Herpes in pregnancy is manageable. The biggest risk is a first-time HSV infection during late pregnancy. For longstanding HSV, the baby risk at delivery is well under 1% with proper management.

Herpes and Pregnancy — What You Actually Need to Know

If you have herpes and you're pregnant (or trying to be), the most common concern is: will the baby be okay? In nearly all cases, yes. Modern obstetric management makes herpes in pregnancy safe in the vast majority of cases.

Here's the practical picture.

The risk depends on timing

The biggest single factor is when you acquired HSV in relation to the pregnancy:

Longstanding HSV (diagnosed before pregnancy)

Your body has antibodies that protect the baby
Risk to the baby at delivery: ~0.04% (1 in 2,500)
With management (suppressive antivirals + visual inspection at labor): even lower

First-time HSV during third trimester

No protective antibodies yet
Risk to baby: ~30-50%
This is the highest-risk scenario; aggressive management needed

First-time HSV during first or second trimester

Some protective antibody development by delivery
Risk to baby: intermediate (~5-10%)
Manageable with appropriate care

The clinical implication: if you're seronegative and your partner has HSV, avoid sexual exposure during late pregnancy. If you're seronegative and pregnant, your partner should consider suppressive antiviral therapy.

What pregnancy with longstanding HSV looks like

First prenatal visit

Tell your OB about your HSV history
They'll note it in your chart
No special testing needed — your existing antibody status confirms it

Routine prenatal care

Standard appointments throughout
No restrictions on activity, diet, travel (except late-pregnancy precautions if seronegative)
Watch for any outbreak symptoms; treat as you normally would

Starting around week 36 — suppressive antiviral therapy

Standard regimen:

Valacyclovir 500 mg twice daily starting at 36 weeks until delivery
OR Acyclovir 400 mg three times daily

Why: suppressive therapy reduces outbreak frequency at the time of delivery, which is the moment when transmission to baby matters. About 75% reduction in outbreak risk at labor.

Both valacyclovir and acyclovir are safe in pregnancy. Acyclovir has more accumulated safety data; valacyclovir is also used widely.

Delivery planning

No outbreak or prodrome at labor: Normal vaginal delivery
Active lesion or prodromal symptoms at labor: C-section is recommended
Visual inspection at admission

C-section rate due to HSV: about 1 in 50 women with HSV history. Most have normal vaginal deliveries.

Postpartum

Baby monitored for neonatal herpes signs (rare): fever, lethargy, seizures, vesicles, jaundice in first 6 weeks
Breastfeeding is fine unless there's a lesion on the breast
You can return to your normal antiviral regimen

What pregnancy with newly-acquired HSV looks like

This is the higher-stakes scenario but still manageable.

Acute outbreak during pregnancy

Notify OB immediately
Antiviral treatment is given (valacyclovir or acyclovir) — both safe
Outbreak resolves typically in 7-14 days

If acquired during the first or second trimester

Standard prenatal care
Suppressive antivirals from week 36 (same as longstanding HSV)
Counseling about reduced but real risk

If acquired during the third trimester (highest risk)

Aggressive management: continuous antiviral treatment, sometimes IV
Consideration of elective C-section
Coordination between OB and maternal-fetal medicine specialist
Baby will get prophylactic antiviral after delivery and close monitoring

This scenario gets escalated care because the risk is meaningfully higher.

What about HSV-1 vs HSV-2?

Both can cause neonatal herpes, but the risk profiles differ:

HSV-2 genital: Higher recurrence rate; more likely to have outbreak at delivery
HSV-1 genital: Lower recurrence rate; lower risk of outbreak at delivery; modestly lower vertical transmission

For management purposes, both are treated similarly — suppressive antiviral from week 36, C-section if active outbreak.

For HSV-1 oral cold sores during pregnancy: not a vertical transmission concern for delivery. The neonate risk is from genital HSV. But avoid kissing newborns when you have a cold sore.

Conception with HSV

For couples where one partner has HSV and the other doesn't, conception is generally straightforward:

Seronegative person attempts conception with HSV-positive partner

Suppressive antiviral for the positive partner reduces transmission risk
Avoid sex during any active outbreak or prodrome
Time conception attempts around the cycle but with these precautions

Both partners have HSV

No transmission concern between you
Standard pregnancy management for the carrying partner

Trying for pregnancy specifically

Same precautions as above
No need to "treat" your HSV before trying to conceive
Your existing antibodies will protect the baby

What NOT to worry about

Common worries that are not actually high-risk:

Outbreak during early or mid-pregnancy — not the dangerous window; treat and move on
Cold sores during pregnancy — not a vertical transmission risk (avoid newborn kissing only)
Asymptomatic shedding during pregnancy — no different from non-pregnancy risk to baby; managed by suppressive therapy at week 36
Sex during pregnancy with herpes — safe with your existing partner; same protections you normally use

Neonatal herpes — what it is

In the rare cases where vertical transmission occurs, neonatal herpes can be serious:

Skin/eye/mouth form (least serious; treatable)
Central nervous system form (more serious; treatable with IV antivirals)
Disseminated form (most serious; high mortality without treatment)

Modern treatment with IV acyclovir has dramatically improved outcomes. Death rates have dropped from ~50% to under 10% with prompt diagnosis and treatment.

Signs of neonatal herpes in first 6 weeks:

Fever or low body temperature
Lethargy, poor feeding
Vesicles or rash
Seizures
Jaundice
Difficulty breathing

If any appear, urgent pediatric evaluation. Most babies of HSV-positive mothers never develop these — but knowing the signs allows fast action if they do.

Coordination of care

Pregnancy with HSV usually involves:

OB-GYN — primary care during pregnancy
Maternal-fetal medicine specialist — for higher-risk scenarios (first-time HSV in late pregnancy, immunocompromised mother)
Pediatrician — postpartum monitoring of baby
Primary care or HSV specialist — for ongoing herpes management

Most pregnancies with HSV require just the standard OB.

Bottom line

Longstanding HSV in pregnancy: baby risk under 1% with management. Suppressive antiviral from week 36; visual inspection at labor; C-section only if active outbreak.
New HSV in third trimester: higher risk; aggressive management needed; coordinate with maternal-fetal medicine.
Conception attempts are not affected by your HSV status.
Modern obstetric care has made HSV in pregnancy a manageable situation in nearly all cases.

If you're newly pregnant and have HSV: tell your OB at the first visit. The conversation is routine for them. Most pregnancies proceed normally.

For more on herpes — outbreak management, transmission, treatment options — see our herpes pillar guide. For broader STI-and-pregnancy info: can I still have kids with an STI.