Placental abruption at near-term and term gestations: pathophysiology, epidemiology, diagnosis, and management

Urinary cotinine levels versus self-reported smoking status for assessing placental abruption risk: the Japan Environment and Children's study

INTRODUCTION

Placental abruption is a serious complication of pregnancy, and smoking is a well-known risk factor thereof. However, evaluations of the effects of smoking mostly rely on self-reported questionnaires, resulting in incorrect representation of smoke exposure owing to incorrect reporting and missing data on passive smoking. Cotinine is a major nicotine metabolite and a sensitive biomarker in smokers. However, to date, there have been no reports on the relationship between urinary cotinine levels and onset of placental abruption. Hence, this study aimed to compare smoking status assessed using self-reports and urinary cotinine levels with placental abruption.

MATERIAL AND METHODS

We analyzed data from the largest nationwide Japanese birth cohort study conducted between January 2011 and March 2014. Women with multiple pregnancies and insufficient data were excluded, leaving 82,637 women eligible for the study. Participants were classified as nonsmokers (<0.31 µg/gCr), passive smokers (0.31-36.7 µg/gCr), or active smokers (≥36.8 µg/gCr) based on comparable cutoffs for urinary cotinine levels, as reported previously. Participants were also classified as never-smokers, quitting before pregnancy, quitting after pregnancy, or current smokers according to a self-reported questionnaire. Logistic regression was used to calculate the adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for the association of urinary cotinine levels and self-reported smoking status with placental abruption.

RESULTS

Among 82,637 participants (mean age: 31.3 years), 346 (0.42%) had placental abruption. Based on urinary cotinine-assessed smoking status, active smokers had a higher incidence of placental abruption (aOR, 1.70; 95% Cl, 1.20-2.40) than nonsmokers. In contrast, based on self-reports, there was no significant difference between current smokers and never-smokers after adjusting for established confounding factors (aOR, 1.54; 95% CI, 0.98-2.36).

CONCLUSIONS

Elevated urinary cotinine levels during pregnancy were significantly associated with an increased risk of placental abruption, whereas self-reported smoking status was not. Urinary cotinine levels are a more accurate and clinically reliable biomarker to assess smoking-related risks during pregnancy than self-reported smoking status. Future research should explore the relationship between urinary cotinine levels and other obstetric complications to validate its utility as a comprehensive pregnancy biomarker.

Preterm placental abruption and its association with adverse maternal and neonatal outcomes: a retrospective study

BACKGROUND

Placental abruption (PA), a severe obstetric complication, defined as the partial or complete detachment of a normally situated placenta from the uterine wall before birth, after 20 weeks of gestation, is associated with significant maternal and neonatal morbidity and mortality. Despite its clinical importance, the pathogenesis of PA remains unclear, and there is limited research specifically comparing outcomes in term and preterm pregnancies with PA. This study aimed to evaluate maternal and neonatal outcomes in pregnancies complicated by PA on basis of the timing of PA onset, with a focus on differences between term and preterm deliveries.

METHODS

This retrospective study included a total of 757 singleton pregnant women with confirmed PA from a tertiary obstetrics hospital care center between June 2020 to March 2024, who were classified into the preterm group (n = 300) and the full-term group (n = 457) based on their gestational age of PA onset. The baseline characteristics, maternal and newborn outcomes were collected from electronic health records in hospital information system, and further analyzed between two groups. The adjusted odds ratios (aORs) for the risk of adverse pregnancy outcomes on basis of term or preterm delivery in women with PA were analyzed by using multivariate logistic regression models.

RESULTS

Women with preterm delivery had about 3 times greater risk for uterus-placenta apoplexy (aOR: 2.93, 95% CI 1.33-6.47, P = 0.01), 3 times greater risk for fetal growth restriction (aOR: 3.47, 95% CI 1.45-8.30, P = 0.01), 3 times greater risk for adult intensive care unit (ICU, aOR: 3.28, 95% CI 1.27-8.46, P = 0.01), and less chances to use oxytocin (aOR: 0.21, 95% CI 0.13-0.32, P < 0.01). Premature newborns had less chances to use forceps (aOR: 0.09, 95% CI 0.01-0.76, P = 0.02), but about 10 times greater risk for stillbirth (aOR: 9.38, 95% CI 1.10 - 79.68, P < 0.01).

CONCLUSIONS

Preterm pregnancies with PA are associated with higher risks of severe maternal complications and adverse neonatal outcomes, underscoring the need for enhanced clinical surveillance and timely intervention. Future research should focus on elucidating underlying mechanisms and developing effective prevention strategies, while long-term follow-up is essential to assess the health outcomes of affected infants.

CLINICAL TRIAL NUMBER

Not applicable.

Hemorrhagic placental lesions on ultrasound: a continuum of placental abruption

Placental abruption has classically been defined as the premature separation of a normally located placenta before delivery of the fetus. Traditionally, this diagnosis was based on clinical symptoms, including vaginal bleeding, pain, and fetal distress. This definition, however, preceded the advent of obstetric ultrasound. Ultrasound frequently identifies various hemorrhagic lesions, such as retroplacental, subchorionic, intraamniotic, intraplacental, and preplacental hematomas in both symptomatic and asymptomatic patients. These variable ultrasound findings lead to new challenges as to what to define as an abruption, particularly in the absence of symptoms. This ambiguity in defining placental abruption affects clinical decision-making and hinders our understanding of the pathophysiology of abruption, presenting challenges in studying abruption. It is likely that these varying sonographic findings may precede the classic presentation of vaginal bleeding and pain and therefore are often concealed abruptions. This commentary highlights the importance of developing clear diagnostic guidelines for placental abruption, given its association with severe outcomes including a high rate of perinatal mortality and maternal morbidity. We aim to elucidate the complexities of ultrasound diagnosis in placental abruption, advocating for precise criteria to better guide clinical practice. We propose that these ultrasound findings of hemorrhagic placental lesions after 20 weeks of gestation in asymptomatic patients should be considered part of the spectrum of abruption, while in symptomatic patients should be taken as confirmation of the diagnosis of abruption.

