Risk factors and outcomes of preterm birth. A study of the associations of preterm birth with cerebral palsy and atopic diseases
Abstract
Background: Children born preterm are at increased risk for a number of chronic diseases, including cerebral palsy and asthma. Asthma is usually categorised among the atopic diseases, but whether preterm birth also affects the risk for other atopic diseases, is less explored. Furthermore, it is known that women with asthma are at increased risk of too early delivery, but the knowledge on risk of preterm birth for mothers with atopic dermatitis or allergic rhinoconjunctivitis is limited. Preterm birth may be caused by interactions between disorders of pregnancy and conditions related to mother and fetus. Whether these pathologic conditions influence the risk of later chronic diseases for preterm children, is still largely unknown. Objectives: We wanted to assess how preterm birth and pregnancy disorders relate to risk of cerebral palsy and severe asthma and atopic dermatitis. In addition, we aimed to explore the risk of preterm birth with maternal atopic diseases. Methods: Prospective national cohort studies were performed by linking data from the Medical Birth Registry of Norway to other compulsory national registries. Results: Preterm birth and several pregnancy disorders were strongly associated with cerebral palsy. Preterm birth was associated with increased risk of severe asthma and decreased risk of severe atopic dermatitis. The two diseases were differently related to pregnancy disorders and other risk factors. Maternal asthma was associated with increased risk of preterm birth, but maternal atopic dermatitis and allergic rhinoconjunctivitis were associated with decreased risk. Conclusions: Risk of cerebral palsy with or without a recorded pregnancy disorder varied within categories of gestational age. Our findings suggest a protective effect of preterm birth on atopic dermatitis and a reduced risk of preterm delivery for mothers with other atopic diseases than asthma. This may shed light on mechanisms of preterm birth, but further studies are needed to confirm and explore these findings.
Has parts
Paper I: Trønnes H, Wilcox AJ, Lie RT, Markestad T, Moster D. Risk of cerebral palsy in relation to pregnancy disorders and preterm birth: a national cohort study. Developmental Medicine & Child Neurology 2014;56:779-85. The article is not available in BORA due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1111/dmcn.12430Paper II: Trønnes H, Wilcox AJ, Markestad T, Lie RT, Moster D. The association of preterm birth with severe asthma and atopic dermatitis: a national cohort study. Pediatric Allergy and Immunology 2013; 24:782-7. The article is not available in BORA due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1111/pai.12170
Paper III: Trønnes H, Wilcox AJ, Lie RT, Tollånes MC, Markestad T, Moster D. Associations of maternal atopic diseases with adverse pregnancy outcomes: a national cohort study. Paediatric and Perinatal Epidemiology 2014;28:489–97. The article is not available in BORA due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1111/ppe.12154