TY - JOUR T1 - Maternal history of miscarriages and measures of fertility in relation to childhood asthma JF - Thorax JO - Thorax DO - 10.1136/thoraxjnl-2018-212598 SP - thoraxjnl-2018-212598 AU - Peter G Gibson Y1 - 2018/11/26 UR - http://thorax.bmj.com/content/early/2018/11/26/thoraxjnl-2018-212598.abstract N2 - The miracle of life is that conception and birth is turning out to be vitally important for airway diseases. Parental factors and events during pregnancy influence neonatal outcomes and infant bronchiolitis,1 2 and increase the risk of childhood asthma and adult COPD.3 4 Crucially, data are now emerging from randomised controlled trials that interventions during pregnancy can modify the incidence of childhood asthma.5–7 Because asthma is so common, and is manageable, this raises the possibility that asthma in pregnancy is an important and potentially modifiable risk factor for the associated adverse maternal and fetal outcomes, and for childhood asthma outcomes. This knowledge is now driving intense interest in the developmental origins of adult lung disease, and the role of interventions to prevent adult lung disease.8 What’s been missing from this conversation is sex, or more specifically conception. Is there something going on here that is also relevant to the development of childhood asthma? In this issue of Thorax, the article by Maria Magnus and colleagues says the answer is yes, and then goes on to tease out some of the relevant factors (Magnus M et al).9 It’s a little known fact that women with asthma have more trouble conceiving than non-asthmatic women. Time to pregnancy is increased in asthma, and this is particularly obvious after the age of 35.10 11 This leads to … ER -