Section 1
Which methods help protect sexual health?
Barrier protection
Correct and consistent condom use reduces the transmission of many STDs and helps prevent unplanned pregnancy.
Regular check-ups
Discuss your sexual history, symptoms, partners and practices so a clinician can recommend suitable tests.
Vaccination
Ask which vaccines are appropriate for you, including HPV and hepatitis vaccination where indicated.
Pregnancy prevention
Use a suitable contraceptive plan when pregnancy is possible; barriers and contraception can be used together.
Use a new barrier for every act and when changing between body sites. Check the expiry date and package, open it without sharp objects, follow the product instructions and hold the base during withdrawal. Never use two external condoms together, because friction can increase breakage. Internal and external condoms should not be used at the same time.
Vaccination and contraception solve different parts of the plan. HPV and hepatitis B vaccination can prevent specific infections when appropriate, while contraception reduces pregnancy risk. PrEP can substantially reduce the chance of acquiring HIV for people who are eligible, but it does not prevent other STDs or pregnancy. A clinician can help combine methods around health history, medicines and personal priorities.
Source: World Health Organization — CondomsCDC — Condom use overviewCDC — STD risk and oral sexCDC — Clinical guidance for PrEPNEPHU — What is Safe Sex? (video)
Section 2
Why can unprotected sex still carry risk?
Unprotected sex should not be assumed safe because a partner looks well, has no symptoms or because sex happens during menstruation. Infection and pregnancy risk can be present without an obvious warning.
No visible symptoms
Many STDs can be present and transmitted without sores, discharge, pain or other noticeable symptoms.
Visual checks are unreliable
Looking at a partner cannot confirm their status; testing and honest communication are more useful.
Cycles vary
Irregular or changing cycle lengths make fertile windows difficult to predict precisely.
Sperm can survive
Sperm may remain viable for up to five days, so sex during a period can still lead to pregnancy if ovulation follows soon after.
Risk is shaped by the activity, body sites, barrier use, vaccination, current infections and whether a partner is receiving effective treatment. Oral sex can transmit several infections even when pregnancy is not possible. Sharing sex toys without cleaning them or changing a barrier may also transfer body fluids between partners or body sites.
Source: ACOG — Fertility awareness and pregnancy timingCDC — Getting tested for STDsCDC — STD risk and oral sexCDC — Clinical guidance for HIV PEPNEPHU — What is Safe Sex? (video)