Oxytocin regimen used for induction of labor and pregnancy outcomes.

BACKGROUND: Following the results of the ARRIVE trial, which demonstrated a reduction in cesarean delivery with no increase in adverse perinatal outcomes after elective induction of labor (IOL) in low-risk nulliparous patients at 39 weeks' gestation compared with expectant management, the use of induction has increased. Current evidence is insufficient to recommend mid-high-dose over low-dose regimens for routine IOL. OBJECTIVE(S): We sought to evaluate the association of oxytocin regimen with cesarean delivery and an adverse perinatal composite outcome in low-risk nulliparous patients undergoing IOL at 39 weeks of gestation or greater. STUDY DESIGN: This is a secondary analysis of the NICHD Maternal-Fetal Medicine Units Network ARRIVE randomized trial. Patients induced with a mid-to high-dose oxytocin regimen (MHD; starting or incremental increase >2 mU/min) were compared with those receiving a low-dose oxytocin regimen (LD; starting and incremental increase ≤2 mU/min). The co-primary outcomes for this secondary analysis were 1) cesarean delivery and 2) composite of perinatal death or severe neonatal complications. Multivariable Poisson regression was used to estimate adjusted relative risks (aRR) and 97.5% confidence intervals (CI) for the co-primary endpoints, 95% CI for binomial outcomes and multinomial logistic regression was used to estimate adjusted odds ratios (aOR) and 95% CIs for multinomial outcomes. RESULTS: Of 6,106 participants enrolled in the primary trial, 2,933 underwent induction with oxytocin: 861 in the MHD group and 2,072 in the LD group. The lower frequency of cesarean delivery in the MHD group compared with the LD group (20.3% vs. 25.2%, RR 0.81, 95%CI (0.69-0.94)) was not significant after adjustment (aRR 0.90, 97.5%CI (0.76-1.07)). The composite of perinatal death or severe neonatal complications was more frequent in the MHD group compared with the LD group (6.7% vs. 4.3%, RR 1.55, 95%CI (1.13-2.14)) and remained significant after adjustment (aRR 1.61, 97.5%CI (1.11-2.35)). The majority of the cases in the composite were from the respiratory support (5.2% vs. 3.1%) component with an increase in transient tachypnea of the newborn (3.8% vs. 2.5%, aRR 1.63, 95% CI (1.04-2.54)). The duration of neonatal respiratory support for one day was significantly higher in the MHD group compared with the LD group (3.5% vs. 1.4%, aRR 2.59, 95%CI (1.52-4.39)); however, support beyond one day was not different between the two groups. The MHD group, when compared with the LD group had a higher operative vaginal delivery rate (10.0% vs. 7.0%, aRR 1.54, 95%CI (1.18-2.00)) and shorter duration of time from start of oxytocin to delivery [crude median (interquartile range) 12 (8-17) vs. 13 (9-19) hours, adjusted median difference -2 (-2 to -1), p<0.001], respectively. CONCLUSION(S): Mid-high-dose oxytocin regimen use for IOL in nulliparas at ≥ 39 weeks' gestation was not associated with improved maternal or neonatal outcomes compared with low-dose regimens. Although mid-high-dose oxytocin regimen use was associated with a shorter duration of labor, there was an increase in self-limited neonatal respiratory support and no difference in cesarean rates. More evidence is needed to define the magnitude of potential maternal and neonatal benefits and risks associated with oxytocin regimens.

Pregnancy Outcomes in Patients With Hepatitis C Virus Infection.

