Is the recitation of the Qur'an by a pregnant wife recommended or an innovation (bid'ah) with the intention of seeking blessings for the child in the mother's womb?

Reading the Quran is goodness, blessing, healing, and light. There is nothing to prevent a pregnant woman or other sick people from reading the Quran for healing and blessing, and it does not prevent the blessing of the recitation from reaching the fetus.