The Independent Pharmacy

Using Metronidazole In Pregnancy: Everything You Need To Know

Andy Boysan
Andy BoysanBPharmDirector & Superintendent Pharmacist

Reviewed on 30 Nov 2023

If you’ve been diagnosed with Bacterial Vaginosis (also known as BV), it can feel embarrassing and uncomfortable. However, the good news is that it’s now easy to buy effective treatments like Metronidazole online from The Independent Pharmacy. But can you use Metronidazole during pregnancy?

If you’re pregnant and you have BV, you probably have some questions about using a treatment like Metronidazole. Is it safe to use? Will continuing treatment harm your baby or be a risk to the pregnancy?

In this post, we’ll be answering these questions and more — providing you with a clear picture of what it means to use Metronidazole in pregnancy.

Metronidazole and pregnancy

Metronidazole is an antimicrobial medicine which is the first-line treatment for bacterial vaginosis (BV) and other vaginal infections. It is normally taken in 400mg tablets twice a day, for a seven-day course. You can find out more about Metronidazole on our ‘What is Metronidazole?’ page.

Alternatively, you can also use a gel or cream containing metronidazole to treat BV; Zidoval is a vaginal gel that contains metronidazole.

Both Metronidazole tablets and gels containing metronidazole can be used during pregnancy, but are generally only recommended if your doctor or midwife decides that the potential benefit outweighs the risk.

Metronidazole 400mg Tablets
Metronidazole 400mg Tablets
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Is it safe to use Metronidazole during pregnancy?

Metronidazole can sometimes be used during pregnancy, and the chance of any risk to the health of the baby is unlikely, however any decision to take medicines during pregnancy should weigh up the possible risks and benefits. It should never be used during the first trimester of a pregnancy.

Vaginal infections like BV normally don't cause any problems during pregnancy, however there can be a small risk to the health of your unborn child, so it is usually thought best to treat them; if untreated, some infections may increase your chance of going into premature labour.

If you are pregnant and you have BV, you should speak to your doctor or midwife about how to proceed; they will advise you on the safest route to take to ensure the health of you and your baby. It is not safe to treat BV during pregnancy online.

Can taking Metronidazole during early pregnancy increase the risk of miscarriage?

Taking Metronidazole during early pregnancy is not thought to increase the risk of miscarriage, however, it is not recommended for use within the first trimester.

A number of studies have been carried out to look into the likelihood of Metronidazole increasing the chance of miscarriage, and none have found a connection. In one small study, there did appear to be a possible link between using Metronidazole during early pregnancy and miscarriage; however, it was unclear whether this increased risk was due to the medication or from the effects of the vaginal infection being treated.

If you want to find out any more about the general risks or side effects of taking Metronidazole, you can visit our Metronidazole side effects page.

Can taking Metronidazole during pregnancy cause birth defects?

It is very unlikely that taking Metronidazole during pregnancy can cause birth defects or any other harm to the unborn baby.

There are currently no studies or data to suggest that there is a risk of birth defects or other harm to the unborn baby. The same goes for general growth and low birth weight.

As an expecting mother, you will be offered a 20-week scan — during this, a medical professional will look for any birth defects or other problems, and will check that the baby is growing as expected. Extra monitoring or scans are not usually required specifically for pregnant women using Metronidazole at the advice of their doctor.

If you are concerned about any risks to the health of your baby, speak to your doctor.

Metronidazole and breastfeeding

The patient information leaflet for Metronidazole suggests that breastfeeding is not advised whilst taking the tablets and for up to 24 hours after you have finished the course. It is a good idea to speak to your doctor or healthcare provider to see what they would recommend.

Metronidazole is absorbed into breast milk quite easily, although the dose in breast milk is much lower than that in your bloodstream. This would still mean, though, that if you are nursing a newborn, you will be passing a small dose of Metronidazole onto the infant.

This dose is much smaller if you use a topical gel like Zidoval rather than oral Metronidazole tablets. If you do decide to use a cream or gel to treat BV while you are nursing, it is important that you do not accidentally get it on your breasts — and if you do, wash it off immediately before feeding your baby.

As with using Metronidazole in pregnancy, it is best to speak to your doctor about whether you should be using Metronidazole whilst breastfeeding. They may recommend using it if the potential benefits outweigh the risks. They will also be able to answer any questions you have.


Metronidazole is a very safe and effective antimicrobial medicine used to treat bacterial vaginosis (BV) and other vaginal infections. Using Metronidazole in pregnancy is a complex decision and should be made by your doctor based on the stage of your pregnancy, your medical condition and symptoms, as well as your medical history.

It is worth noting that using Metronidazole breastfeeding can result in a small dose of Metronidazole being passed to the nursing infant so it's not usually advised.

It is always best to inform your doctor if you have BV or any other vaginal infections during your pregnancy journey — they will be able to advise you on the best course of action if you are concerned about BV and any health risks to yourself or your baby.

For more information on bacterial vaginosis, you can visit our BV treatment page.


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