A recent study conducted in Australia indicates that the season of egg collection can impact the success of in vitro fertilization (IVF). Researchers discovered that eggs harvested in the summer resulted in a higher live birth rate compared to those collected in other seasons. The study focused on the timing of egg retrieval rather than the timing of embryo transfer.
THE SUMMER IMPACT
Analyzing data from a fertility clinic in Perth over eight years, researchers found that eggs collected on days with more than 10 hours of sunshine had a 28% higher likelihood of resulting in a live birth compared to eggs collected on days with less than 7 hours of sunshine. Interestingly, the temperature of the day did not appear to influence the outcome.
While the exact reasons behind this seasonal effect on IVF success remain unclear, previous studies have also suggested a connection between the season of egg retrieval and live birth rates. Another study conducted in the Northern Hemisphere found that eggs collected during the summer were 42% more likely to result in a live birth compared to those collected during winter.
These findings imply that the season may impact ovarian function, potentially influencing egg development. However, the receptiveness of the uterus or the early development of the foetus may not be affected by seasonal factors. The studies differ in their interpretation of the most significant seasonal factor, whether it is ambient temperature or the duration of bright sunshine, possibly related to vitamin D or melatonin production.
DAYLIGHT
While further research is necessary to fully understand the underlying mechanisms, the study suggests that patients undergoing IVF may consider collecting eggs during the summer months when daylight hours are longer. The research highlights the potential impact of environmental factors on IVF success and calls for more comprehensive data collection to investigate other possible contributing factors, such as activity, diet, lifestyle, and pollutants. The study was published in the journal Human Reproduction.
