Heavy work=less fertility?

This concept is counter-intuitive to the old adage of women working hard harvesting in the potato fields, having a baby and going right back to work and then having another baby in less than a year. Back then when woman started their reproductive lives in their teens or early twenties, worked very hard physically day and night without today’s conveniences, it seems many had large numbers of children.

But according to a new study women who work night shifts or do heavy physical labor may be somewhat less fertile than other women, this new research suggests.

In a study of women undergoing fertility treatment, researchers found that those who worked at night or did heavy lifting on the job tended to have fewer “mature” eggs. In theory, that could lower their chances of having a baby. However, experts stressed that the findings have to be viewed with caution.

For one, they do not prove that night shifts or heavy lifting are to blame, said lead researcher Lidia Minguez-Alarcon. She is a research fellow at the Harvard School of Public Health in Boston. It’s possible, she explained, that some women with those jobs are exposed to other environmental factors that might affect their “egg quality.”

Beyond that, the study did not show that women’s job situations directly affected their chances of having a baby, said Dr. James Grifo, director of the NYU Langone Fertility Center in New York City. Grifo, who was not involved in the study, was concerned the findings could cause women undue stress or guilt if their fertility treatment does not work out. In fact, Grifo said, the study results can point only to an association between certain job situations and a measure of fertility.

“Do you tell women to quit their jobs or to stop lifting based on this?” Grifo said. “I don’t think so.”

The findings were based on nearly 500 women who underwent in vitro fertilization (IVF) at one infertility center.

The women in this study were not reproductively “average” woman as they needed IVF to conceive so these findings may not apply to average women trying to conceive normally. But in general, we do consider “lifestyle issues” and recommend those trying to conceive they to optimize their health through these issues. When couples are planning to go through IVF we often recommend reducing their stress level and that may include modifying work schedules.

For more on lifestyle issues please visit our Lifestyle & Fertility pages.