Occupational physical demands and menstrual cycle irregularities in flight attendants and teachers.

OBJECTIVES: Flight attendants perform physically demanding work such as lifting baggage, pushing service carts and spending the workday on their feet. We examined if more frequent exposure to occupational physical demands could explain why previous studies have found that flight attendants have a higher reported prevalence of menstrual cycle irregularities than other workers. METHODS: We conducted a cross-sectional analysis of 694 flight attendants and 120 teachers aged 18-44 years from three US cities. Eligible participants were married, had not had a hysterectomy or tubal ligation, were not using hormonal contraception and were not recently pregnant. Participants reported menstrual cycle characteristics (cramps, pain, irregular cycles, flow, bleed length, cycle length) and occupational physical demands (standing, lifting, pushing/pulling, bending/twisting, overall effort). We used modified Poisson regression to examine associations between occupation (flight attendant, teacher) and menstrual irregularities; among flight attendants, we further examined associations between occupational physical demands and menstrual irregularities. RESULTS: All occupational physical demands were more commonly reported by flight attendants than teachers. Flight attendants reported more frequent menstrual cramps than teachers, and most occupational physical demands were associated with more frequent or painful menstrual cramps. Lifting heavy loads was also associated with irregular cycles. CONCLUSIONS: Occupational physical demands were associated with more frequent and worse menstrual pain among flight attendants. The physical demands experienced by these workers may contribute to the high burden of menstrual irregularities reported by flight attendants compared with other occupational groups, such as teachers.

Maternal occupational exposure to selected organic and chlorinated solvents and delivery of small-for-gestational age or preterm infants.

BACKGROUND: Potential reproductive effects of organic solvent exposure during pregnancy remain unclear. We investigated the association between maternal occupational exposure during pregnancy to six chlorinated solvents, three aromatic solvents, and Stoddard solvent, and delivery of preterm infants or those born small-for-gestational age (SGA). METHODS: In this case-control study of SGA and preterm birth (PTB) nested within the National Birth Defects Prevention Study (NBDPS) from 1997 to 2011, we analyzed data from 7504 singleton live births without major birth defects and their mothers. Self-reported information on jobs held in the periconceptional period was assessed for solvent exposure. Unconditional logistic regression was used to estimate the association between maternal occupational exposure (any, none) during early pregnancy to organic solvents and PTB and SGA. Linear regression was used to examine changes in mean birthweight potentially associated with maternal occupational solvent exposure. RESULTS: Maternal occupational exposure to any organic solvents overall was not associated with an increased odds of PTB (adjusted odds ratio [aOR] = 0.94; 95% confidence interval [CI] 0.67-1.33) or SGA (aOR = 0.93; 95% CI 0.65-1.34). Point estimates increased modestly for higher estimated exposure versus lower, but confidence intervals were wide and not statistically significant. Maternal exposure to solvents was not associated with a statistically significant change in term birthweight among infants. CONCLUSIONS: Occupational exposure to organic solvents at the frequency and intensity levels found in a population-based sample of pregnant workers was not associated with PTB or SGA; however, we cannot rule out any effects among pregnant workers with uncommonly high exposure to organic solvents.

Birth defects associated with paternal firefighting in the National Birth Defects Prevention Study.

BACKGROUND: Few studies have evaluated birth defects among children of firefighters. We investigated associations between birth defects and paternal work as a firefighter compared to work in non-firefighting and police officer occupations. METHODS: We analyzed 1997-2011 data from the multi-site case-control National Birth Defects Prevention Study. Cases included fetuses or infants with major structural birth defects and controls included a random sample of live-born infants without major birth defects. Mothers of infants self-reported information about parents' occupations held during pregnancy. We investigated associations between paternal firefighting and birth defect groups using logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Referent groups included families reporting fathers working non-firefighting and police officer jobs. RESULTS: Occupational groups included 227 firefighters, 36,285 non-firefighters, and 433 police officers. Twenty-nine birth defects were analyzed. In adjusted analyses, fathers of children with total anomalous pulmonary venous return (TAPVR; OR = 3.1; 95% CI = 1.1-8.7), cleft palate (OR = 1.8; 95% CI = 1.0-3.3), cleft lip (OR = 2.2; 95% CI = 1.2-4.2), and transverse limb deficiency (OR = 2.2; 95% CI = 1.1-4.7) were more likely than fathers of controls to be firefighters, versus non-firefighters. In police-referent analyses, fathers of children with cleft palate were 2.4 times more likely to be firefighters than fathers of controls (95% CI = 1.1-5.4). CONCLUSIONS: Paternal firefighting may be associated with an elevated risk of birth defects in offspring. Additional studies are warranted to replicate these findings. Further research may contribute to a greater understanding of the reproductive health of firefighters and their families for guiding workplace practices.

