unintended pregnancies people engage penile vaginal sex may use contraception birth control pills condom diaphragms spermicides hormonal contraception sterilization ref name nobg ref effectiveness various contraceptive methods avoiding pregnancy varies considerably depends method rather user ref name whciapn ref sexually transmitted infections rolled male condom sexual activity involves skin skin contact exposure infected person 's bodily fluids mucous membranes carries risk contracting sexually transmitted infection people may able detect sexual partner one stis example
Social science Sociology Sexology Human sexual behavior