OBJECTIVE: To evaluate the risks of adverse maternal and neonatal outcomes associated with pregnancies complicated by hepatitis C virus (HCV) infection. METHODS: This is a secondary analysis of a multicenter prospective cohort study of HCV infection in pregnancy. Participants were screened for HCV infection with serum antibody tests, and each participant with a positive HCV result (case group) was matched with up to two individuals with negative HCV results (control group) prospectively by gestational age (±2 weeks) at enrollment. Maternal outcomes included gestational diabetes, abruption, preeclampsia or gestational hypertension, cholestasis, and preterm delivery. Neonatal outcomes included hyperbilirubinemia, admission to neonatal intensive care (NICU); small-for-gestational-age (SGA) birth weight; and neonatal infection, defined as sepsis or pneumonia. Models were adjusted for maternal age, body mass index, injection drug use, and maternal medical comorbidities. RESULTS: The 249 individuals in the case group were prospectively matched to 486 individuals in the control group who met eligibility criteria. There were significant differences in demographic characteristics between the groups, including race, socioeconomic markers, education, insurance status, and drug and tobacco use. The frequencies of maternal outcomes of gestational diabetes, preeclampsia, and abruption were similar between the case and control groups. Preterm birth was similar between groups, but neonates born to individuals in the case group were more likely to be admitted to the NICU (45.1% vs 19.0%, adjusted odds ratio [aOR] 2.6, 95% CI, 1.8-3.8) and to have SGA birth weights below the 5th percentile (10.6% vs 3.1%, aOR 2.9, 95% CI, 1.4-6.0). There were no increased odds of hyperbilirubinemia or neonatal infection. CONCLUSION: Despite no increased odds of preterm birth or other adverse maternal outcomes in adjusted analyses, maternal HCV infection was associated with twofold increased odds of NICU admission and nearly threefold increased odds of SGA birth weight below the 5th percentile.

Optimizing Opioid Prescription Quantity After Cesarean Delivery: A Randomized Controlled Trial.

OBJECTIVE: To test whether an individualized opioid-prescription protocol (IOPP) with a shared decision-making component can be used without compromising postcesarean pain management. METHODS: In this multicenter randomized controlled noninferiority trial, we compared IOPP with shared decision making with a fixed quantity of opioid tablets at hospital discharge. We recruited at 31 centers participating in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Study participants had uncomplicated cesarean births. Follow-up occurred through 12 weeks postdischarge. Individuals with complicated cesarean births or history of opioid use in the pregnancy were excluded. Participants were randomized 1:1 to IOPP with shared decision making or fixed quantity (20 tablets of 5 mg oxycodone). In the IOPP group, we calculated recommended tablet quantity based on opioid use in the 24 hours before discharge. After an educational module and shared decision making, participants selected a quantity of discharge tablets (up to 20). The primary outcome was moderate to severe pain (score 4 or higher [possible range 0-10]) on the BPI (Brief Pain Inventory) at 1 week after discharge. A total sample size of 5,500 participants was planned to assess whether IOPP with shared decision making was not inferior to the fixed quantity of 20 tablets. RESULTS: From September 2020 to March 2022, 18,990 individuals were screened and 5,521 were enrolled (n=2,748 IOPP group, n=2,773 fixed-quantity group). For the primary outcome, IOPP with shared decision making was not inferior to fixed quantity (59.5% vs 60.1%, risk difference 0.67%; 95% CI, -2.03% to 3.37%, noninferiority margin -5.0) and resulted in significantly fewer tablets received (median 14 [interquartile range 4-20] vs 20, P <.001) through 90 days postpartum. CONCLUSION: Compared with fixed quantity, IOPP with shared decision making was noninferior for outpatient postcesarean analgesia at 1 week postdischarge and resulted in fewer prescribed opioid tablets at discharge. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT04296396.

Neurodevelopmental Outcomes After Late Preterm Antenatal Corticosteroids: The ALPS Follow-Up Study.

