial (The CHAP [Chronic Hypertension and Pregnancy] trial). Pregnant participants with mild chronic hypertension (BP below 160/105 mm Hg) were randomized into two groups: active (antihypertensive treatment) or control (no treatment unless severe hypertension, BP 160/105 mm Hg or higher). Study outcomes were BP control below 140/90 mm Hg (primary) and medication nonadherence based on a composite score threshold (secondary) at the 6-week postpartum follow-up visit. Participants without follow-up BP measurements were excluded from analysis of the BP control outcome. Participants without health care professional-prescribed antihypertensives at delivery were excluded from the analysis of the adherence outcome. Multivariable logistic regression was used to adjust for potential confounders. RESULTS: Of 2,408 participants, 1,684 (864 active, 820 control) were included in the analysis. A greater percentage of participants in the active group achieved BP control (56.7% vs 51.5%; adjusted odds ratio [aOR] 1.22, 95% CI, 1.00-1.48) than in the control group. Postpartum antihypertensive prescription was higher in the active group (81.7% vs 58.4%, P<.001), and nonadherence did not differ significantly between groups (aOR 0.81, 95% CI, 0.64-1.03). CONCLUSION: Antihypertensive treatment of mild chronic hypertension during pregnancy was associated with better BP control below 140/90 mm Hg in the immediate postpartum period.

Blood Pressure Control in Pregnant Patients with Chronic Hypertension and Diabetes: Should <130/80 be the Target?

BACKGROUND: The Chronic Hypertension and Pregnancy Study (CHAP) demonstrated that a target blood pressure of <140/90 mm Hg during pregnancy is associated with improved perinatal outcomes. Outside of pregnancy, pharmacologic therapy for patients with diabetes and hypertension is adjusted to a target blood pressure of <130/80 mm Hg. During pregnancy, patients with both diabetes and chronic hypertension may also benefit from tighter control with a target blood pressure (BP) <130/80 mm Hg. OBJECTIVE: We compared perinatal outcomes in patients with hypertension and diabetes who achieved BP <130/80 versus 130-139/80-89 mm Hg. STUDY DESIGN: This was a secondary analysis of a multi-center randomized controlled trial. Participants were included in this secondary analysis if they had diabetes diagnosed prior to pregnancy or at <20 weeks' gestation and at least two recorded BP measurements prior to delivery. Average systolic and diastolic BP were calculated using ambulatory antenatal BPs. The primary composite outcome was preeclampsia with severe features, indicated preterm birth <35 weeks, or placental abruption. Secondary outcomes were components of the primary outcome, cesarean delivery, fetal or neonatal death, neonatal intensive care unit (NICU) admission, and small for gestational age (SGA). Comparisons were made between those with an average systolic BP <130 mm Hg and average diastolic BP <80 mm Hg and those with an average systolic blood pressure 130-139 mm Hg or diastolic blood pressure 80-89 mm Hg using Student's t-test and chi-squared tests. Multivariable log-binomial regression models were used to evaluate risk ratios between blood pressure groups for dichotomous outcomes while accounting for baseline covariates. RESULTS: Of 434 participants included, 150 (34.6%) had an average blood pressure less than 130/80 mm Hg. Participants with an average blood pressure less than 130/80 were more likely to be on antihypertensive medications at the start of pregnancy and more likely to have newly diagnosed DM prior to 20 weeks. Participants with an average blood pressure less than 130/80 mm Hg were less likely to have the primary adverse perinatal outcome (19.3% vs 46.5%, adjusted relative risk (aRR) 0.43, 95% CI 0.30-0.61, p<0.01), with decreased risks specifically of preeclampsia with severe features (aRR 0.35, 95% CI 0.23-0.54) and indicated preterm birth prior to 35 weeks (aRR 0.44, 95% CI 0.24-0.79). The risk of NICU admission was lower in the lower blood pressure group (aRR 0.74, 95% CI 0.59-0.94). No differences were noted in cesarean delivery (aRR 1.04, 95% CI 0.90-1.20), fetal or neonatal death (aRR 0.59, 95% CI 0.12-2.92). SGA less than the 10th percentile was lower in the lower blood pressure group (aRR 0.37, 95% CI 0.14-0.96). CONCLUSION: In those with chronic hypertension and diabetes prior to 20 weeks, achieving an average goal blood pressure of <130/80 mm Hg may be associated with improved perinatal outcomes.

Maternal Body Mass Index, Myometrium Contractility and Uterotonic Receptor Expression in Pregnancy.

