Does herpes infection in pregnant women affect the fetus?

Hello, I've seen your question, and this is indeed a concern for many expectant mothers. Don't be too nervous; I'll help you sort it out, trying to explain it in simple terms.

If a pregnant woman gets herpes, will it affect the baby?

Simply put: There's a potential impact, but the level of risk entirely depends on the specific circumstances, and in the vast majority of cases, babies are born safely and healthily.

The key depends on two points: first, when you were infected, and second, whether the virus is active during delivery.

Let's discuss the situations separately:

Situation 1: You had herpes before pregnancy (Recurrent Herpes)

This is the most common situation. For example, you've had a history of oral herpes (commonly known as "cold sores") or genital herpes.

• Risk is very low: ★★☆☆☆
• Reason: Because your body already has "antibodies" to fight this virus. These antibodies act like a "protective suit" for the baby, passing through the placenta to them. So, even if you have a recurrence during pregnancy, the chance of the baby being infected is extremely low (less than 1%).
• What to do:
  1. You must inform your obstetrician about your medical history.
  2. To be safe, your doctor might recommend taking antiviral medication (like acyclovir) in your third trimester (e.g., starting at 36 weeks). The purpose is to suppress the virus and ensure it doesn't "cause trouble" during delivery.
  3. During delivery, the doctor will carefully examine your birth canal. As long as there are no active, broken herpes lesions, a vaginal delivery is usually safe.

Situation 2: You get herpes for the first time during pregnancy (Primary Herpes)

This situation is relatively rare, but the risk is indeed higher and requires special attention.

• Risk is higher: ★★★★☆

• Reason: Because it's a first-time infection, your body hasn't yet produced ready-made antibodies, so it cannot provide protection to the baby through the placenta. The virus is more likely to "do harm."

  • Infection in the first trimester (first 3 months): There's an extremely low chance that the virus could cross the placenta and affect the fetus, increasing the risk of miscarriage or fetal developmental abnormalities, but this is very rare.
  • Infection in the third trimester (last 3 months): This is the period that requires the most vigilance! Because your body has just been infected and hasn't had time to produce enough antibodies, and the baby is about to be born. If the infection occurs close to delivery, the virus in the birth canal will be very active, and the baby is highly susceptible to infection when passing through the birth canal during a vaginal delivery.

• What to do:

  1. If you experience suspected symptoms (e.g., painful blisters in the genital area), seek medical attention immediately!
  2. The doctor will prescribe medication and monitor you closely.
  3. If there are active herpes lesions during delivery, the doctor will strongly recommend a C-section! This is the most direct and effective protective measure, allowing the baby to "bypass" the virus without passing through the birth canal.

What happens if the baby gets infected? (Neonatal Herpes)

This part might make you anxious, but understanding it helps us know why we work so hard to prevent it. Although neonatal herpes is rare, its consequences are severe. There are mainly three types:

1. Skin, Eyes, and Mouth (SEM) type: Symptoms are localized to these areas, with small blisters appearing. With timely treatment, the prognosis is best.
2. Central Nervous System (CNS) type: The virus invades the brain, potentially leading to seizures and lethargy, and can result in neurological sequelae.
3. Disseminated type: The most severe type, where the virus spreads to various organs throughout the body, with a very high mortality rate.

Therefore, all the preventive measures we take are to avoid the baby reaching this stage.

To summarize the key points:

1. Don't scare yourself: Most mothers with a history of herpes have safe babies. The key is management.
2. Be honest with your doctor: During prenatal check-ups, whether you have a "long-standing history" of oral or genital herpes, or new suspected symptoms during pregnancy, you must tell your doctor. This is the basis for all decisions.
3. Follow doctor's orders for medication: If your doctor tells you to take preventive medication in the third trimester, take it on time. These medications are proven and relatively safe for use during pregnancy.
4. Listen to your doctor about delivery method: If the doctor assesses a risk during delivery and recommends a C-section, you must follow their advice. This is for the baby's safety.
5. Be careful postpartum: If you or a family member has a cold sore (herpes lesion) on their mouth, absolutely do not kiss the baby, and wash your hands frequently to avoid contact transmission.

I hope this explanation can put your mind at ease a bit. The key to this matter is "being informed" and "having management," not "panic." Maintain good communication with your doctor; he/she will create the safest plan for you and your baby. Wishing you a smooth pregnancy!