Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Impact of Co-Existing Placental Pathologies in Pregnancies Complicated by Placental Abruption and Acute Neonatal Outcomes

Placental abruption (PA) is a concern for maternal and neonatal morbidity. Adverse neonatal outcomes in the setting of PA include higher risk of prematurity. Placental pathologies include maternal vascular malperfusion (MVM), fetal vascular malperfusion (FVM), acute chorioamnionitis, and villitis of unknown etiology (VUE). We aimed to investigate how placental pathology contributes to acute neonatal outcome in PA. A retrospective cohort study of all placentas with PA were identified. Exposures were MVM, FVM, acute chorioamnionitis and VUE. The primary outcome was NICU admission and the secondary outcomes included adverse base deficit and Apgar scores, need for resuscitation, and small-for-gestational age. A total of 287 placentas were identified. There were 160 (59.9%) of placentas with PA alone vs 107 (40.1%) with PA and additional placental pathologies. Odds of NICU admission were more than two times higher in pregnancies with placental pathologies (OR = 2.37, 95% CI 1.28-4.52). These estimates were in large part mediated by prematurity and birthweight, indirect effect acting through prematurity was OR 1.79 (95% CI 1.12-2.75) and through birthweight OR 2.12 (95% CI 1.40-3.18). Odds of Apgar score ≤ 5 was more than four times higher among pregnancies with placental pathologies (OR = 4.56, 95% CI 1.28-21.26). Coexisting placental pathology may impact Apgar scores in pregnancies complicated by PA. This knowledge could be used by neonatal teams to mobilize resources in anticipation of the need for neonatal resuscitation.

Maternal Cardiovascular and Cerebrovascular Health After Placental Abruption: A Systematic Review and Meta-Analysis (CHAP-SR)

Placental abruption and cardiovascular disease (CVD) have common etiological underpinnings, and there is accumulating evidence that abruption may be associated with future CVD. We estimated associations between abruption and coronary heart disease (CHD) and stroke. The meta-analysis was based on the random-effects risk ratio (RR) and 95% confidence interval (CI) as the effect measure. We conducted a bias analysis to account for abruption misclassification, selection bias, and unmeasured confounding. We included 11 cohort studies comprising 6,325,152 pregnancies, 69,759 abruptions, and 49,265 CHD and stroke cases (1967-2016). Risks of combined CVD morbidity-mortality among abruption and nonabruption groups were 16.7 and 9.3 per 1,000 births, respectively (RR = 1.76, 95% CI: 1.24, 2.50; I2 = 94%; τ2 = 0.22). Women who suffered abruption were at 2.65-fold (95% CI: 1.55, 4.54; I2 = 85%; τ2 = 0.36) higher risk of death related to CHD/stroke than nonfatal CHD/stroke complications (RR = 1.32, 95% CI: 0.91, 1.92; I2 = 93%; τ2 = 0.15). Abruption was associated with higher mortality from CHD (RR = 2.64, 95% CI: 1.57, 4.44; I2 = 76%; τ2 = 0.31) than stroke (RR = 1.70, 95% CI: 1.19, 2.42; I2 = 40%; τ2 = 0.05). Corrections for the aforementioned biases increased these estimates. Women with pregnancies complicated by placental abruption may benefit from postpartum screening or therapeutic interventions to help mitigate CVD risks.

Clinical Experience Over 15 Years with the B-Lynch Compression Suture Technique in the Management of Postpartum Hemorrhage

OBJECTIVE

 To describe the clinical experience with the B-Lynch technique in the management of postpartum hemorrhage as well as the factors related to the indication of the technique and to present the success rates of the application of the B-Lynch technique.

METHODS

 Observational, retrospective, cross-sectional, and analytical study. Patient data was obtained through the study of medical records. The study population comprised of patients who underwent hemostatic suture using the B-Lynch technique, including 104 patients within the period from January 1, 2005, to December 31, 2019.

RESULTS

 Of the total of 104 patients, 82.7% did not present any complications. Blood transfusion and intensive care unit admission were the most prevalent complications, with 13.5% and 15.4%, respectively. Only 1% of the patients had puerperal and surgical site infections. The factors most related to the application of the technique were the presence of previous cesarean section (30.8%), use of oxytocin (16.3%), and preeclampsia (11.6%). Puerperal hysterectomy was performed in 4.8% of the patients due to failure of the method.

CONCLUSION

 The clinical experience with the B-Lynch technique was satisfactory since it presented few complications, with excellent results in hemorrhagic control. Previous cesarean section, the use of oxytocin, and preeclampsia stood out as factors related to the indication of the application of the technique, and the success rate in controlling postpartum hemorrhage was 95.2%.

Antepartum Hemorrhage and Outcome of Very Low Birth Weight, Very Preterm Infants: A Population-Based Study

OBJECTIVE

We aimed to determine the independent effect of maternal antepartum hemorrhage (APH) on mortality and major neonatal morbidities among very low birth weight (VLBW), very preterm infants.

STUDY DESIGN

A population-based cohort study of VLBW singleton infants born at 24 to 31 weeks of gestation between 1995 and 2016 was performed. Infants born with the following pregnancy associated complications were excluded: maternal hypertensive disorders, prolonged rupture of membranes, amnionitis, maternal diabetes, and small for gestational age. APH included hemorrhage due to either placenta previa or placental abruption. Univariate and multivariable logistic regression analyses were performed to assess the effect of maternal APH on mortality and major neonatal morbidities.

