Not difficult to lift: Reduced fertility through physical work
There are numerous reasons why couples who do not want to have children work out. For example, ongoing stress reduces the chances of pregnancy. Apparently, heavy physical work and night shift work can also reduce the likelihood. Because these activities affect the egg quality and number of women - and possibly their fertility.
Effects of heavy physical work and shift work
It has long been known that people who do heavy physical work and who work shifts endanger their health every day. What is new is that the women among them are more likely to have problems having children. But it is precisely this connection that US researchers report in the journal "Occupational and Environmental Medicine".
Egg quality and number is impaired
According to this, heavy physical work and night shift work impair the egg quality and number of women and thus possibly their fertility. According to the scientists, this effect is particularly pronounced in overweight and older women.
Women who want to have children should be aware that heavy lifting and shift work at night affects female fertility.
As the researchers around Lidia Minguez-Alarcón from Harvard T.H. Chan School of Public Health in Boston, Massachusetts, previous studies have shown that a woman's working conditions affect her fertility.
However, it has not yet been investigated which processes in the body are directly affected.
Effects particularly strong in overweight women
The current study looked at women who decided to have fertility treatment because they did not get pregnant naturally. In addition, the subjects had to provide detailed information about their working conditions in a questionnaire.
According to the scientists, the analysis of the data showed that women who lift heavily have fewer eggs maturing in their ovaries during fertility treatment than women who mainly work sitting or do less physical work.
They also found that fewer of these eggs were fully mature. Their supply of fertilizable egg cells also appeared to be smaller overall. However, this relationship was not statistically clear.
The reported effects were particularly pronounced in overweight and obese women and women over 37 years of age. The yield of mature egg cells was also lower for night shift workers than for women who work shifts during the day. Working conditions had no effect on hormone levels.
Disorders of the biological clock
So far it is unclear what causes the observed differences. The researchers suspect that disorders of the biological clock could be involved.
According to the scientists, their results would have immediate clinical significance, since a lower number of mature eggs means that fewer eggs can produce a healthy embryo.
Further studies should now show whether the effects are reversible and, if so, for how long. The experts do not yet know whether the results also apply to women who have become pregnant naturally.
No fundamentally new knowledge
As reported by the dpa news agency, the study for Georg Döhmen, reproductive physician and board member of the German Society for Reproductive Medicine (DGRM) delivers solid results, but does not provide any fundamentally new knowledge.
Earlier studies have shown that physical stress affects fertility, especially in old age and overweight.
"But you have to keep in mind that the causes of reduced fertility are usually multifactorial, there are several things that come together," said the expert. One of the most important harmful factors is tobacco consumption, because smoking reduces fertility.
Sports and healthy eating, on the other hand, promote fertility, according to the doctor, in both men and women.
Live healthy and reduce stress
It is also conceivable that the level of education and related lifestyle factors could help explain the results. The level of education among the examined women who did heavy physical work and worked at night is lower, according to the dpa report.
“The extent to which this may play a role is not answered by the study.” Döhmen recommends that women who come to the fertility center with an unfulfilled desire to live largely healthy and reduce stress without completely relinquishing everyday life.
"If you impose too many rules, it can otherwise create stress and then be counterproductive," says the reproductive doctor. (ad)