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(Date of issue: October 2015, Version: 2)

This is a UKTIS monograph for use by health care professionals. For case-specific advice please contact UKTIS on 0344 892 0909. To report an exposure please download and complete a pregnancy reporting form. Please encourage all women to complete an online reporting form.

A corresponding patient information leaflet on A2RA use in pregnancy is available at


Angiotensin-II receptor antagonists (azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, and valsartan) are typically used in the treatment of hypertension where angiotensin converting enzyme (ACE) inhibitors have not been tolerated, but may also be used in the management of heart failure and diabetic nephropathy.

There are limited data on the use of angiotensin-II receptor antagonists (A2RAs) in human pregnancy, however effects are expected to be similar to those of the ACE inhibitors for which there is considerably more data. There is insufficient evidence to determine whether first trimester exposure to ACE inhibitors/A2RAs is associated with an increased risk of congenital malformation or spontaneous abortion. Data are also insufficient to quantify the risk of preterm delivery, low birth weight, intrauterine death or adverse neurodevelopmental outcome.

Angiotensin-II receptor antagonist use during the second or third trimesters is associated with a well-described, potentially severe fetopathy, characterised by an/oligohydramnios and associated sequelae, including renal tubular dysgenesis, neonatal anuria, hypocalvaria, pulmonary hypoplasia, persistent patent ductus arteriosus, mild to severe intrauterine growth restriction, and increased risk of fetal or neonatal death. Due to the risk of fetopathy, use of A2RAs in the second and third trimester is generally contraindicated. A2RA use during this period should be reserved for cases of severe maternal illness that cannot be managed using alternative classes of antihypertensive medication.

NICE guidelines advise that women taking A2RAs should switch medication before a planned pregnancy, or stop on detection of an unplanned pregnancy due to the high risk of fetopathy. NICE guidelines identify labetalol as the preferred antihypertensive for use during pregnancy. Alternative treatments for chronic or gestational hypertension include methyldopa and nifedipine, and the final choice will depend on expected efficacy as well as the side-effect profile for both the pregnant woman and the fetus/neonate.

Where A2RA use in pregnancy is required, discussion with a maternal and/or fetal medicine specialist is advised to ensure regular maternal review and fetal monitoring for evidence of A2RA fetopathy. All pregnant women and those of childbearing potential who are treated with an A2RA should be fully informed of the fetal risks. Discussion with UKTIS is recommended.

This document is regularly reviewed and updated. Only use full UKTIS monographs downloaded directly from to be sure you are using the most up-to-date version. The summaries of these monographs are openly available on

This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to health care professionals at

If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.

If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.

Disclaimer: Every effort has been made to ensure that this monograph was accurate and up-to-date at the time of writing, however it cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes of the measures recommended. The final decision regarding which treatment is used for an individual patient remains the clinical responsibility of the prescriber. This material may be freely reproduced for education and not for profit purposes within the UK National Health Service, however no linking to this website or reproduction by or for commercial organisations is permitted without the express written permission of this service. This document is regularly reviewed and updated. Only use UKTIS monographs downloaded directly from or to ensure you are using the most up-to-date version.