Is it permissible to abort the fetus in the fourth month if several doctors have diagnosed that it suffers from anencephaly and will not be able to live after birth?

Aborting the fetus is absolutely impermissible. The prohibition becomes more severe after forty days. It is considered killing a human life after the ensoulment (120 days). Only two cases are exempt from this: an imminent danger to the mother's life, based on a reliable medical report, or the confirmed death of the fetus inside its mother's womb.