英國一項研究顯示，夜班可能損害女性的生育能力，常上夜班的女性不孕機率大大增加。夜班與女性生育能力存在關聯的原因可能在於工作、睡眠時間不規律引起生物鐘紊亂，而生物鐘在控制人體激素分泌、體溫、血壓和心率等方面起著重要作用。
Women should 『stick to the day job』 if they want to have children after a study found those who work nightshift have fewer eggs.
一項研究發現，上夜班的女性卵子數量更少。想要生育子女的女性應該「堅持上白班」。
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.
哈佛大學的研究人員跟蹤研究了麻省綜合醫院尋求生育治療的500名女性，結果發現，在非正常時間上班的女性，和工作時需要搬重物的女性，更不易生育。
The findings were based on the number of eggs produced by women when their ovaries were stimulated during IVF.
這些發現基於女性在接受試管受精治療時，卵巢受到刺激時產生的卵子數量。
Women who worked day shift produced an average of 11.2 eggs per session compared with 8.7 percent for nightshift workers, a decrease of 28 percent.
上白班的女性每個生理周期平均產生11.2枚卵子，而上夜班的女性每個周期平均產生8.7枚卵子，降低了28%。
Likewise women whose jobs involved heavy lifting had 14 percent fewer eggs.
同樣，工作中需要搬運重物的女性卵子數量要少14%。
「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 Dr Lidia Mínguez-Alarcón.
研究報告的主要作者莉迪亞博士說：「我們的研究表明，計劃懷孕的女性要明白上夜班和搬重物對其生殖健康可能產生的負面影響。」
The researchers believe that nightshift may disrupt circadian rhythm and prevent eggs from developing or maturing.
研究人員認為，上夜班會打亂生理節律，妨礙卵子發育或成熟。
Prof Alastair Sutcliffe, Professor of Paediatrics at University College London said that women who were trying to become pregnant should try and avoid night work and heavy lifting.
倫敦大學學院兒科學教授阿拉斯泰爾-薩克利夫說，想要懷孕的女性應該嘗試避免上夜班和搬重物。
「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.
他說：「人類喜歡光。當太陽光射進視網膜，『幸福荷爾蒙』血清素水平在大腦中立刻升高。因此我們喜歡陽光充足的冬日，而不是潮溼陰冷的日子。」
「So shift work is not a biologically good way to work and folks who have to do this are known to get many ill health risks such hypertension.
「所以從生物學上講，倒班並不是一種好的工作方式。不得不倒班的人有諸多患病風險，比如高血壓。」
「So what does this study mean? If trying to optimise fertility, stick to the day job and leave the lifting to their partner.」
「所以這個研究意味著什麼？如果想讓生育能力達到最優，要堅持上白班，讓搭檔搬重物。」
The new research was published in the journal Occupational and Environmental Medicine.
這項新研究發表在《職業與環境醫藥》期刊上。
Professor 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 is possible during this time, especially if they are not falling pregnant within the first year of trying.」
肯特大學遺傳學教授達倫-格裡芬補充說：「想要生育子女的女性要考慮一下這項研究結果，或許要在這段時間儘可能避免搬運重物和上夜班，特別是在第一年試孕失敗之後。」
英文來源：每日電訊報