Pregnant individuals with obesity (body mass index, BMI ≥ 30 kg/m2) are more likely to experience prolonged labor and have double the risk of cesarean compared with individuals with normal weight (BMI < 25 kg/m2). The aim of this study was to evaluate whether obesity in pregnancy is associated with reduced spontaneous and oxytocin-stimulated myometrial contractile activity using ex vivo preparations. We also assessed the relationship between maternal BMI and the expression of oxytocin (OXTR) and prostaglandin (FP) receptors in the myometrial tissue. We enrolled 73 individuals with a singleton gestation undergoing scheduled cesarean delivery at term in a prospective cohort study. This included 49 individuals with a pre-pregnancy BMI ≥ 30 kg/m2 and 24 with BMI < 25.0 kg/m2. After delivery, a small strip of myometrium was excised from the upper edge of the hysterotomy. Baseline spontaneous and oxytocin stimulated myometrial contractile activity was measured using ex vivo preparations. Additionally, expression of oxytocin and prostaglandin receptors from myometrial samples were compared using qRT-PCR and western blot techniques. Spontaneous and oxytocin-stimulated contraction frequency, duration, and force were not significantly different in myometrial samples from the obese and normal-weight individuals. Myometrial OXTR gene and protein expression was also similar in the two groups. While FP gene expression was lower in the myometrial samples from the obese group, protein expression did not differ. These data help to address an important knowledge gap related to the biological mechanisms underlying the association between maternal obesity and dysfunctional labor.

Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension.

OBJECTIVE: To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial. METHODS: A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated. RESULTS: A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations. CONCLUSION: Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Sonographic Predictors of Antepartum Bleeding in Placenta Previa.

OBJECTIVE: To evaluate the association between sonographic features of placenta previa and vaginal bleeding (VB). STUDY DESIGN: Retrospective cohort study of women with placenta previa identified on ultrasound between 160/7 and 276/7 weeks gestation. Placental distance past the cervical os (DPO), placental thickness, edge angle, and cervical length (CL) were measured. The primary outcome was any VB and the secondary outcome was VB requiring delivery. Median values of the sonographic features were compared for each of the outcomes using the Mann-Whitney U test. Receiver operating characteristic curves were used to compare the predictive value of sonographic variables markers and to determine optimal cut points for each measurement. Logistic regression was used to estimate the association between each measure and the outcomes while controlling for confounders. RESULTS: Of 149 women with placenta previa, 37% had VB and 15% had VB requiring delivery. Women with VB requiring delivery had significantly more episodes of VB than those who did not require delivery for VB (1.5, interquartile range [IQR] [1-3] vs 1.0 [1-5]; p = 0.001). In univariate analysis, women with VB had decreased CL (3.9 vs. 4.2 cm; p < 0.01) compared with those without. Women with VB requiring delivery had increased DPO (2.6 cm IQR [1.7-3.3] vs. 1.5 cm [1.1-2.4], p = 0.01) compared with those without. After adjusting for confounders, only CL < 4 cm remained independently associated with increased risk of VB (adjusted odds ratio: 2.27, 95% confidence interval [1.12-4.58], p = 0.01). None of the measures were predictive of either outcome (area under the curve < 0.65). CONCLUSION: Decreased CL may be associated with risk of VB in placenta previa. KEY POINTS: · Placenta previa is associated with VB.. · Sonographic markers of placenta previa are associated with VB.. · CL is associated with VB in placenta previa, whereas placental DPO is associated with higher rates of bleeding leading to delivery..

Perinatal Outcomes Associated With Management of Stage 1 Hypertension.

OBJECTIVE: To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes. METHODS: We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA). RESULTS: Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA. CONCLUSION: In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Sodium intake and the development of hypertensive disorders of pregnancy.

BACKGROUND: In nonpregnant populations, sodium intake has been associated with the development of chronic hypertension, and sodium restriction has been identified as a strategy to reduce blood pressure. Data regarding the relationship between sodium intake and the development of hypertensive disorders of pregnancy are limited and conflicting. OBJECTIVE: This study aimed to assess the association between daily periconceptional sodium intake and the risk of hypertensive disorders of pregnancy. STUDY DESIGN: This was a secondary analysis of the prospective Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be study. Individuals with nonanomalous, singleton pregnancies who completed food frequency questionnaires with recorded sodium intake in the 3 months before pregnancy were included in the analysis. Individuals whose pregnancies did not progress beyond 20 weeks of gestation were excluded from the analysis. Sodium intake was categorized as low (<2 g per day), medium (2 to <3 g per day), or high (≥3 g per day), based on thresholds used in the nonpregnant population. The primary outcome was the development of a new-onset hypertensive disorder of pregnancy, including gestational hypertension; preeclampsia; hemolysis, elevated liver enzymes, and low platelet count syndrome; superimposed preeclampsia; or eclampsia. Bivariable analyses were performed using Kruskal-Wallis and chi-square tests. Poisson regression was used to estimate adjusted incidence risk ratios with 95% confidence intervals after controlling for potentially confounding factors. RESULTS: Among 7458 individuals included in this analysis, 2336 (31%) reported low sodium intake, 2792 (37%) reported medium sodium intake, and 2330 (31%) reported high sodium intake. Individuals with high sodium intake were more likely to have chronic hypertension, to use tobacco, and to be living with obesity. The risk of developing a hypertensive disorder of pregnancy was similar among groups (medium vs low adjusted incidence risk ratio: 1.10 [95% confidence interval, 0.94-1.28]; high vs low adjusted incidence risk ratio: 1.17 [95% confidence interval, 1.00-1.37]). There was no difference in neonatal outcomes by sodium intake, including preterm birth, small-for-gestational-age neonate, and admission to the neonatal intensive care unit. CONCLUSION: Sodium intake was not associated with the risk of developing a hypertensive disorder of pregnancy. This lack of association contrasts with that between sodium intake and hypertension in the nonpregnant state and may reflect differences in the pathophysiology underlying pregnancy- vs non-pregnancy-related hypertensive disorders.

