I took a marriage and family class from Dr. Joseph Barnes. As I recall, he provided evidence that about 1/3 of a man's sperm are the only one's that impregnate an egg. A second1/3 of his sperm kind of run with the first 1/3 like protectors. The last 1/3 just swam around in circles and were originally thought to be malformed, until they introduced a second man's sperm. Then those last 1/3 began to attack the second man's sperm. The second 1/3 tried to protect against those attacking sperm to allow the impregnating one's to get to the egg.
So, to from what I learned, a man's sperm, at least 1/3 of them, will attack and kill a second man's sperm.
Evidence was also supported by the occurrence of infertility in prostitute's who often have the presence of sperm from two men or more at a time. Her body develops anti-sperm antibodies that also kill sperm. The remedy was to wait at least three days before having sex with another man to give the first man's sperm a chance to die (since they only live about 72 hours). The result was increased safety of a woman's continued fertility and lowering risk to the second man's sperm being killed by the first.
I've been searching for documentation to confirm what I was taught by Dr. Barnes on this subject. He showed us a film of petri dish recordings of sperm behaving in this manner. It was very compelling to watch. So, maybe "some" sperm is "friendly", but from what I remembers seeing, 1/3 is not friendly at all in the presence of another man's sperm.
So, to from what I learned, a man's sperm, at least 1/3 of them, will attack and kill a second man's sperm.
Evidence was also supported by the occurrence of infertility in prostitute's who often have the presence of sperm from two men or more at a time. Her body develops anti-sperm antibodies that also kill sperm. The remedy was to wait at least three days before having sex with another man to give the first man's sperm a chance to die (since they only live about 72 hours). The result was increased safety of a woman's continued fertility and lowering risk to the second man's sperm being killed by the first.
I've been searching for documentation to confirm what I was taught by Dr. Barnes on this subject. He showed us a film of petri dish recordings of sperm behaving in this manner. It was very compelling to watch. So, maybe "some" sperm is "friendly", but from what I remembers seeing, 1/3 is not friendly at all in the presence of another man's sperm.
