Malik bin Anas (may Allah have mercy on him) narrates from Imam al-Zuhri (may Allah have mercy on him) that a man struck a woman, causing her to miscarry. Ibn Shihab (may Allah have mercy on him) said: For her child a fine (ghurrah) is due from him, and expiation (kaffarah) is due from him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16420