Importance: The Antenatal Late Preterm Steroids (ALPS) trial changed clinical practice in the United States by finding that antenatal betamethasone at 34 to 36 weeks decreased short-term neonatal respiratory morbidity. However, the trial also found increased risk of neonatal hypoglycemia after betamethasone. This follow-up study focused on long-term neurodevelopmental outcomes after late preterm steroids. Objective: To evaluate whether administration of late preterm (34-36 completed weeks) corticosteroids affected childhood neurodevelopmental outcomes. Design, Setting, and Participants: Prospective follow-up study of children aged 6 years or older whose birthing parent had enrolled in the multicenter randomized clinical trial, conducted at 13 centers that participated in the Maternal-Fetal Medicine Units (MFMU) Network cycle from 2011-2016. Follow-up was from 2017-2022. Exposure: Twelve milligrams of intramuscular betamethasone administered twice 24 hours apart. Main Outcome and Measures: The primary outcome of this follow-up study was a General Conceptual Ability score less than 85 (-1 SD) on the Differential Ability Scales, 2nd Edition (DAS-II). Secondary outcomes included the Gross Motor Function Classification System level and Social Responsiveness Scale and Child Behavior Checklist scores. Multivariable analyses adjusted for prespecified variables known to be associated with the primary outcome. Sensitivity analyses used inverse probability weighting and also modeled the outcome for those lost to follow-up. Results: Of 2831 children, 1026 enrolled and 949 (479 betamethasone, 470 placebo) completed the DAS-II at a median age of 7 years (IQR, 6.6-7.6 years). Maternal, neonatal, and childhood characteristics were similar between groups except that neonatal hypoglycemia was more common in the betamethasone group. There were no differences in the primary outcome, a general conceptual ability score less than 85, which occurred in 82 (17.1%) of the betamethasone vs 87 (18.5%) of the placebo group (adjusted relative risk, 0.94; 95% CI, 0.73-1.22). No differences in secondary outcomes were observed. Sensitivity analyses using inverse probability weighting or assigning outcomes to children lost to follow-up also found no differences between groups. Conclusion and Relevance: In this follow-up study of a randomized clinical trial, administration of antenatal corticosteroids to persons at risk of late preterm delivery, originally shown to improve short-term neonatal respiratory outcomes but with an increased rate of hypoglycemia, was not associated with adverse childhood neurodevelopmental outcomes at age 6 years or older.

Elective Induction of Labor Following Prior Cesarean Delivery.

OBJECTIVE: Following the release of A Randomized Trial of Induction versus Expectant Management (ARRIVE) trial, the induction of labor at 39 weeks has increased in the United States. The risk of uterine rupture and optimal timing of elective induction in those patients with a prior cesarean delivery is not well-described, and they were not included in the original trial. We aimed to determine the risk of uterine rupture in those patients undergoing elective induction of labor with prior cesarean delivery. STUDY DESIGN: This was a retrospective cohort of participants with prior cesarean delivery from 1996 to 2000. Participants were included if they had two or more prior cesareans. Participants were excluded if they had a history of an unknown prior incision, a classical incision, gestational age <39 weeks, any diabetes, chronic hypertension, twin gestation, collagen or vascular disease, or HIV. Those undergoing expectant management were compared with those undergoing elective induction with no medical or obstetrical indications for delivery. Analysis was performed at three gestational age groups: 39 weeks, 40 weeks, and 41 weeks. The primary outcomes were uterine rupture, rates of successful vaginal delivery, and a composite major morbidity risk. Multivariable logistic regression was performed. RESULTS: At 39 weeks, 618 (10.3%) elective inductions were compared with 5,365 (89.7%) undergoing expectant management; uterine rupture occurred more frequently (13 patients [2.1%] vs. 49 patients [0.9%]; adjusted odds ratio [aOR], 2.5; 95% confidence interval, 1.3-4.6) with fewer successful vaginal birth after cesarean [VBAC; 66.8 vs. 75%; aOR, 0.6; 95% confidence interval, 0.5-0.7]. The risk of uterine rupture was similar between groups at 40 weeks (5 patients [0.8%] vs. 21 patients [1.2%]; p = 0.387) and 41 weeks (7 patients [1.4%] vs. 2 patients (0.8%); p = 0.448). CONCLUSION: Patients undergoing elective induction of labor with a prior cesarean scar had an increased risk of uterine rupture when compared with expectant management at 39 weeks, with fewer successful VBAC. KEY POINTS: · TOLAC elective induction at 39 weeks has an increased risk of uterine rupture.. · TOLAC elective induction at 39 weeks has a less successful chance of vaginal delivery.. · Awaiting spontaneous labor in this cohort does not increase the risk of uterine rupture..