The association between serum soluble fms-like tyrosine kinase-1, placental growth factor, and soluble fms-like tyrosine kinase-1/placental growth factor ratio in singleton pregnancy and placental abruption: a systematic review and meta-analysis

OBJECTIVE

The study aimed to evaluate whether women with singleton pregnancies who experienced subsequent placental abruption had lower serum placental growth factor concentrations, higher serum soluble fms-like tyrosine kinase-1 concentrations, and a higher soluble fms-like tyrosine kinase-1/placental growth factor ratio compared to women with singleton pregnancies without placental abruption.

DATA SOURCES

PubMed/MEDLINE, Scopus, and the Web of Science and ClinicalTrials.gov databases had been searched electronically until March 2025, using combinations of relevant medical subject heading terms, keywords, and word variants considered suitable for the topic.

STUDY ELIGIBILITY CRITERIA

Prospective and retrospective comparative cohort studies and case-control studies were included. Case reports, editorials, letters to the editor, and conference abstracts were excluded from the systematic review.

STUDY APPRAISAL AND SYNTHESIS METHODS

The outcome of the study included differences in placental growth factor, soluble fms-like tyrosine kinase-1 concentrations, or the soluble fms-like tyrosine kinase-1/placental growth factor ratio between placental abruption cases and a group without placental abruption. The quality assessment of the included studies was performed using the Newcastle-Ottawa Scale. Continuous data were expressed as the mean difference with a 95% confidence interval when the units of measurement for the outcome variable were the same. When conducting the meta-analysis, a random effects model was consistently employed.

RESULTS

The main findings of this systematic review and meta-analysis are as follows: 1) maternal serum placental growth factor concentration did not differ between women with and without placental abruption; 2) maternal serum soluble fms-like tyrosine kinase-1 concentration was higher in women with placental abruption, especially when assessed in the second half of gestation; and 3) maternal serum soluble fms-like tyrosine kinase-1/placental growth factor ratio was higher in women with placental abruption, both in the first and second half of pregnancy, with the difference being no longer significant in women with the diagnosis or symptoms of preeclampsia.

CONCLUSION

The results presented in this systematic review may improve the risk stratification for placental abruption. Understanding the changes of the above markers in placental abruption may support clinical guideline development with regard to prediction models of the above complication.

Association of Ambient Air Pollution and Temperature Exposure with Placental Abruption: A Nested Case-Control Study Based on Live Birth Registrations

BACKGROUND

Placental abruption, a rare disorder of unclear etiology, lacks evidence to illustrate its relationship with exposure to air pollution and temperature.

OBJECTIVE

This study aimed to investigate the association between exposure to ambient pollutants and temperatures and placental abruption to identify susceptible time windows and subpopulations.

METHODS

A nested case-control study was based on a live birth registration database in Chongqing, the largest Chinese municipality in China, from 2018 to 2022. The placental abruption cases were each matched with four controls by maternal age at delivery, gestational week, gravidity, parity, and delivery date. Six ambient pollutants [particulate matter (PM) with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), PM with aerodynamic diameter ≤ 10 μ m (PM 10 ), NO 2 , CO, O 3 , and SO 2 ] and temperature were estimated using machine learning algorithms. A conditional logistic regression model analyzed associations of exposure to air pollution and temperature with placental abruption in five time windows (prepregnancy, the entire pregnancy, and each of the 3 trimesters). Stratification analyses were applied to examine potential modifiers including gravidity, parity, mothers' residential area (urban/rural), pandemic experience, and delivery season.

RESULTS

After data quality control, 798 cases were identified and matched with 3,192 controls. An exposure relationship was identified between NO 2 during the pregnancy period and placental abruption (p < 0.001 ). In comparison with the first quartile level of NO 2 , the odds ratios (ORs) of abruption associated with exposure to the second, third, and fourth quartile levels of NO 2 were 1.42 [95% confidence interval (CI): 1.03, 1.96], 1.90 (95% CI: 1.30, 2.76), and 2.27 (95% CI: 1.39, 3.71), respectively. The association for NO 2 exposure existed in the 3 trimesters but not prepregnancy. Exposure to locally extreme low temperatures (< fifth percentile) in the third trimester was associated with increased risks of abruption (OR = 3.68 ; 95% CI: 1.67, 8.08) in comparison with locally moderate temperatures (25th-75th percentile). Stratified analysis showed no statistical significances within the effect modifiers.

DISCUSSION

Based on a large-scale live birth record, the study suggested that exposure to air pollutants, mainly NO 2 , during pregnancy may be a substantial risk factor for placental abruption. https://doi.org/10.1289/EHP14714.

Independent risk factors for placental abruption: a systematic review and meta-analysis

BACKGROUND

Placental abruption is one of the most severe complications during pregnancy, and its associated risk factors remain incompletely understood and somewhat controversial.

METHODS

This study conducted a systematic search of the PubMed, Embase, Cochrane, Web of Science, and Scopus databases to collect literature related to placental abruption, with a cutoff date of July 30, 2024.

RESULTS

A total of 54 observational studies were included, covering 7,267,241 pregnant women, with 47,702 cases diagnosed with placental abruption. The study identified three categories of independent risk factors: The first category includes baseline maternal characteristics (18 items), such as maternal age ≥ 35 years, black race, low prepregnancy BMI (< 18.5 kg/m²), unmarried status, smoking during pregnancy, alcohol consumption, inadequate prenatal care (< 4 visits), marijuana use, multiple pregnancy, parity ≥ 3, anemia (hemoglobin < 11 g/dL), previous placental abruption, previous cesarean section, previous miscarriage, previous stillbirth, cervical incompetence, habitual abortions, and assisted reproductive technology. Among these, previous placental abruption (AOR = 2.72, 95% CI [2.16, 3.42]) was found to be the most significant risk factor. The second category includes pregnancy-related complications (7 items), such as preterm premature rupture of membranes, preeclampsia, small for gestational age, polyhydramnios, antepartum hemorrhage, gestational hypertension, and placenta previa. Of these, placenta previa (AOR = 7.31, 95% CI [4.78, 11.19]) was identified as the most significant risk factor. The third category consists of other independent risk factors (33 items) and protective factors (3 items). However, methodological inconsistencies and publication bias in the current studies may affect the reliability of the meta-analysis results.

CONCLUSION

This study summarizes 58 independent risk factors for placental abruption, covering various aspects such as maternal baseline characteristics and pregnancy complications. For these high-risk populations, it is essential to strengthen the frequency of prenatal check-ups, establish early warning systems, and provide targeted health guidance. Future research should further refine risk factor models and develop more targeted preventive strategies to reduce the incidence of placental abruption and improve maternal and neonatal outcomes.

