Short answer
If you are trying to become pregnant or could become pregnant, STI testing is preventive care for you, your partner, and a future baby. Testing before pregnancy can help you find and treat infections earlier. Once pregnancy is confirmed, CDC recommends early prenatal testing for HIV, hepatitis B, hepatitis C, and syphilis during each pregnancy, with chlamydia and gonorrhea testing for people younger than 25 and others with increased risk.
Before pregnancy versus already pregnant
| Timing | Useful focus | Why it matters |
|---|---|---|
| Before trying to conceive | Discuss recent STI testing, partner testing, vaccines, symptoms, and any new or multiple partners. | Preconception care can catch infections before pregnancy and reduce uncertainty later. |
| Positive pregnancy test or first prenatal visit | Ask about CDC-recommended pregnancy screening for HIV, syphilis, hepatitis B, hepatitis C, chlamydia, and gonorrhea. | Some infections can be transmitted during pregnancy or birth, and treatment or linkage to care can reduce harm. |
| New risk during pregnancy | Ask whether repeat testing is needed in the third trimester or at delivery. | CDC recommends repeat testing for some infections when risk continues or prenatal screening was missed. |
| Symptoms at any point | Seek clinical evaluation rather than relying only on a routine panel. | Symptoms may need exam, swabs, treatment, and partner steps. |
Common pregnancy-related STI and infection tests
| Test or infection | Common sample | Pregnancy-planning note |
|---|---|---|
| HIV | Blood or rapid test depending on setting. | CDC recommends HIV testing at the first prenatal visit, even if previously tested. Some people should retest later in pregnancy. |
| Syphilis | Blood tests, usually with nontreponemal and treponemal interpretation. | CDC recommends syphilis testing early in pregnancy; some people should retest at 28 weeks and delivery. |
| Hepatitis B | Blood test for hepatitis B surface antigen. | CDC says all pregnant women should be tested early in each pregnancy, even if vaccinated or tested before. See the hepatitis B and C testing guide. |
| Hepatitis C | Blood test. | CDC recommends hepatitis C testing during each pregnancy, except in settings where HCV positivity is very low. See the hepatitis B and C testing guide. |
| Chlamydia | Urine or swab. | Recommended for pregnant women under 25 and older pregnant women with increased risk; repeat testing can matter when risk continues. |
| Gonorrhea | Urine or swab, including exposed sites when relevant. | Recommended for pregnant women under 25 and older pregnant women with increased risk; ask about throat or rectal testing if those sites were exposed. |
| Herpes | Swab from a sore, or blood testing in selected situations. | Routine herpes blood-test screening is different from evaluating symptoms or partner history. Discuss sores, prodrome, or a partner with genital herpes. |
| Trichomoniasis | Swab or urine depending on test and anatomy. | Testing is often symptom- or risk-based rather than universal screening for everyone. See the trichomoniasis testing guide. |
Partner testing belongs in the plan
CDC notes that pregnant women and their sex partners should be asked about STIs and provided access to recommended screening and treatment when needed. For pregnancy planning, that means partner testing is not a side issue. It can help prevent reinfection, reduce uncertainty about timing, and make conversations about condoms, treatment, and follow-up more concrete.
Why repeat testing may come up
A negative result only answers the infections, body sites, and time period covered by that test. CDC's pregnancy timeline includes repeat testing in some situations, such as syphilis retesting for people who live in communities with high syphilis rates or have risk during pregnancy, HIV retesting for certain high-risk groups, and repeat chlamydia, gonorrhea, or hepatitis C testing when risk continues.
At-home kits versus prenatal care
At-home testing can improve access, but pregnancy planning is a situation where follow-up matters. If you are already pregnant, have symptoms, have a known exposure, or receive a positive or unclear result, use a clinician, prenatal care team, public health clinic, or sexual health clinic. They can order the right test, interpret results, arrange treatment, and coordinate partner steps. See the at-home STI tests versus clinic testing guide.
Questions to ask before or during pregnancy
- Which STI and blood tests should I complete before trying to conceive?
- At my first prenatal visit, will I be screened for HIV, syphilis, hepatitis B, and hepatitis C?
- Do I need chlamydia or gonorrhea testing based on my age, partners, symptoms, or local risk?
- Should my partner be tested or treated before we stop using condoms?
- If I have a new partner, partner with an STI, or symptoms during pregnancy, when should I repeat testing?
- Do I need hepatitis B vaccination, HIV PrEP counseling, or other prevention support?
Related Lab Intel guides
For a broader overview, start with the STI testing guide. For timing after a new partner, see the STI testing after a new partner guide. For test menus, see the full STI panel guide. For specific infections, see the HIV window period guide, syphilis testing guide, chlamydia and gonorrhea testing guide, and herpes testing guide.