Q. 1) Why does a pregnant women do Kapores for an unborn child. After all the baby doesn’t have any sins that need a כפרה?
2) Also a pregnant mother doesn't eat at the Pesach Seder, additional matza or grape juice for the unborn baby, so why add additional chickens for the fetus on Kapores?
A. Horav Shlomo Miller’s Shlit’a opinion is that the Kapara and pardon is not for the baby but rather for the parents, since their sins can affect their children.
Rabbi A. Bartfeld as revised by, Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit'a