Is it permissible to abort a four-week-old fetus because the mother became pregnant by a husband who betrayed her, causing her to lose trust and respect for him, and she has three children and fears the fetus will grow up in a broken family?

It is not permissible to abort the fetus, even if it is in the nuṭfah stage. Fearing for it the calamities of this world is not considered a justification for abortion, as this is from the whispers of Satan. If the husband has committed bad practices and has repented from them, the wife should not trouble herself by thinking about the past, because that is from Satan's efforts to corrupt conjugal life. It is not permissible for the wife to seek divorce from her husband without a legitimate Shar'i reason, but if she dislikes staying with him and fears falling short in her duties towards him, she may seek khulʿ in exchange for compensation.