Proverbs 17:21 New English Translation

²¹Whoever brings a fool^[a] into the world^[b] does so^[c] to his grief,
and the father of a fool has no joy.^[d]

Proverbs 17:21 sn Here the Hebrew terms כְּסִיל (k^esil) and נָבָל (naval) are paired. The first one, which occurs about fifty times in the book, refers to a dullard, whether it be in spiritual, intellectual, or moral matters. The second word, rare in the book, primarily focuses on religious folly—it refers to the practical atheist, the one who lives as if there is no God.
Proverbs 17:21 tn The form simply means “bears” or “gives birth to,” but since it is masculine it could be rendered “fathers” (cf. NASB “he who begets a fool”; NIV “To have a fool for a son”). The form for “fool” is masculine, but the proverb is not limited only to male children (cf. NCV “It is sad to have a foolish child”).
Proverbs 17:21 tn The phrase “does so” is supplied for the sake of clarification.
Proverbs 17:21 sn Parents of fools, who had hoped for children who would be a credit to the family, find only bitter disappointment (cf. TEV “nothing but sadness and sorrow”).

New English Translation (NET)