First and Second Stage Risk Factors Associated with Perineal Lacerations.

OBJECTIVE: To determine intrapartum factors associated with perineal laceration at delivery. METHODS: This was a planned secondary analysis of a multicenter randomized clinical trial of delayed versus immediate pushing among term nulliparous women in labor with neuraxial analgesia conducted in the United States. Intrapartum characteristics were extracted from the medical charts. The primary outcome was perineal laceration, defined as second degree or above, characterized at delivery in women participating in longer term pelvic floor assessments post-delivery. Multivariable logistic regression was used to refine risk estimates while adjusting for randomization group, birth weight, and maternal age. RESULTS: Among the 941 women participating in the pelvic floor follow-up, 40.6% experienced a perineal laceration. No first stage labor characteristics were associated with perineal laceration, including type of labor or length of first stage. Receiving an amnioinfusion appeared protective of perineal laceration (adjusted odds ratio, 0.48; 95% confidence interval 0.26-0.91; P = 0.01). Second stage labor characteristics associated with injury were length of stage (2.01 h vs. 1.50 h; adjusted odds ratio, 1.36; 95% confidence interval 1.18-1.57; P < 0.01) and a prolonged second stage (adjusted odds ratio, 1.64; 95% confidence interval 1.06-2.56; P < 0.01). Operative vaginal delivery was strongly associated with perineal laceration (adjusted odds ratio, 3.57; 95% confidence interval 1.85-6.90; P < 0.01). CONCLUSION: Operative vaginal delivery is a modifiable risk factor associated with an increased risk of perineal laceration. Amnioinfusion appeared protective against injury, which could reflect a spurious finding, but may also represent true risk reduction similar to the mechanism of warm perineal compress.

Optimizing the length of the second stage and management of pushing.

Although the optimal length of the second stage of labor to minimize maternal and neonatal morbidities and optimize spontaneous vaginal delivery is not known, available evidence suggests that increasing length of the second stage is associated with increasing maternal and neonatal morbidity. Thus, evidence-based strategies to safely shorten the second stage, such as initiating pushing when complete dilation is reached among those with neuraxial anesthesia, is prudent. Many aspects of optimal management of the second stage of labor require future study to continue to guide clinical second-stage management.

Optimal misoprostol dosing among patients with a body mass index greater than 30: a randomized controlled trial.

