Beginning with a discussion of sexual reproduction at the molecular and cellular level, this volume of the Encyclopedia of the Human Body discusses the reproductive organs, hormones, conception through childbirth and development after birth including puberty. The history of research on the reproductive system is presented and the future of research in this field is considered. Current controversies and dilemmas are also explored. Reproductive system diseases and disorders, symptoms and treatments are discussed, including infertility, sexually transmitted diseases, including HIV and AIDS, complications with pregnancy, and genetic diseases such as Huntington's disease. This reference concludes with a discussion of ethics, a comprehensive glossary, and resources for further information including web sites and contact information for organizations and national health institutions.