KANSAS CITY, Mo. – The case of a Kansas sperm donor being sued by the state for child support underscores a confusing patchwork of aging laws that govern assisted reproduction in the United States and often lead to litigation and frustration among would-be parents.

Complex questions about parental responsibility resurfaced late last year, as Kansas officials went after a Topeka man who answered a Craigslist ad from a lesbian couple seeking a sperm donor. Because no doctor was involved in the artificial insemination, the state sought to hold William Marotta financially responsible for the child when the women split up and one of them sought public assistance. A hearing is set for April.

Many states haven't updated their laws to address the evolution of family structures – such as same-sex families, single women conceiving with donated sperm or artificial inseminations performed without a doctor's involvement. At-home insemination kits are inexpensive, and obtaining sperm from a friend, or even a donor met over the Internet, allows women to avoid medical costs that generally aren't covered by insurance.