Racial disparities in maternal blood transfusion in the United States by mode of delivery.

BACKGROUND: Despite well-documented racial disparities in maternal health in the United States, gaps remain in characterizing the distribution of these disparities in maternal blood transfusion. OBJECTIVE: To assess racial disparities in maternal blood transfusion using detailed, self-identified racial groupings in the United States overall and stratified by mode of delivery. STUDY DESIGN: We performed a population-based, retrospective cohort study of full term, live births (2016-2021) using the National Vital Statistics System's Natality Files. Regression models were constructed to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of maternal blood transfusion by self-identified maternal race in the total population, and among subgroups stratified by mode of delivery. Models were adjusted for maternal and obstetric practice factors. RESULTS: The study included 17,905,699 deliveries; maternal blood transfusion occurred in 3.4 per 1,000 deliveries. Compared with individuals who identified as White (3.3 per 1,000 transfusion rate), higher odds of transfusion were found among those who identified as American Indian and Alaska Native (AIAN; aOR 2.36, 95% CI 2.23-2.49), Black (aOR 1.15, 95% CI 1.12-1.17), Filipino (aOR 1.33, 95% CI 1.22-1.44), Korean (aOR 1.25, 95% CI 1.10-1.42), and Pacific Islander (aOR 1.63, 95% CI 1.45-1.83). The frequency of transfusion and racial disparities in transfusion varied substantially by mode of delivery. Lower rates of transfusion in Black vs White patients were observed in the spontaneous vaginal delivery (2.2 vs 2.3 per 1000; aOR 0.95, 95% CI 0.92-0.99), forceps (6.8 vs 8.9 per 1000; aOR 0.77, 95% CI 0.60-0.99), vacuum (4.2 vs 5.0 per 1000; aOR 0.85, 95% CI 0.74-0.97, and cesarean delivery with trial of labour (8.8 vs 8.9 per 1000; aOR 0.95, 95% CI 0.91-1.00) groups, while a higher rate was shown among cesarean deliveries without trial of labour (6.8 vs 4.3 per 1000; aOR 1.45, 95% CI 1.40-1.51). CONCLUSION: Racial disparities in maternal blood transfusion persist after adjustment for several confounders, particularly for AIAN and Pacific Islander individuals, and vary by mode of delivery.

Spatiotemporal patterns and surveillance artifacts in maternal mortality in the United States: a population-based study.

Background: Reports of high and rising maternal mortality ratios (MMR) in the United States have caused serious concern. We examined spatiotemporal patterns in cause-specific MMRs, in order to obtain insights into the cause for the increase. Methods: The study included all maternal deaths recorded by the Centers for Disease Control and Prevention from 1999 to 2021. Changes in overall and cause-specific MMRs were quantified nationally; in low-vs high-MMR states (i.e., MMRs <20 vs ≥26 per 100,000 live births in 2018-2021); and in California vs Texas (populous states with low vs high MMRs). Cause-specific MMRs included those due to unambiguous causes (e.g., selected obstetric causes such as pre-eclampsia/eclampsia) and less-specific/potentially incidental causes (e.g., "other specified pregnancy-related conditions", chronic hypertension, and malignant neoplasms). Findings: MMRs increased from 9.60 (n = 1543) in 1999-2002 to 23.5 (n = 3478) per 100,000 live births in 2018-2021. The temporal increase in MMRs was smaller in low-MMR states (from 7.82 to 14.1 per 100,000 live births) compared with high-MMR states (from 11.1 to 31.4 per 100,000 live births). MMRs due to selected obstetric causes decreased to a similar extent in low-vs high-MMR states, whereas the increase in MMRs from less-specific/potentially incidental causes was smaller in low- vs high-MMR states (MMR ratio (RR) 5.57, 95% CI 4.28, 7.25 vs 7.07, 95% CI 5.91, 8.46), and in California vs Texas (RR 1.67, 95% CI 1.03, 2.69 vs 10.8, 95% CI 6.55, 17.7). The change in malignant neoplasm-associated MMRs was smaller in California vs Texas (RR 1.21, 95% CI 0.08, 19.3 vs 91.2, 95% CI 89.2, 94.8). MMRs from less-specific/potentially incidental causes increased in all race/ethnicity groups. Interpretation: Spatiotemporal patterns of cause-specific MMRs, including similar reductions in unambiguous obstetric causes of death and variable increases in less-specific/potentially incidental causes, suggest misclassified maternal deaths and overestimated maternal mortality in some US states. Funding: This work received no funding.

