1.   Even men who have no sperm at all or only dead sperm in their ejaculate or men whose sperm cannot swim or cannot penetrate an egg may be helped.

2.   Instead of allowing sperm to swim up to an egg and penetrate it on their own, doctors directly inject a sperm cell into an egg.

3.   Sperm will swim in a culture medium for a day or more.

4.   The first breakthrough in treating men occurred two years ago, when researchers discovered that it did not matter whether sperm could swim vigorously to reach an egg.

5.   With that method, which mimics natural fertilization, the sperm swims tegg and discards its protein coat as it enters.

6.   With that method, which mimics natural fertilization, the sperm swims to the egg and discards its protein coat as it enters.