A scientist creates a virus (bacteria?) which, when encountering a woman, implants a fetal clone of him, which the woman is pregnant with. Millions of his clones have already been born, and society is having a hard time accommodating them.
The man is in hiding, working as a teacher in a special class for his clones. He is evaluating one particular young clone, who apparently suffered from fetal alcohol syndrome, which was detected based on his unexpectedly low test scores.
It's a short story, read in the 2000s or earlier.