COVID-19 Vaccine Uptake and Factors Affecting Hesitancy Among US Nurses, March-June 2021.

Objectives. To characterize COVID-19 vaccine uptake and hesitancy among US nurses. Methods. We surveyed nurses in 3 national cohorts during spring 2021. Participants who indicated that they did not plan to receive or were unsure whether they planned to receive the vaccine were considered vaccine hesitant. Results. Among 32 426 female current and former nurses, 93% had been or planned to be vaccinated. After adjustment for age, race/ethnicity, and occupational variables, vaccine hesitancy was associated with lower education, living in the South, and working in a group care or home health setting. Those who experienced COVID-19 deaths and those reporting personal or household vulnerability to COVID-19 were less likely to be hesitant. Having contracted COVID-19 doubled the risk of vaccine hesitancy (95% confidence interval [CI] = 1.85, 2.53). Reasons for hesitancy that were common among nurses who did not plan to receive the vaccine were religion/ethics, belief that the vaccine was ineffective, and lack of concern about COVID-19; those who were unsure often cited concerns regarding side effects or medical reasons or reported that they had had COVID-19. Conclusions. Vaccine hesitancy was unusual and stemmed from specific concerns. Public Health Implications. Targeted messaging and outreach might reduce vaccine hesitancy. (Am J Public Health. 2022;112(11):1620-1629. https://doi.org/10.2105/AJPH.2022.307050).

Maternal occupation as a nail technician or hairdresser during pregnancy and birth defects, National Birth Defects Prevention Study, 1997-2011.

OBJECTIVE: Nail technicians and hairdressers may be exposed to chemicals with potential reproductive effects. While studies have examined birth defects in children of hairdressers, those in children of nail technicians have not been evaluated. We investigated associations between selected birth defects and maternal occupation as a nail technician or hairdresser versus a non-cosmetology occupation during pregnancy. METHODS: We analysed population-based case-control data from the multisite National Birth Defects Prevention Study, 1997-2011. Cases were fetuses or infants with major structural birth defects; controls were live-born infants without major birth defects. Expert raters classified self-reported maternal jobs as nail technician, combination nail technician-hairdresser, hairdresser, other cosmetology work or non-cosmetology work. We used logistic regression to calculate adjusted ORs and 95% CIs for associations between occupation during pregnancy and birth defects, controlling for age, smoking, education and race/ethnicity. RESULTS: Sixty-one mothers worked as nail technicians, 196 as hairdressers, 39 as combination nail technician-hairdressers and 42 810 as non-cosmetologists. The strongest associations among nail technicians included seven congenital heart defect (CHD) groups (ORs ranging from 2.7 to 3.5) and neural tube defects (OR=2.6, CI=0.8 to 8.4). Birth defects most strongly associated with hairdressing included anotia/microtia (OR=2.1, CI=0.6 to 6.9) and cleft lip with cleft palate (OR=2.0, CI=1.1 to 3.7). All oral cleft groups were associated with combination nail technician-hairdresser work (ORs ranging from 4.2 to 5.3). CONCLUSIONS: Small samples resulted in wide CIs. Still, results suggest associations between maternal nail technician work during pregnancy and CHDs and between hairdressing work and oral clefts.

Maternal occupational exposure to polycyclic aromatic hydrocarbons and the risk of isolated congenital heart defects among offspring.

