Neonatal Outcomes Associated With Placental Abruption

Potential prevention of stillbirth caused by placental abruption: a regional population-based study in Japan

OBJECTIVE

Placental abruption is associated with adverse perinatal outcomes including intrauterine fetal demise, which subsequently results in stillbirth. However, few studies have demonstrated the preventability of stillbirth due to placental abruption. Therefore, we evaluated the possibility of preventing stillbirth caused by placental abruption by reviewing all stillbirths in our region.

METHODS

This study reviewed all stillbirths after 22 weeks of gestation in Shiga Prefecture, Japan from 2010 to 2019, excluding lethal disorders. We evaluated 350 stillbirth cases, with and without placental abruption.

RESULTS

There were 32 stillbirths with PA and 318 without placental abruption. The probability of preventing stillbirth was significantly higher in patients with placental abruption than in those without (30% vs. 8%, p < 0.001). We also determined the recommendations for preventing stillbirths with placental abruption.

CONCLUSION

Some stillbirths caused by placental abruption can be prevented. We recommend improvements to perinatal maternal-fetal care and perinatal emergency transport systems.

Risk factors for neonatal hypoxic ischemic encephalopathy and therapeutic hypothermia: a matched case-control study

BACKGROUND

Peripartum asphyxia is one of the main causes of neonatal morbidity and mortality. In moderate and severe cases of asphyxia, a condition called hypoxic-ischemic encephalopathy (HIE) and associated permanent neurological morbidities may follow. Due to the multifactorial etiology of asphyxia, it may be difficult prevent, but in term neonates, therapeutic cooling can be used to prevent or reduce permanent brain damage. The aim of this study was to assess the significance of different antenatal and delivery related risk factors for moderate and severe HIE and the need for therapeutic hypothermia.

METHODS

We conducted a retrospective matched case-control study in Helsinki University area hospitals during 2013-2017. Newborn singletons with moderate or severe HIE and the need for therapeutic hypothermia were included. They were identified from the hospital database using ICD-codes P91.00, P91.01 and P91.02. For every newborn with the need for therapeutic hypothermia the consecutive term singleton newborn matched by gender, fetal presentation, delivery hospital, and the mode of delivery was selected as a control. Odds ratios (OR) between obstetric and delivery risk factors and the development of HIE were calculated.

RESULTS

Eighty-eight cases with matched controls met the inclusion criteria during the study period. Maternal and infant characteristics among cases and controls were similar, but smoking was more common among cases (aOR 1.46, CI 1.14-1.64, p = 0.003). The incidence of preeclampsia, diabetes and intrauterine growth restriction in groups was equal. Induction of labour (aOR 3.08, CI 1.18-8.05, p = 0.02) and obstetric emergencies (aOR 3.51, CI 1.28-9.60, p = 0.015) were more common in the case group. No difference was detected in the duration of the second stage of labour or the delivery analgesia.

CONCLUSIONS

Smoking, induction of labour and any obstetric emergency, especially shoulder dystocia, increase the risk for HIE and need for therapeutic hypothermia. The decisions upon induction of labour need to be carefully weighed, since maternal smoking and obstetric emergencies can hardly be controlled by the clinician.

Placental abruption and risk for intraventricular hemorrhage in very low birth weight infants: the United States national inpatient database

OBJECTIVE

To examine the association of placental abruption with intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants.

METHODS

We examined the National Inpatient Sample (NIS) datasets. Preterm infants <1500 g birth weight (BW) were included. The odds ratios (OR) of developing IVH and severe IVH in association with placental abruption were calculated. Adjusted OR (aOR) were calculated using logistic regression models.

RESULTS

The study included 113,445 VLBW infants. IVH occurred in 18.7% in the infants who were born to mothers with history of placental abruption versus 14.7% in infants without placental abruption, aOR 1.25 (95%CI: 1.13-1.38), p < 0.001. Severe IVH occurred in 6.4% in infants born to mothers with history of placental abruption versus 4.0% in those without placental abruption, aOR 1.53 (95%CI: 1.30-1.78), p < 0.001.

CONCLUSION

Placental abruption is associated with increased prevalence of IVH and severe IVH in VLBW infants.

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.

Stillbirth and the placenta

Stillbirth affects a large proportion of pregnancies world-wide annually and continues to be a major public health concern. Several causes of stillbirth have been identified and include obstetrical complications, placental abnormalities, fetal malformations, infections, and medical complications in pregnancy. Placental abnormalities such as placental abruption, chorioangioma, vasa previa, and umbilical cord abnormalities have been identified as causes of death for a significant proportion of stillbirths. In the absence of placental abnormalities, the gross and histologic changes in the placenta in stillbirth are found when secondary to other etiologies. Here we describe both gross and histologic changes of the placenta that are associated with stillbirth.

A comparative analysis of Postpartum Hemorrhage incidence and influencing factors between nulliparous and multiparous women in Hunan Province, China: A multicenter retrospective cohort study

Objectives

Postpartum hemorrhage (PPH) is a common cause of maternal death worldwide, but data on PPH incidence and influencing factors for nulliparous and multiparous women is scarce. So, the study aimed to assess the differences in PPH incidence and influencing factors between nulliparous and multiparous women.

Methods

A multicenter retrospective cohort study was conducted among women who gave birth at ≥ 28 weeks of gestation in Hunan Province, China, from January 2017 to December 2018. Logistic regression assessed PPH-influencing factors, and the receiver operating characteristic curve (ROC curve) assessed the predictive performance of identified factors.