RESULTS

The initial cohort included 33,627 VLBW infants. Following exclusions, the final study population comprised 6,235 infants of whom 2,006 (32.2%) were born following APH and 4,229 (67.8%) without APH. In the APH versus no APH group, there were higher rates of extreme prematurity (24-27 weeks of gestation; 51.6% vs. 45.3%, p < 0.0001), mortality (20.2 vs. 18.5%, p = 0.011), bronchopulmonary dysplasia (BPD, 16.1 vs. 13.0%, p = 0.004) and death or adverse neurologic outcome (37.4 vs. 34.5%, p = 0.03). In the multivariable analyses, APH was associated with significantly increased odds ratio (OR) for BPD in the extremely preterm infants (OR: 1.31, 95% confidence interval: 1.05-1.65). The OR's for mortality, adverse neurological outcomes, and death or adverse neurological outcome were not significantly increased in the APH group.

CONCLUSION

Among singleton, very preterm VLBW infants, maternal APH was associated with increased odds for BPD only in extremely premature infants, but was not associated with excess mortality or adverse neonatal neurological outcomes.

KEY POINTS

· Outcome of very low birth weight infants born after antepartum hemorrhage (APH) was assessed.. · APH was not associated with higher infant mortality.. · APH was not associated with adverse neurological outcome.. · APH was associated with increased bronchopulmonary dysplasia in extremely preterm infants..

Pravastatin is useful for prevention of recurrent severe placenta-mediated complications - a pilot study

BACKGROUND

Preeclampsia with severe features and other severe placenta-mediated complications may be life threatening to mother and fetus, especially when they are recurrent. Recurrence of pregnancy complications is common, however, when combined treatment with low molecular weight heparin and low dose aspirin fails, there are not any proven therapeutic options for prevention of recurrence of obstetrical complications.

OBJECTIVE

We aimed to determine the impact of adding pravastatin to low molecular weight heparin and low dose aspirin for improving pregnancy outcome in women with severe recurrent placenta-mediated complications.

DESIGN

A retrospective study of 32 women with severe recurrent placenta-mediated complications (preeclampsia with severe features, placental abruption, severe intrauterine growth retardation or intra uterine fetal death) in spite of treatment with low molecular weight heparin and low dose aspirin in previous pregnancy. All women were treated in the index pregnancy with 20 mg pravastatin starting at 12 weeks, with low molecular weight heparin and low dose aspirin. Antiphospholipid syndrome was evident for 10 of the 32 women.

RESULTS

In the index pregnancy, only one woman had recurrence of severe placenta-mediated complications. Gestational age at delivery in the index pregnancy compared to previous pregnancy when women were treated with low molecular weight heparin and low dose aspirin was 36.5 ± 1.7 vs. 32 ± 3.6 weeks, and mean birth weight 2691 ± 462 vs. 1436 ± 559 grams, compared to previous pregnancy when women were treated with low molecular weight heparin and low dose aspirin (p < .001 for both). Of the 17 women with previous preeclampsia with severe features, 15 had no recurrence of preeclampsia and 2 women had mild preeclampsia at term. Of the 8 women with previous severe intrauterine growth retardation, all delivered at significant higher gestational age compare to previous pregnancy, [37.0 ± 1 vs. 34 ± 3 weeks, (p < .05)] with higher mean birth-weight [2648 ± 212 vs. 1347 ± 465 grams, (p = .05)]. Of the 3 women with previous placental abruption, one delivered at 32 weeks due to non-reassuring fetal heart monitoring, one woman was delivered at 36 weeks due to mild preeclampsia, and one woman underwent elective induction of labor at 37 weeks with no intrauterine growth retardation. Of the 4 women with previous recurrent intrauterine fetal death, 3 women delivered at 37 weeks after elective induction, and one woman at 30 weeks with a birthweight of 960 grams due to severe intrauterine growth retardation.

CONCLUSIONS

Additive treatment with pravastatin to low molecular weight heparin and low dose aspirin may be a promising option in cases of previous severe recurrent placenta-mediated complications.

Molecular Changes on Maternal-Fetal Interface in Placental Abruption-A Systematic Review

Placental abruption is the separation of the placenta from the lining of the uterus before childbirth. It is an infrequent perinatal complication with serious after-effects and a marked risk of maternal and fetal mortality. Despite the fact that numerous placental abruption risk factors are known, the pathophysiology of this issue is multifactorial and not entirely clear. The aim of this review was to examine the current state of knowledge concerning the molecular changes on the maternal–fetal interface occurring in placental abruption. Only original research articles describing studies published in English until the 15 March 2021 were considered eligible. Reviews, book chapters, case studies, conference papers and opinions were excluded. The systematic literature search of PubMed/MEDLINE and Scopus databases identified 708 articles, 22 of which were analyzed. The available evidence indicates that the disruption of the immunological processes on the maternal–fetal interface plays a crucial role in the pathophysiology of placental abruption. The features of chronic non-infectious inflammation and augmented immunological cytotoxic response were found to be present in placental abruption samples in the reviewed studies. Various molecules participate in this process, with only a few being examined. More advanced research is needed to fully explain this complicated process.

Pregnancy Induces an Immunological Memory Characterized by Maternal Immune Alterations Through Specific Genes Methylation

During pregnancy, the maternal immune system undergoes major adaptive modifications that are necessary for the acceptance and protection of the fetus. It has been postulated that these modifications are temporary and limited to the time of pregnancy. Growing evidence suggests that pregnancy has a long-term impact on maternal health, especially among women with pregnancy complications, such as preeclampsia (PE). In addition, the presence of multiple immunological-associated changes in women that remain long after delivery has been reported. To explain these long-term modifications, we hypothesized that pregnancy induces long-term immunological memory with effects on maternal well-being. To test this hypothesis, we evaluated the immunological phenotype of circulating immune cells in women at least 1 year after a normal pregnancy and after pregnancy complicated by PE. Using multiparameter flow cytometry (FCM) and whole-genome bisulfite sequencing (WGBS), we demonstrate that pregnancy has a long-term effect on the maternal immune cell populations and that this effect differs between normal pregnancy and pregnancy complicated by PE; furthermore, these modifications are due to changes in the maternal methylation status of genes that are associated with T cell and NK cell differentiation and function. We propose the existence of an "immunological memory of pregnancy (IMOP)" as an evolutionary advantage for the success of future pregnancies and the proper adaptation to the microchimeric status established during pregnancy. Our findings demonstrate that the type of immune cell populations modified during pregnancy may have an impact on subsequent pregnancy and future maternal health.