A Prediction Model for Severe Maternal Morbidity and Mortality After Delivery Hospitalization.

OBJECTIVE: To develop a risk stratification model for severe maternal morbidity (SMM) or mortality after the delivery hospitalization based on information available at the time of hospital discharge. METHODS: This population-based cohort study included all pregnancies among Ohio residents with Medicaid insurance from 2012 to 2017. Pregnant individuals were identified using linked live birth and fetal death records and Medicaid claims data. Inclusion was restricted to those with continuous postpartum Medicaid enrollment and delivery at 20 or more weeks of gestation. The primary outcome of the study was SMM or mortality after the delivery hospitalization and was assessed up to 42 days postpartum and up to 1 year postpartum separately. Variables considered for the model included patient-, obstetric health care professional-, and system-level data available in vital records or Medicaid claims data. Parsimonious models were created with logistic regression and were internally validated. Receiver operating characteristic curves were used to evaluate model performance, and model calibration was assessed. RESULTS: There were 343,842 pregnant individuals who met inclusion criteria with continuous Medicaid enrollment through 42 days postpartum and 287,513 with continuous enrollment through 1 year. After delivery hospitalization discharge, the incidence of SMM or mortality was 140.5 per 10,000 pregnancies through 42 days of delivery and 330.7 per 10,000 pregnancies through 1 year postpartum. The final model predicting SMM or mortality through 42 days postpartum included maternal prepregnancy body mass index, age, gestational age at delivery, mode of delivery, chorioamnionitis, and maternal diagnosis of cardiac disease, preeclampsia or gestational hypertension, or a mental health condition. Similar variables were included in the model predicting SMM or mortality through 365 days with chronic hypertension, pregestational diabetes, and illicit substance use added and chorioamnionitis removed. Both models demonstrated moderate prediction (area under the curve [AUC] 0.77, 95% CI 0.76-0.78 for 42-day model; AUC 0.72, 95% CI 0.71-0.73 for the 1-year model) and good calibration. CONCLUSION: A prediction model for SMM or mortality up to 1 year postpartum was created and internally validated with information available to health care professionals at the time of hospital discharge. The utility of this model for patient counseling and strategies to optimize postpartum care for high-risk individuals will require further evaluation.

Association of maternal body mass index with success and outcomes of attempted operative vaginal delivery.

BACKGROUND: Increasing maternal body mass index is associated with increased morbidity at cesarean delivery in a dose-dependent manner. In some clinical scenarios, operative vaginal delivery is a strategy to prevent the morbidity associated with second-stage cesarean delivery, but the relationship between maternal body mass index and outcomes of attempted operative vaginal delivery is not well characterized. OBJECTIVE: This study aimed to assess whether the success of and adverse outcomes after attempted operative vaginal delivery are associated with maternal body mass index at delivery among nulliparous individuals. STUDY DESIGN: This was a secondary analysis from the prospective cohort Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be study. This analysis included cephalic live-born nonanomalous singleton pregnancies ≥34 weeks at delivery with an attempted operative vaginal delivery (either forceps or vacuum). The primary exposure was maternal body mass index at delivery (≥30 vs <30 kg/m2 [referent]). The primary outcome was an unsuccessful operative vaginal delivery attempt, defined as a cesarean delivery after an attempted operative vaginal delivery. The secondary outcomes included maternal and neonatal adverse outcomes. Multivariable logistic regression was used, and statistical interaction between operative instrument type (vacuum vs forceps) and body mass index was assessed. RESULTS: Of 10,038 assessed individuals, 791 (7.9%) had an attempted operative vaginal delivery and were included in this analysis. Of note, 325 individuals (41%) had a body mass index ≥30 kg/m2 at delivery. Overall, 42 of 791 participants (5%) experienced an unsuccessful operative vaginal delivery. Individuals with a body mass index ≥30 kg/m2 at delivery were more than twice as likely to have an unsuccessful operative vaginal delivery than those with a body mass index <30 kg/m2 (8.0% vs 3.4%; adjusted odds ratio, 2.23; 95% confidence interval, 1.16-4.28; P=.005). Composite maternal morbidity and composite neonatal morbidity did not vary by body mass index group. There was no evidence of interaction or effect modification by operative instrument type for the rate of unsuccessful operative vaginal delivery attempt, composite maternal morbidity, or composite neonatal morbidity. CONCLUSION: Among nulliparous individuals who underwent an attempted operative vaginal delivery, those with a body mass index ≥30 kg/m2 at delivery were more likely to have an unsuccessful operative vaginal delivery attempt than those with a body mass index <30 kg/m2. There was no difference in composite maternal or neonatal morbidity after attempted operative vaginal delivery by body mass index category.