Results

A total of 144,845 postpartum women were included in the study. The incidence of PPH (blood loss ≥ 500 ml) was 2.1 % and 1.7 % for nulliparous and multiparous women, respectively. Among the nulliparous and multiparous women, similar influencing factors of PPH included erythrocyte suspension transfusion before childbirth, anemia, soft-birth canal avulsion, Cesarean-section, placenta abruption, and general anesthesia administration before birth. Thrombophlebitis was associated [aOR 18.46(1.67-20.31)] with PPH among only the nulliparous women, while instrument-assisted birth [aOR 1.95(1.16-3.28)] and gestational hypertension [aOR 1.57(1.13-2.19)] were associated with PPH among only the multiparous women. The areas under the ROC-curve for the overall-cohort, nulliparous, and multiparous groups were [0.829(0.821-0.838)], [0.828(0.815-0.840)] and [0.833(0.822-0.844)], respectively.

Conclusion

PPH incidence is higher among nulliparous women than among multiparous women, but influencing factors vary relatively by parity. The study findings provide new insights into the use of different approaches to PPH prevention for nulliparous and multiparous women in clinical practice.

Trophectoderm biopsy of blastocysts following IVF and embryo culture increases epigenetic dysregulation in a mouse model

STUDY QUESTION

Does trophectoderm biopsy (TEBx) of blastocysts for preimplantation genetic testing in the clinic affect normal placental and embryo development and offspring metabolic outcomes in a mouse model?

SUMMARY ANSWER

TEBx impacts placental and embryonic health during early development, with some alterations resolving and others worsening later in development and triggering metabolic changes in adult offspring.

WHAT IS KNOWN ALREADY

Previous studies have not assessed the epigenetic and morphological impacts of TEBx either in human populations or in animal models.

STUDY DESIGN, SIZE, DURATION

We employed a mouse model to identify the effects of TEBx during IVF. Three groups were assessed: naturally conceived (Naturals), IVF, and IVF + TEBx, at two developmental timepoints: embryonic day (E)12.5 (n = 40/Naturals, n = 36/IVF, and n = 36/IVF + TEBx) and E18.5 (n = 42/Naturals, n = 30/IVF, and n = 35/IVF + TEBx). Additionally, to mimic clinical practice, we assessed a fourth group: IVF + TEBx + Vitrification (Vit) at E12.5 (n = 29) that combines TEBx and vitrification. To assess the effect of TEBx in offspring health, we characterized a 12-week-old cohort (n = 24/Naturals, n = 25/IVF and n = 25/IVF + TEBx).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our mouse model used CF-1 females as egg donors and SJL/B6 males as sperm donors. IVF, TEBx, and vitrification were performed using standardized methods. Placenta morphology was evaluated by hematoxylin-eosin staining, in situ hybridization using Tpbpa as a junctional zone marker and immunohistochemistry using CD34 fetal endothelial cell markers. For molecular analysis of placentas and embryos, DNA methylation was analyzed using pyrosequencing, luminometric methylation assay, and chip array technology. Expression patterns were ascertained by RNA sequencing. Triglycerides, total cholesterol, high-, low-, and very low-density lipoprotein, insulin, and glucose were determined in the 12-week-old cohort using commercially available kits.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed that at E12.5, IVF + TEBx had a worse outcome in terms of changes in DNA methylation and differential gene expression in placentas and whole embryos compared with IVF alone and compared with Naturals. These changes were reflected in alterations in placental morphology and blood vessel density. At E18.5, early molecular changes in fetuses were maintained or exacerbated. With respect to placentas, the molecular and morphological changes, although different compared to Naturals, were equivalent to the IVF group, except for changes in blood vessel density, which persisted. Of note is that most differences were sex specific. We conclude that TEBx has more detrimental effects in mid-gestation placental and embryonic tissues, with alterations in embryonic tissues persisting or worsening in later developmental stages compared to IVF alone, and the addition of vitrification after TEBx results in more pronounced and potentially detrimental epigenetic effects: these changes are significantly different compared to Naturals. Finally, we observed that 12-week IVF + TEBx offspring, regardless of sex, showed higher glucose, insulin, triglycerides, lower total cholesterol, and lower high-density lipoprotein compared to IVF and Naturals, with only males having higher body weight compared to IVF and Naturals. Our findings in a mouse model additionally support the need for more studies to assess the impact of new procedures in ART to ensure healthy pregnancies and offspring outcomes.

LARGE SCALE DATA

Data reported in this work have been deposited in the NCBI Gene Expression Omnibus under accession number GSE225318.

LIMITATIONS, REASONS FOR CAUTION

This study was performed using a mouse model that mimics many clinical IVF procedures and outcomes observed in humans, where studies on early embryos are not possible.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the importance of assaying new procedures used in ART to assess their impact on placenta and embryo development, and offspring metabolic outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by a National Centers for Translational Research in Reproduction and Infertility grant P50 HD068157-06A1 (M.S.B., C.C., M.M.), Ruth L. Kirschstein National Service Award Individual Postdoctoral Fellowship F32 HD107914 (E.A.R.-C.) and F32 HD089623 (L.A.V.), and National Institutes of Health Training program in Cell and Molecular Biology T32 GM007229 (C.N.H.). No conflict of interest.

The Association between Placental Abruption and Platelet Indices

Objective: Placental abruption (PA) is an obstetric emergency. This study investigated the use of platelet indices in PA in its early stages to determine if it could aid in diagnosis. Materials and Methods: Sixty-two pregnant women with PA and 130 pregnant women who delivered due to idiopathic preterm delivery were included in this case-control study. Blood samples including platelet indices, biochemical, and coagulation parameters were obtained before cesarean section. Maternal and neonatal outcomes were recorded. Results: There was no significant difference between the groups as to hemoglobin, hematocrit, and white blood count. Platelet, mean platelet volume (MPV), and platelet to lymphocyte ratio (PLR) were significantly lower, platelet distribution width (PDW) was significantly higher in the PA patients. Conclusion: In the current study, MPV and PLR were lower and PDW was higher in PA patients. These parameters may be useful in assessment of PA.