BACKGROUND: Patients with obesity experience an increased duration of labor with an increased risk for perinatal morbidity. When compared with parturients without obesity, they also experience fewer uterine contractions after administration of misoprostol. It is unclear if the same dose of misoprostol should be used for induction of labor in patients with obesity compared to non-obese patients. Therefore, we sought to investigate if a higher dose of misoprostol for patients with obesity is more effective. OBJECTIVE: This study aimed to determine if 50 µg compared with 25 µg of vaginal misoprostol reduced the time from induction start to delivery among patients with obesity. STUDY DESIGN: We performed a double-blinded, pragmatic randomized controlled trial, between June 1, 2022, and July 17, 2023. Patients with a body mass index ≥30 kg/m2 who underwent labor induction at ≥ 36 weeks' gestation, had a singleton gestation, and a cervical dilation ≤3 cm at admission were included. Patients were excluded if they had a contraindication to vaginal delivery or misoprostol administration. Patients were randomized to 25 or 50 µg of vaginal misoprostol, stratified by parity, body mass index <40 kg/m2 or ≥40 kg/m2, and provider intent to use mechanical dilation at the onset of labor induction. Usual labor management was followed at the discretion of the provider. The primary outcome was time from induction to delivery. A priori, we estimated that 90 subjects per group (N=180) were needed for an 85% power to detect a 3-hour difference between groups with a type I error of 5%. Analysis was by intention-to-treat. A 2-sample t test was used for the primary outcome, Cohen's d was used as a measure of effect, and P values were reported. RESULTS: Of the 180 patients randomized, 88 were assigned to the 25 µg group and 92 were assigned to the 50 µg group. Of those, 96.1% of patients received the designated intervention. The baseline characteristics were similar between groups. No difference was found in the primary outcome of time to delivery (21.6 hours vs 18.6 hours; d=.28; 95% confidence interval, -0.02 to 0.57). In a planned subgroup analysis, multiparous patients delivered faster in the 50 µg group (15.2 hours vs 12.0 hours; d=.51; 95% confidence interval, 0.04-0.97). The risk for tachysystole associated with fetal heart tracing changes was rare overall (2.2%) and not significantly different between groups. No differences in maternal or neonatal adverse effects were observed. CONCLUSION: Patients with obesity who underwent cervical ripening with 50 µg of vaginal misoprostol experienced a similar time to delivery when compared with those who received 25 µg of misoprostol. However, multiparous patients had a significantly reduced time to delivery when 50 µg was used. A higher dose of misoprostol may be a promising intervention for reducing time in labor, which warrants further study.

Risk Factors for Perinatal Transmission of Hepatitis C Virus.

OBJECTIVE: To estimate the rate of perinatal transmission of hepatitis C virus (HCV) infection, to identify risk factors for perinatal transmission of HCV infection, and to determine the viremic threshold for perinatal transmission. METHODS: This was a prospective, multicenter, observational study of pregnant individuals at less than 24 weeks of gestation screened for HCV infection from 2012 to 2018 in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Individuals found to be HCV antibody-positive were followed throughout pregnancy. Children were followed for evidence of perinatal transmission at 2-6 months (HCV RNA testing) and at 18-24 months (HCV RNA and antibody testing) of life. The primary outcome was perinatal transmission, defined as positive test results at either follow-up time point. RESULTS: A total of 109,379 individuals were screened for HCV infection. Of the 1,224 participants who screened positive, 772 (63.1%) enrolled and 432 of those 772 (56.0%) had data available to assess primary outcome. The overall rate of perinatal transmission was 6.0% (26/432, 95% CI 4.0-8.7%). All children with HCV infection were born to individuals with demonstrable viremia. In viremic participants (n=314), the perinatal transmission rate was 8.0% (95% CI 5.2-11.5%). Risk factors for perinatal transmission included HCV RNA greater than 106 international units/mL (adjusted odds ratio [aOR] 8.22, 95% CI 3.16-21.4) and vaginal bleeding reported at any time before delivery (aOR 3.26, 95% CI 1.32-8.03). A viremic threshold for perinatal transmission could not be established. CONCLUSION: Perinatal transmission of HCV infection was limited to viremic individuals. High viral loads and antepartum bleeding were associated with perinatal transmission.

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.

Maternal and Delivery Characteristics and Self-Reported Perceived Control During Labor.

