LAUSR

Pregnancy is a very particular moment in a woman’s life, characterized not only by metabolic and other physiological changes but also by pathological conditions that may have consequences for the fetus (1). The relatively new intuition and evidence that the early stages of life are important for the health of children throughout their life span as well as for future generations (2, 3) have led to the view that the pregnancy period is an important “window” with an impact on health. This Perspective provides an overview of maternal complications of pregnancy for which the literature suggests a relationship with wheezing and asthma in childhood. More specifically, our research investigated whether maternal preeclampsia, obesity, diabetes, psychological stress during pregnancy, and cesarean delivery (exposures) increase the risk of childhood wheezing, asthma, or altered lung function (outcomes) at any point in childhood (0–17 yr). We searched Medline for articles in English, published from January 2000 until August 2017. In the case of previous meta-analyses, the results of which have been reported, we considered studies published since the metaanalysis was run. Relevant articles were also searched manually from references in the selected articles. The Medline search strategy used is reported in the online supplement. We specifically focused both on birth cohort studies that prospectively collect data on pregnancy and perinatal exposure, and registry-based cohort studies. Long-term birth cohort studies are essential for envisaging the life-course trajectory of early potential risk factors for the development of respiratory disorders from childhood to adulthood (4, 5). In this Perspective we do not address the effect of the maternal environment (e.g., nutrition, pollution, etc.) including smoking, a well-known preventable “environmental” cause of abnormal in utero lung development, offspring respiratory symptoms, and diminished lung function persisting into adolescence and adulthood (6). The “smoke history” should represent a stimulus to further study on whether and how exposures to perinatal pathological conditions can affect fetal lung development and immune responses, contributing to alter lung and airway developmental patterns throughout life (4, 7). For the conditions covered in our overview, we discuss potential mechanisms, as well as mediators and confounding factors involved in associations. This is of paramount importance, as any prevention strategy aimed at reducing the burden of childhood respiratory diseases must act on risk factors that are in the causal chain.