Uterine Vascular Control Preconception and During Pregnancy

Successful pregnancy and reproduction are dependent on adequate uterine blood flow, placental perfusion, and vascular responsivity to fetal demands. The ability to support pregnancy centers on systemic adaptation and endometrial preparation through decidualization, embryonic implantation, trophoblast invasion, arterial/arteriolar reactivity, and vascular remodeling. These adaptations occur through responsiveness to endocrine signaling and local uteroplacental mediators. The purpose of this article is to highlight the current knowledge associated with vascular remodeling and responsivity during uterine preparation for and during pregnancy. We focus on maternal cardiovascular systemic and uterine modifications, endometrial decidualization, implantation and invasion, uterine and spiral artery remodeling, local uterine regulatory mechanisms, placentation, and pathological consequences of vascular dysfunction during pregnancy. © 2021 American Physiological Society. Compr Physiol 11:1-23, 2021.

Air Pollution and Risk of Placental Abruption: A Study of Births in New York City, 2008-2014

We evaluated the associations of exposure to fine particulate matter (particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5) at concentrations of <12 μg/m3, 12-14 μg/m3, and ≥15 μg/m3) and nitrogen dioxide (at concentrations of <26 parts per billion (ppb), 26-29 ppb, and ≥30 ppb) with placental abruption in a prospective cohort study of 685,908 pregnancies in New York, New York (2008-2014). In copollutant analyses, these associations were examined using distributed-lag nonlinear models based on Cox models. The prevalence of abruption was 0.9% (n = 6,025). Compared with a PM2.5 concentration less than 12 μg/m3, women exposed to PM2.5 levels of ≥15 μg/m3 in the third trimester had a higher rate of abruption (hazard ratio (HR) = 1.68, 95% confidence interval (CI): 1.41, 2.00). Compared with a nitrogen dioxide concentration less than 26 ppb, women exposed to nitrogen dioxide levels of 26-29 ppb (HR = 1.11, 95% CI: 1.02, 1.20) and ≥30 ppb (HR = 1.06, 95% CI: 0.96, 1.24) in the first trimester had higher rates of abruption. Compared with both PM2.5 and nitrogen dioxide levels less than the 95th percentile in the third trimester, rates of abruption were increased with both PM2.5 and nitrogen dioxide ≥95th percentile (HR = 1.44, 95% CI: 1.15, 1.80) and PM2.5 ≥95th percentile and nitrogen dioxide <95th percentile (HR = 1.43 95% CI: 1.23, 1.66). Increased levels of PM2.5 exposure in the third trimester and nitrogen dioxide exposure in the first trimester are associated with elevated rates of placental abruption, suggesting that these exposures may be important triggers of premature placental separation through different pathways.

Can a Difference in Gestational Age According to Biparietal Diameter and Abdominal Circumference Predict Intrapartum Placental Abruption?

This study aimed to investigate whether a difference in gestational age according to biparietal diameter (BPD) and abdominal circumference (AC) could be a clinically useful predictor of placental abruption during the intrapartum period. This retrospective cohort study was based on singletons who were delivered after 32 + 0 weeks between July 2015 and July 2020. We only included cases with at least two antepartum sonographies available within 4 weeks of delivery (n = 2790). We divided the study population into two groups according to the presence or absence of placental abruption and compared the clinical variables. The incidence of placental abruption was 2.0% (56/2790) and was associated with an older maternal age, a higher rate of preeclampsia, and being small for the gestational age. A difference of >2 weeks in gestational age according to BPD and AC occurred at a higher rate in the placental abruption group compared to the no abruption group (>2 weeks, 21.4% (12/56) vs. 7.5% (205/2734), p < 0.001; >3 weeks, 12.5% (7/56) vs. 2.0% (56/2734), p < 0.001). Logistic regression analysis revealed that the differences of >2 weeks and >3 weeks were both independent risk factors for placental abruption (odds ratio (OR) (95% confidence interval), 2.289 (1.140-4.600) and 3.918 (1.517-9.771), respectively) after adjusting for maternal age, preeclampsia, and small for gestational age births. We identified that a difference in gestational age of >2 weeks between BPD and AC could be an independent predictor of placental abruption.

Preterm Delivery; Who Is at Risk?

Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality. Adverse effects of preterm birth have a direct correlation with the degree of prematurity, in which infants who are born extremely preterm (24–28 weeks gestation) have the worst outcomes. We sought to determine prominent risk factors for extreme PTB and whether these factors varied between various sub-populations with known risk factors such as previous PTB and multiple gestations. A population-based retrospective cohort study was conducted. Risk factors were examined in cases of extreme PTB in the general population, as well as various sub-groups: singleton and multiple gestations, women with a previous PTB, and women with indicated or induced PTB. A total of 334,415 deliveries were included, of which 1155 (0.35%) were in the extreme PTB group. Placenta previa (OR = 5.8, 95%CI 4.14–8.34, p < 0.001), multiple gestations (OR = 7.7, 95% CI 6.58–9.04, p < 0.001), and placental abruption (OR = 20.6, 95%CI 17.00–24.96, p < 0.001) were the strongest risk factors for extreme PTB. In sub-populations (multiple gestations, women with previous PTB and indicated PTBs), risk factors included placental abruption and previa, lack of prenatal care, and recurrent pregnancy loss. Singleton extreme PTB risk factors included nulliparity, lack of prenatal care, and placental abruption. Placental abruption was the strongest risk factor for extreme preterm birth in all groups, and risk factors did not differ significantly between sub-populations.

