Data linkage between the National Birth Defects Prevention Study and the Occupational Information Network (O*NET) to assess workplace physical activity, sedentary behaviors, and emotional stressors during pregnancy

Maternal physical activity, sitting, and risk of non-cardiac birth defects

BACKGROUND

The relationship between maternal physical activity (PA)/sitting and birth defects is largely unexplored. We examined whether pre-pregnancy PA/sitting were associated with having a pregnancy affected by a birth defect.

METHODS

We used data from two United States population-based case-control studies: 2008-2011 deliveries from the National Birth Defects Prevention Study (NBDPS; 9 states) and 2014-2018 deliveries from the Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS; 7 states). Cases with one of 12 non-cardiac birth defects (n = 3798) were identified through population-based registries. Controls (n = 2682) were live-born infants without major birth defects randomly sampled using vital/hospital records. Mothers self-reported pre-pregnancy PA/sitting. Unconditional logistic regression models estimated associations between PA/sitting categories and the 12 birth defects.

RESULTS

Mothers engaging in pre-pregnancy PA was associated with a reduced odds of five (spina bifida, cleft palate, anorectal atresia, hypospadias, transverse limb deficiency) and a higher odds of two (anencephaly, gastroschisis) birth defects. Mothers spending less time sitting in pre-pregnancy was associated with a reduced odds of two (anorectal atresia, hypospadias) and a higher odds of one (cleft lip with or without cleft palate) birth defect.

CONCLUSIONS

Reasonable next steps include replication of these findings, improved exposure assessment, and elucidation of biologic mechanisms.

IMPACT

Using data from two population-based case-control studies, we found that mothers engaging in different types of physical activity in the 3 months before pregnancy had an infant with a reduced odds of five and a higher odds of two birth defects. Mothers spending less time sitting in the 3 months before pregnancy had an infant with a reduced odds of two and a higher odds of one birth defect. Clarification and confirmation from additional studies are needed using more precise exposure measures, distinguishing occupational from leisure-time physical activity, and elucidation of mechanisms supporting these associations.

Estimation of differential occupational risk of COVID-19 by comparing risk factors with case data by occupational group

BACKGROUND

The disease burden of coronavirus disease 2019 (COVID-19) is not uniform across occupations. Although healthcare workers are well-known to be at increased risk, data for other occupations are lacking. In lieu of this, models have been used to forecast occupational risk using various predictors, but no model heretofore has used data from actual case numbers. This study assesses the differential risk of COVID-19 by occupation using predictors from the Occupational Information Network (O*NET) database and correlating them with case counts published by the Washington State Department of Health to identify workers in individual occupations at highest risk of COVID-19 infection.

METHODS

The O*NET database was screened for potential predictors of differential COVID-19 risk by occupation. Case counts delineated by occupational group were obtained from public sources. Prevalence by occupation was estimated and correlated with O*NET data to build a regression model to predict individual occupations at greatest risk.

RESULTS

Two variables correlate with case prevalence: disease exposure (r = 0.66; p = 0.001) and physical proximity (r = 0.64; p = 0.002), and predict 47.5% of prevalence variance (p = 0.003) on multiple linear regression analysis. The highest risk occupations are in healthcare, particularly dental, but many nonhealthcare occupations are also vulnerable.

CONCLUSIONS

Models can be used to identify workers vulnerable to COVID-19, but predictions are tempered by methodological limitations. Comprehensive data across many states must be collected to adequately guide implementation of occupation-specific interventions in the battle against COVID-19.

Occupational Physical Activity and Coronary Heart Disease in Women's Health Initiative Observational Study

BACKGROUND

Women comprise nearly half of the labor force in our society, but the impact of the occupational psychical activity on women's heart health in later life was unclear. We conducted a case-cohort study to assess the association of occupational physical activity (OPA), alone and jointly with leisure-time physical activity (LTPA) and risk of coronary heart disease (CHD).

METHODS

We included women enrolled in Women's Health Initiative Observational Study who provided an occupational history at baseline and were followed until 2013 for the first occurrence of myocardial infarction or death from CHD (mean age ± SD = 63.4 ± 7.2). A total of 5,243 women free of CHD at baseline were randomly selected into a subcohort and 3,421 CHD events were adjudicated during follow-up. Through linkage of Standard Occupational Classification codes to the Occupational Information Network, we assessed cumulative and most recent exposure of OPA. LTPA was assessed through Women's Health Initiative's physical activity questionnaire. Weighted Cox proportional hazard models were used to evaluate CHD risk.

RESULTS

After adjustment for demographic and socioeconomic factors, levels of OPA were not associated with CHD risk. Compared with women with low OPA and high LTPA, women with moderate to high cumulative OPA and low LTPA had relative high CHD risk (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.26, 1.88 for moderate OPA and HR: 1.46. 95% CI: 1.20, 1.78 for high OPA).

DISCUSSION

Results from this study suggest no overall association between lifetime OPA and CHD risk in women, but the impact of OPA varies by LTPA levels.

