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30-10-2011 | Cardiology | Article

Maternal hypertension linked to increased heart defect risk in newborns


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MedWire News: Maternal hypertension during the first trimester of pregnancy is associated with an increased risk for heart defects in babies, report US researchers.

The team found that children of women who used antihypertensive drugs, and not just ACE inhibitors as previously thought, as well as the children of those with untreated hypertension during the first trimester, had elevated risks for heart malformations.

It is therefore likely that the mothers' underlying hypertension increases the risk for birth defects in their babies, write De-Kun Li (Kaiser Permanente, Oakland, California) and co-authors.

They conducted a population-based retrospective cohort study of 465,754 mother-infant pairs from the Kaiser Permanente Northern California database (1995-2008). The data from this database were then linked to the Pharmacy Information Management System, to ascertain use of ACE inhibitors and other antihypertensives during pregnancy.

The findings, reported in the BMJ, showed that the prevalence of ACE inhibitor use in the first trimester occurred in 0.9 per 1000 pregnancies and use of other antihypertensive medications in 2.4 per 1000.

After adjusting for maternal age, ethnicity, parity, and obesity, women who used ACE inhibitors during the first trimester had a 54% higher risk for congenital heart defects in their children, at 3.9%, than did normal controls (no diagnosis of hypertension or use of any hypertensive drug), at 1.6%.

However, this association was not confined to use of ACE inhibitors. Indeed, use of other antihypertensive drugs during the first trimester was associated with a 52% increased risk for congenital heart defects.

"Our results do not support the argument that maternal use of ACE inhibitors in the first trimester significantly increases the risk for fetal malformations more than any other antihypertensive drug," explain the authors.

Furthermore, the presence of untreated hypertension during the first trimester was associated with a 41% increased risk for congenital heart defects.

Further analysis revealed that compared with the women with untreated hypertension, those who used antihypertensive drugs in the first trimester did not have a significantly increased risk for congenital heart defects.

The authors conclude: "Our finding suggests that it is likely the underlying hypertension, rather than the use of antihypertensive drugs in the first trimester, that increases the risk for malformations in offspring."

MedWire ( is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

By Piriya Mahendra

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