Teenage pregnancy as a risk factor for placental abruption: Findings from the prospective Japan environment and children's study

Objective

Placental abruption is a significant obstetric complication that affects both maternal and neonatal mortality and morbidity. The present study examined the effect of maternal age on the incidence of placental abruption.

Methods

We used data of singleton pregnancies from the Japan Environment and Children’s Study, which was a prospective birth cohort study conducted between January 2011 and March 2014 across 15 regional centers in Japan. A multiple regression model was used to identify whether maternal age (<20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years) is a risk factor for placental abruption. The analyses were conducted while considering the history of placental abruption, assisted reproductive technology, number of previous deliveries, smoking during pregnancy, body mass index before pregnancy, and chronic hypertension.

Results

A total of 94,410 Japanese women (93,994 without placental abruption and 416 with placental abruption) were recruited. Herein, 764, 8421, 25915, 33517, and 25793 women were aged <20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years, respectively. Besides advanced maternal age (≥35 years; adjusted odds ratio: 1.7, 95% confidence interval: 1.1–2.5), teenage pregnancy was also a risk factor for placental abruption (adjusted odds ratio: 2.8, 95% confidence interval: 1.2–6.5) when the maternal age of 20–24 years was set as a reference.

Conclusions

In the Japanese general population, besides advanced maternal age, teenage pregnancy was associated with placental abruption. Recently, the mean maternal age has been changing in Japan. Therefore, it is important for obstetric care providers to provide proper counseling to young women based on up-to-date evidence.

A hierarchical procedure to select intrauterine and extrauterine factors for methodological validation of preterm birth risk estimation

Background

Etiopathogenesis of preterm birth (PTB) is multifactorial, with a universe of risk factors interplaying between the mother and the environment. It is of utmost importance to identify the most informative factors in order to estimate the degree of PTB risk and trace an individualized profile. The aims of the present study were: 1) to identify all acknowledged risk factors for PTB and to select the most informative ones for defining an accurate model of risk prediction; 2) to verify predictive accuracy of the model and 3) to identify group profiles according to the degree of PTB risk based on the most informative factors.

Methods

The Maternal Frailty Inventory (MaFra) was created based on a systematic review of the literature including 174 identified intrauterine (IU) and extrauterine (EU) factors. A sample of 111 pregnant women previously categorized in low or high risk for PTB below 37 weeks, according to ACOG guidelines, underwent the MaFra Inventory. First, univariate logistic regression enabled p-value ordering and the Akaike Information Criterion (AIC) selected the model including the most informative MaFra factors. Second, random forest classifier verified the overall predictive accuracy of the model. Third, fuzzy c-means clustering assigned group membership based on the most informative MaFra factors.

Results

The most informative and parsimonious model selected through AIC included Placenta Previa, Pregnancy Induced Hypertension, Antibiotics, Cervix Length, Physical Exercise, Fetal Growth, Maternal Anxiety, Preeclampsia, Antihypertensives. The random forest classifier including only the most informative IU and EU factors achieved an overall accuracy of 81.08% and an AUC of 0.8122. The cluster analysis identified three groups of typical pregnant women, profiled on the basis of the most informative IU and EU risk factors from a lower to a higher degree of PTB risk, which paralleled time of birth delivery.

Conclusions

This study establishes a generalized methodology for building-up an evidence-based holistic risk assessment for PTB to be used in clinical practice. Relevant and essential factors were selected and were able to provide an accurate estimation of degree of PTB risk based on the most informative constellation of IU and EU factors.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12884-021-03654-3).

Easily generated hematological biomarkers and prediction of placental abruption

OBJECTIVE

Placental abruption (PA) is associated with adverse maternal and neonatal outcomes. Increasing evidence has shown an association between abruption and inflammation as well as utilization of hematological biomarkers to predict the later. We aimed to evaluate the feasibility of using neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ration (PLR) taken early in pregnancy in predicting later occurrence of PA.

STUDY DESIGN

A nested case control study, which compared parturient with PA (cases) to parturient without PA (controls). Parturient were matched by hospitalization date and maternal age. Demographic, clinical, and obstetrical characteristics were retrieved. Hematological indices derived from complete blood count taken during the first trimester of pregnancy, specifically NLR and PLR were retrieved and compared between the groups. Mann-Whitney and T-test were performed for not normally and normally distributed continuous variables respectively, categorical variables were analyzed using Chi-Square or Fisher Exact test as appropriate.

RESULTS

The study comprised of 232 patients. Of these, 131 had suffered from PA and 131 without PA. Parturient who had PA has significantly higher rates of hypertensive disorders of pregnancy, mean neutrophil, lymphocyte and platelet count did not differ between the groups. A comparison of NLR and PLR between the study groups yielded no significant differences.

CONCLUSION

NLR and PLR taken early in the course of pregnancy were not found associated with PA. Given the potentially severe consequences of PA, the biological plausibility and the readiness of these hematological markers, further investigation of this method with larger, prospective studies are needed.

Summary of clinically diagnosed amniotic fluid embolism cases in Korea and disagreement with 4 criteria proposed for research purpose

OBJECTIVE

This study aimed 1) to investigate the clinical characteristics of amniotic fluid embolism (AFE) cases clinically diagnosed by maternal fetal medicine (MFM) specialists in Korea, 2) to check the disagreement with 4 recently proposed criteria by the Society for Maternal-Fetal Medicine (SMFM) for research purpose, and 3) to compare maternal outcomes between cases satisfying all 4 criteria and cases with at least 1 missing criterion.

METHODS

This study included 12 patients clinically diagnosed with AFE from 7 referral hospitals in Korea. We collected information, including maternal age, symptoms of AFE, the amount of transfusion, and maternal mortality.

