Anti-thyroid Rx exposure ups risk of congenital malformations

Anti-thyroid rx exposure ups risk of congenital malformations

(HealthDay)—Exposure to anti-thyroid drugs (ATDs) during the first trimester of pregnancy is associated with increased risk of congenital malformations, according to a study published online Jan. 23 in the Annals of Internal Medicine.

Gi Hyeon Seo, M.D., from Health Insurance Review and Assessment Service in Wonju-si, South Korea, and colleagues examined the correlation between maternal ATD prescriptions and in live births. Data were included for 2,886,970 completed pregnancies linked to live-born infants in 2,210,253 women between 2008 and 2014 from the Korean National Health Insurance database.

The researchers found that 0.45 percent of pregnancies were exposed to ATDs in the first . The prevalence of malformations was 7.27 versus 5.94 percent in exposed offspring versus offspring of women who were not prescribed ATDs during pregnancy (adjusted odds ratio, 1.19). Compared to pregnancies without ATD prescriptions, the absolute increases in the prevalence of congenital malformations were 8.81, 17.05, and 16.53 cases per 1,000 for propylthiouracil alone, methimazole (MMI) alone, and propylthiouracil and MMI, respectively. A high cumulative dose (>495 mg) versus a low dose (1 to 126 mg) during the first trimester in the MMI group correlated with increased risk for malformations (adjusted odds ratio, 1.87).

"Exposure to ATDs during the first trimester was associated with increased risk for congenital malformations, particularly for pregnancies in which women received prescriptions for MMI or both ATDs," the authors write.

Explore further

First trimester exposure to antithyroid drugs associated with birth defects

More information: Abstract/Full Text (subscription or payment may be required)
Journal information: Annals of Internal Medicine

Copyright © 2018 HealthDay. All rights reserved.

Citation: Anti-thyroid Rx exposure ups risk of congenital malformations (2018, January 23) retrieved 19 October 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more