PROSPERO

CRD42024546514.

CLINICAL TRIAL NUMBER

Not applicable.

Obstetric and neonatal outcomes in clinically diagnosed placental abruption with and without placental histopathologic confirmation-A retrospective study

OBJECTIVE

Placental abruption is a major obstetrical complication bearing potentially life-threatening consequences. Though the diagnosis of placental abruption is a clinical one, the nonspecific nature of common presenting symptoms, mainly vaginal bleeding and contractions, pose a challenge, and the contribution of placental pathology has been debated. In this study, we assessed the clinical significance of related placental lesions by comparing obstetric and neonatal outcomes among cases of placental abruption with versus without supporting histopathologic placental lesions.

METHODS

We retrospectively analyzed placental abruption cases diagnosed during an 8-year period at a single tertiary center. Maternal, neonatal, and placental outcomes were compared between cases of placental abruption with versus without histopathologic placental lesions. The primary outcome was a composite of severe neonatal morbidity and included 1 ≤ of the following: seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, blood transfusion or neonatal death.

RESULTS

A total of 305 clinical placental abruption cases were included: 95 in the placental abruption with histopathologic lesions group (31.3%) and 210 without such lesions (68.8%). The group with histopathologic lesions was characterized by higher rates of vaginal bleeding at presentation and prematurity (P = 0.012 and P < 0.001, respectively). Additionally, this group had substantially higher rates of composite severe neonatal outcomes (the primary outcome) (P = 0.005) and concurrent maternal vascular malperfusion lesions (P < 0.001).

CONCLUSION

Our findings shed light on the association between placental abruption-related histopathologic lesions and adverse obstetric and neonatal outcomes. Thus, histopathologic examination can be advocated in suspected placental abruption, as patients with related placental lesions may require closer follow-up in subsequent pregnancies.

Association of maternal calprotectin plasma levels with abruption placenta

OBJECTIVE

The aim of this study was to investigate the relationship between placental abruption and maternal plasma calprotectin levels.

MATERIALS AND METHODS

This prospective study included 3865 pregnant women aged 24 weeks' gestation and older who were admitted to Etlik Zübeyde Hanım Women's Health Training and Research Hospital between January 2021 and January 2024. Calprotectin levels were prospectively studied in 33 pregnant women with placental abruption and compared with 48 healthy pregnant women matched for age, parity, body mass index (BMI) and week of gestation. Pregnant women with preeclampsia, gestational diabetes, chorioamnionitis, premature rupture of membranes, preterm labor, corticosteroid use within 7 days, cholestasis, fetal growth restriction, fetal anomalies, systemic infections and multiple pregnancies were excluded from the study. The calprotectin concentration in serum was measured with a Rayto Microplate Reader RT 2100 C (Rayto) using an immunoassay method at 450 wavelengths.

RESULTS

There was no difference between the groups regarding maternal age, gravidity, parity and BMI. Calprotectin levels were significantly higher in the placental abruption group (p < 0.001). The optimal cutoff value for calprotectin was 91.95 ng/ml (sensitivity 66.67%, specificity 89.58%, the area under the curve (AUC) 0.763, 95% confidence interval 0.649-0.876, and p < 0.001).

CONCLUSION

The results obtained in the present study revealed an association between placental abruption and higher maternal serum calprotectin levels.

Causal effects of competing obstetrical interventions: mediators of placental abruption and perinatal mortality

Placental abruption, the premature placental separation, confers increased perinatal mortality risk with preterm delivery as an important pathway through which the risk appears mediated. Although pregnancies complicated by abruption are often delivered through an obstetrical intervention, many deliver spontaneously. We examined the contributions of clinician-initiated (PTDIND) and spontaneous (PTDSPT) preterm delivery at < 37 weeks as competing causal mediators of the abruption-perinatal mortality association. Using the Consortium for Safe Labor (2002-2008) data (n = 203 990; 1.6% with abruption), we applied a potential outcomes-based mediation analysis to decompose the total effect into direct and mediator-specific indirect effects through PTDIND and PTDSPT. Each mediated effect describes the reduction in the counterfactual mortality risk if that preterm delivery subtype was shifted from its distribution under abruption to without abruption. The total effect risk ratio (RR) of abruption on perinatal mortality was 5.4 (95% CI, 4.6-6.3). The indirect effect RRs for PTDIND and PTDSPT were 1.5 (95% CI, 1.4-1.6) and 1.5 (95% CI, 1.5-1.6), respectively; these corresponded to mediated proportions of 25% each. These findings underscore that PTDIND and PTDSPT each play essential roles in shaping perinatal mortality risks associated with placental abruption.

Ischemic Placental Disease: Epidemiology and Impact on Maternal and Offspring Health Along the Life Course

Ischemic placental disease (IPD) is a constellation of obstetrical complications that include preeclampsia, placental abruption, and fetal growth restriction and affects 12% to 15% of pregnancies. The unifying pathophysiological mechanism that precedes all 3 complications is uteroplacental ischemia as a consequence of inadequate (or failure of) physiological transformation of the maternal uterine spiral arteries, endothelial cell dysfunction, and increased oxidative stress. This review summarizes the IPD literature, focusing on the epidemiology and risk factors, the effects of IPD on short and long-term maternal complications, and the association of IPD with perinatal, childhood, and long-term complications in offspring.

Placental Abruption: Pathophysiology, Diagnosis, and Management

Placental abruption is a complete or partial separation of the placenta from the uterine decidua. Clinical manifestations include vaginal bleeding, abdominal pain, uterine contractions, and abnormalities in the fetal heart rate tracing. Placental abruption occurs in 0.4% to 1.0% of all pregnancies. However, the pathophysiology remains incompletely understood. We present a review of the pathophysiology, diagnosis, and management of placental abruption, exploring overlapping processes which contribute to premature placental separation. Classic findings and limitations of ultrasound in evaluating placental abruption are explained. Finally, we discuss the management of placental abruption based on gestational age, fetal status, and maternal hemodynamic stability.

