In rare cases, people have been known to have allergic reactions to proteins in their partner's semen (semen allergy). Semen allergy isn't a direct cause of infertility.

Signs and symptoms of semen allergy include redness, burning and swelling where the semen has contacted the skin, usually in the outer genital area. Some people may have a systemic response, including hives, itching and difficulty breathing. If you experience these signs and symptoms, see your doctor. Your doctor can help determine whether you have a semen allergy. Allergy testing may be necessary.

Treatment to desensitize your allergic reaction to your partner's semen may allow you to conceive naturally. If you have a severe sensitivity to semen, intrauterine insemination — using sperm washed free of semen proteins to prevent a reaction — or in vitro fertilization may be options for conceiving.