Could a future form of contraception be based on anti-sperm antibodies?

To avoid the use of hormonal contraception in women, which can cause bloating, nausea or irregular bleeding, researchers from the University of North Carolina are currently working on a new technology to avoid pregnancy. The advances are published in Science Translational Medicine. "Many women avoid hormonal contraception because of real and perceived side effects," noted Samuel Lai, professor in the Division of Pharmacoengineering and Molecular Pharmaceutics at the UNC Eshelman School of Pharmacy.

The idea was inspired by cases of immune infertility. This autoimmune disease causes women to produce antibodies against sperm in the female reproductive system, preventing them from reaching the egg.

The researchers took these antibodies from a woman suffering from this disease and modified them to improve an effect called "agglutination." They then proceeded to a test phase on sheep. Administered directly into the vagina, this contraceptive had a success rate of 99.9%.

The results were also promising in that long-term fertility was not affected. Unlike with the pill, whose effects can last up to several months, this solution could allow a woman wishing to have a child to regain her fertility right after ceasing treatment with this contraceptive.