OBJECTIVE: To evaluate the association between maternal and delivery characteristics and self-reported perceived control during childbirth. METHODS: A secondary analysis of a multicenter randomized trial was conducted to compare labor induction at 39 weeks of gestation with expectant management in low-risk nulliparous people. Six to 96 hours after delivery, participants who experienced labor completed the Labor Agentry Scale, a validated self-administered questionnaire to ascertain perceived control during childbirth. Scores range from 29 to 203, with higher scores indicating a sense of greater control. Multivariable linear regression was used to determine which maternal and delivery characteristics were associated with the Labor Agentry Scale score. Eligible characteristics included age, self-reported race and ethnicity, marital status, employment status, type of insurance, previous pregnancy loss before 20 weeks of gestation, body mass index (BMI), smoking, alcohol use, mode of delivery, labor pain (0-10 points), and a composite of perinatal death or severe neonatal complications. Significant variables ( P <.05) were retained in the final multivariable model, and adjusted mean differences (95% CIs) between groups were estimated. RESULTS: Of 6,106 people enrolled in the trial, 6,038 experienced labor, of whom 5,750 (95.2%) completed the Labor Agentry Scale and were included in this analysis. Mean [95% CI] adjusted Labor Agentry Scale scores were significantly lower among those who identified as Asian (-6.4 [-10.5 to -2.3]) or Hispanic (-3.7 [-5.7 to -1.7]) compared with White, smoked compared with did not smoke (-2.8 [-5.5 to -0.1]), had BMIs of 35 or higher compared with less than 30 (-2.0 [-3.8 to -0.2]), were unemployed (-3.15 [-4.76 to -1.55]), did not have private health insurance (-2.61 [-4.47 to -0.76]), underwent operative vaginal (-5.1 [-7.7 to -2.6]) or cesarean (-14.4 [-16.1 to -12.6]) delivery compared with spontaneous vaginal delivery, and reported greater labor pain score of 8 or higher compared with less than 8 (-11.9 [-13.4 to -10.4]). Mean [95% CI] adjusted Labor Agentry Scale scores were significantly higher among people who were employed compared with unemployed (3.2 [1.6-4.8]) and had private compared with nonprivate insurance (2.6 [0.76-4.5]). CONCLUSION: In nulliparous people at low risk, unemployment, lack of private health insurance, Asian race, Hispanic ethnicity, smoking, operative delivery, and more labor pain were associated with lower perceived control during labor. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT01990612.

Electromyometrial Imaging of Uterine Contractions in Pregnant Women.

During normal pregnancy, the uterine smooth muscle, the myometrium, begins to have weak, uncoordinated contractions at late gestation to help the cervix remodel. In labor, the myometrium has strong, coordinated contractions to deliver the fetus. Various methods have been developed to monitor uterine contraction patterns to predict labor onset. However, the current techniques have limited spatial coverage and specificity. We developed electromyometrial imaging (EMMI) to noninvasively map uterine electrical activity onto the three-dimensional uterine surface during contractions. The first step in EMMI is to use T1-weighted magnetic resonance imaging to acquire the subject-specific body-uterus geometry. Next, up to 192 pin-type electrodes placed on the body surface are used to collect electrical recordings from the myometrium. Finally, the EMMI data processing pipeline is performed to combine the body-uterus geometry with body surface electrical data to reconstruct and image uterine electrical activities on the uterine surface. EMMI can safely and noninvasively image, identify, and measure early activation regions and propagation patterns across the entire uterus in three dimensions.

The Temporal Relationship Between the Coronavirus Disease 2019 (COVID-19) Pandemic and Preterm Birth.

OBJECTIVE: To evaluate whether preterm birth rates changed in relation to the onset of the coronavirus disease 2019 (COVID-19) pandemic and whether any change depended on socioeconomic status. METHODS: This is an observational cohort study of pregnant individuals with a singleton gestation who delivered in the years 2019 and 2020 at 1 of 16 U.S. hospitals of the Maternal-Fetal Medicine Units Network. The frequency of preterm birth for those who delivered before the onset of the COVID-19 pandemic (ie, in 2019) was compared with that of those who delivered after its onset (ie, in 2020). Interaction analyses were performed for people of different individual- and community-level socioeconomic characteristics (ie, race and ethnicity, insurance status, Social Vulnerability Index (SVI) of a person's residence). RESULTS: During 2019 and 2020, 18,526 individuals met inclusion criteria. The chance of preterm birth before the COVID-19 pandemic was similar to that after the onset of the pandemic (11.7% vs 12.5%, adjusted relative risk 0.94, 95% CI 0.86-1.03). In interaction analyses, race and ethnicity, insurance status, and the SVI did not modify the association between the epoch and the chance of preterm birth before 37 weeks of gestation (all interaction P >.05). CONCLUSION: There was no statistically significant difference in preterm birth rates in relation to the COVID-19 pandemic onset. This lack of association was largely independent of socioeconomic indicators such as race and ethnicity, insurance status, or SVI of the residential community in which an individual lived.

