Valtrex / Acyclovir is considered safe to use while pregnant

Valtrex is actually a very well studied drug. It is a prodrug for acyclovir, which has been around for 30+ years. Valtrex turns into acyclovir after it is absorbed which allows your body to get more of the drug into your system for longer (which is why you take Valtrex less frequently than acyclovir).

Although it has not been officially tested for use during pregnancy (very few drugs ever are as to do this would require testing on pregnant women … not a thing most people are happy with), it is considered safe to use when pregnant — a category “B” medication. There was at one time a pregnancy registry for acyclovir (the drug your body converts Valtrex into) that followed pregnant women. Somewhere close to 1000 women taking Valtrex while pregnant were followed and the rate of defects amongst that group was considered to be the same as for women not taking any medication. There was for a while a registry for Valtrex as well, but it ran for a shorter period of time and, although the results were similar, the number of women followed was not enough to draw as strong of conclusions.

Taking Acyclovir or Valtrex suppressively during the last weeks of pregnancy is recommended. Even though you are passing the antibodies onto your infant, the suppressive therapy should prevent you from shedding the virus and/or having an outbreak. During the last weeks of pregnancy your child is less likely to suffer any ill effects from any medication you may take. This is not to say you should not weigh your options and make your own decisions.

I took Valtrex throughout my pregnancy and my child is fine and beautiful. I was comfortable enough with the drug’s profile that I told my doctor up front that I intended to take the drug throughout my pregnancy to protect my partner.

I doubt you need to be concerned about allergic reactions, especially if you’ve taken the drug before as you would have had the reaction then. Valtrex/Acyclovir have very low allergic profiles (aka even people with a bad history of allergies normally don’t react to them). Antivirals are completely different beasts from antibiotics and just don’t wreak the havoc on your body that an antibiotic can. Valtrex/Acyclovir very specifically targets herpes by mimicking a substance the virus needs to reproduce. When the virus grabs onto the antiviral, the antiviral gets in the way of the virus being able to reproduce. The substance Valtrex/acyclovir mimics is not a substance your body needs so your body doesn’t tend to react to the drug much.

I’m trying to break down a complex bit of biochemistry here, so I may be guilty of oversimplifying how Valtrex/acyclovir works. There are some resources on the net that go into this stuff in detail and you may want to read up on them if you are interested in a more advanced explanation. – Lorraine

If you have something to say about herpes and what it’s like to be pregnant when you have herpes I’d love to hear from you. You can send me bits of advice OR your own personal story and I would be more than happy to publish it so that we can work to help people that don’t know enough about this to make a decision for themselves.

As with anything health related please see your own doctor. Our personal experiences shared do not indicate truth for everybody that is in similar situations. The information shared is based on our own personal experiences. No two herpes cases are alike.

156 thoughts on “Valtrex / Acyclovir is considered safe to use while pregnant

  1. Anna1980 – Firstly, you ARE NOT disgusting and unclean. 1 in 3 people have genital herpes! And I think it’s about the same for hpv! Secondly, your husband loves you, sweetheart. He knows you have it, he is willing to have unprotected sex with you (and has done so to produce a baby already!) and I’m sure he is of the mind, as was my husband, that there are worse things out there to worry about. I know EXACTLY how the concern over herpes can be especially when pregnant and your hormones just want to take over all mental integrity and rule you and make you worry, and I know how time consuming it is to be worried about it for so long, endlessly worried, and then when you have your perfect little baby and absolutely nothing is wrong, there’s burnoff from all that worry which it sounds like you’re still going through. I’m in my early 30s, now almost 3 months pregnant with my second child. :) I’ve had hsv2 for almost a decade. I took no valtrex with my first child because at that time, there wasn’t enough information around to convince me it was okay in early pregnancy (this was 6 years ago) so I chose not to (although I think I chose not to because I just worried about freakin everything!) And just like you, I worried when trying to conceive that I would pass it on to my husband who quite honestly couldn’t have cared less as all he ever said was that he loved me and it didn’t bother him. So I took the chance. And to this day, he still doesn’t have herpes and continues to test negative. I took valtrex when my first child was a few weeks old (to eliminate all the fear I was having at the time as sleep deprivation can make you lose the plot at times!) and took 1g a day the entire six months I breast fed my baby who, by the way, is absolutely perfect. :) I stayed on valtrex ever since, and whilst trying for our second child, I decided to eliminate the chance of stress, worry and concern rearing it’s ugly head again (like you say you’re having about passing it onto your husband) so I decided to take it whilst trying for this baby. I would stop taking it a few days after I thought I had ovulated and could potentially be pregnant. Then I’d stop taking it and wait a couple of weeks and if I got my period, I’d just go back on it until a few days after I ovulated again (when we finished ‘trying’ that month), until I fell pregnant. I’ve decided to not take it in the first trimester, although I’ve found studies in Europe that state thousands of women fall pregnant on valtrex and don’t know they have and there has been no increase in fetal abnormalites as per the rate of the normal population. Two obstetricians I’ve spoken with told me to just take it until I fell pregnant, but I still chose to take it up till about the time we conceived. So I have had absolutely hideous morning sickness lately, fatigue, and everything else associated with early pregnancy and I was certain with the hormone changes, I would get an outbreak … still haven’t! And should I have an outbreak after my first trimester, I will take a course of valtrex. I will also take it as suppressant therapy in my last trimester (from 36 weeks I believe it is) as this pregnancy, I want to have a normal vaginal birth. And more importantly, this time, I WANT TO ENJOY BEING PREGNANT! And not let herpes or the fear of passing it on effect me! Last time the constant concern made me develop antenatal and post natal depression and I will not let that happen again. Please be assured that your next baby will be just as perfect as the first. And remember, your baby carries your antibodies to herpes for up to 3 months after it is born. (For people reading this who think they contracted herpes during pregnancy, or who aren’t sure, it’s best to go for a caesar as you won’t have as many antibodies to it.) Oh and yes, to answer your other question, valtrex greatly reduces the shedding of the virus. Moreso than aciclovir too, as valtrex lasts longer in your system. Valtrex also greatly reduces viral load (how infectious the lesions/blisters are). And please remember that 80% of the population has hsv1. Cold sores on the mouth. This has also been reported to reduce the rate of contracting genital herpes by up to 40%. Last thing … this is the drug they give to premature babies too, to avoid any viral infections being contracted while in hospital. So that may shed abit more light on things for other people out there who are worried. I hope this helps. :)

