Yahya related to me from Malik from Nafi that Abdullah ibn Umardid not sacrifice for the child in the womb.Malik said, "Thesacrifice is sunna, and it is not obligatory. I prefer that anyone whohas the price of the animal should not abandon it.'' (JA)
USC-MSA web (English) reference: Book 23, Hadith 13 (JA)
Arabic reference (JA): Book 23, Hadith 1044 (JA)