Does influenza vaccination improve pregnancy outcome? Methodological issues and research needs

AbstractEvidence that influenza vaccination during pregnancy is safe and effective at preventing influenza disease in women and their children through the first months of life is increasing. Several reports of reduced risk of adverse outcomes associated with influenza vaccination have generated interest in its potential for improving pregnancy outcome. Gavi, the Vaccine Alliance, estimates maternal influenza immunization programs in low-income countries would have a relatively modest impact on mortality compared to other new or under-utilized vaccines, however the impact would be substantially greater if reported vaccine effects on improved pregnancy outcomes were accurate. Here, we examine the available evidence and methodological issues bearing on the relationship between influenza vaccination and pregnancy outcome, particularly preterm birth and fetal growth restriction, and summarize research needs. Evidence for absence of harm associated with vaccination at a point in time is not symmetric with evidence of benefit, given the scenario in which vaccination reduces risk of influenza disease and, in turn, risk of adverse pregnancy outcome. The empirical evidence for vaccination preventing influenza in pregnant women is strong, but the evidence that influenza itself causes adverse pregnancy outcomes is inconsistent and limited in quality. Studies of vaccination and pregnancy outcome have produced mixed evidence of potential benefit but are limited in terms of influenza disease assessment and control of confounding, and their analytic methods often fail to fully address the longitudinal nature of pregnancy and influenza prevalence. We recommend making full use of results of randomized trials, re-analysis of existing observational studies to account for confounding and time-related factors, and quantitative assessment of the potential benefits of vaccination in improving pregnancy outcome, all of which should be informed by the collective engagement of experts in influenza, vaccines, and perinatal health

The speaking vocabulary of grade two

Thesis (M.A.)--Boston Universit

Maternal ethnicity and pre-eclampsia in New York City, 1995-2003: Pre-eclampsia and maternal ethnicity

Studies on ethnic differences in risk of preeclampsia are limited. We linked birth records for 902,460 singleton births for the period 1995–2003 in New York City with hospital discharge data to evaluate the association between ethnicity and the risk of preeclampsia and compare risks between US-born and foreign-born women. Logistic regression models adjusted for maternal age, maternal education, parity, self-reported prepregnancy maternal weight, smoking during pregnancy, and year of delivery, were used to estimate the adjusted odds ratios of preeclampsia and 95% confidence intervals, comparing each ethnic group to non-Hispanic white women. The prevalence of preeclampsia in this study population was 3.2%. Among the major ethnic groups considered in our study, East Asian women had the lowest risk of preeclampsia (1.4%) and Mexican women had the highest risk (5.0%). Compared to non-Hispanic white women, there was a slightly decreased risk for East Asian women (adjusted OR=0.8, 95% CI [0.7, 0.8]), similar risk for North African women (adjusted OR=1.1, 95% CI [0.9, 1.3]), and increased risk for all other major ethnic groups (adjusted ORs: 1.3–2.9), with the highest risk for Mexican women (adjusted OR=2.9, 95% CI [2.7, 3.1]). No difference in risks was observed for US versus foreign born women with the exception that foreign-born South-East Asian and Pacific Islanders had increased risk of preeclampsia (adjusted OR=1.8, 95% CI [1.0, 3.1]) relative to those born in the US. We concluded that there was ethnic heterogeneity in the development of preeclampsia among women in New York City and Asian subgroups should be examined separately in future studies on ethnicity. Our results should contribute to screening for preeclampsia taking ethnic variation into account and may help to suggest leads for study of etiology

Temporal variability of daily personal magnetic field exposure metrics in pregnant women

Recent epidemiology studies of power-frequency magnetic fields and reproductive health have characterized exposures using data collected from personal exposure monitors over a single day, possibly resulting in exposure misclassification due to temporal variability in daily personal magnetic field exposure metrics, but relevant data in adults are limited. We assessed the temporal variability of daily central tendency (time-weighted average, median) and peak (upper percentiles, maximum) personal magnetic field exposure metrics over seven consecutive days in 100 pregnant women. When exposure was modeled as a continuous variable, central tendency metrics had substantial reliability, whereas peak metrics had fair (maximum) to moderate (upper percentiles) reliability. The predictive ability of a single day metric to accurately classify participants into exposure categories based on a weeklong metric depended on the selected exposure threshold, with sensitivity decreasing with increasing exposure threshold. Consistent with the continuous measures analysis, sensitivity was higher for central tendency metrics than for peak metrics. If there is interest in peak metrics, more than one day of measurement is needed over the window of disease susceptibility to minimize measurement error, but one day may be sufficient for central tendency metrics

