Charles Ellicott Commentary Exodus 21:22

"And if men strive together, and hurt a woman with child, so that her fruit depart, and yet no harm follow; he shall be surely fined, according as the woman`s husband shall lay upon him; and he shall pay as the judges determine." — Exodus 21:22 (ASV)

If men strive, and hurt a woman with child. — It is assumed that this hurt would probably take place through the interference of a pregnant wife in some strife in which her husband was engaged. It would almost certainly be accidental.

And yet no mischief follow — i.e., no further mischief—nothing beyond the loss of the child.