The success of an IVF cycle depends on many factors: the age of the couple and their lifestyle. It could also be influenced by the time of year when the eggs were harvested.
According to a study, eggs collected in the summer and fertilised are three times more likely to lead to a pregnancy than ones taken in the autumn.
These findings could explain some natural variations in birth rates, as well as ways to improve the IVF process. The scientists warn that this work needs to be replicated in other climates and with different groups. These findings are based on an analysis of over 3,500 IVF transfers in Australia.
Natural birth rates show patterns that vary.