Daylight saving time (DST) contributes to a higher miscarriage rates among women undergoing in-vitro fertilisation (IVF) and who had a prior pregnancy loss, according to new research….reports Asian Lite News
DST is the practice of setting the clocks forward one hour from Standard Time during the summer months, in order to make better use of natural daylight. The findings, led by researchers from Boston University School of Medicine in the US, showed that DST — which causes disruption to daily circadian rhythms — may impact reproduction and fertility.
For the study, the team looked at the pregnancy and miscarriage rates among a sample of patients undergoing IVF prior to and during daylight savings time.
The results, appearing in the journal Chronobiology International, showed that miscarriage rates in IVF patients who had a prior miscarriage were significantly higher among women whose embryo transfers occurred 21 days after spring DST began, compared to patients whose embryo transfers occurred before or well outside the spring DST window.
“While our findings on the impact of DST on pregnancy loss among IVF pregnancies are intriguing, they need to be replicated in larger IVF cohorts in different parts of the world that observe DST,” said Wendy Kuohung, Associate Professor at Boston University School of Medicine.
Meanwhile, another report says women who lift heavy loads at work may be at risk of harming their fertility, with the effect appearing stronger among overweight and older women.
The findings showed that women who reported moving or lifting heavy loads at work had 8.8 per cent fewer total eggs and 14.1 per cent fewer mature eggs compared with women who reported never lifting or moving heavy objects at work.
Further, working at night or on rotating shifts may also lead to decreased fertility.
“Our study suggests that women who are planning pregnancy should be cognizant of the potential negative impacts that non-day shift and heavy lifting could have on their reproductive health,” said lead author Lidia Minguez-Alarcon, research fellow at Harvard T.H. Chan School of Public Health.
The inverse association between heavy lifting and mature egg yield was stronger among women who were overweight or obese and those aged 37 or older.
Previous studies have suggested a link between work schedule, physical factors on the job and the biologic capacity for reproduction.
“Our study is the first which shows that occupational heavy lifting and non-day shifts may be adversely affecting egg production and quality, rather than accelerating ovarian ageing,” added Audrey Gaskins, research associate at Harvard T.H. Chan School of Public Health.
For the new study, published in the journal Occupational and Environmental Medicine, the team analysed nearly 500 women seeking infertility treatment at Massachusetts General Hospital (MGH) in the US, from 2004-2015.
However, the mechanism by which moving or lifting heavy loads could affect egg quality is still unknown.
As for how working non-day shifts may affect egg yields, it is speculated that it may have to do with circadian rhythm disruption, the researchers said.
In an another study, Survival rates for children in Britain diagnosed with cancer have dramatically increased in the past 15 years, according to figures released by the Office for National Statistics (ONS).
For all childhood cancers combined, the general trend of increasing five-year survival has continued for children (0 to 14 years) diagnosed between 1990 and 2014, Xinhua news agency reported.
The ONS report issued showed that for children diagnosed in 1990, the five-year survival was 67.3 per cent, while five-year survival is predicted to be 83.9 per cent for children diagnosed with cancer in 2015.
A similar increasing trend was observed for 10-year survival, added the report.
ONS said the increases in 5-year and 10-year survival rates have been observed in each of the age groups 0 to 4 years, 5 to 9 years and 10 to 14 years.
The statistics were collected by the National Cancer Registration Service at Public Health England, produced in partnership with the Cancer Survival Group at the London School of Hygiene and Tropical Medicine.
ONS said the most common cancers in children are leukaemias and malignant neoplasms of the brain.
It added the increases in survival are likely to be due to improvements in treatment and supportive care.