Cervical Pessary for Prevention of Preterm Birth in Individuals With a Short Cervix: The TOPS Randomized Clinical Trial.

Importance: A short cervix as assessed by transvaginal ultrasound is an established risk factor for preterm birth. Study findings for a cervical pessary to prevent preterm delivery in singleton pregnancies with transvaginal ultrasound evidence of a short cervix have been conflicting. Objective: To determine if cervical pessary placement decreases the risk of preterm birth or fetal death prior to 37 weeks among individuals with a short cervix. Design, Setting, and Participants: We performed a multicenter, randomized, unmasked trial comparing a cervical pessary vs usual care from February 2017 through November 5, 2021, at 12 centers in the US. Study participants were nonlaboring individuals with a singleton pregnancy and a transvaginal ultrasound cervical length of 20 mm or less at gestations of 16 weeks 0 days through 23 weeks 6 days. Individuals with a prior spontaneous preterm birth were excluded. Interventions: Participants were randomized 1:1 to receive either a cervical pessary placed by a trained clinician (n = 280) or usual care (n = 264). Use of vaginal progesterone was at the discretion of treating clinicians. Main Outcome and Measures: The primary outcome was delivery or fetal death prior to 37 weeks. Results: A total of 544 participants (64%) of a planned sample size of 850 were enrolled in the study (mean age, 29.5 years [SD, 6 years]). Following the third interim analysis, study recruitment was stopped due to concern for fetal or neonatal/infant death as well as for futility. Baseline characteristics were balanced between participants randomized to pessary and those randomized to usual care; 98.9% received vaginal progesterone. In an as-randomized analysis, the primary outcome occurred in 127 participants (45.5%) randomized to pessary and 127 (45.6%) randomized to usual care (relative risk, 1.00; 95% CI, 0.83-1.20). Fetal or neonatal/infant death occurred in 13.3% of those randomized to receive a pessary and in 6.8% of those randomized to receive usual care (relative risk, 1.94; 95% CI, 1.13-3.32). Conclusions and Relevance: Cervical pessary in nonlaboring individuals with a singleton gestation and with a cervical length of 20 mm or less did not decrease the risk of preterm birth and was associated with a higher rate of fetal or neonatal/infant mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02901626.

Characterization of Patients with Frequent Utilization of the Obstetric Triage Unit: A Retrospective Cohort Study.

OBJECTIVE: This study aimed to identify characteristics of patients with frequent obstetric triage visits ("superusers") compared to those with fewer visits and to evaluate the association of frequent obstetric triage visits with preterm birth and cesarean delivery. STUDY DESIGN: This retrospective cohort included patients presenting to the obstetric triage unit at a tertiary care center from March through April 2014. Superusers were defined as individuals having four or more triage visits. Participant characteristics, including demographic, clinical, visit acuity, and health care characteristics of superusers and nonsuperusers, were summarized and compared. In the subset of patients where data were available regarding prenatal care, prenatal visit patterns were analyzed and compared between the two groups. The outcomes of preterm birth and cesarean were compared between groups using modified Poisson regression to control for confounding. RESULTS: Of the 656 patients evaluated in the obstetric triage unit during the study period, 648 patients met the inclusion criteria. Factors associated with frequent triage use included race/ethnicity, multiparity, insurance status, high-risk pregnancy, and a prior preterm birth. Superusers were more likely to present at an earlier gestational age and had a higher proportion of visits for hypertensive disease. Patient acuity scores were not different between the groups. In the subset of patients receiving prenatal care at the institution, prenatal visit patterns were similar. The risk of preterm birth (adjusted risk ratio [aRR]: 1.06; 95% confidence interval [CI]: 0.66-1.70) did not differ between groups; however, the risk of a cesarean delivery was increased in superusers (aRR: 1.39; 95% CI: 1.01-1.92) when compared to nonsuperusers. CONCLUSION: Superusers, compared to nonsuperusers, have distinct clinical and demographic characteristics and are more likely to be seen in the triage unit at earlier gestational ages. Superusers tended to have a higher proportion of visits for hypertensive disease and had an increased risk of cesarean delivery. KEY POINTS: · Patients with frequent triage visits did not have an increased risk of preterm birth.. · Patients with frequent triage visits were more likely to undergo cesarean delivery.. · Acuity scales were similar for patients with frequent visits compared to those with few visits..

Association between Diabetes in Pregnancy and Shoulder Dystocia by Infant Birth Weight in an Era of Cesarean Delivery for Suspected Macrosomia.