The Association of Placental Abruption and Pediatric Neurological Outcome: A Systematic Review and Meta-Analysis

Placental histopathology provides insights, or "snapshots", into relevant antenatal factors that could elevate the risk of perinatal brain injury. We present a systematic review and meta-analysis comparing frequencies of adverse neurological outcomes in infants born to women with placental abruption versus without abruption. Records were sourced from MEDLINE, Embase, and the CENTRAL Trials Registry from 1946 to December 2019. Studies followed the PRISMA guidelines and compared frequencies of neurodevelopmental morbidities in infants born to pregnant women with placental abruption (exposure) versus women without placental abruption (comparator). The primary endpoint was cerebral palsy. Periventricular and intraventricular (both severe and any grades of IVH) and any histopathological neuronal damage were the secondary endpoints. Study methodologic quality was assessed by the Ottawa-Newcastle scale. Estimated odds ratios (OR) and hazards ratio (HR) were derived according to study design. Data were meta-analyzed using a random effects model expressed as pooled effect sizes and 95% confidence intervals. We included eight observational studies in the review, including 1245 infants born to women with placental abruption. Results of the random effects meta-analysis show that the odds of infants born to pregnant women with placental abruption who experience cerebral palsy is higher than in infants born to pregnant women without placental abruption (OR 5.71 95% CI (1.17, 27.91); I² = 84.0%). There is no statistical difference in the odds of infants born to pregnant women with placental abruption who experience severe IVH (grade 3+) (OR 1.20 95% CI (0.46, 3.11); I² = 35.8%) and any grade of IVH (OR 1.20 95% CI (0.62, 2.32); I² = 32.3%) vs. women without placental abruption. There is no statistically significant difference in the odds of infants born to pregnant women with placental abruption who experience PVL vs. pregnant women without placental abruption (OR 6.51 95% CI (0.94, 45.16); I² = 0.0%). Despite our meta-analysis suggesting increased odds of cerebral palsy in infants born to pregnant women with placental abruption versus without abruption, this finding should be interpreted cautiously, given high heterogeneity and overall poor quality of the included studies.

Prospective evaluation of placental abruption in nulliparous women

INTRODUCTION

Because most data on placental abruption are derived from retrospective studies, multiple sources of bias may have affected the results. Thus, we aimed to characterize risk factors and outcomes for placental abruption in a large prospective cohort of nulliparous women.

METHODS

This was a secondary analysis of women enrolled in the Nulliparous Pregnancy Outcomes Study Monitoring-to-be (nuMom2b) study, a prospective observational cohort. Participants were recruited in their first trimester of pregnancy from 8 sites and had 4 study visits, including at delivery. Placental abruption was defined by confirmed clinical criteria. The primary analysis was restricted to abruption identified antepartum and intrapartum. As a secondary analysis, we examined antepartum and intrapartum abruptions separately. We compared risk factors (maternal demographic and clinical characteristics) and outcomes in women with and without placental abruption using univariable and multivariable analyses as appropriate.

RESULTS

9450 women were included in the primary analysis. Abruption was identified in 0.66% (n = 62), of which 35 (56%) were antepartum and 27 (44%) intrapartum. For women with abruption, the mean gestational age at delivery was 35.6 ± 4.4 weeks and 38.8 ± 2.2 weeks for women without abruption. Gravidity was associated with abruption (OR 3.1, 95% CI: 1.6-6.0). In univariate analysis, abruption was associated with cesarean delivery (OR 3.7, 95% CI: 2.2-6.0), blood transfusion (OR 3.8, 95% CI: 1.4-10.7), PPROM (OR 9.0, 95% CI: 5.4-15.1), preterm birth (OR 8.5, 95% CI: 5.1-14.2), SGA (OR 4.0, 95% CI: 2.3-6.95), RDS (OR 5.5, 95% CI: 2.6-11.2), IVH 20.2 (OR 20.2, 95% CI: 5.9-68.8) and ROP (OR 12.2, 95% CI: 2.8-52.6). However, after adjustment for confounders including gestational age, abruption was only associated with increased odds of cesarean delivery and blood transfusion. Results were similar when restricted to antepartum and intrapartum abruptions.

CONCLUSION

Abruption was identified in <1% of nulliparous women. However, few maternal risk factors were identified. Neonatal morbidities were associated with an abruption and were primarily driven by gestational age due to preterm birth.

Understanding Etiologic Pathways Through Multiple Sequential Mediators: An Application in Perinatal Epidemiology

BACKGROUND

Causal mediation analysis facilitates decomposing the total effect into a direct effect and an indirect effect that operates through an intermediate variable. Recent developments in causal mediation analysis have clarified the process of evaluating how-and to what extent-different pathways via multiple causally ordered mediators link the exposure to the outcome.

METHODS

Through an application of natural effect models for multiple mediators, we show how placental abruption might affect perinatal mortality using small for gestational age (SGA) birth and preterm delivery as two sequential mediators. We describe methods to disentangle the total effect into the proportions mediated via each of the sequential mediators, when evaluating natural direct and natural indirect effects.

RESULTS

Under the assumption that SGA births causally precedes preterm delivery, an analysis of 16.7 million singleton pregnancies is consistent with the hypothesis that abruption exerts powerful effects on perinatal mortality (adjusted risk ratio = 11.9; 95% confidence interval = 11.6, 12.1). The proportions of the estimated total effect mediated through SGA birth and preterm delivery were 2% and 58%, respectively. The proportion unmediated via either SGA or preterm delivery was 41%.

