Researchers from the European Society of Human Reproduction and Embryology report that IVF outcomes improve when egg collection occurs during the summer rather than in the fall. The findings come from a study published in the journal Human Reproduction and offer new insight into how seasonal timing may influence fertility treatment success.
The study focused on a Perth clinic and analyzed eight years of frozen embryo transfer data, spanning January 2013 to December 2021. By examining a large dataset, the researchers sought to understand whether the season in which eggs are collected could affect the likelihood of a successful pregnancy after IVF.
Results indicated that the birth rate following fall egg collection stood at 26 births per 100 transfers, while summer collection yielded 31 births per 100 transfers. When egg collection occurred in winter or spring, the differences in live birth rates were not statistically significant. Additionally, the team noted a notable association between sunlight exposure and outcomes: women who had eggs collected on days with higher natural daylight experienced about a 28 percent greater chance of a live birth.
Experts highlighted that natural birth patterns also vary with the seasons, but this study is among the first to link seasonal timing with IVF results in a meaningful way. The implications point to potential strategies for optimizing IVF efficiency and success rates through careful scheduling and consideration of environmental factors that accompany different seasons.
Earlier observations from scholars at University College London indicated that roughly one in five women can achieve natural pregnancy after an IVF cycle, underscoring the ongoing dialogue about how assisted reproduction intersects with natural fertility rhythms and timing.