Scientists at Northwestern University in Chicago believe they have photographed the moment human life begins. They have filmed a flash of light as sperm enters the human egg.
The phenomenon has been seen in animal experiments, but this is the first time its been seen in humans.
The researchers explain that as the sperm enters the egg an increase in calcium causes zinc to shoot out and bind with small molecules and this emits a fluorescent light that is detectible by camera microscopes.
Professor Tom O’Halloran, co-senior author of the study to be published today, said, “These fluorescence microscopy studies establish that the zinc spark occurs in human egg biology, and that can be observed outside of the cell.”
Researchers are touting this as a way to increase the success rate of in vitro fertilization, which currently is unsuccessful in 50 percent of the attempts, the problem being that IVF doctors have no way of knowing which of the eggs are healthy and which are not.
The Northwestern researchers believe the brighter the light, the greater chance there is for a successful pregnancy once the human embryo is implanted. During the experiment, nine human eggs were put in contact with sperm enzyme. Two of the nine showed flashes brighter than the rest, telling researchers these would be the more successful conceptions.
Dr. Eve Feinberg, who cared for the women who provided the eggs for the experiment, said, “There are no tools currently available that tell us if it’s a good quality egg. Often we don’t know whether the egg or embryo is truly viable until we see if a pregnancy ensues. That’s the reason this is so transformative. If we have the ability up front to see what is a good egg and what’s not, it will help us know which embryo to transfer, avoid a lot of heartache and achieve pregnancy much more quickly.”
The uses of this knowledge may be limited to in vitro fertilization; after all the human eye cannot see conception that happens naturally, but it could inform the current arguments about the beginning of life and therefore the morality of abortifacient contraception.
While most medical textbooks and medical dictionaries teach that life begins at fertilization, that is, the moment sperm meets egg, in recent years advocates have begun to argue that human life doesn’t begin until implantation. This neatly sidesteps the moral question of contraceptives, such as IUDs, that prevent the implantation of a living human embryo.
Professor Teresa Woodruff, one of the study’s two senior authors, said, “All biology starts at the time of fertilization, yet we know next to nothing about the events that occur in the human.”