CONCLUSIONS

Through an application of causal mediation analysis with sequential mediators, we uncovered new insights into the pathways along which abruption impacts perinatal mortality.

Placental abruption: assessing trends in risk factors over time

PURPOSE

To evaluate changes in the independent contribution of different risk factors for placental abruption over time.

METHODS

In this retrospective nested case-control study, trends of change in ORs for known risk factors for placental abruption occurring in three consecutive 8-year intervals were compared. A univariate assessment of factors associated with placental abruption and two multivariable logistic regression models were constructed to identify independent risk factors for placental abruption. Trends of change in the incidence and specific contribution of various risk factors were compared along the study time-period.

RESULTS

During the study period, 295,946 pregnancies met the inclusion criteria; of these, 2170 (0.73%) were complicated with placental abruption. Using logistic regression models, previous cesarean delivery, in vitro fertilization (IVF) pregnancy, hypertensive disorders, polyhydramnios, and inadequate prenatal care were recognized as independent risk factors for placental abruption. While the relative contribution of IVF pregnancy and polyhydramnios to the overall risk for abruption decreased over the course of the study, previous cesarean delivery became a stronger contributor for placental abruption.

CONCLUSION

In our study, a change over time in the specific contribution of different risk factors for placental abruption has been demonstrated.

Epidemiology, Risk Factors, and Perinatal Outcomes of Placental Abruption-Detailed Annual Data and Clinical Perspectives from Polish Tertiary Center

Placental abruption (PA) is a separation of the placenta from the uterine wall occurring with the fetus still present in the uterine cavity. It contributes to numerous neonatal and maternal complications, increasing morbidity and mortality. We conducted a retrospective study at a tertiary perinatal care center, which included 2210 cases of labor that took place in 2015 with a PA occurrence of 0.7%. No maternal or fetal death during delivery was reported in this period. The identified PA risk factors were uterine malformations, pPROM, placenta previa spectrum, and oligohydramnios. The significant maternal PA complications identified were maternal anemia, uterine rupture, and HELLP syndrome. Preterm delivery occurred significantly more often in the PA group, and the number of weeks of pregnancy and the birth weight at delivery were both significantly lower in the PA group. PA is a relatively rare perinatal complication with very serious consequences, and it still lacks effective prophylaxis and treatment. Despite its rare occurrence, each center should develop a certain strategy for dealing with this pathology or predicting which patients are at risk. Much work is still needed to ensure the proper care of the mother and the baby in this life-threatening condition.

The environmental risk factors prior to conception associated with placental abruption: an umbrella review

BACKGROUND

The present umbrella review evaluated risk factors prior to conception associated with placental abruption based on meta-analyses and systematic reviews.

METHODS

We searched PubMed, Scopus, and Web of Science until June 25, 2021. All meta-analyses that had focused on assessing the risk factors associated with placental abruption were included. We calculated summary effect estimates, 95% CI, heterogeneity I², 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2).

RESULTS

There was no risk factor in the present umbrella review with the high level of evidence (class I or II). Eight risk factors including maternal asthma (RR 1.29 95% CI 1.14, 1.47), prior cesarean section (RR 1.38, 95% CI 1.35-1.42), cocaine using (RR 4.55, 95% CI 1.78-6.50), endometriosis (OR 1.40, 95% CI 1.12-1.76), chronic hypertension (OR 3.13, 95% CI 2.04-4.80), advanced maternal age (OR 1.44, 95% CI 1.35-1.54), maternal smoking (OR 1.80, 95% CI 1.75-1.85) (RR 1.65, 95% CI 1.51-1.80), and use of assisted reproductive techniques (ART) (OR 1.87, 95% CI 1.70-2.06) were graded as suggestive evidence (class III). The other four risk factors including pre-pregnancy underweight (OR 1.38, 95% CI 1.12-1.70), preeclampsia (OR 1.73, 95% CI 1.47-2.04), uterine leiomyoma (OR 2.63, 95% CI 1.38-3.88), and marijuana use (OR 1.78, 95% CI 1.32-2.40) were graded as risk factors with weak evidence (class IV).

CONCLUSION

Maternal asthma, prior cesarean section, cocaine use, endometriosis, chronic hypertension, advanced maternal age, maternal smoking, and use of ART, pre-pregnancy underweight, preeclampsia, uterine leiomyoma, and marijuana use were risk factors associated with placental abruption. Although factors associated with placental abruption have been investigated, the current meta-analytic associations cannot disentangle the complex etiology of placental abruption mainly due to their low quality of evidence.

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.

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..

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.

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.

Neonatal delivery room CPR: An analysis of the Get with the Guidelines®-Resuscitation Registry

BACKGROUND

Cardiopulmonary resuscitation (CPR) in the delivery room (DR) after birth is rare. We hypothesized that factors related to maternal, delivery, infant and resuscitation event characteristics associated with outcomes could be identified. We also hypothesized there would be substantial variation from the Neonatal Resuscitation Program (NRP) algorithm.

METHODS

Retrospective review of all neonates receiving chest compressions in the DR from the AHA Get With The Guidelines-Resuscitation registry from 2001 to 2014. The primary outcome was return of spontaneous circulation (ROSC) in the DR. Secondary outcome was survival to hospital discharge. Descriptive statistics were used to characterize data. Odds ratios with confidence intervals were calculated as appropriate to compare survivors and non-survivors.

