The development of effective, safe, and acceptable contraceptive methods for men is an important part of preventing and reducing unintended pregnancies. NICHD invests in male contraceptive research and development, including studies of vasectomy.
Most NICHD research on vasectomy is supported through the institute's Contraceptive Research Branch (CRB), formerly the Contraceptive Discovery and Development Branch (CDDB). Branch-supported vasectomy research has focused on the procedure's long-term safety and effectiveness as well as on the development and evaluation of less-invasive surgical techniques. For example:
- CRB supported a large, national population-based case-control study in response to some studies published in the early 1990s suggesting that vasectomy might increase the risk of prostate cancer. Several other studies found no increased risk of prostate cancer among vasectomized men. Despite this conflicting evidence, urologists had been concerned enough to increase screening for prostate cancer among vasectomized men and to discourage vasectomies in men with a family history of prostate cancer. The results of the branch-supported national case-control study, published in 2002 in the Journal of the American Medical Association, were considered definitive evidence that prostate cancer was not linked with vasectomy1 (PMID: 12069674).
- CRB provided support through Family Health International for Cochrane Reviews of scalpel versus no-scalpel incision for vasectomy.
Vasectomy research is one piece of CRB’s portfolio in male contraception research and development. In addition, the branch leads the Preclinical Contraceptive Development Program to encourage and support basic, applied, and clinical studies on topics such as mechanisms that regulate sperm maturation and motility and identification of new therapeutic targets for male contraception. A group of scientists also supported by CRB are building on the promising results of their work from 2004, when they demonstrated complete and reversible contraception in male monkeys immunized with Eppin, a protein found only in the testes and epididymis (PMID: 15539605).
Additionally, CRB funds the Biological Testing Facility and Chemical Synthesis Facility through contract mechanisms. These facilities support research on the identification and development of male and female contraceptive agents.
A study supported by the Fertility and Infertility (FI) Branch evaluated the role of epididymal dendritic cells in male reproductive function. The study could have implications for both contraceptive development and treating male infertility (Project number: 1R01HD069623-01).
NICHD was actively involved in the 2001 and 2003 Expert Consultations on Vasectomy, interagency workshops that included more than 50 experts from 24 organizations, institutions, and universities. The 3-day workshops prioritized future research related to vasectomy techniques and developed guidelines for techniques in diverse health care settings. Attendees reviewed recent clinical research findings and discussed their programmatic implications. Participants also reviewed key steps needed to improve vasectomy services in Africa, Latin America, Asia, and other areas of the world.