OBJECTIVE: We estimated the association between diabetes and shoulder dystocia by infant birth weight subgroups (<4,000, 4,000-4,500, and >4,500 g) in an era of prophylactic cesarean delivery for suspected macrosomia. STUDY DESIGN: A secondary analysis from the National Institute of Child Health and Human Development U.S. Consortium for Safe Labor of deliveries at ≥24 weeks with a nonanomalous, singleton fetus with vertex presentation undergoing a trial of labor. The exposure was either pregestational or gestational diabetes compared with no diabetes. The primary outcome was shoulder dystocia and secondarily, birth trauma with a shoulder dystocia. We calculated adjusted risk ratios (aRRs) with modified Poison's regression between diabetes and shoulder dystocia and the number needed to treat (NNT) to prevent a shoulder dystocia with cesarean delivery. RESULTS: Among 167,589 assessed deliveries (6% with diabetes), pregnant individuals with diabetes had a higher risk of shoulder dystocia at birth weight <4,000 g (aRR: 1.95; 95% confidence interval [CI]: 1.66-2.31) and 4,000 to 4,500 g (aRR: 1.57; 95% CI: 1.24-1.99), albeit not significantly at birth weight >4,500 g (aRR: 1.26; 95% CI: 0.87-1.82) versus those without diabetes. The risk of birth trauma with shoulder dystocia was higher with diabetes (aRR: 2.29; 95% CI: 1.54-3.45). The NNT to prevent a shoulder dystocia with diabetes was 11 and 6 at ≥4,000 and >4,500 g, versus without diabetes, 17 and 8 at ≥4,000 and >4,500 g, respectively. CONCLUSION: Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered. Guidelines providing the option of cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights. KEY POINTS: · >Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered.. · Cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights.. · These findings can inform delivery planning for providers and pregnant individuals with diabetes..

Outcomes of shared institutional review board compared with multiple individual site institutional review board models in a multisite clinical trial.

BACKGROUND: Institutional review boards play a crucial role in initiating clinical trials. Although many multicenter clinical trials use an individual institutional review board model, where each institution uses their local institutional review board, it is unknown if a shared (single institutional review board) model would reduce the time required to approve a standard institutional review board protocol. OBJECTIVE: This study aimed to compare processing times and other processing characteristics between sites using a single institutional review board model and those using their individual site institutional review board model in a multicenter clinical trial. STUDY DESIGN: This was a retrospective study of sites in an open-label, multicenter randomized control trial from 2014 to 2021. Participating sites in the multicenter Chronic Hypertension and Pregnancy trial were asked to complete a survey collecting data describing their institutional review board approval process. RESULTS: A total of 45 sites participated in the survey (7 used a shared institutional review board model and 38 used their individual institutional review board model). Most sites (86%) using the shared institutional review board model did not require a full-board institutional review board meeting before protocol approval, compared with 1 site (3%) using the individual institutional review board model (P<.001). Median total approval times (41 vs 56 days; P=.42), numbers of submission rounds (1 vs 2; P=.09), and numbers of institutional review board stipulations (1 vs 4; P=.12) were lower for the group using the shared institutional review board model than those using the individual site institutional review board model; however, these differences were not statistically significant. CONCLUSION: The findings supported the hypothesis that the shared institutional review board model for multicenter studies may be more efficient in terms of cumulative time and effort required to obtain approval of an institutional review board protocol than the individual institutional review board model. Given that these data have important implications for multicenter clinical trials, future research should evaluate these findings using larger or multiple multicenter trials.

A Comparison of Vaginal and Intramuscular Progesterone for the Prevention of Recurrent Preterm Birth.

OBJECTIVE: This study aimed to examine whether vaginal progesterone is noninferior to 17-α hydroxyprogesterone caproate (17OHP-C) in the prevention of recurrent preterm birth (PTB). STUDY DESIGN: This retrospective cohort study included singleton pregnancies among women with a history of spontaneous PTB who received prenatal care at a single tertiary center from 2011 to 2016. Pregnancies were excluded if progesterone was not initiated prior to 24 weeks or the fetus had a major congenital anomaly. The primary outcome was PTB <37 weeks. A priori, noninferiority was to be established if the upper bound of the adjusted two-sided 90% confidence interval (CI) for the difference in PTB fell below 9%. Inverse probability of treatment weighting (IPTW) was used to carefully control for confounding associated with choice of treatment and PTB. Adjusted differences in PTB proportions were estimated via IPTW regression, with standard errors adjustment for multiple pregnancies per woman. Secondary outcomes included PTB <34 and <28 weeks, spontaneous PTB, neonatal intensive care unit admission, and gestational age at delivery. RESULTS: Among 858 pregnancies, 41% (n = 353) received vaginal progesterone and 59% (n = 505) were given 17OHP-C. Vaginal progesterone use was more common later in the study period, and among women who established prenatal care later, had prior PTBs at later gestational ages, and whose race/ethnicity was neither non-Hispanic white nor non-Hispanic Black. Vaginal progesterone did not meet noninferiority criteria compared with 17-OHPC in examining PTB <37 weeks, with an IPTW adjusted difference of 3.4% (90% CI: -3.5, 10.3). For secondary outcomes, IPTW adjusted differences between treatment groups were generally small and CIs were wide. CONCLUSION: We could not conclude noninferiority of vaginal progesterone to 17OHP-C; however, women and providers may be willing to accept a larger difference (>9%) when considering the cost and availability of vaginal progesterone versus 17OHP-C. A well-designed randomized trial is needed. KEY POINTS: · Vaginal progesterone is not noninferior to 17OHP-C.. · PTB risk may be 10% higher with vaginal progesterone.. · Associations did not differ based on obesity status..

