Provided herein are methods for determining ethanol exposure of a prenatal subject, including measuring whether or not amniotic fluid stem cells collected from amniotic fluid surrounding the prenatal subject have a upregulation or expression of one or more genes of a first predetermined combination and/or a downregulation of expression of one or more genes of a second predetermined combination. Also provided are methods for determining ethanol exposure of a prenatal subject which methods include measuring alkaline phosphatase activity and/or calcium deposition of amniotic fluid stem cells collected from amniotic fluid surrounding the prenatal subject.