Tranexamic Acid to Prevent Obstetrical Hemorrhage after Cesarean Delivery.

BACKGROUND: Prophylactic use of tranexamic acid at the time of cesarean delivery has been shown to decrease the calculated blood loss, but the effect on the need for blood transfusions is unclear. METHODS: We randomly assigned patients undergoing cesarean delivery at 31 U.S. hospitals to receive either tranexamic acid or placebo after umbilical-cord clamping. The primary outcome was a composite of maternal death or blood transfusion by hospital discharge or 7 days post partum, whichever came first. Key secondary outcomes were estimated intraoperative blood loss of more than 1 liter (prespecified as a major secondary outcome), interventions for bleeding and related complications, the preoperative-to-postoperative change in the hemoglobin level, and postpartum infectious complications. Adverse events were assessed. RESULTS: A total of 11,000 participants underwent randomization (5529 to the tranexamic acid group and 5471 to the placebo group); scheduled cesarean delivery accounted for 50.1% and 49.2% of the deliveries in the respective groups. A primary-outcome event occurred in 201 of 5525 participants (3.6%) in the tranexamic acid group and in 233 of 5470 (4.3%) in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Estimated intraoperative blood loss of more than 1 liter occurred in 7.3% of the participants in the tranexamic acid group and in 8.0% of those in the placebo group (relative risk, 0.91; 95% CI, 0.79 to 1.05). Interventions for bleeding complications occurred in 16.1% of the participants in the tranexamic acid group and in 18.0% of those in the placebo group (relative risk, 0.90; 95% CI, 0.82 to 0.97); the change in the hemoglobin level was -1.8 g per deciliter and -1.9 g per deciliter, respectively (mean difference, -0.1 g per deciliter; 95% CI, -0.2 to -0.1); and postpartum infectious complications occurred in 3.2% and 2.5% of the participants, respectively (relative risk, 1.28; 95% CI, 1.02 to 1.61). The frequencies of thromboembolic events and other adverse events were similar in the two groups. CONCLUSIONS: Prophylactic use of tranexamic acid during cesarean delivery did not lead to a significantly lower risk of a composite outcome of maternal death or blood transfusion than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT03364491.).

The "30-minute rule" for expedited delivery: fact or fiction?

Initially developed from hospital feasibility data from the 1980s, the "30-minute rule" has perpetuated the belief that the decision-to-incision time in an emergency cesarean delivery should be <30 minutes to preserve favorable neonatal outcomes. Through a review of the history, available data on delivery timing and associated outcomes, and consideration of feasibility across several hospital systems, the use and applicability of this "rule" are explored, and its reconsideration is called for. Moreover, we have advocated for balanced consideration of maternal safety with rapidity of delivery, encouraged process-based approaches, and proposed standardization of terminology regarding delivery urgency. Furthermore, a standardized 4-tier classification system for delivery urgency, from class I, for a perceived threat to maternal or fetal life, to class IV, a scheduled delivery, and a call for further research with a standardized structure to facilitate comparison have been proposed.

Knowledge, Judgment, and Skills in Reproductive Health Care and Abortion Are Essential to the Practice of Obstetrics and Gynecology.