Trends in Active Treatment of Live-born Neonates Between 22 Weeks 0 Days and 25 Weeks 6 Days by Gestational Age and Maternal Race and Ethnicity in the US, 2014 to 2020.

Importance: Birth in the periviable period between 22 weeks 0 days and 25 weeks 6 days' gestation is a major source of neonatal morbidity and mortality, and the decision to initiate active life-saving treatment is challenging. Objective: To assess whether the frequency of active treatment among live-born neonates in the periviable period has changed over time and whether active treatment differed by gestational age at birth and race and ethnicity. Design, Setting, and Participants: Serial cross-sectional descriptive study using National Center for Health Statistics natality data from 2014 to 2020 for 61 908 singleton live births without clinical anomalies between 22 weeks 0 days and 25 weeks 6 days in the US. Exposures: Year of delivery, gestational age at birth, and race and ethnicity of the pregnant individual, stratified as non-Hispanic Asian/Pacific Islander, non-Hispanic Black, Hispanic/Latina, and non-Hispanic White. Main Outcomes and Measures: Active treatment, determined by whether there was an attempt to treat the neonate and defined as a composite of surfactant therapy, immediate assisted ventilation at birth, assisted ventilation more than 6 hours in duration, and/or antibiotic therapy. Frequencies, mean annual percent change (APC), and adjusted risk ratios (aRRs) were estimated. Results: Of 26 986 716 live births, 61 908 (0.2%) were periviable live births included in this study: 5% were Asian/Pacific Islander, 37% Black, 24% Hispanic, and 34% White; and 14% were born at 22 weeks, 21% at 23 weeks, 30% at 24 weeks, and 34% at 25 weeks. Fifty-two percent of neonates received active treatment. From 2014 to 2020, the overall frequency (mean APC per year) of active treatment increased significantly (3.9% [95% CI, 3.0% to 4.9%]), as well as among all racial and ethnic subgroups (Asian/Pacific Islander: 3.4% [95% CI, 0.8% to 6.0%]); Black: 4.7% [95% CI, 3.4% to 5.9%]; Hispanic: 4.7% [95% CI, 3.4% to 5.9%]; and White: 3.1% [95% CI, 1.1% to 4.4%]) and among each gestational age range (22 weeks: 14.4% [95% CI, 11.1% to 17.7%] and 25 weeks: 2.9% [95% CI, 1.5% to 4.2%]). Compared with neonates born to White individuals (57.0%), neonates born to Asian/Pacific Islander (46.2%; risk difference [RD], -10.81 [95% CI, -12.75 to -8.88]; aRR, 0.82 [95% CI, [0.79-0.86]), Black (51.6%; RD, -5.42 [95% CI, -6.36 to -4.50]; aRR, 0.90 [95% CI, 0.89 to 0.92]), and Hispanic (48.0%; RD, -9.03 [95% CI, -10.07 to -7.99]; aRR, 0.83 [95% CI, 0.81 to 0.85]) individuals were significantly less likely to receive active treatment. Conclusions and Relevance: From 2014 to 2020 in the US, the frequency of active treatment among neonates born alive between 22 weeks 0 days and 25 weeks 6 days significantly increased, and there were differences in rates of active treatment by race and ethnicity.

Association of Prepregnancy Body Mass Index With Risk of Severe Maternal Morbidity and Mortality Among Medicaid Beneficiaries.

