The scientists at the University of Southampton in England claim that night shift leads to disruption of the menstrual cycle and subfertility.
Scientists have analyzed the results of several studies on the subject, which were published from 1969 to 2013. In the course of the study, they processed the data from 119 345 women. As a result, they found that shift work (night, evening, or alternating shifts) most likely leads to the disruption of the menstrual cycle by 33%. Nothing like this was observed in women who worked during the day. Furthermore, night shifts increase risk of infertility by 80%.
Women who worked only at night did not have a significant risk of menstrual disorders and problems with conception, but they had an increased risk of miscarriage. However, the risk did not increase when alternating day and night shifts.
The authors say that the results of their study are important not only for women planning pregnancy, but also for their employers.
In an earlier study, the Canadian scientists found out that long-term night schedule doubles the risk of breast cancer. Night shift also leads to blood pressure increase and the development of diabetes.