Women working irregular shifts may be at risk of low fertility

Women who work at night or follow irregular shift patterns could be in danger of suffering from low fertility, a new study has indicated. 

Research from Harvard University found that shift and night workers had fewer eggs capable of developing into healthy embryos compared to staff who operated in regular daytime hours. 

The study, which was carried out by the university’s Chan School of Public Health and published in Occupational and Environmental Medicine, discovered that there was a reduction of roughly 15 per cent in the number of eggs ready for fertilisation in women with jobs that called for heavy lifting, such as nursing. 

Women who moved or lifted heavy loads at work had 8.8 per cent fewer total eggs and 14.1 per cent fewer mature eggs when compared to those who never carried out such duties. 

The connection between heavy lifting and mature egg yield was also stronger among women who were overweight, obese or aged 37 or over. 

Factors that the researchers looked at included the number of antral follicles, levels of follicle-stimulating hormone and estrogen levels. 

Audrey Gaskins, research associate in the Department of Nutrition, said: “Our study is the first to show that occupational heavy lifting and non-day shifts may be adversely affecting egg production and quality, rather than accelerating ovarian aging. 

“Future work, however, is needed to determine whether egg production and quality can be improved, and if so, how quickly, if these work exposures are avoided.”

Although scientists were not able to analyse the possible effects of factors such as working hours, testosterone levels or exposure to smoking, anxiety caused by a changing body clock or through physical exertion was one explanation for the findings. 

How moving or lifting heavy loads impacts egg quality is currently unknown, while night time and irregular shift patterns impacted egg yields through circadian rhythm disruption. ADNFCR-2094-ID-801832240-ADNFCR