Foreword: Clinically Focused Insights on the Placenta and Umbilical Cord: An Evidence-based Symposium

In this symposium, we introduce a collection of reviews that delve into the diverse clinically relevant aspects of the placenta and umbilical cord. The symposium addresses placenta previa and abruption; pathology, genetics, and imaging of the placenta; infections of the placenta; and ischemic placental disease. The umbilical cord's essential function as a fetal lifeline is explored, with an emphasis on the clinical repercussions of its dysfunction, including vasa previa and other umbilical cord abnormalities. This curated collection of reviews, which synthesizes the placenta's and umbilical cord's fundamental role in maternal-fetal health, underscores the clinical importance of these structures in pregnancy.

Perinatal outcomes and predictors of placental abruption: a retrospective study in an Ethiopian tertiary care center

Background

Placental abruption is a critical obstetric condition characterized by the premature separation of the placenta from the uterus, leading to severe maternal and fetal complications. In Ethiopia, the maternal and perinatal morbidity and mortality rates are alarmingly high, and placental abruption significantly contributes to these adverse outcomes. Despite its severity, there is a lack of comprehensive data on the burden, risk factors, and outcomes associated with placental abruption in the Ethiopian context. Thus, the study aimed to investigate the adverse perinatal outcomes of placental abruption and the factors associated with these outcomes among pregnant women admitted to the University of Gondar Comprehensive Specialized Hospital in Ethiopia.

Method

An institution-based retrospective cross-sectional study was conducted among 367 pregnant women who were admitted and managed for placental abruption from January 1, 2021, to January 1, 2023, at the University of Gondar Comprehensive Specialized Hospital. A simple random sample method was employed to choose the medical records. Data was collected using a checklist prepared with the KOBO collect tool and then exported to SPSS version 25.0. Variables having a p-value of less than 0.05 were deemed significant in the multivariable logistic regression analysis that was done. The adjusted odds ratio with a 95% confidence interval was reported.

Result

The prevalence of adverse perinatal outcome of placental abruption was 39.2, 95% CI: 34.3-44.1. The most common adverse outcomes were prematurity (25.6%), low birth weight (25.6%), and NICU admission (13.9%). Severe placental abruption [AOR (CI) = 8.82 (4.48-17.31)] and abruption at preterm gestation [AOR (CI) = 18.71 (9.59-36.42)] were significant predictors of adverse perinatal outcomes.

Conclusion

The adverse perinatal outcomes of pregnancies complicated by placental abruption in this study were higher compared to other studies in Ethiopia. The degree of placental abruption and gestational age at diagnosis were significant associates of adverse perinatal outcomes. The study highlights the critical need for patient-centered counseling on antenatal bleeding to encourage early healthcare-seeking behavior, close follow up for those undergoing expectant management and the early detection and management of placental abruption to improve perinatal outcomes.

Predicting purulent meningitis in very preterm infants: a novel clinical model

BACKGROUND

Purulent meningitis (PM) is a commonly encountered infectious condition in newborns, which unfortunately can result in infant mortality. Newborns with PM often present nonspecific symptoms. The success of lumbar puncture, an invasive test, relies on the operator's expertise. Preterm infants pose diagnostic challenges compared to full-term babies. The objective of this study is to establish a convenient and effective clinical prediction model based on perinatal factors to assess the risk of PM in very preterm infants, thereby assisting clinicians in developing new diagnostic and treatment strategies.

METHODS

This study involved very preterm infants (gestational age < 32 weeks) admitted to the Qilu Hospital of Shandong University from January 2020 to December 2023. All included infants underwent lumbar puncture. We gathered comprehensive data that included information on maternal health conditions and the clinical features of very preterm infants. The PM was diagnosed according to the diagnostic criteria. This study conducted data analysis and processing using R version 4.1.2. A stepwise regression method was applied for multivariate Logistic regression analysis to select the best predictors for PM and to develop a predictive model. Differences were considered statistically significant at P < 0.05.

RESULTS

This study enrolled a total of 201 preterm infants, including 117 boys and 84 girls. The gestational age was 28.7 ± 1.7 weeks, and the weight was 1166.2 ± 302.7 g. Ninety infants were diagnosed with PM, while 111 did not have PM. The influencing factors include birth weight, PCT within 24 h after birth, cesarean delivery, and premature rupture of membranes. These were used to construct a risk prediction nomogram and verified its accuracy. The Brier score was 0.157, the calibration slope was 1.0, and the concordance index was 0.849.

CONCLUSIONS

We developed and validated a personalized nomogram to identify high-risk individuals for early prediction of purulent meningitis in very preterm infants. This practical predictive model may help reduce unnecessary lumbar puncture procedures.

Clinical implications of a Couvelaire uterus with placental abruption: A retrospective study

OBJECTIVE

This study aimed to clarify the maternal and neonatal outcomes based on the presence or absence of a Couvelaire uterus with placental abruption.

METHODS

This single-center retrospective study was conducted at a tertiary perinatal center in Japan, including patients diagnosed with acute placental abruption who delivered live births via cesarean section between 2016 and 2023. Patients were divided into two groups based on the presence or absence of a Couvelaire uterus during surgery: the Couvelaire and normal uterus groups. Maternal and neonatal outcomes were assessed.

RESULTS

This study included 76 patients: 24 in the Couvelaire group and 52 in the normal uterus group. No patients underwent hysterectomies. The Couvelaire group had significantly higher intraoperative blood loss (median 1152 vs 948 g, P = 0.010), blood transfusion rates (58% vs 31%, P = 0.022), fibrinogen administration rates (38% vs 13%, P = 0.038), intensive care unit/high care unit admission rates (29% vs 7.7%, P = 0.013), and disseminated intravascular coagulation complication rates (25% vs 7.7%, P = 0.038). There were no differences in birth weight, gestational age (median 2387 vs 2065 g, P = 0.082), Apgar score <4 at 5 min (4.2% vs 3.9%, P = 0.95), umbilical artery blood pH <7.1 (25% vs 22%, P = 0.82), and neonatal death (4.2% vs 1.9%, P = 0.57).

CONCLUSION

A Couvelaire uterus indicated adverse maternal outcomes but not neonatal ones. Its presence necessitates preparation for blood transfusions and/or intensive patient follow-up.