RESULTS

The median maternal age was 33 years (range, 28-40 years). Regarding symptoms, cardiovascular arrest, hypotension, respiratory compromise, clinical coagulopathy, and neurologic signs were observed in 41.7%, 83.3%, 83.3%, 100%, and 66.7% of the cases, respectively. Among the 12 cases, 5 women died and 2 suffered severe neurologic disability, showing an intact survival rate of 41.7%. Disagreement with all 4 criteria proposed by the SMFM was found in 66.7% of the cases, due to the lack of criteria for disseminated intravascular coagulation or strict onset time (<30 minutes after delivery). There was no difference in maternal mortality and the amount of transfusion between cases satisfying all 4 criteria and cases with at least 1 missing criterion.

CONCLUSION

Two-thirds of clinically confirmed AFE cases did not satisfy all 4 criteria proposed by the SMFM, despite similar rates of maternal mortality with cases satisfying all 4 criteria. Our study suggests that there may be some discrepancy between the clinical diagnosis of AFE and the recent diagnostic criteria proposed by the SMFM for research purpose.

Optimizing Term Delivery and Mode of Delivery

Full-term deliveries are defined as occurring between 39 weeks and 40 weeks and 6 days. Because contemporary research suggests improved outcomes with delivery in the term period compared with the early term period, nonindicated delivery should be pursued no earlier than 39 weeks. There are, however, multiple medical, obstetric, and fetal indications for delivery before 39 weeks, and the obstetric provider must weigh the risks and benefits of delivery versus expectant management on both the mother and fetus. This review serves to provide a basic framework of evidentiary support toward optimizing the term delivery.

Association of MTHFR 677C>T polymorphism with IUGR and placental abruption risk: A systematic review and meta-analysis

OBJECTIVE

The effects of the MTHFR 677C > T polymorphism on the intrauterine growth restriction (IUGR) and placental abruption risk have been evaluated in some studies. However, those studies results were conflicting and ambiguous. Therefore, we carried out the current meta-analysis to evaluate the association of MTHFR 677C > T polymorphism with risk of IUGR and placental abruption from all eligible studies.

METHODS

An electronic search of the PubMed, Embase, Scopus and CNKI databases was performed up to February 25, 2020.

RESULTS

A total of 25 case-control studies including eight studies with 687 cases and 2336 controls for IUGR and 17 studies with 1574 cases and 5758 controls for placental abruption were selected. The analysis results indicated that MTHFR 677C > T polymorphism was associated with an increased risk of IUGR and placental abruption in global population. When stratified by ethnicity a significant association between the MTHFR 677C > T polymorphism and IUGR risk was found in Caucasians and Africans. However, there was no a significant association between the MTHFR 677C > T polymorphism and placental abruption risk by ethnicity.

CONCLUSIONS

Our pooled data indicated that the MTHFR 677C > T polymorphism might play a role in development of IUGR and placental abruption.

Associations between glycosylated hemoglobin level at less than 24 weeks of gestation and adverse pregnancy outcomes in Japan: The Japan Environment and Children's Study (JECS)

AIMS

To investigate the associations between glycosylated hemoglobin (HbA1c) levels at less than 24 weeks of gestation and adverse pregnancy outcomes in Japan.

METHODS

This was a prospective nationwide birth cohort study of 77,526 subjects with an HbA1c level of <6.5% (<48 mmol/mol) at less than 24 weeks of gestation. Associations of HbA1c level with adverse pregnancy outcomes were evaluated using multivariate analyses.

RESULTS

The adjusted odds ratios per 1% (11 mmol/mol) increase in HbA1c level were 1.77 (95% confidence interval [CI]: 1.48-2.12) for hypertensive disorders of pregnancy; 1.78 (95% CI: 1.12-2.83) for placental abruption; 1.30 (95% CI: 1.12-1.50) for preterm birth; 2.11 (95% CI: 1.41-3.16) for very preterm birth; 1.49 (95% CI: 1.33-1.68) for low birth weight infants; 1.95 (95% CI: 1.42-2.70) for macrosomia; 1.23 (95% CI: 1.09-1.39) for small for gestational age; 1.15 (95% CI: 1.04-1.28) for large for gestational age; and 1.29 (95% CI: 1.20-1.39) for the composite adverse pregnancy outcome.

CONCLUSIONS

The higher the HbA1c level, the higher the risk of adverse pregnancy outcomes in Japan. Further studies will be needed to determine prenatal management based on the HbA1c level in pregnant women with HbA1c <6.5% (<48 mmol/mol) at less than 24 weeks of gestation.

Prediction of stillbirth: an umbrella review of evaluation of prognostic variables

BACKGROUND

Stillbirth accounts for over 2 million deaths a year worldwide and rates remains stubbornly high. Multivariable prediction models may be key to individualised monitoring, intervention or early birth in pregnancy to prevent stillbirth.

OBJECTIVES

To collate and evaluate systematic reviews of factors associated with stillbirth in order to identify variables relevant to prediction model development.

SEARCH STRATEGY

MEDLINE, Embase, DARE and Cochrane Library databases and reference lists were searched up to November 2019.

SELECTION CRITERIA

We included systematic reviews of association of individual variables with stillbirth without language restriction.

DATA COLLECTION AND ANALYSIS

Abstract screening and data extraction were conducted in duplicate. Methodological quality was assessed using AMSTAR and QUIPS criteria. The evidence supporting association with each variable was graded.

RESULTS

The search identified 1198 citations. Sixty-nine systematic reviews reporting 64 variables were included. The most frequently reported were maternal age (n = 5), body mass index (n = 6) and maternal diabetes (n = 5). Uterine artery Doppler appeared to have the best performance of any single test for stillbirth. The strongest evidence of association was for nulliparity and pre-existing hypertension.

CONCLUSION

We have identified variables relevant to the development of prediction models for stillbirth. Age, parity and prior adverse pregnancy outcomes had a more convincing association than the best performing tests, which were PAPP-A, PlGF and UtAD. The evidence was limited by high heterogeneity and lack of data on intervention bias.