A social contract exists between medicine and society. In fulfilling the social contract to our patients and society, physicians have an obligation to provide the evidence-based care that patients want and need. What do the data regarding knowledge, judgment, and skills required to practice obstetrics and gynecology show? Obstetrics and gynecology job task analyses assess the importance of knowledge, judgment, and skills through surveys asking practicing physicians about the criticality and frequency of a variety of task statements to create an importance score. Excerpts from a 2018 practice analysis survey clearly indicate that reproductive health care and abortion are important components of the knowledge, judgment, and skills to practice obstetrics and gynecology in the United States. These standards help to assure the knowledge, judgment, and skills of current and future generations of ob-gyns, so their patients and the public can be provided the comprehensive reproductive health care they want and need. It is sometimes important to restate principles and standards that have become ingrained in thoughts and practices that guide physicians and serve to protect our patients. This concept is important now, as our country, health care professionals, and patients examine the future of reproductive health care, including abortion.

Noninvasive electromyometrial imaging of human uterine maturation during term labor.

Electromyometrial imaging (EMMI) was recently developed to image the three-dimensional (3D) uterine electrical activation during contractions noninvasively and accurately in sheep. Herein we describe the development and application of a human EMMI system to image and evaluate 3D uterine electrical activation patterns at high spatial and temporal resolution during human term labor. We demonstrate the successful integration of the human EMMI system during subjects' clinical visits to generate noninvasively the uterine surface electrical potential maps, electrograms, and activation sequence through an inverse solution using up to 192 electrodes distributed around the abdomen surface. Quantitative indices, including the uterine activation curve, are developed and defined to characterize uterine surface contraction patterns. We thus show that the human EMMI system can provide detailed 3D images and quantification of uterine contractions as well as novel insights into the role of human uterine maturation during labor progression.

Effect of Second-Stage Pushing Timing on Postpartum Pelvic Floor Morbidity: A Randomized Controlled Trial.

OBJECTIVE: To assess whether immediate or delayed pushing in the second-stage results in higher risk of pelvic floor morbidity. METHODS: This study was a planned secondary aim of a multicenter randomized clinical trial that included nulliparous patients at 37 weeks of gestation or greater in labor with neuraxial analgesia. Participants were randomized in the second stage to initiate pushing immediately or wait 60 minutes before pushing. Participants had pelvic floor assessments at 1-5 days postpartum, 6 weeks postpartum, and 6 months postpartum. Rates of perineal lacerations, pelvic organ prolapse quantification (POP-Q) measures, and scores on validated symptom-specific distress and quality-of-life questionnaires (PFDI-20 [Pelvic Floor Distress Inventory], PFIQ [Pelvic Floor Impact Questionnaire], FISI [Fecal Incontinence Severity Index], and MMHQ [Modified Manchester Health Questionnaire]) were compared. It was estimated that 630 participants would provide more than 80% power to detect a 40% difference in second-degree or greater perineal lacerations and approximately 80% power to detect a 40% difference in stage 2 or greater pelvic organ prolapse (POP). RESULTS: Among 2,414 participants in the primary trial conducted between May 19, 2014, and December 16, 2017, 941 (39%) had pelvic floor assessments: 452 immediate pushing and 489 delayed pushing. The mean age was 24.8 years, and 93.4% had vaginal delivery. There were no significant differences in perineal lacerations at delivery and POP at 6 weeks and 6 months postpartum. Changes from baseline in total and subscale scores for the PFDI-20, the PFIQ, and the MMHQ were not significantly different at 6 weeks postpartum and 6 months postpartum. The change in FISI score was higher in the immediate pushing group at 6 months (2.9±5.7 vs 2.0±4.5, difference 0.9, P =.01), but less than the minimum important difference of 4. CONCLUSION: Among nulliparous patients in the second stage with neuraxial analgesia, immediate pushing, compared with delayed pushing, did not increase perineal lacerations, POP-Q measures, or patient-reported pelvic floor symptoms at 6 weeks and 6 months postpartum. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02137200.