The 36-week preeclampsia risk by the Fetal Medicine Foundation algorithm is associated with fetal compromise following induction of labor

BACKGROUND

Previous studies demonstrated that placental dysfunction leads to intrapartum fetal distress, particularly when an abnormal pattern of angiogenic markers is demonstrated at 36 weeks of gestation. The prediction of intrapartum fetal compromise is particularly important in patients undergoing induction of labor because of different indications for delivery, as this can be a useful in optimizing the method and timing of induction of labor.

OBJECTIVE

This study aimed to examine whether the risk of preeclampsia assessed using the Fetal Medicine Foundation algorithm (derived from a combination of maternal risk factors, mean arterial pressure, placental growth factor, and soluble fms-like tyrosine kinase-1) is associated with the risk of intrapartum fetal compromise requiring cesarean delivery in a population of patients with singleton pregnancies undergoing induction of labor for various indications.

STUDY DESIGN

This was a retrospective analysis on prospectively collected data from women with singleton pregnancies who underwent routine assessments at 35 0/7 to 36 6/7 weeks of gestation at King's College Hospital (London, United Kingdom). The study outcome was the rate of fetal compromise requiring cesarean delivery, examined in relation to the risk of preeclampsia assessed at 36 weeks of gestation using the Fetal Medicine Foundation risk model. Patients who underwent spontaneous labor and prelabor cesarean deliveries were excluded. In addition, 5 risk categories for preeclampsia were created on the basis of the Fetal Medicine Foundation 36-week risk model: A (≥1/2), B (<1/2- ≥1/5), C (<1/5- ≥1/20), D (<1/20-≥1/50), and E (<1/50). Based on the reason for induction of labor, we created 5 categories: premature rupture of membranes, postterm pregnancy (˃41 weeks of gestation), preeclampsia, fetal growth restriction (estimated fetal weight of ˂5th percentile), and preeclampsia and fetal growth restriction. A multinomial logistic regression was used to assess the risk of fetal compromise across the Fetal Medicine Foundation risk categories, accounting for all delivery outcomes (spontaneous or operative vaginal delivery and urgent cesarean delivery for fetal compromise, failure to progress, or other reasons) and allowing accurate and generalizable risk assessment of fetal compromise.

RESULTS

Of 45,375 pregnant women, 26,597 (58.6%) had spontaneous onset of labor, 6529 (14.0%) underwent elective prelabor cesarean delivery, which were excluded from the analysis. A total of 12,249 pregnant women were included, of which 182 had birth at ≤37 weeks of gestation and 1444 had fetal compromise (crude risk of 11.8%). The rate of vaginal delivery in the study population was 69.4%. The rates of fetal compromise in the 5 induction categories were 9.7% for premature rupture of membranes, 13.5% for postterm pregnancy, 14.8% for preeclampsia, 17.2% for fetal growth restriction, and 23.4% for preeclampsia and fetal growth restriction. Cases with intrapartum fetal compromise had a higher mean preeclampsia risk than cases without intrapartum fetal compromise (1/45 vs 1/81, respectively; P<.001). The risk of cesarean delivery for fetal compromise increased with (1) advancing gestational age (each week increase at 35-40 weeks: +1%; at 41-42 weeks: +5%), (2) nulliparity (+7%-10%) vs multiparity, (3) higher Fetal Medicine Foundation risk of preeclampsia (from the low-risk category of <1/50 to the high-risk category of ≥1/2: +18%; with greater effect for higher preeclampsia risk). In this study population, the rates of fetal compromise were lower with diagnoses of preeclampsia and rupture of membranes and higher with fetal growth restriction (alone or in combination with preeclampsia) and postterm pregnancy.

CONCLUSION

Our study highlights the clinical use of the Fetal Medicine Foundation 36-week PE risk model in determining the risk of fetal compromise requiring cesarean delivery after induction of labor. The same model can be combined with standard obstetric indications to induction of labour to establish the risk of fetal compromise requiring cesarean delivery. Therefore, the Fetal Medicine Foundation 36-week PE risk model can be used to optimize induction of labor.

Potential causal associations between perfluoroalkyl substances exposure and adverse pregnancy outcomes: A bidirectional two-sample mendelian randomization study

Maternal exposure to per- and polyfluoroalkyl substances (PFASs) has been linked to adverse pregnancy outcomes (APOs). Nonetheless, the genetic causality underlying this association remains unknown. This research employed a bidirectional two-sample Mendelian randomization (MR) to investigate the potential causal associations between PFASs exposure and APOs risk. PFASs data were sourced from the GWAS Catalog, and APOs data were retrieved from the FinnGen consortium. Causal estimation primarily employed inverse variance weighting, with Cochran's Q test for instrumental variable heterogeneity, and MR-Egger, MR-PRESSO, and leave-one-out tests for sensitivity analyses. The possibility of reverse causality was investigated through reverse MR. MR evidence revealed a notable correlation between perfluorooctanoic acid (PFOA) and abruptio placentae (OR=1.498, P=0.026), as well as short gestation and low birth weight (OR=1.720, P=0.013). Exposure to perfluorooctanesulfonic acid (PFOS) increased the risk of preeclampsia or eclampsia (OR=1.128, P=0.030) and gestational hypertension (OR=1.076, P=0.049), but decreased the risk of premature rupture of membranes (OR=0.916, P=0.033). The results obtained were consistent across various sensitivity analyses. Reverse MR results was negative. These findings may provide a reference for prevention strategies and intervention measures for PFASs exposure and APOs, and provide a framework for studying the causal effects of environmental pollutant exposure and human diseases.

The peripheral chemoreflex and fetal defenses against intrapartum hypoxic-ischemic brain injury at term gestation

Fetal hypoxemia is ubiquitous during labor and, when severe, is associated with perinatal death and long-term neurodevelopmental disability. Adverse outcomes are highly associated with barriers to care, such that developing countries have a disproportionate burden of perinatal injury. The prevalence of hypoxemia and its link to injury can be obscure, simply because the healthy fetus has robust coordinated defense mechanisms, spearheaded by the peripheral chemoreflex, such that hypoxemia only becomes apparent in the minority of cases associated with stillbirth, severe metabolic acidemia or adverse neurodevelopmental outcomes. This represents only the extreme end of the spectrum, when defense mechanisms have failed due to severe/prolonged hypoxemia, or the fetal defenses are compromised by additional risk factors. Understanding the fetal defenses to hypoxemia and when the fetus begins to decompensate is crucial to understanding perinatal health and disease, by linking antenatal health, intrapartum events, the neonatal trajectory and ultimately life-long neurodevelopmental health.

