The only way this option could be possible would be by looking for a natural sperm donor, which basically involves one of the partners engaging into sexual intercourse with a man. However, this practice is totally unadvisable for various reasons.
On the one hand, his semen has not been screened for infectious, genetic and viral diseases likely to be transmitted to offspring. On the other hand, legal problems may rise regarding the parental responsibilities and rights of the donor.
Read the full article on: Assisted reproduction for homosexual women: becoming lesbian moms ( 80).

Andrea Rodrigo
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia. Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia along with the Valencian Infertility Institute (IVI). Postgraduate course in Medical Genetics.