Muhammad bin Umar bin Waqid (may Allah have mercy on him) said concerning Malik bin Anas (may Allah have mercy on him) that his mother carried him in her womb for three years; that is, Malik bin Anas (may Allah have mercy on him) remained in his mother's womb for three years.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العدد / 15556