BACKGROUND: Although there is evidence in experimental model systems that exposure to polycyclic aromatic hydrocarbons (PAHs) is linked with congenital heart defects (CHDs), few studies have examined the association in humans. We conducted a case-control study to examine the association between maternal exposure to PAHs and CHDs in offspring using data from the National Birth Defects Prevention Study (NBDPS) (1997-2011). METHODS: We obtained detailed information on maternal occupation during the month before to three months after conception. Expert raters, masked to case-control status, assessed job descriptions to assign categorical levels of exposure. Categories were quantitatively mapped to estimate cumulative exposure to PAHs, incorporating exposure intensity, frequency, work duration, and work hours. Quartiles were generated for cumulative maternal exposure to PAHs. Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using unconditional logistic regression for quartiles of PAH exposure and six CHD groupings (e.g. conotruncal) and specific subtypes (e.g. tetralogy of Fallot [ToF]). Final models were adjusted for maternal age, race/ethnicity, education, smoking, anticonvulsant use, folic acid supplementation, and study center. RESULTS: There were 4,775 case and 7,734 control infants eligible for the study. The prevalence of occupational exposure to PAHs was 10.2% among both case and control mothers. In adjusted analysis, compared to mothers with no occupational PAH exposure, those in the highest quartile of exposure were more likely to have offspring in the conotruncal heart defects group (OR 1.41; 95% CI 1.00-2.00), and with ToF (OR 1.83; 95% CI 1.21-2.78). CONCLUSIONS: Women in the highest quartile of estimated cumulative occupational PAH exposure during early pregnancy were more likely to have offspring with conotruncal heart defects, specifically ToF, compared to women with no occupational PAH exposure. Other comparisons between PAHs and other CHDs subgroups did not show any statistically precise associations.

Structure and Control of Healthy Worker Effects in Studies of Pregnancy Outcomes.

Much of the literature on the healthy worker effect focuses on studies of chronic disease and mortality; however, when studying pregnancy outcomes, these effects might differ because of the short, defined risk periods of most pregnancy outcomes. Three pregnancy-specific healthy worker effects have also been described, but the structure of these effects has not yet been investigated when occupational exposure, and not employment status, is the exposure of interest. We used directed acyclic graphs to examine healthy worker effects in studies of occupational exposures and pregnancy outcomes: the healthy hire effect, the healthy worker survivor effect, the desperation/privilege effect (differential workforce reentry after pregnancy), the reproductively unhealthy worker effect (women with live births leave the workforce, while women with nonlive births do not), and the insecure pregnancy effect (women with adverse pregnancy outcomes reduce their exposures in subsequent pregnancies). Given our assumptions, we conclude that the healthy hire effect, the desperation/privilege effect, the reproductively unhealthy worker effect, and the insecure pregnancy effect result from confounding that can be addressed if data on measured confounders, such as employment status, are available. The presence of the healthy worker survivor effect, however, varies by study design. Different types of healthy worker effects can be present in studies of occupational exposure and pregnancy outcomes, and many of them are easily addressed analytically.

Factors associated with employment status before and during pregnancy: Implications for studies of pregnancy outcomes.

BACKGROUND: Potential confounding or effect modification by employment status is frequently overlooked in pregnancy outcome studies. METHODS: To characterize how employed and non-employed women differ, we compared demographics, behaviors, and reproductive histories by maternal employment status for 8,343 mothers of control (non-malformed) infants in the National Birth Defects Prevention Study (1997-2007) and developed a multivariable model for employment status anytime during pregnancy and the 3 months before conception. RESULTS: Sixteen factors were independently associated with employment before or during pregnancy, including: maternal age, pre-pregnancy body mass index, pregnancy intention, periconceptional/first trimester smoking and alcohol consumption, and household income. CONCLUSIONS: Employment status was significantly associated with many common risk factors for adverse pregnancy outcomes. Pregnancy outcome studies should consider adjustment or stratification by employment status. In studies of occupational exposures, these differences may cause uncontrollable confounding if non-employed women are treated as unexposed instead of excluded from analysis. Am. J. Ind. Med. 60:329-341, 2017. © 2017 Wiley Periodicals, Inc.

Agreement between two methods for retrospective assessment of occupational exposure intensity to six chlorinated solvents: Data from The National Birth Defects Prevention Study.

The wide variety of jobs encountered in population-based studies makes retrospective exposure assessment challenging in occupational epidemiology. In this analysis, two methods for estimating exposure intensity to chlorinated solvents are compared: rated (assigned by an expert rater) and modeled (assigned using statistical models). Estimates of rated and modeled intensities were compared for jobs held by mothers participating in the National Birth Defects Prevention Study with possible exposure to six chlorinated solvents: carbon tetrachloride, chloroform, methylene chloride, perchloroethylene, 1,1,1-trichloroethane, and trichloroethylene. For each possibly exposed job, an industrial hygienist assigned (1) an exposure intensity (rated intensity) and (2) determinants of exposure to be used in a statistical model of exposure intensity (modeled intensity). Of 12,326 reported jobs, between 31 (0.3%) and 746 (6%) jobs were rated as possibly exposed to each of the six solvents. Agreement between rated and modeled intensities was low overall (Spearman correlation coefficient range: -0.09 to 0.28; kappa range: -0.23 to 0.43). Although no air measurements were available to determine if rated or modeled estimates were more accurate, review of participants' job titles showed that modeled estimates were often unexpectedly high given the low-exposure tasks found in these jobs. Differences between the high-exposure jobs used to create the statistical models (obtained from air measurements in the published literature) and the low-exposure jobs in the actual study population is a potential explanation for the disagreement between the two methods. Investigators should be aware that statistical models estimating exposure intensity using existing data from one type of worker population might not be generalizable to all populations of workers.

