If you’ve ever had cold sores — those annoying, painful, tiny, fluid-filled blisters that usually form around your mouth and on your lips — you know how inconvenient they can be.
But also if you’ve ever had cold sores (and therefore already have the virus that causes them), did you know they can recur, especially when you’re under stress or are undergoing hormonal fluctuations?
Stress and hormonal changes. That sounds an awful lot like pregnancy.
Cold sores in pregnancy aren’t unheard of, and they don’t usually have any impact on your growing baby. So first, let out a deep sigh of relief. Next, read on — because there are still important things to know about cold sores if you’re expecting.
Cold sores are caused by a virus — the herpes simplex virus (HSV). Of the two types of HSV, cold sores are generally caused by HSV-1, whereas genital herpes is usually a result of exposure to HSV-2. There have been a few instances where HSV-1 sores have been found in the genitals and vice versa.
Once you’ve had a cold sore (oral herpes), the virus remains in your system for life — it’s just not active unless you have a current outbreak.
But when we say that stress and hormones can cause the virus to reactivate, it’s important to know that stress and hormones don’t cause the virus in the first place.
If you’ve never had HSV, you can only get it through contact with someone who has. When it comes to a first-time cold sore infection, this can happen via activities like:
- sharing food or utensils
- using someone else’s ChapStick or lip gloss
- oral sex
Here’s the really good news: If you already have the virus that causes cold sores, and you have an outbreak of oral herpes during pregnancy, it’s most likely not going to have any impact on your growing baby.
Cold sores are a localized infection, usually around the mouth area. They don’t typically cross the placenta and reach your baby.
When you get the virus for the first time, your body hasn’t developed any protective antibodies to it yet. And while HSV-1 is usually associated with oral herpes, it can cause a genital herpes outbreak, which can be dangerous to your baby — especially as they pass through the birth canal.
Birth-acquired herpes is serious. However, it’s a concern with genital rather than oral herpes. That being said, because the same virus can cause both, it’s important to talk to your OB about any cold sores during pregnancy.
The most common treatment for cold sores is docosanol (Abreva), an over-the-counter topical cream. But the Food and Drug Administration hasn’t evaluated it for safety in pregnancy.
If you’ve had herpes in the past, your doctor may recommend antivirals — like acyclovir or valacyclovir — starting at week 36 and continuing until delivery of your baby, even if you don’t have a current outbreak of lesions around the genital area. This helps prevent reactivation and spread of the virus to the genital area.
This precaution is because you shouldn’t expose your baby to herpes in the vaginal area during delivery.
Alternatively, your doctor may suggest a cesarean delivery, which avoids the birth canal altogether — something that’s especially important if you have a current outbreak of genital herpes.
Cold sores are highly contagious, despite the fact that they won’t affect your baby in the womb. If you have them after your baby is born, avoid kissing those adorable little cheeks or touching any sores and then touching your newborn without first washing your hands with soap.
In the extremely rare event that you have cold sores on either breast, avoid breastfeeding from that breast while you’re still contagious.
Your cold sores are contagious until they crust over, at which point they’ll start to heal.
If you do pass a cold sore infection on to your newborn, it’s known as neonatal herpes. While not as serious as the birth-acquired version, it can still cause serious complications in a baby who hasn’t yet developed a robust immune system.
The cold sore on your mouth is likely to be more of an annoyance to you than a serious risk to your developing baby, particularly in your first two trimesters of pregnancy and especially if you’ve had one before. But you should still let your OB know about it.
The virus that causes cold sores — usually HSV-1 — can also cause genital herpes, which is more of a risk to your pregnancy and growing little one.
If you have an outbreak in your third trimester — or if you acquire the virus for the first time in your third trimester — your doctor may want you to follow certain treatment or precautionary guidelines, like antivirals or a cesarean delivery.