I have renounced my mother's estate. I am currently two months pregnant. Will I also need to renounce the estate on behalf of my child once they are born?

Yes. Under Article 725 of the French Civil Code, a child who was already conceived at the time of the deceased’s death may inherit, provided they are born viable. Since you have renounced the succession, your unborn child becomes the next heir to your mother’s estate. However, the renunciation on behalf of your child can only be made after birth, and with the prior authorisation of the guardianship judge, as this is considered a disposition of rights by a minor.