Understanding the Pathways from Prenatal and Post-Birth PM2.5 Exposure to Infant Death: An Observational Analysis Using US Vital Records (2011–2013)

We studied the relationship of prenatal and post-birth exposure to particulate matter < 2.5 μm in diameter (PM2.5) with infant mortality for all births between 2011 and 2013 in the conterminous United States. Prenatal exposure was defined separately for each trimester, post-birth exposure was defined in the 12 months following the prenatal period, and infant mortality was defined as death in the first year of life. For the analysis, we merged over 10 million cohort-linked live birth–infant death records with daily, county-level PM2.5 concentration data and then fit a Structural Equation Model controlling for several individual- and county-level confounders. We estimated direct paths from the two exposures to infant death as well as indirect paths from the prenatal exposure to the outcome through preterm birth and low birth weight. Prenatal PM2.5 exposure was positively associated with infant death across all trimesters, although the relationship was strongest in the third trimester. The direct pathway from the prenatal exposure to the outcome accounted for most of this association. Estimates for the post-birth PM2.5–infant death relationship were less precise. The results from our study add to a growing literature that provides evidence in favor of the potential harmful effects on human health of low levels of air pollution.

Risk of Adverse Fetal Outcomes Following Nonobstetric Surgery During Gestation: A Nationwide Population-Based Analysis

Background: Literature suggests that nonobstetric surgery during gestation is associated with a higher risk of spontaneous abortion, prematurity, and a higher cesarean section rate, but the direct impact on fetal outcomes is still unclear. In this study, we aimed to investigate whether nonobstetric surgery during pregnancy is associated with negative fetal outcomes by analysing a nation-wide database in Taiwan.Methods: This population-based retrospective observational study was based on the linkage of Taiwan’s National Health Insurance Research Database, Birth Reporting Database, and Maternal and Child Health Database between 2004 and 2014. For every pregnancy with nonobstetric surgery during gestation, four controls were randomly matched according to maternal age and delivery year. We estimated adjusted odds ratios (aOR) and 95% confidence intervals (CIs) of adverse fetal outcomes with the non-surgery group as the reference. The primary outcomes involved stillbirth, prematurity, low birth weight, low Apgar scores, and neonatal and infant death.Results: Among 23,721 identified pregnancies, 4,747 underwent nonobstetric surgery. Pregnancies with nonobstetric surgery had significantly higher risks of prematurity (aOR: 1.46; 95% CI: 1.31–1.62), lower birth weight (aOR: 1.49; 95% CI: 1.33–1.67), Apgar scores <7 (1 min, aOR: 1.58; 95% CI: 1.33–1.86; 5 min, aOR: 1.34; 95% CI: 1.03–1.74), neonatal death (aOR: 2.01; 95% CI: 1.18–3.42), and infant death (aOR: 1.69; 95% CI: 1.12–2.54) than those without nonobstetric surgery after adjustment for socioeconomic deprivation, hospital level, and other comorbidities. Surgery performed in the third trimester was associated with a significantly increased rate of prematurity (aOR: 1.38; 95% CI: 1.03–1.85), but lower rates of stillbirth (aOR: 0.1; 95% CI: 0.01–0.75) and Apgar score <7 at the 5th minute (aOR: 0.2; 95% CI: 0.05–0.82), than surgery performed in the first trimester.Conclusions: Pregnancies with nonobstetric surgery during gestation were associated with increased risks of prematurity, low birth weight, low Apgar scores, neonatal and infant death, longer admission, and higher medical expenses than those without surgery. Furthermore, surgery in the third trimester was associated with a higher rate of prematurity than surgery performed in the first trimester.Trial registration: Not applicable

Medullary Serotonergic Binding Deficits and Hippocampal Abnormalities in Sudden Infant Death Syndrome: One or Two Entities?

Sudden infant death syndrome (SIDS) is understood as a syndrome that presents with the common phenotype of sudden death but involves heterogenous biological causes. Many pathological findings have been consistently reported in SIDS, notably in areas of the brain known to play a role in autonomic control and arousal. Our laboratory has reported abnormalities in SIDS cases in medullary serotonin (5-HT) receptor 1A and within the dentate gyrus of the hippocampus. Unknown, however, is whether the medullary and hippocampal abnormalities coexist in the same SIDS cases, supporting a biological relationship of one abnormality with the other. In this study, we begin with an analysis of medullary 5-HT1A binding, as determined by receptor ligand autoradiography, in a combined cohort of published and unpublished SIDS (n = 86) and control (n = 22) cases. We report 5-HT1A binding abnormalities consistent with previously reported data, including lower age-adjusted mean binding in SIDS and age vs. diagnosis interactions. Utilizing this combined cohort of cases, we identified 41 SIDS cases with overlapping medullary 5-HT1A binding data and hippocampal assessment and statistically addressed the relationship between abnormalities at each site. Within this SIDS analytic cohort, we defined abnormal (low) medullary 5-HT1A binding as within the lowest quartile of binding adjusted for age and we examined three specific hippocampal findings previously identified as significantly more prevalent in SIDS compared to controls (granular cell bilamination, clusters of immature cells in the subgranular layer, and single ectopic cells in the molecular layer of the dentate gyrus). Our data did not find a strong statistical relationship between low medullary 5-HT1A binding and the presence of any of the hippocampal abnormalities examined. It did, however, identify a subset of SIDS (~25%) with both low medullary 5-HT1A binding and hippocampal abnormalities. The subset of SIDS cases with both low medullary 5-HT1A binding and single ectopic cells in the molecular layer was associated with prenatal smoking (p = 0.02), suggesting a role for the exposure in development of the two abnormalities. Overall, our data present novel information on the relationship between neuropathogical abnormalities in SIDS and support the heterogenous nature and overall complexity of SIDS pathogenesis.

Impact of Neonatal Outcome on Language Used to Describe Periviable Birth Experience

Motivation and Purpose: The experience of giving birth to a periviable neonate between 22-25 weeks gestation varies greatly among women depending on numerous factors. Studying periviable narrative experiences will allow us to isolate those factors that create a more positive experience, even in the instance of a negative neonatal outcome (infant death). Results may be used to advise future caregiving approaches so they may be tailored to the needs of women in these situations. This study aimed to qualitatively assess the extent of the relationship between neonatal outcome and the language used by women and their important others (IOs) to describe periviable birth experience three months postpartum. Method: A semi-structured interview guide was used to investigate participants’ perceptions of their delivery experience and subsequent NICU experience, if applicable, at three months postpartum. Interviews were transcribed verbatim and coded for themes by three investigators. Conventional content analysis was conducted using NVivo 12. Results: Twenty-three women and twelve IOs were recruited at two hospitals between 2016 and 2018. Women and IOs who experienced infant death negatively described their delivery experience if they also negatively described healthcare team (HCT) interactions, including providers’ communication, clinical judgement, and personality traits. Specifically, participants with overall negative birth experiences described not understanding various clinical decisions and felt uninformed on topics pertinent to their or their infant’s care. Alternatively, women and IOs who experienced infant death who positively described their delivery experience also positively described NICU care (including HCT interactions) and infant death experience (comfort care). These results highlight the impact of HCT interactions and communication on a patient’s perception of delivery despite a negative neonatal outcome. Conclusion: These findings could suggest that improvements in communication and information dissemination from the HCT may have the ability to improve a patient’s periviable birth experience despite a negative neonatal outcome.