Importance: The association between body mass index (BMI, which is calculated as weight in kilograms divided by height in meters squared) and severe maternal morbidity (SMM) and/or mortality is uncertain, judging from the current evidence. Objective: To examine the association between prepregnancy BMI and SMM and/or mortality through 1 year post partum and to identify both the direct and indirect implications of maternal obesity for SMM and/or mortality by examining hypertensive disorders and pregestational diabetes as potential mediators. Design, Setting, and Participants: This population-based cohort study was conducted from March to October 2021 using the vital records and linked Medicaid claims data in the state of Ohio from January 1, 2012, through December 31, 2017. The cohort comprised pregnant Medicaid beneficiaries who delivered at 20 weeks' gestation or later and had prepregnancy BMI information. Exposures: The primary exposure was maternal prepregnancy BMI, which was categorized as follows: underweight (<18.5), healthy weight (18.5-24.9), overweight (25.0-29.9), class 1 obesity (30.0-34.9), class 2 obesity (35.0-39.9), and class 3 obesity (≥40.0). Main Outcomes and Measures: The primary outcome was a composite of SMM (defined using Centers for Disease Control and Prevention criteria) and/or maternal mortality between 20 weeks' gestation and 1 year post partum. Additional periods were assessed, including 20 weeks' gestation through delivery hospitalization and 20 weeks' gestation through 42 days post partum. Generalized estimating equation models were used to estimate adjusted relative risks (aRRs) for the primary outcome according to BMI category. Maternal hypertensive diseases and pregestational diabetes were assessed as potential meditators. Results: In a cohort of 347 497 pregnancies among 276 691 Medicaid beneficiaries (median [IQR] maternal age at delivery, 25 [21-29] years; 210 470 non-Hispanic White individuals [60.6%]), the prevalence of maternal obesity was 30.5% (n = 106 031). Composite SMM and/or mortality outcome occurred in 5.3% of pregnancies (n = 18 398). Overweight (aRR, 1.07; 95% CI, 1.03-1.11) and obesity (class 1: aRR, 1.19 [95% CI, 1.14-1.24]; class 2: aRR, 1.37 [95% CI, 1.30-1.44]; class 3: aRR, 1.71 [95% CI, 1.63-1.80]) were associated with an elevated risk of SMM and/or mortality during pregnancy to 1 year post partum compared with healthy BMI. Similar findings were observed when the follow-up period was shortened to 42 days post partum or the delivery hospitalization. Hypertension mediated 65.1% (95% CI, 64.6%-65.6%) of the association between obesity and the primary outcome. Conclusions and Relevance: Results of this study showed that maternal prepregnancy obesity was associated with an elevated risk of SMM and/or mortality. Hypertensive disorders appeared to mediate this association, suggesting that improved prevention and management of hypertensive disorders in pregnancy may reduce morbidity and mortality in individuals with obesity.

A One-Year Cross Sectional Analysis of Emergency Medical Services Utilization and Its Association with Hypertension in Pregnancy.

Objective: To evaluate the prehospital obstetric population that utilizes emergency medical services (EMS) and their association with hypertensive disorders of pregnancy. Methods: We conducted a retrospective evaluation of one year of all medical calls from a large, municipal, midwestern fire department. Inclusion criteria included all pregnant patients transported to a hospital by EMS. Descriptive statistics were calculated to evaluate prehospital event information (e.g., zip code, time, and duration of call), patient characteristics, and clinical management data regarding blood pressure. Census data were used to compare neighborhood information with poverty rates. Results: Of the 1,575 identified patients, 64.4% (1015/1575) presented with obstetric complaints, 57.4% (700/1220) were in their third trimester and 72.7% (686/944) were multiparous. The median call duration was 17 (interquartile range 12-22) minutes. In the areas where EMS usage was highest, one quarter of individuals lived below the poverty level. Of the studied population, 32.0% (504/1575) were found to be hypertensive; 14.9% (75/504) of hypertensive patients were found to have severe hypertension. Only one patient (1/1575, 0.06%) presented with a chief complaint of hypertension; the rest were discovered by EMS. The highest rates of hypertension were noted in wealthier areas of the city. Patients with severe hypertension were more likely to present with seizures, consistent with eclampsia. Conclusion: Hypertension is common in the obstetric population using EMS. Prehospital management of hypertensive disorders of pregnancy may focus on identification and treatment of severe pre-eclampsia or eclampsia. Areas with longer call times may consider treatment of severe hypertension. Prehospital treatment of hypertensive disorders of pregnancy could be optimized.

Vaginal progesterone for preterm birth prevention in women with arrested preterm labor.

OBJECTIVE: We tested the hypothesis that administration of vaginal progesterone in women with arrested preterm labor would result in lower rates of preterm birth <37 weeks compared to placebo. STUDY DESIGN: We performed a randomized, placebo-controlled trial comparing vaginal progesterone to placebo in women with arrested preterm labor. Our trial included women with a singleton or twin gestation at 240/7-336/7 weeks' gestation who presented with preterm labor with cervical dilation ≥1 centimeter but remained undelivered. Participants were randomized to receive vaginal progesterone 200 mg daily or an identical placebo. The primary outcome was preterm birth <37 weeks. We performed an updated systematic review and meta-analysis of clinical trials, including our results. We searched MEDLINE, EMBASE, CINHAL, Scopus, the Cochrane Database of Systematic Reviews, and ClinicalTrials.gov using the key terms to identify relevant trials. The risk of bias was appraised using the Cochrane risk-of-bias tool. Data were synthesized using random-effects models. Heterogeneity was assessed using Higgins I2. RESULTS: The randomized trial was prematurely terminated due to slow recruitment. There were 18 women randomized to receive vaginal progesterone who had complete follow-up data and 18 women in the placebo group. The risk of preterm birth <37 weeks was not significantly different in the groups (RR 1.10, 95% CI 0.63-1.19). Secondary outcomes were also similar. Thirteen trials with 1658 women (835 in the vaginal progesterone and 823 in the control groups) were included in the meta-analysis. Risk of preterm birth <37 weeks was similar in women who received progesterone and those in the control group (pooled RR 1.06, 95% CI 0.83-1.35). Latency was significantly longer among women with arrested preterm labor who received vaginal progesterone (weighted mean difference: 9.2 d, 95% CI 3.2-15.1), but further analysis showed that prolonged latency was only observed in the subgroup of studies that were not placebo-controlled. CONCLUSIONS: This randomized controlled trial and meta-analysis do not support the use of vaginal progesterone for the prevention of preterm birth in women who present in preterm labor.