TWEETABLE ABSTRACT

Review shows key predictors for use in developing models predicting stillbirth include age, prior pregnancy outcome and PAPP-A, PLGF and Uterine artery Doppler.

The predictive value of pre-delivery laboratory test results for the severity of placental abruption and pregnancy outcome

INTRODUCTION

To analyze the relationship between placental abruption severity and maternal pregnancy outcome and to explore the predictive value of pre-delivery laboratory test results for the severity of placental abruption.

METHODS

The clinical datas of 126 patients with placental abruption diagnosed and treated in our hospital over the past 4 years were retrospectively analyzed. The severity of placental abruption was divided into degrees I to III. The pre-delivery laboratory results of all patients and data on maternal and fetal delivery outcomes were collected.

RESULTS

The analysis of maternal outcomes showed that the volumes of antepartum, intrapartum and postpartum hemorrhage and the rates of utero-placental apoplexy, uterine compression sutures and vascular embolization significantly increased with increasing placental abruption severity. Fetal delivery data revealed that 1- and 5-min Apgar scores decreased significantly with increasing placental abruption severity. Pre-delivery laboratory findings suggest that the white blood cell count, hemoglobin, hematocrit, platelet count, albumin, aspartate aminotransferase (AST), creatinine, prothrombin time (PT), prothrombin activity, prothrombin time - international standardization ratio (INR), D-dimer, fibrinogen (FIB), and fibrin degradation products (FDP) changed significantly with increasing placental abruption severity. Further analysis by Spearman and Pearson correlation found that the pre-delivery volume of antepartum hemorrhage, D-dimer, FDP and other indicators were correlated with placental abruption severity.

CONCLUSIONS

The harm of placental abruption to pregnant women and neonates increases with increasing abruption severity. Some laboratory test results can be predictors of placental abruption degree.

Why can't I exercise during pregnancy? Time to revisit medical 'absolute' and 'relative' contraindications: systematic review of evidence of harm and a call to action

BACKGROUND

Clinical guidelines recommend pregnant women without contraindication engage in regular physical activity. This is based on extensive evidence demonstrating the safety and benefits of prenatal exercise. However, certain medical conditions or contraindications warrant a reduction, modification or cessation of activity due to potential health risks.

AIM

To review and evaluate the evidence related to medical disorders which may warrant contraindication to prenatal exercise.

METHODS

Online databases were searched up to 5 April 2019. Forty-four unique studies that reported data on our Population (pregnant women with contraindication to exercise), Intervention (subjective/objective measures of acute or chronic exercise), Comparator (not essential) and Outcomes (adverse maternal or fetal outcomes) were included in the review.

KEY FINDINGS

We found that the majority of medical conditions listed as contraindications were based on expert opinion; there is minimal empirical evidence to demonstrate harm of exercise and benefit of activity restriction. We identified 11 complications (eg, gestational hypertension, twin pregnancy) previously classified as contraindications where women may in fact benefit from regular prenatal physical activity with or without modifications. However, the evidence suggests that severe cardiorespiratory disease, placental abruption, vasa previa, uncontrolled type 1 diabetes, intrauterine growth restriction, active preterm labour, severe pre-eclampsia and cervical insufficiency are associated with strong potential for maternal/fetal harm and warrant classification as absolute contraindications.

CONCLUSION

Based on empirical evidence, we provide a call to re-evaluate clinical guidelines related to medical disorders that have previously been considered contraindications to prenatal exercise. Removing barriers to physical activity during pregnancy for women with certain medical conditions may in fact be beneficial for maternal-fetal health outcomes.

Thrombin-Induced Decidual Colony-Stimulating Factor-2 Promotes Abruption-Related Preterm Birth by Weakening Fetal Membranes

Preterm premature rupture of membranes (PPROM) and thrombin generation by decidual cell-expressed tissue factor often accompany abruptions. Underlying mechanisms remain unclear. We hypothesized that thrombin-induced colony-stimulating factor-2 (CSF-2) in decidual cells triggers paracrine signaling via its receptor (CSF2R) in trophoblasts, promoting fetal membrane weakening and abruption-associated PPROM. Decidua basalis sections from term (n = 10), idiopathic preterm birth (PTB; n = 8), and abruption-complicated pregnancies (n = 8) were immunostained for CSF-2. Real-time quantitative PCR measured CSF2 and CSF2R mRNA levels. Term decidual cell (TDC) monolayers were treated with 10^-8 mol/L estradiol ± 10^-7 mol/L medroxyprogesterone acetate (MPA) ± 1 IU/mL thrombin pretreatment for 4 hours, washed, and then incubated in control medium with estradiol ± MPA. TDC-derived conditioned media supernatant effects on fetal membrane weakening were analyzed. Immunostaining localized CSF-2 primarily to decidual cell cytoplasm and cytotrophoblast cell membranes. CSF-2 immunoreactivity was higher in abruption-complicated or idiopathic PTB specimens versus normal term specimens (P < 0.001). CSF2 mRNA was higher in TDCs versus cytotrophoblasts (P < 0.05), whereas CSF2R mRNA was 1.3 × 10⁴-fold higher in cytotrophoblasts versus TDCs (P < 0.001). Thrombin enhanced CSF-2 secretion in TDC cultures fourfold (P < 0.05); MPA reduced this effect. Thrombin-pretreated TDC-derived conditioned media supernatant weakened fetal membranes (P < 0.05), which MPA inhibited. TDC-derived CSF-2, acting via trophoblast-expressed CSFR2, contributes to thrombin-induced fetal membrane weakening, eliciting abruption-related PPROM and PTB.

