Is It Permissible to Abort a Foetus with Down Syndrome?
Question

If it becomes known in the third month of pregnancy that the foetus has Down syndrome, is it permissible to abort it?
Praise be to Allah.If it is proven and confirmed by a committee of trustworthy doctors that the foetus has Down syndrome, and that is before the pregnancy has reached 120 days, it is permissible to abort it. It is not permissible to abort it after 120 days.
It says in a statement of the Islamic Fiqh Council belonging to the Muslim World league, issued during its twelfth session, held in Makkah Al-Mukarramah, 15 Rajab 1410 AH/10 February 1990 CE:
If the pregnancy has reached one hundred and twenty days, it is not permissible to abort it, even if the medical diagnosis indicates that there is a physical deformity, unless it is proven by a medical report from a council of trustworthy specialist doctors that continuing the pregnancy will definitely pose a risk to the life of the mother. In that case it is permissible to abort it, whether it is deformed or not, so as to ward off the greater of two harms.
But before one hundred and twenty days of the pregnancy have passed, if it is proven and confirmed by a medical committee of trustworthy specialist doctors, based on medical examinations and laboratory tests that the foetus is severely deformed and cannot be treated, and that if the pregnancy continues and the child is born at full term, his life will be unbearable and will cause suffering to him and his family, then in that case it is permissible to abort the foetus, if the parents request that.
Having stated the above, the Council advises doctors and parents to fear Allah and verify this matter [before proceeding with an abortion]." (Qararat Al-Majma` Al-Fiqhi Al-Islami bi Makkah Al-Mukarramah, p.277)
For more details, please see the following answers: 171943 , 42321 , 85046 , 11875 , 13319 .
And Allah knows best.