Women should “stick to the day job” if they want to have children after a study found those who work nightshifts have fewer eggs.

Researchers at Harvard University followed 500 women who were seeking fertility treatment at Massachusetts General Hospital and found those who worked unsociable hours, or whose jobs involved heavy lifting, were less fertile.

The findings were based on the number of eggs produced by women when their ovaries were stimulated during IVF.

Women who worked day shift produced an average of 11.2 eggs per session compared with 8.7 for nightshift workers, a decrease of 28 percent.

Likewise women whose jobs involved heavy lifting had 14 percent fewer eggs.

“Our study suggests that women who are planning pregnancy should be aware of the potential negative impacts that non-day shift and heavy lifting could have on their reproductive health,” said lead author Lidia Mínguez-Alarcón.

The researchers believe that nightshifts may disrupt circadian rhythm and prevent eggs from developing or maturing.

Alastair Sutcliffe, professor of pediatrics at University College London said that women who were trying to become pregnant should try and avoid night work and heavy lifting.

“Human beings like light,” he said. “When sunlight hits our retinae, the serotonin ‘happy hormone’ goes up instantly in the brain. Hence we love sunny winter days, but not dank overcast ones.

“So shift work is not a biologically good way to work and folks who have to do this are known to get many health risks such hypertension.

“What does this study mean? If trying to optimize fertility, stick to the day job and leave the lifting to their partner.”

The new research was published in the journal Occupational and Environmental Medicine.

Darren Griffin, professor of genetics, University of Kent, added, “Women who are trying to start a family may take the study into account, perhaps avoiding heavy lifting and unsociable work hours as much as possible during this time, especially if they are not getting pregnant within the first year of trying.”

一项研究发现，上夜班的女性卵子数量更少。想生孩子的女性应该“坚持上白班”。

哈佛大学的研究人员跟踪研究了麻省综合医院寻求生育治疗的500名女性，结果发现，在非正常时间上班的女性和工作时需要搬重物的女性，更不易生育。

这些发现基于女性在接受试管婴儿治疗时卵巢受到刺激时产生的卵子数量。

上白班的女性每个生理周期平均产生11.2枚卵子，而上夜班的女性每个周期平均产生8.7枚卵子，降低了28%。

同样，工作中需要搬运重物的女性卵子数量要少14%。

研究报告的主要作者莉迪亚 阿拉贡说：“我们的研究发现，计划怀孕的女性应该明白上夜班和搬重物对其生殖健康可能产生的负面影响。”

研究人员认为，上夜班会打乱生理节律，妨碍卵子发育或成熟。

伦敦大学学院儿科学教授阿拉斯泰

尔•萨克利夫说，想要怀孕的女性应该避免上夜班和搬重物。

他说：“人类喜欢光。当太阳光射进视网膜，‘幸福荷尔蒙’血清素水平在大脑中立刻升高。因此我们喜欢阳光充足的冬日，而不是潮湿阴冷的日子。”

“所以从生物学上讲，倒班并不是一种好的工作方式。不得不倒班的人有诸多患病风险，比如高血压。”

“所以这个研究意味着什么？如果想让生育能力达到最优，要坚持上白班，让另一半搬重物。”

这项新研究发表在《职业与环境医

药》期刊上。

肯特大学遗传学教授达伦•格里芬补充说：“想要生育子女的女性要考虑一下这项研究结果，或许要在这段时间尽可能避免搬运重物和上夜班，特别是在第一年试孕失败后。”

(Chinadaily.com.cn)

    Words to Learn 相关词汇

    【夜班】yèbān nightshift a period during the nighttime scheduled to work

    【使...达到最佳】shǐ...dádào zuìjiā optimize make as effective, perfect, or useful as possible