Placental abruption and perinatal mortality in twins: novel insight into management at preterm versus term gestations

Twins suffer a disproportionately higher burden of adverse perinatal outcomes than singletons. However, the degree to which preterm delivery shapes the relationship between abruption and perinatal mortality in twins is unknown. Through causal mediation decomposition, we examine how preterm delivery mediates the effect of abruption on perinatal mortality among twins using the US-matched multiple birth data (1995-2000). We estimated the hazard ratio (HR) from Cox models with gestational age as the timescale. We decomposed the total effect (TE) into counterfactual natural direct (NDE) and natural indirect (NIE) effects. 557,220 matched twin births, 1.3% (n = 7032) resulted in abruption with higher perinatal mortality rates than non-abruption births (143 versus 36 per 1000 births, respectively) and a 4.53-fold (95% confidence interval [CI]: 4.23, 4.82) increased hazard of perinatal mortality. HRs for NDE and NIE were 3.05 (95% CI: 2.84, 3.24) and 1.49 (95% CI: 1.49, 1.47, 1.50), respectively, and the proportion mediated (PM) was 41%. PM increased as the gestational age at delivery decreased. Associations persisted after correction for unmeasured confounders. The best strategies to improve perinatal delivery are delivery when abruption complicates twin pregnancies at term gestations and expectant management (avoiding early preterm delivery), if feasible, when abruption complicates twin pregnancies at preterm gestations.

Successful vaginal delivery in a patient with reconstructed bladder exstrophy and vaginoplasty after cesarean section, a case report from Syria

INTRODUCTION AND IMPORTANCE

Bladder exstrophy (BE) is a rare congenital anomaly in which the anterior wall of the bladder is absent. In females, sexuality and fertility may be negatively affected with the association with pubic diastasis, dysplasia of the pelvic floor muscles, clitoris bifurcated, short vagina or narrow introitus.

PRESENTATION OF CASE

We present a case of 26-year-old woman with treated BE, vaginoplasty, and bicornuate uterus that came at week 36 of gestation. An elective cesarean section was made by paramedian section. Five years later, she came back with placental abruption at week 30 of gestation, and a successful vaginal delivery was made.

DISCUSSION

Bladder exstrophy is a challenging disease that is accompanied with other morbidities. Impaired fertility is common due to previous surgeries and concomitant diseases, and pregnancy is high risk for both mother and baby. Delivery should be at a tertiary referral obstetric hospital.

CONCLUSION

Balancing the pros and cones of medical decision in order to achieve the best outcomes for both the mother and child is crucial, as choosing the right decision depends on the presentation and past history of the patient not only the existence of the bladder exstrophy.

Factors Associated with Maternal Morbidity in Patients with Eclampsia in Three Obstetric Intensive Care Units: A Retrospective Study

(1) Introduction. Eclampsia is a rare complication that can occur during pregnancy and has a significant impact on maternal and neonatal outcomes. The aim of this study was to investigate the risk factors associated with significant maternal morbidity after an eclamptic seizure. (2) Methods. An observational retrospective study was performed in three maternity hospitals in Romania between 2015 and 2023 and included pregnant patients diagnosed with eclampsia. Clinical and paraclinical data were investigated, and the impact of several risk factors was assessed using multiple logistic regression analysis. The results were reported as risk ratios (RRs) and 95% confidence intervals (Cis). (3) Results. A total of 104 patients with preeclampsia, of whom 23 experienced eclamptic seizures, were included in this study. A total of 82.6% of the patients diagnosed with eclampsia experienced a form of significant morbidity (stroke, PRES syndrome, or any organ failure/dysfunction). Our regression analysis revealed that advanced maternal age (RR: 12.24 95% CI: 4.29-36.61, p = 0.002), the presence of thrombotic disorders (RR: 9.17, 95% CI: 3.41-23.70, p = 0.03), obesity (RR: 4.89, 95% CI: 0.78-18.15, p = 0.036), and smoking status (RR: 2.18, 95% CI: 0.13- 6.51, p = 0.042) significantly increase the risk of maternal comorbidities. (4) Conclusions. Careful monitoring of pregnant patients, adequate weight control during pregnancy, and correct anticoagulation of individual patients could reduce the extent of postpartum comorbidities that can result from an eclamptic seizure.

Can inflammatory biomarkers based on first trimester complete blood count parameters predict placental abruption ?: A case-control study

OBJECTIVES

Placental abruption (PA) is associated with adverse maternal and neonatal outcomes and has an etiological mechanism that is not yet fully understood. The prediction of PA, which has been the subject of numerous studies, remains a challenge. In particular, there is evidence that PA can be considered a chronic process. So, this study aimed to show inflammatory biomarkers based on complete blood count parameters may be used to predict PA.

STUDY DESIGN

A sample of 110 cases (pregnant women with PA) and 110 controls (healthy pregnant women with spontaneous labor) were required the study. The present case-control study included a total of 220 pregnant women. Inflammatory makers were used to evaluate the PA prediction RESULTS: Increases in body mass index, mean corpuscular volume and paletelet lymphocyte ratio are considered protective factors, while increases in neutrophil, the systemic inflammatory response index, neutrophil lymphocyte ratio and the pan-immune inflammation score are considered risk factors. Each 1 unit increase in neutrophil count increases the risk of a PA diagnosis by 1.81 times.

CONCLUSION

Recent studies indicate a strong heterogeneity of clinical courses leading to PA in premature and term births. In the present study, our results showed that, inflammation is associated with PA.

A novel predictive marker for placental abruption with composite adverse outcomes: creatinine-fibrinogen ratio

PURPOSE

To develop a new cost-effective marker named creatinine-fibrinogen ratio (CFR) for the prediction of composite adverse outcomes (CAO) in placental abruption cases.

METHODS

A total of 109 placental abruption patients (30 with adverse outcomes, 79 without adverse outcomes) were enrolled in this retrospective cohort study. Patients with at least one of the features listed below were included in the abruption with CAO group: requirement of blood product transfusion (erythrocyte suspension, fresh frozen plasma, pooled thrombocyte, thrombocyte apheresis), development of acute kidney injury or disseminated intravascular coagulation, and need for intensive care unit. Laboratory parameters and CFR values at admission to the hospital were compared between the two groups.