Immunological Role of the Maternal Uterine Microbiota in Postpartum Hemorrhage

Recent metagenomics and microbiology studies have identified microorganisms that are typical of the fetoplacental unit. Considering this emerging evidence, the placenta, uterus, and the amniotic cavity are not sterile and not immune privileged. However, there is evidence for a beneficial interaction between active maternal immune system and the presence of commensal pathogens, which lead to an immune-tolerant state, thereby preventing fetal rejection. Multiple conditions associated with the loss of the normal flora are described (dysbiosis), which could result in perinatal and puerperal adverse events, including, directly or indirectly, postpartum hemorrhage. Altered flora when associated with a severe proinflammatory state and combined with patient's genetic and environmental factors confers a high-risk adverse outcome. Better understanding of the adverse role of dysbiosis in pregnancy outcome will improve maternal outcome.

Obstetric Care Consensus #10: Management of Stillbirth: (Replaces Practice Bulletin Number 102, March 2009)

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained, even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Management of Stillbirth: Obstetric Care Consensus No, 10

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Trauma in pregnancy and severe adverse perinatal outcomes

BACKGROUND

Trauma, including accidental and violent trauma, is a rare but severe complication of pregnancy. The incidence of adverse perinatal outcomes in pregnancies affected by traumatic injury has not been well-studied.

OBJECTIVE

We sought to characterize the association between traumatic injury during pregnancy and severe adverse perinatal outcomes in a large population.

STUDY DESIGN

We performed a retrospective cohort study of California Birth Registry data from 2007 to 2011. ICD-9 diagnosis and procedure codes were used to categorize patients into trauma and non-trauma cohorts and to assess the prevalence of severe adverse fetal and neonatal outcomes. Chi-square tests were used to characterize maternal demographics and perform univariate analyses, and logistic regression was used to control for potential confounders.

RESULTS

Of 2,406,605 singleton nonanomalous pregnancies, 1262 (0.05%) experienced trauma prior to delivery. The rate of composite perinatal outcomes was higher in pregnancies with trauma compared to those without (3.1 versus 0.87%, p < .001). Trauma was associated with higher occurrences of preterm birth <37 weeks, preterm birth <32 weeks, very low birth weight and neonatal death. Fetal demise at any gestational age was more common among trauma patients (1.9 versus 0.53%, p < .001), though this difference was not statistically significant among term fetuses (0.28 versus 0.14%, p = .21). A difference in composite adverse perinatal outcomes was seen even after controlling for important maternal characteristics (aOR 3.2, 95% CI). Trauma patients with severe morbidity compared to those without had higher rates of preterm birth <37 weeks, preterm birth <32 weeks, and composite severe perinatal outcomes.

CONCLUSION

Trauma in pregnant women is associated with an increased risk of severe adverse perinatal outcomes, including fetal and neonatal demise. Prevalence of fetal demise is not different between trauma and non-trauma mothers when looking at term fetuses only, suggesting that the greatest risk of fetal demise in the setting of trauma occurs in the preterm period. These data can be used to counsel patients and to inform more detailed research into the mechanisms of trauma in pregnancy outcomes.

Clinical analysis and classification of placental abruption

OBJECTIVE

To investigate the diagnosis, treatment, and maternal and fetal outcomes of placental abruption.

MATERIALS AND METHODS

We recruited 585 cases of placental abruption from the Women and Children's Hospital Affiliated to Xiamen University between January 2012 and December 2017. Cases were categorized into four groups (class 0-III) according to the clinical guidelines published by the Obstetrics and Gynecology Branch of the Chinese Medical Association. We then compared clinical data and auxiliary examinations across the four groups.

RESULTS

The differences were statistically significant (p < .01) among the four groups of placental abruption with regard to the incidence of an abnormal ultrasound finding. Positive ultrasound signs were evident in 6.4% of the patients categorized as class 0 and 100.0% of patients categorized as class III. Monitoring showed that fetal heart rate (FHR) was abnormal in class II patients with placental abruption; patients in class III showed no fetal heart sounds. Cesarean section was carried out for 26.6%, 75.1%, 65.2%, and 47.1% of patients in classes 0, I, II, and III, respectively. The rate of cesarean section for classes I and II was the highest, while the lowest rate occurred for class 0. Postpartum hemorrhage occurred in 2.5%, 9.3%, 15.2%, and 29.4% of patients across the four groups, DIC occurred in 0.0%, 1.3%, 2.3%, and 23.5% of cases, and perinatal death occurred in 1.0%, 1.3%, 7.6%, and 100.0% of cases, respectively. The highest incidence of postpartum hemorrhage was in class III (29.4%) and the lowest was in class 0 (2.5%). The highest incidence of DIC was in class III (23.5%) and the lowest was in class 0 (0.0%). The highest incidence of neonatal asphyxia was in class II (34.1%) and the lowest was in class 0 (10.1%). Regarding perinatal death, the highest incidence was in class III (100.0%) and the lowest was in class 0 (1.0%). These data showed significance differences when compared across the four groups of patients (p < .01).

CONCLUSIONS

We recommend that the diagnosis of placental abruption should consider risk factors, clinical features, FHR monitoring, and dynamic ultrasound monitoring. Early diagnosis and treatment can improve maternal and infant prognosis.

Placental abruption and long-term neurological hospitalisations in the offspring

BACKGROUND

Placental abruption is a major determinant of maternal and perinatal morbidity and mortality, often related to asphyxia and preterm birth. However, the impact of abruption on the long-term morbidity of the offspring is less investigated.

METHODS

We designed a hospital-based cohort study, in which the incidence of long-term neurology-related hospitalisations of offspring to women with and without placental abruption was assessed. All singleton deliveries between 1991 and 2014 were included in the study. Congenital anomalies, perinatal mortality, and multifetal pregnancies were excluded from the analyses. We compared cumulative morbidity incidence using Kaplan-Meier survival curves and estimated the risk for long-term neurological hospitalisations from Cox proportional hazards models after adjustment for putative including maternal age, parity, hypertensive disorders, pre-gestational and gestational diabetes, gender, ethnicity, and year of birth.

