References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
STIs during pregnancy can have serious implications for both mother and baby if left untreated. UK antenatal care routinely screens for several STIs early in pregnancy, and treatment is effective and safe. Understanding what’s screened, what to watch for and how infections are managed helps you have the healthiest pregnancy possible.
Here’s what you need to know.
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Routine Antenatal STI Screening
In the UK, pregnant women are routinely offered testing for:
| Infection | When Tested |
|---|---|
| HIV | First antenatal appointment |
| Syphilis | First antenatal appointment |
| Hepatitis B | First antenatal appointment |
| Rubella immunity | First antenatal appointment |
| Chlamydia | Offered in some areas |
| Gonorrhoea | Offered if at risk |
Why Screening Matters
- Early detection allows prompt treatment
- Treatment in pregnancy protects the baby
- Preventive measures at birth can stop transmission
- Some STIs have specific management plans during delivery
Effects on the Baby
HIV
Without treatment, mother-to-baby transmission is 15-45%. With effective ART and proper management, the risk drops to under 1%.
Syphilis
Untreated syphilis can cause stillbirth, preterm birth or congenital syphilis, which can affect multiple organs. Treatment with penicillin during pregnancy cures the infection and protects the baby.
Hepatitis B
Mother-to-baby transmission can cause lifelong infection in the baby. Preventive measures at birth — hepatitis B vaccine and immunoglobulin — almost completely prevent this.
Chlamydia and gonorrhoea
Can cause eye infection (ophthalmia neonatorum) in newborns. Also associated with preterm birth and low birth weight. Treatment during pregnancy prevents these issues.
Herpes
Most mothers with herpes have healthy babies. Active outbreaks at delivery can rarely cause neonatal herpes, a serious infection. Caesarean delivery is sometimes offered if an outbreak is present at labour.
HPV
Usually doesn’t affect the baby. Rarely, HPV can cause a condition called laryngeal papillomatosis in infants.
Safe Treatments in Pregnancy
- Most antibiotics used for bacterial STIs are safe
- HIV treatment is continued or started; pregnancy-safe regimens are chosen
- Penicillin for syphilis is standard and safe
- Aciclovir for herpes is safe
- Some drugs need adjustment or substitution
Preventing STIs in Pregnancy
- Use condoms with new partners
- Get screened as part of routine antenatal care
- Your partner should also consider testing
- Avoid sharing personal items that might transmit bloodborne infections
If You Test Positive
Specialist antenatal and HIV (or sexual health) teams will work together to:
- Start or optimise treatment
- Plan your delivery
- Arrange neonatal prevention
- Support you with any emotional or practical concerns
Read more: Getting pregnant with HIV | Pregnancy and birth with HIV | What is HIV?
Frequently Asked Questions
Will STIs harm my baby?
Untreated STIs can cause problems. Early screening and treatment virtually eliminate most risks.
Is STI testing in pregnancy compulsory?
Screening is routinely offered, but you can opt out. Most women accept testing given the clear benefits.
Can I have a normal delivery with HIV?
Yes, if your viral load is undetectable at the end of pregnancy. Vaginal delivery is often recommended.
Related reading
- Getting Pregnant When You Have HIV
- How STIs Affect Pregnancy and Breastfeeding
- Should I Be Tested for STIs During Pregnancy?
- STI Treatments During Pregnancy
- Safer Breastfeeding Rules for Women Living with HIV
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