Risk of cervical laceration in forceps vs vacuum delivery: A systematic review and meta-analysis.

INTRODUCTION: Cervical laceration is an obstetric injury associated with severe postpartum hemorrhage and subsequent spontaneous preterm birth. While operative vaginal delivery is a known risk factor for cervical laceration, it is unclear whether forceps and vacuum deliveries incur the same risk. The aim of this systematic review was to compare the risk of cervical laceration between operative instruments (forceps vs vacuum). MATERIAL AND METHODS: Medline, Embase, Global Health, CENTRAL, Emcare, and Web of Science were searched from inception until August 2024 with terms related to operative vaginal delivery and cervical laceration. Studies comparing the risk of cervical laceration in individuals undergoing forceps or vacuum delivery were included. Two authors conducted screening, data extraction, and quality assessment of all studies. Random-effects models were used to pool risk ratios across studies and certainty of evidence was assessed using Cochrane methods and the GRADE approach. PROSPERO Registration Number CRD42023421890. RESULTS: Thirteen studies were eligible for inclusion, 3 randomized controlled trials (RCTs) and 10 observational studies. The overall rate of cervical laceration was 0.35% (990/284218 births) where 1.04% of forceps deliveries (456/43817) were complicated by cervical laceration compared to 0.22% of vacuum deliveries (534/240401). The risk of cervical laceration was 2-5 fold greater in forceps deliveries than in vacuum deliveries: pooled unadjusted risk ratio [RR] 4.83, 95% confidence interval [CI] 1.56-14.98 among RCTs and pooled unadjusted RR 1.89, 95% CI 1.59-2.24 among observational studies. The overall quality of evidence was low to moderate mainly due to the lack of attention to confounding in the included literature. The GRADE assessment indicated that the certainty of evidence was very low for observational studies and moderate for RCTs. CONCLUSIONS: Low certainty of evidence indicates that forceps deliveries may be associated with an increased risk of cervical laceration compared to vacuum deliveries.

Unintended Upper Uterine Wall Extensions at the Time of Cesarean Delivery: Risk Factors and Associated Adverse Maternal and Neonatal Outcomes.

OBJECTIVE: This study aims to estimate the frequency of unintended upper uterine wall extensions during cesarean delivery (CD) and identify associated risk factors and adverse outcomes. STUDY DESIGN: A multicenter retrospective cohort study was conducted, including patients who underwent CD between 2005 and 2021. Demographic factors, obstetric history, CD indications, delivery and surgical characteristics, adverse maternal and neonatal outcomes were compared between those with unintended upper uterine wall extensions during CD and those without extensions. Crude and adjusted estimates (odds ratios [ORs] and 95% confidence intervals [CIs]) were used. RESULTS: Among 30,517 patients meeting inclusion criteria, 117 (0.4%) had an unintended upper uterine wall extension. In univariate analysis, upper uterine wall extensions were associated with higher rates of intrapartum CD, second-stage CD, unplanned or emergency CD, CD following failed vacuum delivery or trial of labor after CD, chorioamnionitis, prolonged labor, increased vaginal exams, lower fetal head station, and higher birth weight. During surgery, higher rates of general anesthesia, significant intraperitoneal adhesion, fetal malpresentation, and fetal extraction by the leg were observed. Multivariable analysis identified fetal extraction not by head (adjusted OR [aOR]: 9.17, 95% CI: 5.35-15.73), vertex fetal presentation (aOR: 3.65, 95% CI: 1.81-7.35), second-stage CD (aOR: 3.07, 95% CI: 1.24-7.59), and trial of labor after cesarean (aOR: 2.04, 95% CI: 1.08-3.84) as significant risk factors for unintended upper uterine wall extensions. Additionally, upper uterine wall extensions were associated with higher rates of maternal and neonatal complications, including longer operating times, excessive bleeding, postpartum hemorrhage, intraperitoneal drainage, blood product transfusion, puerperal fever, paralytic ileus, Apgar score < 7 at 1 and 5 minutes, and fetal intracranial hemorrhage. CONCLUSION: Our study identifies risk factors for unintended upper uterine wall extensions during CD. While these extensions are infrequent, their occurrence is associated with increased maternal and neonatal morbidity. KEY POINTS: · Unintended upper uterine wall extensions occur in 0.4% of cesarean deliveries.. · Significant risk factors include fetal extraction not by head and second-stage CD.. · Extensions are associated with increased maternal complications like excessive bleeding and prolonged surgery.. · Neonatal complications include lower Apgar scores and intracranial hemorrhage.. · Awareness of these risks is critical for improving cesarean delivery outcomes..