RESULTS

There were 1153 neonates who received chest compressions in the DR. ROSC was achieved in 968 (84%) newborns and 761 (66%) survived to hospital discharge. Fifty-one percent of the cohort received chest compressions without medications. Cardiac compressions were initiated within the first minute of life in 76% of the events, and prior to endotracheal intubation in 79% of the events. In univariate analysis, factors such as prematurity, number of endotracheal intubation attempts, increased time to first adrenaline dose, and CPR duration were associated with decreased odds of ROSC in the DR. Longer CPR duration was associated with decreased odds of ROSC in multivariate analysis.

CONCLUSION

In this cohort of infants receiving chest compressions following delivery, recognizable pre-birth risk factors as well as resuscitation interventions associated with increased and decreased odds of achieving ROSC were identified. Chest compressions were frequently initiated in the first minute of the event and often prior to endotracheal intubation. Further investigations should focus on methods to decrease time to critical resuscitation interventions, such as successful endotracheal intubation and administration of the first dose of adrenaline, in order to improve DR-CPR outcomes.

Does macroscopic estimation of the extent of placental abruption correlate with pregnancy outcomes?

INTRODUCTION

We aimed to study the correlation between the extent of placental abruption (PA), as grossly estimated immediately after delivery, and pregnancy outcomes, in correlation with placental histopathology.

MATERIALS AND METHODS

Pregnancy and placental reports of all pregnancies complicated by PA (clinically diagnosed) between 11/2008-12/2018 were reviewed. We compared maternal background, pregnancy outcomes, and placental histopathology between cases of PA divided into three groups according to the extent of abruption: Group 1-<30 %, Group 2-30-49 %, and Group 3->50 % of placental surface. Placental lesions were classified according to the current "Amsterdam" criteria. The primary outcome was defined as a composite of severe neonatal morbidity and included ≥ 1 of the following complications: seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, periventricular leukomalacia, blood transfusion, necrotizing enterocolitis, intrauterine fetal demise, or neonatal death.

RESULTS

A total of 260 PA cases were included: 111 (42.7 %) in Group 1, 94 (36.2 %) in Group 2, and 55 (21.1 %) in Group 3. The rate of the primary outcome (7.2 % vs. 11.7 % vs. 27.3 %, p = 0.02) was associated with the degree of PA as well as maternal heavy smoking (p = 0.04), DIC (p = 0.03), umbilical artery Ph <7.1 (p = 0.02), 5-minute Apgar scores <7 (p = 0.03), NICU admissions, placental maternal vascular malperfusion lesions (p = 0.04), and neonatal weights <5th percentile (0.04). In multivariable analysis severe adverse neonatal outcome was independently associated with the percentage of PA (aOR = 1.4, 95 % CI = 1.3-3.9).

CONCLUSION

The extent of placental abruption, as estimated by the examiner, correlated with DIC and severe neonatal outcomes and may serve as an early alarming sign in deliveries complicated by PA.

The Underlying Causes of Respiratory Distress in Late-Preterm and Full-Term Infants Are Different From Those of Early-Preterm Infants

Background: A diagnosis of neonatal respiratory distress syndrome (RDS) is common among newborns in China. Some late-preterm and full-term (LP/FT) infants with respiratory distress (RD) symptoms but not primary surfactant deficiency are also diagnosed with RDS and given exogenous surfactant replacement therapy (SRT). Objectives: An increasing number of neonatologists have proposed that RD etiologies should be specifically classified to guide clinical treatment. Methods: The therapeutic effects of SRT on infants of different gestational ages (GAs) were compared in a large retrospective multicenter cohort study performed at 26 Neonatal Intensive Care units in China. The cause of RD at different GAs was further analyzed by comparing the different risk factors closely related to RDS severity at different GAs. Results: Analysis of 1240 infants diagnosed with RDS showed that SRT was less effective in LP/FT infants than in early-preterm (EP) infants. GA < 30 weeks and no prenatal corticosteroid use were closely related to RDS severity in EP infants, whereas perinatal infection- and perinatal hypoxia-associated risk factors and a high cesarean rate were closely related to RDS severity in LP/FT infants. Conclusions: The causes of RD might differ between LP/FT and EP infants, and the diagnosis of RDS might be overused in LP/FT infants. RD in LP/FT infants is more likely related to perinatal infection, perinatal hypoxia, elective cesarean and hereditary factors, which are important causes of neonatal pulmonary edema. New strategies for the treatment of refractory RD in LP/FT infants should concentrate more on pulmonary edema and neonatal ARDS.

Systematic review with meta-analysis: risk of adverse pregnancy-related outcomes in inflammatory bowel disease

BACKGROUND

The effect of inflammatory bowel disease (IBD) on pregnancy-related outcomes remains unknown.

AIM

To determine the risk of adverse maternal, placental and obstetric outcomes in IBD METHODS: We searched Medline, Embase and Cochrane library through May 2019 for studies reporting adverse maternal, placental and obstetric outcomes in patients with IBD. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for these outcomes in patients with IBD compared to healthy controls.

RESULTS

Fifty-three studies were included (7917 IBD pregnancies and 3253 healthy control pregnancies). Caesarean delivery was more common in patients with IBD compared to healthy controls (OR 1.79, 95% CI, 1.16-2.77). This remained significant for UC (OR 1.80, 95% CI, 1.21-2.90) but not CD (OR 1.48, 95% CI, 0.94-2.34). Similarly, gestational diabetes occurred more commonly in IBD (OR 2.96, 95% CI, 1.47-5.98). The incidences of placental diseases were 2.0% (95% CI, 0.9%-3.1%) for pre-eclampsia, 3.3% (95% CI, 0%-7.2%) for placental abruption, 0.5% (95% CI, 0.2%-0.9%) for placenta previa and 0.3% (95% CI, 0%-0.5%) for chorioamnionitis. Patients with IBD were more likely to experience preterm prelabour rupture of membranes (OR 12.10, 95% CI, 2.15-67.98), but not early pregnancy loss (OR 1.63, 95% CI 0.49-5.43). Anti-tumour necrosis factor therapy was not associated with chorioamnionitis (OR 1.12, 95% CI, 0.16-7.67), early pregnancy loss (OR 1.49, 95% CI, 0.83-2.64) or placenta previa (OR 1.58, 95% CI, 0.30-8.47).