  2. This might help a little more too … From everydayhealth.com:

    Valtrex (valacyclovir) is an antiviral medication classified by the U.S. Food and Drug Administration (FDA) as Pregnancy Category B. Studies of Valtrex performed in animals, at doses which precipitated 10 and 7 times the human plasma levels in rats and rabbits respectively, during the formation and differentiation of organs and organ systems during embryonic development, revealed no evidence of teratogenicity. However, there are no adequate and well-controlled studies evaluating Valtrex in pregnant women. According to Briggs’ Drugs in Pregnancy and Lactation, for the management of herpes in pregnancy, Valtrex is recommended for primary or first-episode infection (for 7 to 10 days), symptomatic recurrent episode (for 5 days), and daily suppression (from 36 weeks’ gestation until delivery). Experience with Valtrex in early pregnancy is limited. The Briggs’ Fetal Risk Recommendation indicates that previous experience with Valtrex in human pregnancy, either for the drug itself or drugs in the same class or with similar mechanisms of action, is adequate to demonstrate that the risk to the embryo/fetus is very low or nonexistent. According to the prescribing information, Valtrex should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. The use of Valtrex during pregnancy is patients specific and must be properly evaluated by a health care provider.

  3. Many women wonder about taking antiviral medication during pregnancy to suppress outbreaks in the third trimester. The U.S. Food and Drug Administration (FDA) has approved no drug against herpes for this purpose. Nonetheless, acyclovir is used by some physicians to treat women with genital herpes at the end of pregnancy. Small studies suggest that acyclovir taken daily during the last month of pregnancy will prevent recurrences and, therefore, decrease the need for Cesarean sections, but some experts remain concerned about the safety of fetal exposure to the medication.

    At the present time, acyclovir’s manufacturer does not recommend its use during pregnancy. On the other hand, the company has tracked the experiences of several hundred women who took the drug during pregnancy, some of them inadvertently, and the evidence to date suggests that acyclovir does not carry increased risk of birth defects or adverse pregnancy outcome. On the strength of this data, the use of daily, suppressive treatment during the last month of pregnancy is becoming increasingly common.

    H/T: ASHA

  4. Hi, I am pregnant with baby number 2 and I have recurrent genital herpes. With my first baby I didn’t take any medication but I had a c-section because the p,acenta ruptured. With this second pregnancy, I had outbreaks twice, and now a third outbreak at 33weeks, I am taking aciclovir 400 mg twice daily because I’m worried the baby might come early whilst I have an outbreak. My question is , is it safe to take aciclovir at 33weeks since they usually recommend it from 36 weeks? I am so worried, about harming my innocent baby because my mistakes.

  5. I went on suppressive therapy the last six weeks of my pregnancy with both of my kiddos. I think you’re going to be okay. Have you talked with your doctor about this?

  6. I’m currently 7 weeks. I found out I was pregnant at 6 weeks 5 days. I took an acyclovir a day when I missed days I doubled my dosage to prevent outbreaks. Im terrified, how could I have been so inconsiderate. I didn’t even know I was pregnant due to the fact I have fibroids which causes irregular cycles. Please help im going insane wordering have I harmed my unborn.

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