Sexual behavior and risk for pelvic inflammatory disease.

Sexual behavior characteristics of 35 patients with pelvic inflammatory disease (PID) and 44 healthy controls was studied prospectively. Patients with PID had sex more often than did controls (P less than 0.001). The mean number of sexual partners or age at first intercourse did not differ significantly between cases and controls. PID patients more often had oral sex than controls (P less than 0.05). These results suggest that sexual behavior characteristics may be important risk factors for PID, and should be prospectively studied in larger populations.