CONCLUSIONS

Gestational diabetes and preterm prelabour rupture of membranes occurs more commonly in patients with IBD, although the incidence of placental diseases remains low.

The Impact of Severe Maternal Morbidity on Very Preterm Infant Outcomes

OBJECTIVE

To estimate the prevalence of severe maternal morbidity among very preterm births and determine its association with very preterm infant mortality and morbidity.

STUDY DESIGN

This study used New York City Vital Statistics birth and death records linked with maternal and newborn discharge abstract data for live births between 2010 and 2014. We included 6901 infants without congenital anomalies born between 24^0/7 and 32^6/7 weeks of gestation. Severe maternal morbidity was identified as life-threatening conditions or life-saving procedures. Outcomes were first-year infant mortality, severe neonatal morbidity (bronchopulmonary dysplasia, severe necrotizing enterocolitis, stage 3-5 retinopathy of prematurity, and intraventricular hemorrhage grades 3-4), and a combined outcome of death or morbidity.

RESULTS

Twelve percent of very preterm live-born infants had a mother with severe maternal morbidity. Maternal and pregnancy characteristics associated with occurrence of severe maternal morbidity were multiparity, being non-Hispanic black, and preexisting health conditions, but gestational age and the percentage small for gestational age did not differ. Infants whose mothers experienced severe maternal morbidity had higher first-year mortality, 11.2% vs 7.7% without severe maternal morbidity, yielding a relative risk of 1.39 (95% CI: 1.14-1.70) after adjustment for maternal characteristics, preexisting comorbidities, pregnancy complications, and hospital factors. Severe neonatal morbidity was not associated with severe maternal morbidity.

CONCLUSIONS

Severe maternal morbidity is an independent risk factor for mortality in the first year of life among very preterm infants after consideration of other maternal and pregnancy risk factors.

Associations of systolic blood pressure trajectories during pregnancy and risk of adverse perinatal outcomes

This study aimed to explore the association of systolic blood pressure (SBP) trajectories of pregnant women with the risk of adverse outcomes of pregnant women and their fetuses. A register-based cohort of 63,724 pregnant women and their fetuses from January 2013 to December 2017 was investigated. Demographic characteristics, history of disease and family history of disease for pregnant women and perinatal outcomes were recorded, and blood pressure was measured during the whole pregnancy. SBP trajectories were estimated with latent mixture modeling by Proc Traj in SAS using SBP data from the first antenatal care appointment (8-14 weeks), the highest SBP before admission, the admission SBP and the SBP at 2 h postpartum. A censored normal model (CNORM) was considered appropriate, and model fit was assessed using the Bayesian information criterion (BIC). A logistic regression model was used to examine the association between SBP trajectories and the risk of adverse perinatal outcomes. Four distinct SBP trajectory patterns over the pregnancy period were identified and were labeled as low-stable, moderate-stable, high-decreasing and moderate-increasing. Three maternal and three fetal adverse outcomes were selected as the main outcome measures. After adjusting for confounding factors, compared with pregnant women with the low-stable pattern, those with the high-decreasing pattern had a higher risk of developing poor growth outcomes of fetuses, while those with the moderate-increasing pattern had higher risks of developing both adverse maternal and fetal outcomes. Our study results suggest that pregnant women should pay attention to the control of blood pressure throughout pregnancy.

Exposure to Asian dust within a few days of delivery is associated with placental abruption in Japan: a case-crossover study

OBJECTIVE

Asian dust is a natural phenomenon in which dust particles are transported from desert areas in China and Mongolia to East Asia. Short-term exposure to Asian dust has been associated with cardiovascular disease through mechanisms such as systemic inflammation. Because inflammation is a potential trigger of placental abruption, exposure may also lead to abruption. We examined whether exposure to Asian dust was associated with abruption.

DESIGN

A bi-directional, time-stratified case-crossover design.

SETTING AND POPULATION

From the Japan Perinatal Registry Network database, we identified 3014 patients who delivered singleton births in hospitals in nine Japanese prefectures from 2009 to 2014 with a diagnosis of placental abruption.

METHODS

Asian dust levels were measured at Light Detection and Ranging monitoring stations, and these measurements were used to define the Asian dust days. As there was no information on the onset day of abruption, we assumed this day was the day before delivery (lag1).

MAIN OUTCOME MEASURES

Placental abruption.

RESULTS

During the study period, the Asian dust days ranged from 15 to 71 days, depending on the prefecture. The adjusted odds ratio of placental abruption associated with exposure to Asian dust was 1.4 (95% confidence interval = 1.0, 2.0) for cumulative lags of 1-2 days. Even after adjustment for co-pollutant exposures, this association did not change substantially.

CONCLUSIONS

In this Japanese multi-area study, exposure to Asian dust was associated with an increased risk of placental abruption.

TWEETABLE ABSTRACT

Exposure to environmental factors such as Asian dust may be a trigger of placental abruption.

Temperature, placental abruption and stillbirth

BACKGROUND

Pregnant women may be vulnerable to changes in ambient temperature and warming climates. Recent evidence suggests that temperature increases are associated with placental abruption, a risk factor for stillbirth.

