With the transition from summer to winter the days get longer, but you lose an hour of sleep. A study from Boston University suggests that the time change increases the risk of miscarriage. A risk much more pronounced in women who have had recourse to in vitro fertilization.
The researchers analyzed the results of in vitro fertilization throughout the year. In particular, they compared those performed close to the time change with those that occurred in other periods. Among women who have resorted to IVF during the 21 days before the time change, 23.4% suffered a miscarriage. In the rest of the year the percentage is 10.2%. This suggests that there is some correlation, but the reasons are not yet clear.
It is the first research that examines the effects of the time change on the outcome of a pregnancy. Nevertheless, there are other studies that examine the health effects of the daylight saving. For example, according to the American Academy of Neurology stroke risk increases by 2% in the days following the time change. It is assumed that the fault is the shift of the circadian rhythm, what is commonly called "biological clock."
The time change could have detrimental effects not limited to the outcome of IVF or the risk of stroke. A study at the University of Maryland, in fact, suggests a link with the onset of migraines. The cause may be in a cluster of nerves in the hypothalamus responsible for melatonin, the sleep hormone, and biological rhythms.