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Remember what we learned in basic statistic class: correlation does not mean causation.

Petra Hapsari   12 July 2017 12:00

A new research from Harvard University shows that women working at night shifts has lesser egg cells to grow as healthy embryo compared to those who work during daytime.

How working night shifts affects women’s fertility

For the research, 313 women went through in vitro fertilization (IVF) test to find out their egg cells quality. As the result, researcher Audrey Gaskins said there are around 15 percent of egg cells with not so good quality in women working night shifts. Moreover, only few of them has quite good quality of egg cells to grow.

According to Gaskins, disorder on the circadian rhythm might be one of factors that triggers the lesser quality of egg cells. This disorder affects the production of hormone and menstrual cycle, especially for women who often has different working shifts. The research also reveals the similar risk on women who has to work too hard. The examples of profession which put the women at risk are nurse and interior designer.

Similar research done by professor of Obstetrics and Gynecology in University of Southampton also shows similar result. It is found that almost one third of women who work at night has 22 percent chance of miscarriage and menstrual cycle disruption.

The research concludes that women who work at night or do heavy physical work tend to have less fertility rate compared to women who work during normal work hours. Theoretically, it might decrease the chance for women to get pregnant and give birth.

Not all women’s infertility comes from night shift

However, experts from Harvard School of Public Health emphasize that working night shifts does not always become the reason for women’s infertility. There might be other factors such as environment.

Besides, the research does not show that the condition of women who work can affect their chance to get pregnant and give birth, said Dr. James Grifo, director of NYU Langone Fertility Center in New York City.

Grifo, who was not involved in the research from Harvard University, worried that the research might cause stress and misperception about fertility. He also said that the result is aimed only to refer to the relation between certain working conditions and fertility rate.

Grifo suggested women has to eat healthy food, get enough rest and stay hydrated to balance between their works and fertility for their own health and good.

The article was previously published in and all medical data have been reviewed by a licensed medical doctor.

Women Health

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