"Will my work affect my pregnancy?" Resources for anticipating and answering patients' questions.

BACKGROUND: Authoritative information on occupational reproductive hazards is scarce and complex because exposure levels vary, multiple exposures may be present, and the reproductive toxicity of many agents remains unknown. For these reasons, women's health providers may find it challenging to effectively address workplace reproductive health issues with their patients who are pregnant, breast-feeding, or considering pregnancy. Reproductive epidemiologists at the Centers for Disease Control and Prevention National Institute for Occupational Safety and Health answered >200 public requests for occupational reproductive health information during 2009 through 2013. The most frequent occupations represented were health care (41%) and laboratory work (18%). The most common requests for exposure information concerned solvents (14%), anesthetic gases (10%), formaldehyde (7%), infectious agents in laboratories (7%) or health care settings (7%), and physical agents (14%), including ionizing radiation (6%). Information for developing workplace policies or guidelines was sought by 12% of the requestors. Occupational exposure effects on breast-feeding were an increasing concern among working women. Based on information developed in response to these requestors, information is provided for discussing workplace exposures with patients, assessing potential workplace reproductive hazards, and helping patients determine the best options for safe work in pregnancy. Appendices provide resources to address specific occupational exposures, employee groups, personal protective equipment, breast-feeding, and workplace regulations regarding work and pregnancy. These tools can help identify those most at risk of occupational reproductive hazards and improve workers' reproductive health. The information can also be used to inform research priorities and assist the development of workplace reproductive health policies.

Birth defects in infants born to employees of a microelectronics and business machine manufacturing facility.

BACKGROUND: Concerns about solvent releases from a microelectronics/business machine manufacturing facility in upstate New York led to interest in the health of former workers, including this investigation of birth defects in children of male and female employees. METHODS: Children born 1983 to 2001 to facility employees were enumerated and matched to New York State's Congenital Malformations Registry. Reported structural birth defects were compared with numbers expected from state rates (excluding New York City), generating standardized prevalence ratios (SPRs). Exposure assessors classified employees as ever/never potentially exposed at the facility to metals, chlorinated hydrocarbons, and other hydrocarbons during windows critical to organogenesis (female workers) or spermatogenesis (male workers). Among workers, adjusted prevalence ratios were generated to evaluate associations between potential exposures and specific birth defects. RESULTS: External comparisons for structural defects were at expectation for infants of male workers (SPR = 1.01; 95% confidence interval [CI], 0.77-1.29; n = 60) and lower for births to female workers (SPR = 0.84; 95% CI, 0.50-1.33; n = 18). Among full-term infants of male workers, ventricular septal defects (VSDs) were somewhat elevated compared with the general population (SPR = 1.58; 95% CI, 0.99-2.39; n = 22). Within the cohort, potential paternal metal exposure was associated with increased VSD risk (adjusted prevalence ratio = 2.70; 95% CI, = 1.09-6.67; n = 7). CONCLUSION: While overall SPRs were near expectation, paternal exposure to metals (primarily lead) appeared to be associated with increased VSD risk in infants. Take-home of occupational exposures, nonoccupational exposures, and chance could not be ruled out as causes. Case numbers for many defects were small, limiting assessment of the role of occupational exposures. Birth Defects Research (Part A) 106:696-707, 2016. © 2016 Wiley Periodicals, Inc.

Maternal occupational exposure to polycyclic aromatic hydrocarbons and craniosynostosis among offspring in the National Birth Defects Prevention Study.