Economic Downturns and Inequities in Birth Outcomes: Evidence From 149 Million US Births

Using birth certificate data for nearly all registered US births from 1976 to 2016 and monthly data on state unemployment rates, we reexamined the link between macroeconomic variation and birth outcomes. We hypothesized that economic downturns reduce exposure to work-related stressors and pollution while increasing exposure to socioeconomic stressors like job loss. Because of preexisting inequalities in health and other resources, we expected that less-educated mothers and black mothers would be more exposed to macroeconomic variation. Using fixed-effect regression models, we found that a 1-percentage-point increase in state unemployment during the first trimester of pregnancy increased the probability of preterm birth by 0.1 percentage points, while increases in the state unemployment rate during the second/third trimester reduced the probability of preterm birth by 0.06 percentage points. During the period encompassing the Great Recession, the magnitude of these associations doubled in size. We found substantial variation in the impact of economic conditions across different groups, with highly educated white women least affected and less-educated black women most affected. The results highlight the increased relevance of economic conditions for birth outcomes and population health as well as continuing, large inequities in the exposure and impact of macroeconomic fluctuations on birth outcomes.

Maternal occupational physical activity and risk for orofacial clefts

OBJECTIVES

To perform a case-control study of maternal occupational physical activity and risk for orofacial clefts in Texas during 1999-2009.

METHODS

We used logistic regression to assess 14 measures of physical activity estimated from a job exposure matrix, using the maternal occupation reported on the birth certificate, among 887 children with cleft lip with or without cleft palate (CLP), 436 children with cleft palate only (CP), and 1932 controls.

RESULTS

After adjusting for several potential confounders, seven measures of physical activity (as a categorical and/or continuous variable) were significantly associated with CLP, CP, or both. Positive associations were seen for keeping balance, kneeling, standing, and walking/running (odds ratio 95% confidence interval range 1.0-1.9 for fourth versus first quartile). A significant positive trend was also seen for bending/twisting. Negative associations were seen for repetitive motion and sitting.

CONCLUSIONS

Maternal occupational physical activity may be related to the etiology of orofacial clefts.

Role of maternal occupational physical activity and psychosocial stressors on adverse birth outcomes

OBJECTIVES

We examined the association of an array of estimated maternal occupational physical activities and psychosocial stressors during pregnancy with odds for preterm birth (PTB) and small-for-gestational age (SGA).

METHODS

Data for infants born without major birth defects delivered from 1997 to 2009 whose mothers reported working at least 1 month during pregnancy were obtained from the National Birth Defects Prevention Study. We linked occupational codes to the US Department of Labor's Occupational Information Network, which provides estimates of exposure for multiple domains of physical activity and psychosocial stressors by occupational categories. We conducted factor analysis using principal components extraction with 17 occupational activities and calculated factor scores. ORs for PTB and SGA across quartiles of factor scores in each trimester were computed using logistic regression.

RESULTS

Factor analysis grouped occupational domains into 4 groups based on factor loadings. These groups were 'occupational physical activity', 'interpersonal stressor', 'automated work' and 'job responsibility'. High levels of 'occupational physical activity' were significantly associated with SGA (adjusted OR (AOR) for highest quartile compared with lowest quartile of factor score: 1.36; 95% CIs 1.02 to 1.82; p for trend=0.001) and were also positively associated with PTB (AOR: 1.24; 95% CI 0.93 to 1.64; p for trend=0.01). No clear results were observed across domains of psychosocial stressors.

CONCLUSIONS

Our findings expand understanding of associations between occupational physical activity and psychosocial stressors and PTB and SGA and suggest that additional research is needed to further examine these relationships.

Deprivation, occupational hazards and perinatal outcomes in pregnant workers

BACKGROUND

Recent global economic difficulties have widened social inequalities, but their impact on pregnant workers is not known.

AIMS

To investigate the association between deprivation, exposure to occupational hazards and adverse perinatal outcomes in pregnant workers.

METHODS

A cross-sectional study performed in 2014 in French occupational health services. Eligible workers were women who had worked during their pregnancy and had a medical visit by occupational health physicians (OHPs) after delivery and at the time of returning to work. Deprivation was measured using the EPICES scale (Evaluation of Precariousness and Inequalities in Health Examination Centres). Information on birth outcomes was self-reported. Occupational risks for pregnancy were assessed by OHPs. Jobs were coded by the occupational health team using standardized French nomenclature. The groups (deprivation/no deprivation) were compared using univariate (chi-squared test) and multivariate Poisson regression analyses.

RESULTS

Of 1402 pregnant workers, 293 (21%) were classed as deprived. This group more frequently encountered occupational hazards, particularly for physical exposures (P < 0.001), and had a higher risk of cumulated occupational hazards of three or more for pregnancy [adjusted relative risk (RRa) = 4.2; 95% confidence interval (CI) 2.2-7.9]. Our findings suggest that deprivation and exposure to three or more occupational hazards during pregnancy cumulatively increased the risk of pre-term birth (RRa = 3.9; 95% CI 1.2-12.4).

CONCLUSIONS

Our data suggest that deprived pregnant workers are an occupationally vulnerable group.