RESULTS

Higher creatinine and lower fibrinogen levels were found in the CAO group (p = 0.007 and p < 0.001 respectively). The CFR value of the CAO group was significantly higher (p < 0.001). In the ROC curve analysis performed to investigate the value of CFR in CAO prediction, the area under the curve (AUC) was calculated as 0,802 (95% CI 0.709-0.895, 77% sensitivity, 65% specificity).

CONCLUSION

CFR seems to be a practical marker for the prediction of CAOs in pregnant women with ablatio placenta.

Risks of Placental Abruption and Preterm Delivery in Patients Undergoing Assisted Reproduction

Importance

Patients using assisted reproductive technology (ART) may need additional counseling about the increased risks of placental abruption and preterm delivery. Further investigation into the potential additive risk of ART and placental abruption is needed.

Objective

To ascertain the risk of placental abruption in patients who conceived with ART and to evaluate if placental abruption and ART conception are associated with an increased risk of preterm delivery (<37 weeks' gestation) over and above the risks conferred by each factor alone.

Design, Setting, and Participants

This cross-sectional study used data from the National Inpatient Sample, which includes data from all-payer hospital inpatient discharges from 48 states across the US. Participants included women aged 15 to 54 years who delivered from 2000 through 2019. Data were analyzed from January 17 to April 18, 2024.

Exposures

Pregnancies conceived with ART.

Main Outcomes and Measures

Risks of placental abruption and preterm delivery in ART conception compared with spontaneous conceptions. Associations were expressed as odds ratios (ORs) and 95% CIs derived from weighted logistic regression models before and after adjusting for confounders. The relative excess risk due to interaction (RERI) of the risk of preterm delivery based on ART conception and placental abruption was also assessed.

Results

Of 78 901 058 deliveries, the mean (SD) maternal age was 27.9 (6.0) years, and 9 212 117 patients (11.7%) were Black individuals, 14 878 539 (18.9%) were Hispanic individuals, 34 899 594 (44.2%) were White individuals, and 19 910 807 (25.2%) were individuals of other races and ethnicities. Of the total hospital deliveries, 98.2% were singleton pregnancies, 68.8% were vaginal deliveries, and 52.1% were covered by private insurance. The risks of placental abruption among spontaneous and ART conceptions were 11 and 17 per 1000 hospital discharges, respectively. After adjusting for confounders, the adjusted OR (AOR) of placental abruption was 1.42 (95% CI, 1.34-1.51) in ART pregnancies compared with spontaneous conceptions, with increased odds in White women (AOR, 1.42; 95% CI, 1.31-1.53) compared with Black women (AOR, 1.16; 95% CI, 0.93-1.44). The odds of preterm delivery were significantly higher in pregnancies conceived by ART compared with spontaneous conceptions (AOR, 1.46; 95% CI, 1.42-1.51). The risk of preterm delivery increased when patients had both ART conception and placental abruption (RERI, 2.0; 95% CI, 0.5-3.5).

Conclusions and Relevance

In this cross-sectional study, patients who conceived using ART and developed placental abruption had a greater risk of preterm delivery compared with spontaneous conception without placental abruption. These findings have implications for counseling patients who seek infertility treatment and obstetrical management of ART pregnancies.

Outpatient labor induction-Exploring future potential by assessing eligibility in a historical cohort

INTRODUCTION

Labor induction rates have increased over the last decades, and in many high-income countries, more than one in four labors are induced. Outpatient management of labor induction has been suggested in low-risk pregnancies to improve women's birth experiences while also promoting a more efficient use of healthcare resources. The primary aim of this paper was to assess the proportion of women in a historical cohort that would have been eligible for outpatient labor induction with oral misoprostol. Second, we wanted to report safety outcomes and assess efficacy outcomes for mothers and infants in pregnancies that met the criteria for outpatient care.

MATERIAL AND METHODS

Criteria for outpatient labor induction with oral misoprostol were applied to a historical cohort of women with induction of labor at two Norwegian tertiary hospitals in the period January 1, through July 31, 2021. The criteria included low-risk women with an unscarred uterus expecting a healthy, singleton baby in cephalic position at term. The primary outcome was the proportion of women eligible for outpatient labor induction. Secondary outcomes included reasons for ineligibility and, for eligible women, safety and efficacy outcomes.

RESULTS

Overall, 29.7% of the 1320 women who underwent labor induction in a singleton term pregnancy met the criteria for outpatient labor induction. We identified two serious adverse events that potentially could have occurred outside the hospital if the women had received outpatient care. The mean duration from initiation of labor induction to administration of the last misoprostol was 22.4 h. One in 14 multiparous women gave birth within 3 h after the last misoprostol dose.

CONCLUSIONS

In this historical cohort, three in ten women met the criteria for outpatient management of labor induction with oral misoprostol. Serious adverse events were rare. The average time span from the initiation of labor induction to the last misoprostol was nearly 24 h. This suggests a potential for low-risk women with an induced labor to spend a substantial period of time at home before labor onset. However, larger studies testing or evaluating labor induction with oral misoprostol as an outpatient procedure are needed to draw conclusions.

Placental abruption: Incidence and risk of recurrence in subsequent pregnancies

AIM

To estimate the incidence of abruption in first births and recurrence in the subsequent birth in patients of a large US-based integrated health care system.

METHODS

Retrospective population-based cohort study of patients with first two consecutive singleton births using data from the Kaiser-Permanente South California health care system who delivered over a period of 30 years (1991-2021), using longitudinally linked electronic health records. ICD-9/ICD-10 codes "641.20" and "O45.x" identified placental abruption. We calculated the incidence and rates of abruption in first and second pregnancies. We used logistic regression to estimate the adjusted odds ratios (aOR) for abruption in second pregnancies in patients with and without abruptions in their first pregnancies.

RESULTS

Of the 126 264 patients with first two consecutive singleton births over the period, 805 had abruptions in their first births, and 861 in their second births. Rates of abruption in first and second births were 0.63% and 0.68%, respectively. Twenty-seven patients had abruptions in both first and second births. Rates of abruption in the second birth among individuals with and without previous placental abruption were 3.35% and 0.66%, respectively, giving an approximately five-fold increased odds of abruption in a second pregnancy in individuals who had abruption in their first birth when compared with those who did not have placental abruption in their first birth (aOR: 4.95, 95% confidence interval: 3.35-7.31, p < 0.00001). Interpregnancy interval had no statistically significant association with recurrence.