BACKGROUND: Evidence in animal models and humans suggests that exposure to polycyclic aromatic hydrocarbons (PAHs) may lead to birth defects. To our knowledge, this relationship has not been evaluated for craniosynostosis, a birth defect characterized by the premature closure of sutures in the skull. We conducted a case-control study to examine associations between maternal occupational exposure to PAHs and craniosynostosis. METHODS: We used data from craniosynostosis cases and control infants in the National Birth Defects Prevention Study (NBDPS) with estimated delivery dates from 1997 to 2002. Industrial hygienists reviewed occupational data from the computer-assisted telephone interview and assigned a yes/no rating of probable occupational PAH exposure for each job from 1 month before conception through delivery. We used logistic regression to assess the association between occupational exposure to PAHs and craniosynostosis. RESULTS: The prevalence of exposure was 5.3% in case mothers (16/300) and 3.7% in control mothers (107/2,886). We observed a positive association between exposure to PAHs during the 1 month before conception through the third month of pregnancy and craniosynostosis (odds ratio [OR] = 1.75; 95% confidence interval [CI], 1.01-3.05) after adjusting for maternal age and maternal education. The number of cases for each craniosynostosis subtype limited subtype analyses to sagittal craniosynostosis; the odds ratio remained similar (OR = 1.76, 95% CI, 0.82-3.75), but was not significant. CONCLUSION: Our findings support a moderate association between maternal occupational exposure to PAHs and craniosynostosis. Additional work is needed to better characterize susceptibility and the role PAHs may play on specific craniosynostosis subtypes.

Paternal and joint parental occupational pesticide exposure and spina bifida in the National Birth Defects Prevention Study, 1997 to 2002.

BACKGROUND: Because of persistent concerns over the association between pesticides and spina bifida, we examined the role of paternal and combined parental occupational pesticide exposures in spina bifida in offspring using data from a large population-based study of birth defects. METHODS: Occupational information from fathers of 291 spina bifida cases and 2745 unaffected live born control infants with estimated dates of delivery from 1997 to 2002 were collected by means of maternal report. Two expert industrial hygienists estimated exposure intensity and frequency to insecticides, herbicides, and fungicides. Multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for exposure to any pesticide and to any class of pesticide (yes/no; and by median), and exposure to combinations of pesticides (yes/no) and risk of spina bifida. Adjusted odds ratios were also estimated by parent exposed to pesticides (neither, mother only, father only, both parents). RESULTS: Joint parental occupational pesticide exposure was positively associated with spina bifida (aOR, 1.5; 95% CI, 0.9-2.4) when compared with infants with neither maternal nor paternal exposures; a similar association was not observed when only one parent was exposed. There was a suggested positive association between combined paternal insecticide and fungicide exposures and spina bifida (aOR, 1.5; 95% CI, 0.8-2.8), however, nearly all other aORs were close to unity. CONCLUSION: Overall, there was little evidence paternal occupational pesticide exposure was associated with spina bifida. However, the small numbers make it difficult to precisely evaluate the role of pesticide classes, individually and in combination. Birth Defects Research (Part A) 106:963-971, 2016. © 2016 Wiley Periodicals, Inc.

Maternal occupational pesticide exposure and risk of congenital heart defects in the National Birth Defects Prevention Study.

BACKGROUND: Congenital heart defects (CHDs) are common birth defects, affecting approximately 1% of live births. Pesticide exposure has been suggested as an etiologic factor for CHDs, but previous results were inconsistent. METHODS: We examined maternal occupational exposure to fungicides, insecticides, and herbicides for 3328 infants with CHDs and 2988 unaffected control infants of employed mothers using data for 1997 through 2002 births from the National Birth Defects Prevention Study, a population-based multisite case-control study. Potential pesticide exposure from 1 month before conception through the first trimester of pregnancy was assigned by an expert-guided task-exposure matrix and job history details self-reported by mothers. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression. RESULTS: Maternal occupational exposure to pesticides was not associated with CHDs overall. In examining specific CHD subtypes compared with controls, some novel associations were observed with higher estimated pesticide exposure: insecticides only and secundum atrial septal defect (OR = 1.8; 95% CI, 1.3-2.7, 40 exposed cases); both insecticides and herbicides and hypoplastic left heart syndrome (OR = 5.1; 95% CI, 1.7-15.3, 4 exposed cases), as well as pulmonary valve stenosis (OR = 3.6; 95% CI, 1.3-10.1, 5 exposed cases); and insecticides, herbicides, and fungicides and tetralogy of Fallot (TOF) (OR = 2.2; 95% CI, 1.2-4.0, 13 exposed cases). CONCLUSION: Broad pesticide exposure categories were not associated with CHDs overall, but examining specific CHD subtypes revealed some increased odds ratios. These results highlight the importance of examining specific CHDs separately. Because of multiple comparisons, additional work is needed to verify these associations.