Risk of postpartum hemorrhage with increasing first stage labor duration.

With increasing rates of postpartum hemorrhage (PPH) in high-income countries, an important clinical concern is the impact of labor duration on the risk of PPH. This study examined the relationship between increasing active first stage labor duration and PPH and explored the role of second stage labor duration and cesarean delivery (CD) in this association. Including 77,690 nulliparous women with spontaneous labor onset, first stage labor duration was defined as the time from 5 cm to 10 cm, second stage duration from 10 cm dilation to birth and PPH as estimated blood loss > 1000 ml. Using modified Poisson regression for risk ratios (RR) and confidence intervals (CI), we found a 1.5-fold (RR, 1.53; 95% CI, 1.41‒1.66) increased PPH risk when first stage of labor exceeded 12.1 h compared to the reference (< 7.7 h). Mediation analysis showed that 18.5% (95% CI, 9.7‒29.6) of the increased PPH risk with a prolonged first stage (≥ 7.7 h) was due to a prolonged second stage (> 3 h) or CD. These results suggest that including first stage duration in intrapartum assessments could improve PPH risk identification in first-time mothers with a singleton fetus in vertex presentation at full term with spontaneous labor onset.

Neonatal abstinence syndrome and infant mortality and morbidity: a population-based study.

Background: Infant health among newborns with neonatal abstinence syndrome (NAS) has been understudied. We examined infant mortality and hospitalizations among infants diagnosed with NAS after birth. Methods: All live births in British Columbia (BC), Canada, for fiscal years from 2004-2005 to 2019-2020, were included (N = 696,900). NAS was identified based on International Classification of Diseases, version 10, Canadian modification (ICD-10-CA) codes; the outcomes included infant death and hospitalizations during the first year of life, ascertained from BC linked administrative data. Generalized estimating equation models were used to adjust for maternal factors. Results: There were 2,439 infants with NAS (3.50 per 1,000 live births). Unadjusted for other factors, infant mortality was 2.5-fold higher in infants with vs. without NAS (7.79 vs. 3.08 per 1,000 live births, respectively) due to increased post-discharge mortality NAS (5.76 vs. 1.34 per 1,000 surviving infants, respectively). These differences diminished after adjustment: adjusted odds ratio (AOR) for infant death was 0.85 [95% confidence interval (CI): 0.52-1.39]; AOR for post-discharge death was 1.75 (95% CI 1.00-3.06). Overall, 22.3% infants with NAS had at least one hospitalization after post-neonatal discharge, this proportion was 10.7% in those without NAS. During the study period, discharge to foster care declined from 49.5% to 20.3% in infants with NAS. Conclusion: Unadjusted for other factors, infants with NAS had increased post-discharge infant mortality and hospitalizations during the first year of life. This association diminished after adjustment for adverse maternal and socio-medical conditions. Infants with NAS had a disproportionately higher rate of placement in foster care after birth, although this proportion declined dramatically between 2004/2005 and 2019/2020. These results highlight the importance of implementing integrated care services to support infants born with NAS and their mothers during the first year of life and beyond, even though NAS itself is not independently associated with increased infant mortality.

Temporal trends in peripartum hysterectomy among individuals with a previous cesarean delivery by race/ethnicity in the United States: A population-based cohort study.

