PI (pronounced "pee-eye") can stand for partial insemination, partial intercourse, or partial insertion. It is a technique used in private free sperm donations that involves intercourse limited to the minimum required for pregnancy. This minimizes physical contact and intimacy but still allows recipients to benefit from the higher success rate of natural donation (that is to say, sexual intercourse).

Although there is some variation between how individual recipients and donors will do PI, recipients frequently ask for no kissing, no oral sex, and no exposure of or fondling of their breasts. In the strictest definition of PI, the donor tries to get himself as close to ejaculation as possible by masturbation, so that he ejaculates as soon as he inserts his penis in the recipient.

This book compiles a history of the term PI and its use in law, medicine, and the life sciences and real-life stories of pregnancies resulting from PI as told in interviews with 10 different free sperm donors.

We hope this book educates donors and recipients on additional options they may not have considered previously, and will help them to understand the expectations that arise on either side when recipients and donors decide to do PI.