Maternal periconceptional occupational pesticide exposure and neural tube defects.

BACKGROUND: Adverse associations between maternal pesticide exposure and neural tube defects (NTDs) have been suggested but not consistently observed. This study used data from the multisite National Birth Defects Prevention Study to examine associations between maternal periconceptional (1 month preconception through 2 months postconception) occupational pesticide exposure and NTDs. METHODS: Mothers of 502 NTD cases and 2950 unaffected live-born control infants with estimated delivery dates from 1997 through 2002 were included. Duration, categorical intensity scores, and categorical frequency scores for pesticide classes (e.g., insecticides) were assigned using a modified, literature-based job-exposure matrix and maternal-reported occupational histories. Adjusted odds ratios (aORs) and 95% confidence intervals were estimated based on fitted multivariable logistic regression models that described associations between maternal periconceptional occupational pesticide exposure and NTDs. The aORs were estimated for pesticide exposure (any [yes/no] and cumulative exposure [intensity × frequency × duration] to any pesticide class, each pesticide class, or combination of pesticide classes) and all NTD cases combined and NTD subtypes. RESULTS: Positive, but marginally significant or nonsignificant, aORs were observed for exposure to insecticides + herbicides for all NTD cases combined and for spina bifida alone. Similarly, positive aORs were observed for any exposure and cumulative exposure to insecticides + herbicides + fungicides and anencephaly alone and encephalocele alone. All other aORs were near unity. CONCLUSION: Pesticide exposure associations varied by NTD subtype and pesticide class. Several aORs were increased, but not significantly. Future work should continue to examine associations between pesticide classes and NTD subtypes using a detailed occupational pesticide exposure assessment and examine pesticide exposures outside the workplace.

Maternal occupational exposure to polycyclic aromatic hydrocarbons and small for gestational age offspring.

OBJECTIVES: While some of the highest maternal exposures to polycyclic aromatic hydrocarbons (PAHs) occur in the workplace, there is only one previous study of occupational PAH exposure and adverse pregnancy outcomes. We sought to extend this literature using interview data combined with detailed exposure assessment. METHODS: Data for 1997-2002 were analysed from mothers of infants without major birth defects in the National Birth Defects Prevention Study, a large population-based case-control study in the USA. Maternal telephone interviews yielded information on jobs held in the month before conception through delivery. From 6252 eligible control mothers, 2803 completed the interview, had a job, met other selection criteria, and were included in the analysis. Two industrial hygienists independently assessed occupational exposure to PAHs from the interview and reviewed results with a third to reach consensus. Small for gestational age (SGA) was the only adverse pregnancy outcome with enough exposed cases to yield meaningful results. Logistic regression estimated crude and adjusted ORs. RESULTS: Of the 2803 mothers, 221 (7.9%) had infants who were SGA. Occupational PAH exposure was found for 17 (7.7%) of the mothers with SGA offspring and 102 (4.0%) of the remaining mothers. Almost half the jobs with exposure were related to food preparation and serving. After adjustment for maternal age, there was a significant association of occupational exposure with SGA (OR=2.2, 95% CI 1.3 to 3.8). CONCLUSIONS: Maternal occupational exposure to PAHs was found to be associated with increased risk of SGA offspring.

Multiple Job Holding, Job Changes, and Associations with Gestational Diabetes and Pregnancy-Related Hypertension in the National Birth Defects Prevention Study.

We used National Birth Defects Prevention Study data to investigate associations between working patterns shortly before and during pregnancy and gestational diabetes and pregnancy-related hypertension. We analyzed working patterns (multiple-job holders, job changers, single-job holders) during the three months before and during pregnancy for 8140 participants who delivered a live-born child without a birth defect. "Multiple-job holders" worked more than one job simultaneously, "job changers" worked more than one job with no overlap, and "single-job holders" (referent) worked one job. We used multivariable logistic regression to estimate associations between working pattern and each outcome, adjusting for maternal age and educational attainment at delivery. We explored effect measure modification by household income, peak weekly working hours, and maternal race/ethnicity. Multiple-job holders had higher odds of gestational diabetes (adjusted odds ratio [aOR]: 1.5; 95% confidence interval [CI]: 1.1-2.1) and pregnancy-related hypertension (aOR: 1.5; 95% CI: 1.0-2.2) compared with single-job holders. Multiple-job holders with a household income of more than 30,000 USD per year, 32-44 peak weekly working hours, and from racial/ethnic minority groups had higher odds of gestational diabetes compared with single-job holders in respective categories. Detailed occupational information is important for studies of occupation and maternal health.

