Cetirizine

What is it?

Cetirizine (Benadryl one-a-day®, Zirtek®, Piriteze®, Pollenshield®) is a non-drowsy antihistamine used to treat allergies.

When deciding whether to use cetirizine during pregnancy it is important to weigh up the potential benefits to your health and wellbeing against any possible risks to you or your baby, some of which may depend on how many weeks pregnant you are. Your doctor or specialist will be able to help you make decisions about your treatment.

What if I have already taken cetirizine during pregnancy?

If you are taking any medicines while pregnant you can discuss this with your doctor. You can then decide together whether ongoing treatment is appropriate, and, if so, your doctor will ensure that you are taking the most effective dose.

Can taking cetirizine in pregnancy cause birth defects in the baby?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.

There is no evidence that pregnant women taking cetirizine have a higher chance of having a baby with a birth defect. However, because fewer than 500 pregnancies where the mother took cetirizine during the first trimester have been studied, further research is required to confirm these findings.

Can taking cetirizine in pregnancy cause miscarriage?

The likelihood of miscarriage has been assessed in around 430 women taking cetirizine in early pregnancy. Although the studies do not raise concern that cetirizine causes miscarriage, ongoing research is ideally required to confirm this.

Can taking cetirizine in pregnancy cause preterm birth, or my baby to be small at birth (low birth weight)?

No links between cetirizine use in pregnancy and pre-term birth (before 37 weeks of pregnancy) or low birth weight (<2500 g) were found in any of the three studies that investigated these outcomes.

Can taking cetirizine in pregnancy cause stillbirth?

There is no known link between cetirizine use in pregnancy and stillbirth. However, the chance of stillbirth has been investigated in fewer than 200 pregnant women taking cetirizine, so ongoing research is required.

Can taking cetirizine in pregnancy cause learning and behavioural problems in the child?

A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.

No studies have assessed the learning and behaviour of children exposed in the womb to cetirizine.

Will my baby need extra monitoring?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Taking cetirizine in pregnancy would not normally require extra monitoring of your baby. 

Are there any risks to my baby if the father has taken cetirizine?

We would not expect any increased risk to your baby if the father took cetirizine before or around the time you became pregnant.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.