Maternal occupational exposure to endocrine-disrupting chemicals linked to urogenital anomalies in offspring

Published 16 November 2021

A large-scale case control study has shown an association between exposure during pregnancy to certain endocrine-disrupting chemicals in the workplace and a greater risk of urogenital anomalies – though not hypospadias – in offspring. Employers ‘need to be aware’ of this risk.

There are said to be more than 1400 endocrine disrupting chemicals (EDCs) and many of them - phthalates, polychlorinated biphenyls (PCBs) and organochloride pesticides – appear to have a negative correlation with male and female fertility. All of them can be variously found in our diets, personal care products, cosmetics, plastic packaging, textiles and construction materials. The reproductive effects of these EDCs have more commonly been studied in men, as one possible explanation for an overall decline in sperm count seen over the past 50 years. EDCs have also been associated with both male and female fertility during the periconception period - in their effects on reproductive hormone concentrations, gamete and embryo characteristics, as well as time to pregnancy in the general population.(1)

Exposure to EDCs seems greatest in the workplace, where a variety of materials and products, such as pesticides, phthalates and organic solvents, may be present as an occupational hazard. In men, studies have implicated such products in both declining sperm counts and quality, and in a rising prevalence of male gonadal dysfunction. Indeed, in their landmark paper of 1992, Carlsen et al found the biological significance of these changes ‘emphasised by a concomitant increase in the incidence of genitourinary abnormalities such as testicular cancer and possibly also cryptorchidism and hypospadias’.(2)

A new study has now asked if exposure to EDCs in women early in their pregnancy is similarly associated with hypospadias and congenital anomalies of kidney and urinary tract in their offspring – and found a link with the latter, but not with the former.(3) This was a registry-based case-control study with cases (530 children with kidney and urinary tract anomalies, and 364 with hypospadias) derived from two registries and matched with 5602 non-malformed controls. Information on maternal occupation in early pregnancy was collected via questionnaires from the mothers, with job titles used to reflect occupational exposure to EDCs.

When both cases and controls were analysed alongside ‘any’ EDC exposures in the mothers, there was a higher rate of exposure among the cases for both kidney and urinary tract anomalies and for hypospadias (23% vs 19%, OR 1.21), though after adjustments the associations with hypospadias became non-significant. The authors note that women exposed to organic solvents and other EDCs were working in the agriculture sector and life sciences, while those exposed to phthalates (and others) worked ‘mainly as cleaners, hairdressers or beauticians’.

The authors review many former studies of the effects of maternal exposure to multiple EDCs and find conflicting results or, with relevance to their own study, little on urinary tract anomalies in offspring. Hypospadias, they report, is the most common anomaly, apparently present in some 14 per 10,000 male births in Europe. However, in this study and despite some evidence that EDCs can interfere with the development of the reproductive tract, no significant association was found between maternal exposure to EDCs and hypospadias.

It is tempting to regard the results of such studies as merely a sign of the times, but in this case the Dutch authors inform readers of legislation in the Netherlands which requires employers ‘to identify occupational risks for pregnant employees’. The risks which this and other studies reflect suggests that employers should at least be aware of EDCs in their workplace risk assessments.

1. Green MP, Harvey AJ, Finger BJ, Tarulli GA. Endocrine disrupting chemicals: Impacts on human fertility and fecundity during the peri-conception period. Environment Res 2021; doi.org/10.1016/j.envres.2020.110694
2. Carlsen E, Giwercman A, Keiding N, Skakkebaek N. Evidence for decreasing quality of semen during past 50 years. BMJ 1992; 305: 609-613.
2. Spinder N, Bergman JEH, Van Tongeren M, et al. Maternal occupational exposure to endocrine-disrupting chemicals and urogenital anomalies in the offspring. Hum Reprod 2021; doi:10.1093/humrep/deab205

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