Occupational exposures among nurses and risk of spontaneous abortion.

OBJECTIVE: We investigated self-reported occupational exposure to antineoplastic drugs, anesthetic gases, antiviral drugs, sterilizing agents (disinfectants), and X-rays and the risk of spontaneous abortion in US nurses. STUDY DESIGN: Pregnancy outcome and occupational exposures were collected retrospectively from 8461 participants of the Nurses' Health Study II. Of these, 7482 were eligible for analysis using logistic regression. RESULTS: Participants reported 6707 live births, and 775 (10%) spontaneous abortions (<20 weeks). After adjusting for age, parity, shift work, and hours worked, antineoplastic drug exposure was associated with a 2-fold increased risk of spontaneous abortion, particularly with early spontaneous abortion before the 12th week, and 3.5-fold increased risk among nulliparous women. Exposure to sterilizing agents was associated with a 2-fold increased risk of late spontaneous abortion (12-20 weeks), but not with early spontaneous abortion. CONCLUSION: This study suggests that certain occupational exposures common to nurses are related to risks of spontaneous abortion.

Differences in folic acid use, prenatal care, smoking, and drinking in early pregnancy by occupation.

OBJECTIVE: To describe differences in four high risk periconceptional behaviors (lack of folic acid supplementation, lack of early prenatal care, smoking, and drinking) by maternal occupation. METHODS: Analyses were conducted among women in the National Birth Defects Prevention Study who delivered liveborn infants without birth defects. Periconceptional occupational data were collected using a computer-assisted telephone interview and occupational coding was performed using the 2000 Standard Occupational Classification System. Logistic regression analyses were conducted to determine whether prevalence of behaviors differed between occupational groups. RESULTS: Subjects included 5153 women employed during early pregnancy from 1997 to 2007. Compared to women in management, business, science, and arts occupations, women in other occupations (e.g., service occupations) were significantly more likely to engage in all four high risk behaviors. Specifically, women in food preparation/serving-related occupations were significantly more likely to engage in all four behaviors compared to women in all other occupational groups (odds ratios: 1.8-3.0), while women in education/training/library occupations were significantly less likely to do so (odds ratios: 0.2-0.5). CONCLUSION: We identified several occupational groups with an increased prevalence of high-risk maternal behaviors during pregnancy. Our findings could aid in developing interventions targeted towards women in these occupational groups.

Effect of survey instrument on participation in a follow-up study: a randomization study of a mailed questionnaire versus a computer-assisted telephone interview.

BACKGROUND: Many epidemiological and public health surveys report increasing difficulty obtaining high participation rates. We conducted a pilot follow-up study to determine whether a mailed or telephone survey would better facilitate data collection in a subset of respondents to an earlier telephone survey conducted as part of the National Birth Defects Prevention Study. METHODS: We randomly assigned 392 eligible mothers to receive a self-administered, mailed questionnaire (MQ) or a computer-assisted telephone interview (CATI) using similar recruitment protocols. If mothers gave permission to contact the fathers, fathers were recruited to complete the same instrument (MQ or CATI) as mothers. RESULTS: Mothers contacted for the MQ, within all demographic strata examined, were more likely to participate than those contacted for the CATI (86.6% vs. 70.6%). The median response time for mothers completing the MQ was 17 days, compared to 29 days for mothers completing the CATI. Mothers completing the MQ also required fewer reminder calls or letters to finish participation versus those assigned to the CATI (median 3 versus 6), though they were less likely to give permission to contact the father (75.0% vs. 85.8%). Fathers contacted for the MQ, however, had higher participation compared to fathers contacted for the CATI (85.2% vs. 54.5%). Fathers recruited to the MQ also had a shorter response time (median 17 days) and required fewer reminder calls and letters (median 3 reminders) than those completing the CATI (medians 28 days and 6 reminders). CONCLUSIONS: We concluded that offering a MQ substantially improved participation rates and reduced recruitment effort compared to a CATI in this study. While a CATI has the advantage of being able to clarify answers to complex questions or eligibility requirements, our experience suggests that a MQ might be a good survey option for some studies.