CONCLUSION

Abruption in a first birth is associated with an approximately five-fold increased odds of abruption in a second birth.

Placental Abruption and Cardiovascular Event Risk (PACER): Design, data linkage, and preliminary findings

BACKGROUND

Obstetrical complications impact the health of mothers and offspring along the life course, resulting in an increased burden of chronic diseases. One specific complication is abruption, a life-threatening condition with consequences for cardiovascular health that remains poorly studied.

OBJECTIVES

To describe the design and data linkage algorithms for the Placental Abruption and Cardiovascular Event Risk (PACER) cohort.

POPULATION

All subjects who delivered in New Jersey, USA, between 1993 and 2020.

DESIGN

Retrospective, population-based, birth cohort study.

METHODS

We linked the vital records data of foetal deaths and live births to delivery and all subsequent hospitalisations along the life course for birthing persons and newborns. The linkage was based on a probabilistic record-matching algorithm.

PRELIMINARY RESULTS

Over the 28 years of follow-up, we identified 1,877,824 birthing persons with 3,093,241 deliveries (1.1%, n = 33,058 abruption prevalence). The linkage rates for live births-hospitalisations and foetal deaths-hospitalisations were 92.4% (n = 2,842,012) and 70.7% (n = 13,796), respectively, for the maternal cohort. The corresponding linkage rate for the live births-hospitalisations for the offspring cohort was 70.3% (n = 2,160,736). The median (interquartile range) follow-up for the maternal and offspring cohorts was 15.4 (8.1, 22.4) and 14.4 (7.4, 21.0) years, respectively. We will undertake multiple imputations for missing data and develop inverse probability weights to account for selection bias owing to unlinked records.

CONCLUSIONS

Pregnancy offers a unique window to study chronic diseases along the life course and efforts to identify the aetiology of abruption may provide important insights into the causes of future CVD. This project presents an unprecedented opportunity to understand how abruption may predispose women and their offspring to develop CVD complications and chronic conditions later in life.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

Characteristics of Serum Lipid Metabolism among Women Complicated with Hypertensive Disorders in Pregnancy: A Retrospective Cohort Study in Mainland China

Background

Altered maternal serum lipid metabolism is associated with hypertensive disorders in pregnancy (HDP). However, its range in pregnancy and characteristic among different subgroups of HDPs are unclear.

Methods

Pregnant women with HDP who underwent antenatal care and delivered in Obstetrics and Gynecology Hospital of Fudan University during January 2018 to August 2022 were enrolled. The levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), apolipoprotein (Apo)-A, B, and E, free fatty acids (FFA), and small and dense low-density lipoprotein cholesterol (sdLDL) were measured during 4-16 weeks and 28-42 weeks of pregnancy.

Results

A total of 2648 pregnant women were diagnosed with HDP, 1,880 of whom were enrolled for final analysis, including 983 (52.3%) preeclampsia (PE), 676 (36.0%) gestational hypertension (GH), and 221 (11.7%) chronic hypertension (CH). For all HDPs, serum TC, TG, LDLC, HDLC, Apo-A, Apo-B, Apo-E, and sdLDL increased significantly during pregnancy, while FFA decreased significantly. Notably, the levels of TC, LDLC, Apo-B, and sdLDL in PE group were equal to or lower than those in CH group at 4-16 weeks of pregnancy, but increased greatly during pregnancy (P < 0.05).

Conclusions

Maternal serum lipid levels changed through pregnancy among women with HDPs. Women complicated with PE seem to have undergone a more significant serum lipid change compared to those with GH or CH.

Combined impact of Hepatitis B virus and gestational diabetes mellitus on ultrasound-measured fetal growth and adverse perinatal outcomes: A seven-year retrospective study

AIMS

To investigate the impact of pregnancy with combined hepatitis B virus (HBV) infection and Gestational diabetes mellitus (GDM) on fetal growth and adverse perinatal outcomes.

METHODS

All the pregnant women with HBV infection and/or GDM who delivered at Women's Hospital, Zhejiang University between January 2015, and September 2022 were included. A total of 1633 pregnant women were recruited in the final analysis, including 409 women with HBV infection and GDM, 396 with HBV infection only, 430 with GDM only, and 398 without HBV infection and GDM. Linear and logistic regression models were used to study the impact of pregnancy with combined HBV infection and GDM on fetal growth and adverse perinatal outcomes.

RESULTS

Pregnancy with combined HBV infection and GDM was associated with increased Z-scores on primary fetal ultrasound parameters and significantly increased the risk of fetal femur length overgrowth (OR: 2.88, 95 % CI: 1.13 ∼ 7.35), placental abruption (OR: 3.64, 95 % CI: 1.18 ∼ 11.22), and macrosomia (OR: 4.19, 95 % CI: 1.66 ∼ 10.56) compared to pregnancy without HBV infection and GDM.

CONCLUSIONS

Both maternal HBV infection and GDM are independently associated with adverse perinatal outcomes. Their combination further increases the risk of adverse perinatal outcomes.

Bloody Amniotic Fluid and Neonatal Outcomes

Information on the effect of bloody amniotic fluid during labor at term is scarce. This study assessed risk factors and adverse outcomes in labors with bloody amniotic fluid. During the six years of this study, all nulliparas in our institution, with a trial of labor, were included. Multiple pregnancies and preterm deliveries were excluded. Outcomes were compared between the bloody amniotic fluid group and the clear amniotic fluid group. Overall, 11,252 women were included. Among them, 364 (3.2%) had bloody amniotic fluid and 10,888 (96.7%) had clear amniotic fluid. Women in the bloody amniotic fluid group were characterized by shorter duration of the second stage and higher rate of cesarean section due to non-reassuring fetal heart rate. In addition, there were higher rates of low cord pH (<7.1) and NICU admissions in the bloody amniotic fluid group. In multivariate logistic regression analysis, cesarean delivery, cord blood pH < 7.1, and NICU admission were independently associated with increased odds ratio for bloody amniotic fluid. Bloody amniotic fluid at term is associated with adverse outcomes and must be considered during labor.