Can STDs Be Transmitted Through Breastfeeding? What Parents Need to Know

Breastfeeding is widely recognized as one of the healthiest ways to nourish an infant, providing essential nutrients and immune protection. However, many parents wonder whether sexually transmitted diseases (STDs) can be transmitted through breastfeeding.

While most STDs do not pass through breast milk, certain infections—such as HIV and cytomegalovirus (CMV)—can pose risks if left untreated. Understanding how these infections spread, how to reduce transmission risks, and when to get tested is essential for new and expecting parents.

This article explores the risks of STD transmission through breastfeeding, CDC guidelines on safe feeding practices, and testing recommendations for mothers before and during pregnancy.

Can STDs Be Passed Through Breast Milk?

Not all STDs can be transmitted through breastfeeding. However, some viral infections have been documented to pass from mother to infant through breast milk.

STDs That Can Be Transmitted Through Breastfeeding

1. HIV (Human Immunodeficiency Virus)

   • HIV can be transmitted through breast milk, especially if the mother is not on antiretroviral therapy (ART).

   • According to the Centers for Disease Control and Prevention (CDC), the risk of HIV transmission through breastfeeding is as high as 15-20% if the mother is not receiving ART.

   • With effective ART treatment, the risk drops below 1%, but formula feeding is still recommended in countries where safe alternatives are available.

2. CMV (Cytomegalovirus)

   • CMV is a common virus that can be present in breast milk and passed to infants.

   • In healthy full-term babies, CMV infection is usually harmless, but premature or immunocompromised infants may develop serious complications.

STDs That Do NOT Spread Through Breastfeeding

Most bacterial STDs, including chlamydia, gonorrhea, and syphilis, do not pass through breast milk. However, direct contact between sores and the baby’s mouth during feeding can pose a risk.

• Syphilis – While syphilis cannot be transmitted through breast milk, active syphilis sores on the breast can infect the baby.

• Herpes (HSV-1 and HSV-2) – If a mother has active herpes lesions on or near the breast, direct contact should be avoided to prevent transmission.

• Hepatitis B and C – Neither hepatitis B nor C spreads through breast milk, but open sores or cracked nipples can expose infants to infected blood.

For more details, refer to the CDC’s guidelines on HIV and breastfeeding: CDC - Breastfeeding and HIV.

How to Reduce the Risk of STD Transmission While Breastfeeding

1. HIV-Positive Mothers: Follow CDC Breastfeeding Guidelines

If a mother is HIV-positive, the CDC strongly recommends avoiding breastfeeding, even if she is receiving ART.

• Alternative feeding options such as infant formula or donor milk are advised in regions where safe, clean water is available.

• In resource-limited settings, ART can significantly lower transmission risks, but breastfeeding should still be carefully managed under medical supervision.

2. Safe Feeding Options for Mothers with CMV

For healthy full-term infants, breastfeeding with CMV is usually safe. However, if the baby is premature or immunocompromised, consider:

• Pasteurization of breast milk, which can reduce CMV transmission risk.

• Consulting a pediatric specialist before deciding to breastfeed.

3. Managing Herpes and Syphilis Risks While Breastfeeding

If a mother has active herpes sores or syphilitic lesions on or near the breast, she should:

• Avoid breastfeeding from the affected breast until sores have fully healed.

• Pump and discard milk from the infected breast if sores are present.

• Wash hands thoroughly before touching the baby or breast pump equipment.

4. Ensure Safe Nipple and Breast Health

Mothers who test positive for hepatitis B, hepatitis C, or syphilis should:

• Monitor for cracked or bleeding nipples, as blood exposure could increase transmission risk.

• Use lanolin-based creams or hydrogel pads to prevent nipple damage.

• Seek medical treatment if they experience prolonged breast pain, sores, or swelling.

STD Testing Before and During Pregnancy: Why It’s Important

Routine STD screening before and during pregnancy is critical to:

• Detect infections early and begin treatment before the baby is exposed.

• Reduce transmission risks through appropriate medications and lifestyle adjustments.

• Ensure a safe delivery by identifying potential complications.

When Should Pregnant Women Get Tested for STDs?

The CDC recommends STD screening at key points in pregnancy:

✔ First prenatal visit – Routine tests for HIV, syphilis, hepatitis B, and chlamydia.
✔ Third trimester (28-32 weeks) – Retesting for HIV and syphilis in high-risk individuals.
✔ At delivery (for high-risk mothers) – Additional screening if STD status is unknown.

Regular testing ensures early intervention and safe breastfeeding decisions.

Recommended STD Tests for Expecting Mothers

• Comprehensive 10-Test STD Panel – Covers common infections that may impact pregnancy or breastfeeding.

• HIV Testing – Essential for preventing mother-to-child transmission.

• Syphilis Screening – Required in most states during pregnancy.

For confidential STD testing, consider our partner STDCheck for fast, private results.

When Should a Mother Avoid Breastfeeding?

While breastfeeding is safe for most women with STDs, it should be avoided if:

• The mother has HIV and alternative feeding options are available.

• There are active syphilis or herpes sores on the breast.

• The baby is premature and at risk of CMV complications.

• The mother has severe hepatitis complications or cracked, bleeding nipples.

If a mother is unsure about her breastfeeding safety, consulting with a pediatrician or infectious disease specialist is the best course of action.

Conclusion

While most STDs do not pass through breast milk, some infections—particularly HIV and CMV—can pose risks to infants. By following proper medical guidance, choosing safe feeding alternatives, and ensuring routine STD testing, mothers can make informed decisions about breastfeeding.

Key Takeaways:

• HIV can be transmitted through breast milk, so the CDC recommends formula feeding when possible.

• CMV can be present in breast milk but usually does not cause harm to full-term infants.

• Syphilis and herpes are not transmitted through breast milk but can spread if sores are present on the breast.

• Routine STD testing before and during pregnancy is essential to ensure safe breastfeeding practices.