Teratogenicity
World Health Organization recommendation on Maternal Supplementation During Pregnancy states that "health benefits are expected for the mother and her developing fetus with little risk of detriment to either, from a daily supplement not exceeding 10,000IU vitamin A (3000mcg RE) at any time during pregnancy." Preformed Vitamin A refers to retinyl palmitate and retinyl acetate.
http://whqlibdoc.who.int/hq/1998/WHO_NUT_98.4_eng.pdf
Read more about this topic: Retinyl Palmitate