In the past, the identity of a child's mother was always clear. However, thanks to reproductive technologies, a woman can gestate, nourish, and give birth to a child to whom she is not genetically connected. In addition, a person can be legally male and conceive, carry, and give birth to a child. The law has had to adapt to these circumstances. This chapter looks at how the law has defined parentage. It considers reproductive technologies and the various permutations of conception that exist today. It then turns to parental responsibility before concluding by looking at the position of unmarried fathers.