OBJECTIVES: Rates of severe maternal morbidity have highlighted persistent and growing racial disparities in the United States (US). We aimed to contrast temporal trends in peripartum hysterectomy by race/ethnicity and quantify the contribution of changes in maternal and obstetric factors to temporal variations in hysterectomy rates. METHODS: We conducted a population-based, retrospective study of 5,739,569 US residents with a previous cesarean delivery, using National Vital Statistics System's Natality Files (2011-2021). Individuals were stratified by self-identified race/ethnicity and classified into four periods based on year of delivery. Temporal changes in hysterectomy rates were estimated using odds ratios (ORs) and 95% confidence intervals (CIs). We used sequential logistic regression models to quantify the contribution of maternal and obstetric factors to temporal variations in hysterectomy rates. RESULTS: Over the study period, the peripartum hysterectomy rate increased from 1.23 (2011-2013) to 1.44 (2019-2021) per 1,000 deliveries (OR 2019-2021 vs. 2011-2013 = 1.17, 95% CI 1.10 to 1.25). Hysterectomy rates varied by race/ethnicity with the highest rates among Native Hawaiian and Other Pacific Islander (NHOPI; 2.73 per 1,000 deliveries) and American Indian or Alaskan Native (AIAN; 2.67 per 1,000 deliveries) populations in 2019-2021. Unadjusted models showed a temporal increase in hysterectomy rates among AIAN (2011-2013 rate = 1.43 per 1,000 deliveries; OR 2019-2021 vs. 2011-2013 = 1.87, 95% CI 1.02 to 3.45) and White (2011-2013 rate = 1.13 per 1,000 deliveries; OR 2019-2021 vs. 2011-2013 = 1.21, 95% CI 1.11 to 1.33) populations. Adjustment ranged from having no effect among NHOPI individuals to explaining 14.0% of the observed 21.0% increase in hysterectomy rates among White individuals. CONCLUSION: Nationally, racial disparities in peripartum hysterectomy are evident. Between 2011-2021, the rate of hysterectomy increased; however, this increase was confined to AIAN and White individuals.

Maternal mortality in the United States: are the high and rising rates due to changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance?

BACKGROUND: National Vital Statistics System reports show that maternal mortality rates in the United States have nearly doubled, from 17.4 in 2018 to 32.9 per 100,000 live births in 2021. However, these high and rising rates could reflect issues unrelated to obstetrical factors, such as changes in maternal medical conditions or maternal mortality surveillance (eg, due to introduction of the pregnancy checkbox). OBJECTIVE: This study aimed to assess if the high and rising rates of maternal mortality in the United States reflect changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance. STUDY DESIGN: The study was based on all deaths in the United States from 1999 to 2021. Maternal deaths were identified using the following 2 approaches: (1) per National Vital Statistics System methodology, as deaths in pregnancy or in the postpartum period, including deaths identified solely because of a positive pregnancy checkbox, and (2) under an alternative formulation, as deaths in pregnancy or in the postpartum period, with at least 1 mention of pregnancy among the multiple causes of death on the death certificate. The frequencies of major cause-of-death categories among deaths of female patients aged 15 to 44 years, maternal deaths, deaths due to obstetrical causes (ie, direct obstetrical deaths), and deaths due to maternal medical conditions aggravated by pregnancy or its management (ie, indirect obstetrical deaths) were quantified. RESULTS: Maternal deaths, per National Vital Statistics System methodology, increased by 144% (95% confidence interval, 130-159) from 9.65 in 1999-2002 (n=1550) to 23.6 per 100,000 live births in 2018-2021 (n=3489), with increases occurring among all race and ethnicity groups. Direct obstetrical deaths increased from 8.41 in 1999-2002 to 14.1 per 100,000 live births in 2018-2021, whereas indirect obstetrical deaths increased from 1.24 to 9.41 per 100,000 live births: 38% of direct obstetrical deaths and 87% of indirect obstetrical deaths in 2018-2021 were identified because of a positive pregnancy checkbox. The pregnancy checkbox was associated with increases in less specific and incidental causes of death. For example, maternal deaths with malignant neoplasms listed as a multiple cause of death increased 46-fold from 0.03 in 1999-2002 to 1.42 per 100,000 live births in 2018-2021. Under the alternative formulation, the maternal mortality rate was 10.2 in 1999-2002 and 10.4 per 100,000 live births in 2018-2021; deaths from direct obstetrical causes decreased from 7.05 to 5.82 per 100,000 live births. Deaths due to preeclampsia, eclampsia, postpartum hemorrhage, puerperal sepsis, venous complications, and embolism decreased, whereas deaths due to adherent placenta, renal and unspecified causes, cardiomyopathy, and preexisting hypertension increased. Maternal mortality increased among non-Hispanic White women and decreased among non-Hispanic Black and Hispanic women. However, rates were disproportionately higher among non-Hispanic Black women, with large disparities evident in several causes of death (eg, cardiomyopathy). CONCLUSION: The high and rising rates of maternal mortality in the United States are a consequence of changes in maternal mortality surveillance, with reliance on the pregnancy checkbox leading to an increase in misclassified maternal deaths. Identifying maternal deaths by requiring mention of pregnancy among the multiple causes of death shows lower, stable maternal mortality rates and declines in maternal deaths from direct obstetrical causes.