OBJECTIVES

We investigated the effect of acute exposures to apparent temperature on stillbirths in Harris County, Texas, 2008-2013.

METHODS

We conducted a case-crossover study to investigate the association between temperature and stillbirth among 708 women. We used data from the National Climatic Data Center to estimate maternal exposure to daily average apparent temperature over the days (lag days 1 through 6) preceding the stillbirth event. We employed symmetric bidirectional sampling to select six control periods one to three weeks before and after each event and applied conditional logistic regression to examine associations between increases of apparent temperature and stillbirths during the warm season (May-September). We adjusted for fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) and used stratified analysis to examine differences in risk by maternal race/ethnicity. We also examined the association among stillbirths with and without placental abruptions.

RESULTS

Independent of air pollutant exposures, a 10 °F increase in apparent temperature in the week preceding delivery (lag days 1 to 6) was positively associated with a 45% (adjusted OR = 1.45, 95% confidence interval (CI): 1.18, 1.77) increase in risk for stillbirth. Risks were elevated for stillbirths occurring in June through August, for Hispanic and non-Hispanic Black women, but not for non-Hispanic Whites. We also observed elevated risks associated with temperature increases in the few days preceding delivery among stillbirths caused by placental abruption, with the risk being highest on lag day 1 (OR = 1.93, 95% CI: 1.15, 3.23).

CONCLUSIONS

Independent of maternal ambient air pollutant exposure, we found evidence of an association between apparent temperature increases in the week preceding an event and risk of stillbirth. Risks for stillbirth varied by race/ethnicity. Further, in the first study to evaluate the impact of temperature on a specific complication during pregnancy, the risks were higher among mothers with placental abruption.

The impact of pre-pregnancy body mass index and gestational weight gain on placental abruption risk: a systematic review and meta-analysis

PURPOSE

The aim of this systematic review was to evaluate the associations between pre-pregnancy body mass index and gestational weight gain and placental abruption.

METHODS

Relevant studies were identified from PubMed, EMBASE, Scopus and CINAHL. Unpublished findings from analyses of linked population-based data sets from Western Australia (2012-2015, n = 114,792) were also included. Studies evaluating pre-pregnancy body mass index and/or gestational weight gain and placental abruption were included. Two independent reviewers evaluated studies for inclusion and quality. Data including odds ratios (ORs) and 95% confidence intervals (CIs) were extracted and analysed by random effects meta-analysis.

RESULTS

21 studies were included, of which 15 were eligible for meta-analyses. The summary ORs for the association of being underweight, overweight and obese, and placental abruption, compared to normal weight women, were 1.4 (95% CI 1.1, 1.7), 0.8 (95% CI 0.8, 0.9) and 0.8 (95% CI 0.7, 0.9), respectively. These findings remained unchanged when each study was eliminated from the analysis and in subgroup analyses. Although data were scarce, women with gestational weight gain below the Institute of Medicine recommendations appeared to be at greater risk of abruption compared with women who had optimal weight gain.

CONCLUSIONS

Mothers that are underweight prior to or in early pregnancy are at a moderately increased risk of placental abruption.

Cumulative Antenatal Risk and Kindergarten Readiness in Preterm-Born Preschoolers

A suboptimal intrauterine environment is thought to increase the probability of deviation from the typical neurodevelopmental trajectory, potentially contributing to the etiology of learning disorders. Yet the cumulative influence of individual antenatal risk factors on emergent learning skills has not been sufficiently examined. We sought to determine whether antenatal complications, in aggregate, are a source of variability in preschoolers’ kindergarten readiness, and whether specific classes of antenatal risk play a prominent role. We recruited 160 preschoolers (85 girls; ages 3–4 years), born ≤33⁶/₇ weeks’ gestation, and reviewed their hospitalization records. Kindergarten readiness skills were assessed with standardized intellectual, oral-language, prewriting, and prenumeracy tasks. Cumulative antenatal risk was operationalized as the sum of complications identified out of nine common risks. These were also grouped into four classes in follow-up analyses: complications associated with intra-amniotic infection, placental insufficiency, endocrine dysfunction, and uteroplacental bleeding. Linear mixed model analyses, adjusting for sociodemographic and medical background characteristics (socioeconomic status, sex, gestational age, and sum of perinatal complications) revealed an inverse relationship between the sum of antenatal complications and performance in three domains: intelligence, language, and prenumeracy (p = 0.003, 0.002, 0.005, respectively). Each of the four classes of antenatal risk accounted for little variance, yet together they explained 10.5%, 9.8%, and 8.4% of the variance in the cognitive, literacy, and numeracy readiness domains, respectively. We conclude that an increase in the co-occurrence of antenatal complications is moderately linked to poorer kindergarten readiness skills even after statistical adjustment for perinatal risk.

Exposures to Air Pollution and Risk of Acute-onset Placental Abruption: A Case-crossover Study

BACKGROUND

Despite abruption's elusive etiology, knowledge of triggers that precede it by just a few days prior to delivery may help to understand the underpinnings of this acute obstetrical complication. We examine whether air pollution exposures immediately preceding delivery are associated with acute-onset abruptions.

METHODS

We applied a bidirectional, time-stratified, case-crossover design to births with an abruption diagnosis in New York City, 2008-2014. We measured ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2). We fit distributed lag nonlinear models based on conditional logistic regression to evaluate individual exposure and cumulative exposures over lags 0-7 days before abruption, adjusted for temperature and relative humidity (similar lags to the main exposures).

