Should infanticide be legalised?

I’d like to clarify my earlier statement so it is not misused. Conditions that I can imagine are sufficiently “dire” that a woman’s request for an abortion should be ignored include:

For an individual woman: she’s showing signs of mental illness where she varies from sincerely demanding an abortion to sincerely insisting that she’ll kill anyone who tries to hurt her baby.

For society in general: some sort of Children of Men scenario occurs where birth rates drop to near-zero, putting the human race at risk for extinction.
I’m sure I could think up some others, but the loss of the fetus under typical conditions doesn’t qualify.