A new study found that getting pregnant may be more challenging among women who do routine heavy lifting and work for more than 40 hours per week.
The researchers conducted the study by analyzing data from the Nurse's Health Study, involving nurses working outside the home, who are trying to get pregnant. The participants were asked to fill up a questionnaire regarding their work schedule and the physical labor required of their jobs. Every six months, the subjects were asked whether they have been successful in their pregnancy attempt or not. The data, which were collated from 2010-2014, comprised of 50 percent women aged 33 years and above, 44 percent were overweight and 22 percent have had a history of past and present smoking. The women were either working on rotating or irregular shifts (16 percent) and majority had exclusive or regular day or night shifts. The nature of work activity include staying on their feet for about eight hours (approximately 33.3 percent) and lifting heavy objects for up to five occasions per day (40 percent).
The findings of the study, published in the journal Occupational and Environmental Medicine, show that 16 percent of the participants were not able to conceive within 12 months and 5 percent still did not become pregnant after two years. The researchers compared the fecundity of nurses who worked for more than 40 hours and those who worked on a range of 21-40 hours only. As per analysis, transporting objects weighing 25 lbs. at the minimum for multiple times within the day may prolong the attainment of conception by up to 50 percent. Meanwhile, engaging in frequent night or shifting/ non-shifting schedules was not associated with prolonged conception.
To decrease the factor of impaired fertility, women with irregular menstrual cycles were not included in the study; however, the overall results still presented with a 33 percent prolonged conception time for those lifting heavy loads. Overweight and obese women were found to be more affected by the effects of heavy lifting.
"Our results show that heavy work, both in terms of physical strain and long hours, appears to have a detrimental impact on female nurses' ability to get pregnant," wrote Audrey Gaskin, lead author and a researcher at Harvard T.H. Chan School of Public Health in Boston, in an email.
The researchers think that one of the main factors behind the study results is the possibility that particular working conditions may not be conducive for pregnancy. Another potential factor is that women who struggle to conceive prefer to work longer hours.
A reproductive health specialist at the Ohio State University named Courtney Lynch comments that one of the much straightforward interpretations for the late pregnancy is that women may become more exhausted from heavy lifting and long work hours. "If this effect is real, it is likely due to the fact that these women are having less frequent intercourse due to their work demands," she explains in an email. Lynch was not involved in the study.
Lynch advised that for couples who would want to conceive faster, sexual intercourse should be performed at least twice in a week, and not only during weekends. Women should also make an effort to maintain a healthy weight, exercise and prevent stress and smoking.
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