It was observed that shift workers were 80 percent more likely to have conception problems compared with women engaged in a nine to five routine.
Lead author of the study, Dr Linden Stocker from the University of Southampton, UK said, “Our findings have implications for women attempting to become pregnant, as well as for their employers.
“If our results are confirmed by other studies, there may be implications for shift workers and their reproductive plans. More friendly shift patterns with less impact on circadian rhythm could be adopted where practical – although the optimal shift pattern required to maximise reproductive potential is yet to be established.”
Meta-analysis of previous studies
In order to get some insight into whether working shifts hits a woman’s fertility, the researchers carried out a meta-analysis of all studies on the subject published between 1969 and January 2013.
The study was designed to compare the impact of non-standard working schedules (night shifts, evening shifts, split shifts and rotating shifts) with regular shifts. Experts focused on end-points like early reproductive outcome parameters, including menstrual dysregulation, female fertility and miscarriage rates.
Findings of the study
The data analysis on 119,345 women working alternating shifts had a 33 per cent higher risk of irregular periods and an 80 per cent higher risk of “subfertility” (being less fertile than a normal couple).
Women who worked only night shifts were not prone to higher infertility or menstrual disruption but did have an increased rate of miscarriage (29 percent). However, the latter condition was not found in those who operate on night shift as part of a pattern.
Though the mechanism behind the findings is unclear, that shift work’s disruption of the body’s circadian rhythm can affect the biological function of “clock genes,” which have been tied to changes in biological functions.
Stocker stated, “We don’t fully understand why shift workers have an increased risk of certain diseases but obviously shift work impacts on your biological functioning, your psychological functioning and your social functioning.
“More friendly shift patterns, with less impact on circadian rhythm, could be adopted where practical. If replicated, our findings have implications for women attempting to become pregnant, as well as for their employers.”
The study was presented at the annual meeting of the European Society of Human Reproduction and Embryology, in London.