Obstetric History and Risk of Short Cervix in Women with a Prior Preterm Birth.

OBJECTIVE: We aimed to assess the relationship between obstetric history and incidence of short cervical length (CL) at <24 weeks gestational age (GA) in women with a prior spontaneous preterm birth (PTB). STUDY DESIGN: Women with a singleton gestation and a history of spontaneous PTB on progesterone who received prenatal care at a single center from 2011 to 2016 were included. Those who did not undergo screening or had a history-indicated cerclage were excluded. The associations between short CL (<25 mm) before 24 weeks and obstetrical factors including: number of prior PTBs, history of term birth, and GA of earliest spontaneous PTB were estimated through modified Poisson regression, adjusting for confounding factors. Multiple pregnancies for the same woman were accounted for through robust sandwich standard error estimation. RESULTS: Among 773 pregnancies, 29% (n = 224) had a CL <25 mm before 24 weeks. The number of prior PTBs was not associated with short CL, but a prior full-term delivery conferred a lower risk of short CL (absolute risk reduction or aRR 0.79, 95% CI 0.63-1.00). Earliest GA of prior spontaneous PTB was associated with short CL. The strongest association was observed in women with a prior PTB at 160/7 to 236/7weeks (aRR 1.98, 95% CI: 1.46-2.70), compared with those with deliveries at 340/7 to 366/7 weeks. Yet, even women whose earliest PTB was 340/7 to 366/7 weeks remained at risk for a short CL, as 21% had a CL <25 mm. The number of prior PTBs did not modify the effect of GA of the earliest prior PTB (interaction test: p = 0.70). CONCLUSION: GA of earliest spontaneous PTB, but not the number of prior PTBs, is associated with short CL. Nevertheless, women with a history of later PTBs remain at sufficiently high risk of having a short CL at <24 weeks gestation that we cannot recommend modifications to existing CL screening guidelines in this group of women. KEY POINTS: · Prior 16 to 236/7 weeks birth is a key risk factor for CL <25 mm.. · One in five women with prior late PTB had a short CL.. · Number of PTBs is a less important risk factor..

Optimal antenatal corticosteroid exposure in women with history of preterm birth and asymptomatic short cervical length.

BACKGROUND: A proposed benefit of cervical length assessment after 24 weeks' gestation in women with a history of preterm birth is to aid in the timing of antenatal corticosteroids in otherwise asymptomatic women. OBJECTIVE: We sought to investigate whether the use of an ultrasonographic short cervical length as an indication for antenatal corticosteroids in asymptomatic women results in optimal exposure compared with women receiving antenatal corticosteroids for preterm labor symptoms. STUDY DESIGN: Retrospective cohort study of all women with a previous spontaneous preterm birth and a singleton gestation who underwent serial cervical length assessment at a large academic tertiary medical center from 2011 to 2016. Patients were included in the analysis if they received antenatal corticosteroids for either an asymptomatic short cervical length or symptoms of preterm labor. The primary outcome was optimal antenatal corticosteroids exposure (latency to delivery of ≤7 days). PROPOSED CHANGE IN RESULTS: Poisson regression with robust error variance was used to calculate incidence rate ratios (IRR) and confidence intervals (CI) for primary and secondary outcomes adjusting for primary and secondary outcomes adjusting for race, earliest previous preterm birth, and current cerclage. RESULTS: There were 287 women meeting inclusion criteria, among whom 166 (57.8%) received antenatal corticosteroids for a short cervical length and 121 (42.2%) for preterm labor symptoms. Women who received antenatal corticosteroids for a short cervical length were less likely to have optimal exposure (1.2% vs 19.0%; incidence rate ratios, 0.06; confidence interval, 0.02-0.27) compared with women with preterm labor symptoms. They were also more likely to have exposure with eventual term delivery (43.2% vs 33.4%; incidence rate ratios, 1.6; confidence interval, 1.2-2.0). Importantly, women who received antenatal corticosteroids for a short cervical length were significantly less likely to receive either an initial or rescue antenatal corticosteroids course within 7 days of a preterm delivery of less than 34 weeks' gestation (42.9% vs 76.9%; incidence rate ratios, 0.52; confidence interval, 0.35-0.75). CONCLUSION: Women with a previous preterm birth who receive antenatal corticosteroids for an asymptomatic short cervical length are less likely to have optimal exposure than women with symptoms of preterm labor. These data challenge the practice of cervical length surveillance for the sole indication of timing antenatal corticosteroids administration.