Maternal occupation and the risk of major birth defects: A follow-up analysis from the National Birth Defects Prevention Study

Abstract

This study further examined the association between selected maternal occupations and a variety of birth defects identified from prior analysis and explored the effect of work hours and number of jobs held and potential interaction between folic acid and occupation. Data from a population-based, multi-center case-control study was used. Analyses included 45 major defects and specific sub-occupations under five occupational groups: healthcare workers, cleaners, scientists, teachers and personal service workers. Both logistic regression and Bayesian models (to minimize type-1 errors) were used, adjusted for potential confounders. Effect modification by folic acid was also assessed. More than any other occupation, nine different defects were positively associated with maids or janitors [odds ratio (OR) range: 1.72-3.99]. Positive associations were also seen between the following maternal occupations and defects in their children (OR range: 1.35-3.48): chemists/conotruncal heart and neural tube defects (NTDs), engineers/conotruncal defects, preschool teachers/cataracts and cleft lip with/without cleft palate (CL/P), entertainers/athletes/gastroschisis, and nurses/hydrocephalus and left ventricular outflow tract heart defects. Non-preschool teachers had significantly lower odds of oral clefts and gastroschisis in their offspring (OR range: 0.53-0.76). There was a suggestion that maternal folic acid use modified the effects with occupations including lowering the risk of NTDs and CL/P. No consistent patterns were found between maternal work hours or multiple jobs by occupation and the risk of birth defects. Overall, mothers working as maids, janitors, biologists, chemists, engineers, nurses, entertainers, child care workers and preschool teachers had increased risks of several malformations and non-preschool teachers had a lower risk of some defects. Maternal folic acid use reduced the odds of NTDs and CL/P among those with certain occupations. This hypothesis-generating study will provide clues for future studies with better exposure data.

Genetic and nongenetic etiology of nonsyndromic anorectal malformations: A systematic review

“…Parental occupational exposures were not extensively studied in relation to ARM (Supporting Information Table S3). However, mothers prenatally exposed to industrial cleaning agents and solvents while working as cleaners or janitors seemed to have an increased risk of giving birth to a child with ARM (Herdt-Losavio et al, 2010;van Rooij et al, 2010;Wijers et al, 2010;Lin et al, 2012a). In one study, the risk was also elevated for mothers employed as scientists during pregnancy (Herdt-Losavio et al, 2010).…”

“…Although only 2–8% of patients with ARM have an affected first‐ or second‐degree relative (Spouge and Baird, ; Stoll et al, ; Forrester and Merz, ; Falcone et al, ; van Rooij et al, ; Wijers et al, ), ARM co‐occurs more often among family members than would be expected by chance (Lie et al, ; Oyen et al, ; van Rooij et al, ; Wijers et al, ). Familial occurrence seems to be most frequent when a perineal or vestibular fistula is present (Falcone et al, ).…”

8 Epidemiology of Cleft Lip and Palate

“…The most common risk factors reported were maternal exposure to tobacco products [81,82], alcohols [83], some viral infections [70], pesticides [84], and teratogens in the workplace or at home in early pregnancy [85][86][87]. Recognized teratogens included rare exposures such as phenytoin, valproic acid, thalidomide, and herbicides such as dioxin.…”

Genetic Study of 12 SNPs involved in 11 Folate Metabolism Genes and Neural Tube Defects in Suzhou Children

“…NTDs are the second most common of birth defects, which are preventable and are significant causes of infant death and childhood disability [1,2]. It is estimated that there are more than 300,000 NTDs worldwide each year, many of these occurring in low-resource countries [3]. Anencephaly and spina bifida are the most common NTDs and occur with about equal frequency, whereas encephalocele is seen less frequently.…”