Health visitors can reassure pregnant women with asthma that the condition does not usually lead to complications, a large UK study suggests.
Nottingham University researchers said asthma affected up to 10% of pregnant women, and previous studies had raised concerns it increased the risk of adverse obstetric and paediatric complications.
They compared pregnancy complications in 37,585 women with asthma and 243,434 women without asthma. The authors said the risk of most obstetric complications was similar between both groups, though miscarriage risk increased moderately in women with more severe asthma.
The authors said: Â'We found reassuring evidence of no increased risks for most adverse pregnancy outcomes.Â'
A separate study, due to be published in the journal BJOG, said non-anaemic women should avoid high does of iron supplements during pregnancy, as it may increase blood pressure.
American Journal of Respiratory and Critical Care Medicine (2007): 175: 991-997