The study carried out by Stockholm University, in partnership with the Manchester University NHS Foundation Trust (MFT) looked into the chemicals used by a female egg to attract male sperm and results show that a woman’s eggs may prefer sperm cells of some men to others.
‘Human eggs release chemicals called chemoattractants that attract sperm to unfertilized eggs. We wanted to know if eggs use these chemical signals to pick which sperm they attract,’ said John Fitzpatrick, an associate professor at Stockholm University.
The study specifically looked at follicular fluid, which surrounds the eggs and contains the chemicals that attract sperm.
The study checked if the fluids from different women attracted certain sperm more than others and the result showed it does. The research team obtained anonymous egg and sperm samples from couples undergoing IVF at St Mary’s Hospital in Manchester.
‘Follicular fluid from one female was better at attracting sperm from one male, while follicular fluid from another female was better at attracting sperm from a different male,’ said Professor Fitzpatrick.
According to Professor Fitzpatrick, sperm have only one job which is to fertilise the eggs. So they won’t be choosy about which egg they fertilise.
The study suggests that eggs have evolved and now pick high quality or genetically compatible sperm.