RESULTS

Over the 22-year period, 2 202 269 person-years of follow-up, there were 217 910 deliveries of which 0.5% (n = 1003) were complicated with placental abruption. The median (interquartile range) follow-up of children in the abruption and non-abruption groups was 10.3 (4.6, 15.9) and 12.0 (6.3, 16.5) years, respectively. The cumulative incidence of total neurological hospitalisations was comparable between abruption (3.32 per 1000 person-years) and non-abruption (3.16 per 1000 person-years). Abruption was associated with increased rates of cerebral palsy (hazard ratio [HR] 6.71, 95% CI 3.32, 13.58) and developmental disorders (HR 3.36, 95% CI 1.38, 8.13), but not for total neurology-related hospitalisations (HR 1.08, 95% CI 0.78, 1.49).

CONCLUSION

Placental abruption is associated with increased rate of cerebral palsy and developmental disorders in the offspring later in life. This study may define risk factors for childhood neuropsychiatric disorders, enabling early diagnosis and intervention in children with such disorders, and perhaps improving their prognosis.

Unexpected term NICU admissions: a marker of obstetrical care quality?

BACKGROUND

Unexpected admissions of term neonates to the neonatal intensive care unit and unexpected postnatal complications have been proposed as neonatal-focused quality metrics for intrapartum care. Previous studies have noted significant variation in overall hospital neonatal intensive care unit admission rates; however, little is known about the influence of obstetric practices on these rates or whether variation among unanticipated admissions in low-risk, term neonates can be attributed to systemic hospital practices.

OBJECTIVE

The objective of the study was to examine the relative effects of patient characteristics and intrapartum events on unexpected neonatal intensive care unit admissions and to quantify the between-hospital variation in neonatal intensive care unit admission rates among this group of neonates.

STUDY DESIGN

We performed a retrospective cross-sectional study using data collected as part of the Consortium for Safe Labor study. Women who delivered term (≥37 weeks), singleton, nonanomalous, liveborn infants without an a priori risk for neonatal intensive care unit admission were included. The primary outcome was neonatal intensive care unit admission among this population. Multilevel mixed-effect models were used to calculate adjusted odds ratios for demographics (age, race, insurer), pregnancy characteristics (parity, gestational age, tobacco use, birthweight), maternal comorbidities (chronic and pregnancy-induced hypertension), hospital characteristics (delivery volume, hospital and neonatal intensive care unit level, academic affiliation), and intrapartum events (prolonged second stage, induction of labor, trial of labor after cesarean delivery, chorioamnionitis, meconium-stained amniotic fluid, and abruption). Intraclass correlation coefficients were used to estimate the between-hospital variance in a series of hierarchical models.

RESULTS

Of the 143,951 infants meeting all patient and hospital inclusion criteria, 7995 (5.6%) were admitted to the neonatal intensive care unit after birth. In the fully adjusted model, the factors associated with the highest odds for neonatal intensive care unit admission included: nulliparity (adjusted odds ratio, 1.62 [95% confidence interval, 1.53-1.71]), large for gestational age (adjusted odds ratio, 1.59 [95% confidence interval, 1.47-1.71]), and small for gestational age (adjusted odds ratio, 1.60 [95% confidence interval, 1.47-1.73]). Induction of labor (adjusted odds ratio, 0.95 [95% confidence interval, 0.89-1.01]) was not associated with increased odds of neonatal intensive care unit admission compared with women who labored spontaneously. The events associated with higher odds of neonatal intensive care unit admission included: prolonged second stage (adjusted odds ratio, 1.66 [95% confidence interval, 1.51-1.83]); chorioamnionitis (adjusted odds ratio, 3.89 [95% confidence interval, 3.42-4.44]), meconium-stained amniotic fluid (adjusted odds ratio, 1.96 [95% confidence interval, 1.82-2.10]), and abruption (adjusted odds ratio, 2.64 [95% confidence interval, 2.16-.21]). Compared with women who did not labor, the odds of neonatal intensive care unit admission were lower for women who labored: adjusted odds ratio, 0.48 (95% confidence interval, 0.45-0.52) for women with no uterine scar and adjusted odds ratio, 0.83 (95% confidence interval, 0.73-0.94) for women with a uterine scar. There was significant variation in neonatal intensive care unit admission rates by hospital, ranging from 2.9% to 11.2%. After accounting for case mix and hospital characteristics, the between-hospital variance was 1.9%, suggesting that little of the variation was explained by the effect of the hospital.

CONCLUSION

This study contributes to the currently limited understanding of term, neonatal intensive care unit admission rates as a marker of obstetrical care quality. We demonstrated that significant variation exists in hospital unexpected neonatal intensive care unit admission rates and that certain intrapartum events are associated with an increased risk for neonatal intensive care unit admission after delivery. However, the between-hospital variation was low. Unmeasured confounders and extrinsic factors, such as neonatal intensive care unit bed availability, may limit the ability of unexpected term neonatal intensive care unit admissions to meaningfully reflect obstetrical care quality.

Invited Commentary: Physical Exertion and Placental Abruption-Public Health Implications and Future Directions

Chahal et al. (Am J Epidemiol. 2018;187(10):2073-2079) assessed the risk of placental abruption due to physical exertion using a case-crossover design. The authors found an increased risk of placental abruption following increased physical exertion in the hour prior to the abruption. The risk was greater among women who were primarily sedentary during pregnancy or prior to becoming pregnant compared with those who were more physically active. The authors used a case-crossover design to assess the association of an intermittent exposure on an acute event. Chahal et al. address the limitations of the study, including the inability to control for time-varying confounders as well as the potential for recall bias. The public health implications of the study must be carefully evaluated given that physical activity prior to and during pregnancy can lead to healthy outcomes and is likely recommended. While the current study is unable to determine the type of physical exertion associated with placental abruption, future studies are recommended to determine the type of activity that presents increased risk. Additionally, studies among larger samples and in other countries will help determine the generalizability of the results.