- Donors must not be pregnant. Pregnancy is an absolute contraindication under this protocol. The effects of cytokine administration on a fetus are unknown. Donors of childbearing potential must use an effective method of contraception. Effective forms of contraception include one or more of the following: intrauterine device (IUD), hormonal (birth control pills, injections, or implants), tubal ligation/hysterectomy, partners vasectomy, barrier methods, (condom, diaphragm, or cervical cap), or abstinence.