deeply disturbing Talk of the Nation (NPR) radio talk program

[http://dummy.us.eu.org/robert (robert)]

Today's program is "Unwanted Fatherhood" and everyone's arguing that if a
birth control method fails (e.g., vasectomy), that the pregnancy should be
up to the mother.

Can a contract (prenuptual?) that can be written saying that if a pregnancy
occurs during a marriage that the woman would be compelled to get an abortion?

Is this legally supportable?

Thanks.