It has been shown from recent studies that infertility treatments offered during summer have a high success rate. Yes! Women who undergo fertility treatment during the summer are twice as likely to become pregnant when compared to trials in winter. The success rate in summer was 15.7 % compared to a 7.5% in the winter.
British researchers have done an in-depth analysis of over 3,000 cycles of fertility treatment, over a four-year period. Longer daylight hours are believed to improve the chances of successful treatment. Furthermore, lower doses of drugs were required to stimulate the follicular development in these women before embryo transfer could be accomplished.
An analysis of the sperm quality in men revealed that there was a comparative decline in the sperm quality and sperm concentrations of the samples given during winter. This finding could serve to explain the effect of Vitamin D (a potential anti-oxidant, derived from sunlight) in enhancing the sperm quality.
The phenomenon is called as photoperiodism, and is linked to the hormone melatonin, that regulates sleeping and walking cycles. It was believed that melatonin acted through the pituitary gland, which is "switched off" during IVF cycles, However, researchers have now found that melatonin is found in receptors throughout the reproductive system. Although very little is known at the present about how the hormone controls fertility, it is indeed true that it plays a crucial role in determining the outcome of treatment.
One of the reasons for this observation may be evolutionary; it is known that mammals are more likely to conceive during the summer because it means their offspring will be born in the spring, when food is more plentiful, the weather warmer and they have a higher chance of survival.
The findings on this study have valuable clinical implications. However, further research is needed in order to identify the positive effect of daylight on reproduction.