The association between unintended hysterotomy extensions with cesarean delivery and subsequent preterm birth.

BACKGROUND: An increased risk for preterm birth has been observed among individuals with a previous second stage cesarean delivery when compared with those with a previous vaginal delivery. One mechanism that may contribute to the increased risk for preterm birth following a second stage cesarean delivery is the increased risk for cervical injury because of extension of the uterine incision (hysterotomy) into the cervix. The contribution of hysterotomy extension to the rate of preterm birth in a subsequent pregnancy has not been investigated and may shed light on the mechanism underlying the observed relationship between the mode of delivery and subsequent preterm birth. OBJECTIVE: We aimed to quantify the association between unintended hysterotomy extension and preterm birth in a subsequent delivery. STUDY DESIGN: We performed a retrospective cohort study using electronic perinatal data collected from 2 university-affiliated obstetrical centers. The study included patients with a primary cesarean delivery of a term, singleton live birth and a subsequent singleton birth in the same catchment (2005-2021). The primary outcome was subsequent preterm birth <37 weeks' gestation; secondary outcomes included subsequent preterm birth at <34, <32, and <28 weeks' gestation. We assessed crude and adjusted associations between unintended hysterotomy extensions and subsequent preterm birth with log binomial regression models using rate ratios and 95% confidence intervals. Adjusted models included several characteristics of the primary cesarean delivery such as maternal age, length of active labor, indication for cesarean delivery, chorioamnionitis, and maternal comorbidity. RESULTS: A total 4797 patients met the study inclusion criteria. The overall rate of unintended hysterotomy extension in the primary cesarean delivery was 6.0% and the total rate of preterm birth in the subsequent pregnancy was 4.8%. Patients with an unintended hysterotomy extension were more likely to have a longer duration of active labor, chorioamnionitis, failed vacuum delivery attempt, second stage cesarean delivery, and persistent occiput posterior position of the fetal head in the primary cesarean delivery and higher rates of smoking in the subsequent pregnancy. Multivariable analyses that controlled for several confounders showed that a history of hysterotomy extension was not associated with a higher risk for preterm birth <37 weeks' gestation (adjusted rate ratio, 1.55; 95% confidence interval, 0.98-2.47), but it was associated with preterm birth <34 weeks' gestation (adjusted rate ratio, 2.49; 95% confidence interval, 1.06-5.42). CONCLUSION: Patients with a uterine incision extension have a 2.5 times higher rate of preterm birth <34 weeks' gestation when compared with patients who did not have this injury. This association was not observed for preterm birth <37 weeks' gestation. Future research should aim to replicate our analyses with incorporation of additional data to minimize the potential for residual confounding.

Prepregnancy body mass index and other risk factors for early-onset and late-onset haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome: a population-based retrospective cohort study in British Columbia, Canada.

