Disruptions to the circadian rhythm or the bodys biological clock may cause fertility problems,a new study has claimed. A team at Northwestern University in the US disrupted the circadian rhythms of female mice for five to six days after they mated. One group of 18 mice got an extra six hours of light,while another 18 mice lost daylight. By the end of the experiment,only half of the mice with extra daylight had litters and mice that lost daylight fared worse only 20 per cent gave birth. But 90 per cent of a control group exposed to a steady 12 hours of daylight gave birth. Mammals,and even trees,are known to synchronise their internal clocks,which control metabolism and other functions,to cues of night and day. Experts in fertility and circadian rhythms agreed the mouse experiments showed a strong connection between the mouses internal clock and pregnancy. However,critics expressed doubts over the study,saying stress may play a role in womens fertility problem. Keith Summa,who led the study,said the details may be different across species,but what they found in mice will be relevant to humans,LiveScience reported.