Medically Attended Illness due to Respiratory Syncytial Virus Infection Among Infants Born in the United States Between 2016 and 2020

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization in the United States. Preterm infants and those with select comorbidities are at highest risk of RSV-related complications. However, morbidity due to RSV infection is not confined to high-risk infants. We estimated the burden of medically attended (MA) RSV-associated lower respiratory tract infection (LRTI) among infants in the United States. METHODS: We analyzed commercial (MarketScan Commercial [MSC], Optum Clinformatics [OC]), and Medicaid (MarketScan Medicaid [MSM]) insurance claims data for infants born between April 2016 and February 2020. Using both specific and sensitive definitions of MA RSV LRTI, we estimated the burden of MA RSV LRTI during infants' first RSV season, stratified by gestational age, comorbidity status, and highest level of medical care associated with the MA RSV LRTI diagnosis. RESULTS: According to the specific definition 75.0% (MSC), 78.6% (MSM), and 79.6% (OC) of MA RSV LRTI events during infants' first RSV season occurred among term infants without known comorbidities. CONCLUSIONS: Term infants without known comorbidities account for up to 80% of the MA RSV LRTI burden in the United States during infants' first RSV season. Future prevention efforts should consider all infants

Serum kynurenic acid is reduced in affective psychosis

A subgroup of individuals with mood and psychotic disorders shows evidence of inflammation that leads to activation of the kynurenine pathway and the increased production of neuroactive kynurenine metabolites. Depression is hypothesized to be causally associated with an imbalance in the kynurenine pathway, with an increased metabolism down the 3-hydroxykynurenine (3HK) branch of the pathway leading to increased levels of the neurotoxic metabolite, quinolinic acid (QA), which is a putative Nmethyl- D-aspartate (NMDA) receptor agonist. In contrast, schizophrenia and psychosis are hypothesized to arise from increased metabolism of the NMDA receptor antagonist, kynurenic acid (KynA), leading to hypofunction of GABAergic interneurons, the disinhibition of pyramidal neurons and striatal hyperdopaminergia. Here we present results that challenge the model of excess KynA production in affective psychosis. After rigorous control of potential confounders and multiple testing we find significant reductions in serum KynA and/or KynA/QA in acutely ill inpatients with major depressive disorder (N = 35), bipolar disorder (N = 53) and schizoaffective disorder (N = 40) versus healthy controls (N = 92). No significant difference was found between acutely ill inpatients with schizophrenia (n = 21) and healthy controls. Further, a post hoc comparison of patients divided into the categories of non-psychotic affective disorder, affective psychosis and psychotic disorder (non-affective) showed that the greatest decrease in KynA was in the affective psychosis group relative to the other diagnostic groups. Our results are consistent with reports of elevations in proinflammatory cytokines in psychosis, and preclinical work showing that inflammation upregulates the enzyme, kynurenine mono-oxygenase (KMO), which converts kynurenine into 3-hydroxykynurenine and quinolinic acid

First-trimester bleeding characteristics associate with increased risk of preterm birth: data from a prospective pregnancy cohort

Prior evidence linking first-trimester bleeding with preterm birth (PTB

Gestational Weight Gain and Birth Outcome in Relation to Prepregnancy Body Mass Index and Ethnicity

The obesity epidemic raises concerns about the impact of excessive and insufficient weight gain during pregnancy

Maternal Active and Passive Smoking and Hypertensive Disorders of Pregnancy: Risk with Trimester-Specific Exposures

The inverse association between prenatal smoking and preeclampsia is puzzling, given the increased risks of prematurity and low birthweight associated with both smoking and preeclampsia. We analyzed the Norwegian Mother and Child Birth Cohort (MoBa) to determine whether the associations varied by timing of prenatal smoking

Physical activity and maternal–fetal circulation measured by Doppler ultrasound

To examine the association of physical activity on maternal-fetal circulation measured by uterine and umbilical artery Doppler flow velocimetry waveforms