BACKGROUND: Obesity increases risk of pre-eclampsia, but the association with haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome is understudied. OBJECTIVE: To examine the association between prepregnancy body mass index (BMI) and HELLP syndrome, including early-onset versus late-onset disease. STUDY DESIGN: A retrospective cohort study using population-based data. SETTING: British Columbia, Canada, 2008/2009-2019/2020. POPULATION: All pregnancies resulting in live births or stillbirths at ≥20 weeks' gestation. METHODS: BMI categories (kg/m2) included underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9) and obese (≥30.0). Rates of early-onset and late-onset HELLP syndrome (<34 vs ≥34 weeks, respectively) were calculated per 1000 ongoing pregnancies at 20 and 34 weeks' gestation, respectively. Cox regression was used to assess the associations between risk factors (eg, BMI, maternal age and parity) and early-onset versus late-onset HELLP syndrome. MAIN OUTCOME MEASURES: Early-onset and late-onset HELLP syndrome. RESULTS: The rates of HELLP syndrome per 1000 women were 2.8 overall (1116 cases among 391 941 women), and 1.9, 2.5, 3.2 and 4.0 in underweight, normal BMI, overweight and obese categories, respectively. Overall, gestational age-specific rates of HELLP syndrome increased with prepregnancy BMI. Obesity (compared with normal BMI) was more strongly associated with early-onset HELLP syndrome (adjusted HR (AHR) 2.24 (95% CI 1.65 to 3.04) than with late-onset HELLP syndrome (AHR 1.48, 95% CI 1.23 to 1.80) (p value for interaction 0.025). Chronic hypertension, multiple gestation, bleeding (<20 weeks' gestation and antepartum) also showed differing AHRs between early-onset versus late-onset HELLP syndrome. CONCLUSIONS: Prepregnancy BMI is positively associated with HELLP syndrome and the association is stronger with early-onset HELLP syndrome. Associations with early-onset and late-onset HELLP syndrome differed for some risk factors, suggesting possible differences in aetiological mechanisms.

COVID-19 Pandemic-Related Changes in Rates of Neonatal Abstinence Syndrome.

This cross-sectional study examines COVID-19 pandemic­related changes in rates of neonatal abstinence syndrome (NAS) and whether infants in urban or rural areas and those with low socioeconomic status were disproportionately affected.

Variation in Episiotomy Use Among Nulliparous Individuals by Maternity Care Provider and Associated Rates of Obstetric Anal Sphincter Injury.

OBJECTIVES: To quantify variation in the association between episiotomy and obstetric anal sphincter injury (OASI) by maternity care provider in spontaneous and operative vaginal deliveries (SVDs and OVDs). METHODS: Population-based retrospective cohort study of vaginal, term deliveries among nullipara in Canada (2004-2015). Adjusted rate ratios (ARRs) and 95% CIs were estimated using log-binomial regression to quantify the associations between episiotomy and OASI, stratified by care provider (obstetrician [OB], family physician [FP], or registered midwife [RM]) while adjusting for potential confounders. RESULTS: The study included 631 642 deliveries. Episiotomy use varied by provider: among SVDs, the episiotomy rate was 19.6%, 14.4%, and 8.4% in the OB, FP, and RM groups, respectively. The rate of OASI was higher among SVDs with versus without episiotomy (5.8% vs 4.6%). Conversely, OASI occurred less frequently in operative vaginal deliveries with episiotomy (15.3%) compared with those without (16.7%). In all provider groups, the ARR for OASI was increased with episiotomy in SVD and decreased with episiotomy with forceps delivery. No differences in these associations were observed by provider except among vacuum delivery (ARR with episiotomy vs. without, OB: 0.88, 95% CI 0.84-0.92; FP: 0.89, 95% CI 0.83-0.96, RM: 1.22, 95% CI 1.02-1.48). CONCLUSIONS: In nullipara, irrespective of maternity care provider, there is a positive association between episiotomy and OASI among SVDs and an inverse association between episiotomy and deliveries with forceps. The relationship between episiotomy and OASI is modified by maternity care providers among vacuum deliveries.

Impacted fetal head extraction methods at second stage cesarean and subsequent preterm delivery: A multicenter study.

