Mai XM, Almqvist C, Nilsson L, Wickman M Arch Dis Child 2007 May 2; (Epub ahead of print)
This study from Canada investigated the perceived link between infant birth weight and potential allergic disease. The authors also looked at BMI at age four as a covariate. A large prospective birth cohort of nearly 3,000 infants was analysed.
The researchers obtained details about perinatal weight and length from child care health centres. The parents were sent questionnaires when their children were two months, one, two and four years old. Questions were asked about environmental factors and allergic symptoms, such as wheeze, rhinitis and eczema. At the age of four, the children were examined and their BMI was calculated. They also had blood drawn for specific IgE analysis to common inhalant allergens.
The authors found no clear link between birth weight and the presence of allergic disease at age four. They did, however, find an inverse relationship with birth length and wheeze at age four, but only in children who developed late onset wheeze. Persistent or transient wheeze had no such association.
No association with other allergic symptoms and birth length was seen.
The authors found no association with birth weight and wheeze or allergic disease. They postulated that increased birth length might have a protective role for late onset wheeze in children younger than four.
The conclusions of this study are interesting but the results should be treated with caution, owing to the potential bias and variables; for example, measuring birth length can be inaccurate and data were received from different centres. In addition, parents' perception of disease varies, which may lead to problems interpreting the questionnaires.
- Dr Waseem Chaudhry, a GPSI in dermatology in Caerphilly