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18-11-2009 | Respiratory | Article

High dose ICSs in early pregnancy linked to congenital malformations


Free abstract

MedWire News: Children born to women who use high-dose inhaled corticosteroids (ICSs) during early pregnancy may face an increased risk for congenital malformations, results from a Canadian study indicate.

“Although reassuring data exist on the use of low-to-moderate doses of ICSs during pregnancy, there are inadequate data for women receiving high doses,” explain Lucie Blais (University of Montreal, Quebec) and team.

To address this, the researchers studied the use of ICSs during the first trimester by 10,099 women (13,280 pregnancies) with asthma who gave birth between 1990 and 2002. Data on congenital malformations among children born to these women were gathered from hospital records.

The average daily dose of ICSs used during the first trimester was categorized as low-to-moderate (0–1000 µg) or high (more than 1000 µg).

In total, 1257 infants were born with at least one congenital malformation and 782 were born with a major malformation.

The researchers found that children born to the 154 women who used high-dose ICSs during the first trimester of pregnancy were 1.63 times more likely to have a congenital malformation than those born to the 4392 women who used low-to-moderate dose ICSs.

Reassuringly, children born to women who used low-to-moderate dose ICSs were no more likely to have congenital malformations than those born to the 8734 women who did not use ICSs during pregnancy.

The team also notes that there were similar associations between high-dose ICS use and major malformations, but the findings did not reach statistical significance.

Blais and team conclude in the Journal of Allergy and Clinical Immunology: “Our study adds evidence on the safety of low-to-moderate doses of ICSs taken during the first trimester, but raises concerns about high doses.”

They add: “Despite the uncertainty about the direct cause of the observed increased risk, women planning a pregnancy and using high doses of ICSs should be followed closely to identify the minimal dose needed to maintain asthma under control.”

MedWire ( is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2009

By Mark Cowen

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