RESULTS

We identified 1,190 abruption cases. We observed increased odds of abruption for exposure to PM2.5 (per 10 μg/m) on lag day 3 (odds ratio [OR] 1.19, 95% confidence interval [CI] = 0.98, 1.43), lag day 4 (OR 1.21, 95% CI = 1.01, 1.46), and lag day 5 (OR 1.17, 95% CI = 1.03, 1.33). Similarly, the odds of abruption increased with exposure to NO2 (per 5 ppb) on lag day 3 (OR 1.16, 95% CI = 0.98, 1.37), lag day 4 (OR 1.19, 95% CI = 1.02, 1.39), and lag day 5 (OR 1.16, 95% CI = 1.05, 1.27). Exposures to PM2.5 and NO2 at other lags, or cumulative exposures, were not associated with abruption of acute onset.

CONCLUSIONS

This case-crossover study showed evidence of an association between short-term ambient air pollution exposures and increased abruption risk of acute onset.

"Doing something" about the cesarean delivery rate

There is a general consensus that the cesarean delivery rate in the United States is too high, and that practice patterns of obstetricians are largely to blame for this situation. In reality, the US cesarean delivery rate is the result of 3 forces largely beyond the control of the practicing clinician: patient expectations and misconceptions regarding the safety of labor, the medical-legal system, and limitations in technology. Efforts to "do something" about the cesarean delivery rate by promulgating practice directives that are marginally evidence-based or influenced by social pressures are both ineffective and potentially harmful. We examine both the recent American Congress of Obstetricians and Gynecologists (ACOG)/Society for Maternal-Fetal Medicine Care Consensus Statement "Safe Prevention of Primary Cesarean Delivery" document and the various iterations of the ACOG guidelines for vaginal birth after cesarean delivery in this context. Adherence to arbitrary time limits for active phase or second-stage arrest without incorporating other clinical factors into the decision-making process is unwise. In a similar manner, ever-changing practice standards for vaginal birth after cesarean driven by factors other than changing data are unlikely to be effective in lowering the cesarean delivery rate. Whether too high or too low, the current US cesarean delivery rate is the expected result of the unique demographic, geographic, and social forces driving it and is unlikely to change significantly given the limitations of current technology to otherwise satisfy the demands of these forces.

Placental Abruption and Child Mortality

BACKGROUND AND OBJECTIVES

Placental abruption causes asphyxia and leads to high perinatal mortality. Our objective was to study the overall mortality and causes of death among children born after placental abruption.

METHODS

Data on children born from singleton pregnancies complicated by placental abruption between 1987 and 2005 were collected from the Finnish Medical Birth Register, the Hospital Discharge Register, and the Cause-of-Death Register. A reference group consisted of children born from pregnancies without placental abruption. After excluding stillbirths, the final study sample comprised 3888 children born after placental abruption (index children) and 12 530 referent children. The main outcome measure was overall mortality.

RESULTS

By the end of 2013, there were 280 deaths among the index children and 107 deaths among the referent children. Compared with the referent children, the overall mortality among the index children was significantly increased (hazard ratio: 8.70; 95% confidence interval 6.96-10.90). During the neonatal period (0-27 days) the mortality was nearly 15-fold (14.8; 10.9-20.0), birth-related asphyxia being the leading cause of death (108; 34-341). The mortality remained high during days 28 to 365 (10.3; 4.83-21.8) and beyond 365 days (1.70; 1.03-2.79). Furthermore, the overall mortality was increased among the index children born at 32 to 36 + 6 gestational weeks (2.77; 1.54-4.98) and at ≥37 weeks (4.98; 3.54-6.99) and among children with a birth weight of 2500 g or more (5.94; 4.33-8.14).

CONCLUSIONS

The impact of abruption on offspring mortality extends far beyond the perinatal period. This is mainly due to birth-related asphyxia and prematurity-related consequences.

Increased incidence of respiratory distress syndrome in neonates of mothers with abnormally invasive placentation

BACKGROUND

The incidence of abnormally invasive placentation (AIP) is increasing. Most of these pregnancies are delivered preterm. We sought to characterize neonatal outcomes in AIP pregnancies.

METHODS

In this retrospective case-control study (2006-2015), AIP neonates (n = 108) were matched to two controls each for gestational age, antenatal glucocorticoid exposure, sex, plurity, and delivery mode. Medical records were reviewed for neonatal and maternal characteristics/outcomes. Univariate and multivariate Poisson regressions were performed to determine relative risk ratios (RR).

RESULTS

There were no mortalities. All neonatal outcomes were similar except for respiratory distress syndrome (RDS), which affected 37% of AIP neonates (versus 21% of controls). AIP neonates required respiratory support (64.8% vs. 51.9%) and continuous positive airway pressure (53.7% vs. 42.1%) for a longer duration. Univariate regression yielded elevated RRs for RDS for AIP (RR 1.78, 95% CI 1.24-2.54), placenta previa (RR = 1.94, 95% CI 1.36-2.76), and placenta previa with bleeding (RR 2.29, 95% CI 1.36-3.86). One episode of bleeding had a RR of 2.43 (95% CI 1.57-3.76), 2 or more episodes had a RR of 2.95 (95% CI 1.96-4.44), and bleeding/abruption as the delivery indication had a RR of 2.57 (95% CI 1.82-3.64). A multivariate regression stratifying for AIP and evaluating the combined and individual associations of AIP, bleeding, placenta previa, and GA, resulted in elevated RRs for placenta previa alone (RR 2.16, 95% CI 1.15-4.06) and placenta previa and bleeding (RR 1.69, 95% CI 1.001-2.85).

CONCLUSIONS

The increased incidence of RDS at later gestational ages in AIP is driven by placenta previa. AIP neonates required respiratory support for a longer duration than age-matched controls. Providers should be prepared to counsel expectant parents and care for affected neonates.