All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
There is nothing in Islam that prohibits the husband and wife from talking about their unborn child and its stage of growth if that is based on a scientific basis describing the stages of fetal growth.
However, it is impermissible to talk about those matters as a way of promoting lies or false assumptions as is the case with soothsayers and sorcerers who claim to know the matters of the unseen. Verily, the unseen is known only to Allaah; He says (what means): {Say, "None in the heavens and earth knows the unseen except Allaah, and they do not perceive when they will be resurrected."}[Quran 27:65]
Allaah Knows best.