OBJECTIVE: Second-stage cesarean delivery (CD) is associated with subsequent preterm birth (PTB). It has been suggested that an increased risk of PTB after second-stage cesarean delivery could be linked to a higher chance of cervical injury due to the extension of the uterine incision. Previous studies have shown that reverse breech extraction is associated with lower rates of uterine incision extensions compared to the "push" method. We aimed to investigate the association between the method of fetal extraction during second-stage CD and the rate of spontaneous PTB (sPTB), as well as other maternal and neonatal outcomes during the subsequent pregnancy. METHODS: This was a multicenter retrospective cohort study. The study population included women in their first subsequent singleton delivery following a second-stage CD between 2004 and 2021. The main exposure of interest was the method of fetal extraction in the index CD ("push" method vs. reverse breech extraction). The primary outcome of this study was sPTB <37 weeks in the subsequent pregnancy. Secondary outcomes were overall PTB, trial of labor, and other adverse maternal and neonatal outcomes. Univariate analysis was followed by multiple logistic regression modeling. RESULTS: During the study period, 2969 index CD during second stage were performed, of those 583 met the inclusion criteria, of whom 234 (40.1%) had fetal extraction using the reverse breech extraction method, while 349 (59.9%) had the "push" method for extraction. In univariate analysis, women in those two groups had statistically similar rates of sPTB (3.7% vs. 3.0%; odds ratio [OR] 1.25, 95% CI: 0.49-3.19) and overall PTB (<37, <34 and <32 weeks), as well as other maternal, neonatal, and trial of labor outcomes. This was confirmed by multivariate analyses with an adjusted OR of 1.27 (95% CI: 0.43-3.71) for sPTB. CONCLUSION: Among women with a previous second-stage CD, no significant difference was observed in PTB rates in the subsequent pregnancies following the "push" method compared to the reverse breech extraction method.

Asian-White disparities in obstetric anal sphincter injury: a systematic review and meta-analysis.

OBJECTIVE: Obstetrical anal sphincter injury describes a severe injury to the perineum and perianal muscles after birth. Obstetrical anal sphincter injury occurs in approximately 4.4% of vaginal births in the United States; however, racial and ethnic inequities in the incidence of obstetrical anal sphincter injury have been shown in several high-income countries. Specifically, an increased risk of obstetrical anal sphincter injury in individuals who identify as Asian vs those who identify as White has been documented among residents of the United States, Australia, Canada, Western Europe, and the Scandinavian countries. The high rates of obstetrical anal sphincter injury among the Asian diaspora in these countries are higher than obstetrical anal sphincter injury rates reported among Asian populations residing in Asia. A systematic review and meta-analysis of studies in high-income, non-Asian countries was conducted to further evaluate this relationship. DATA SOURCES: MEDLINE, Ovid, Embase, EmCare, and the Cochrane databases were searched from inception to March 2023 for original research studies. STUDY ELIGIBILITY CRITERIA: Observational studies using keywords and controlled vocabulary terms related to race, ethnicity and obstetrical anal sphincter injury. All observational studies, including cross-sectional, case-control, and cohort were included. 2 reviewers followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Meta-analysis of Observational Studies in Epidemiology recommendations. METHODS: Meta-analysis was performed using RevMan (version 5.4; Cochrane Collaboration, London, United Kingdom) for dichotomous data using the random effects model and the odds ratios as effect measures with 95% confidence intervals. Subgroup analysis was performed among Asian subgroups. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal tools. Meta-regression was used to determine sources of between-study heterogeneity. Results: A total of 27 studies conducted in 7 countries met the inclusion criteria encompassing 2,337,803 individuals. The pooled incidence of obstetrical anal sphincter injury was higher among Asian individuals than White individuals (pooled odds ratio, 1.64; 95% confidence interval, 1.48-1.80). Subgroup analyses showed that obstetrical anal sphincter injury rates were highest among South Asians and among population-based vs hospital-based studies. Meta-regression showed that moderate heterogeneity remained even after accounting for differences in studies by types of Asian subgroups included, study year, mode of delivery included, and study setting. Conclusion: Obstetrical anal sphincter injury is more frequent among Asian versus white birthing individuals in multiple high-income, non-Asian countries. Qualitative and quantitative research to elucidate underlying causal mechanisms responsible for this relationship are warranted.