title: Maternal cancer and congenital anomalies in children - a Danish nationwide cohort study.
abstract: Several studies on pregnancy-associated cancers have suggested an association with congenital anomalies in offspring. Previous studies have included maternal cancers diagnosed up to 2 years after pregnancy; however, long latency periods of some cancers mean that cancers diagnosed many years postpartum might have been present during pregnancy in a preclinical state. This paper considers the association between maternal cancers diagnosed from 2 years prior to pregnancy until the mother reaches 50 years of age, and congenital anomalies, as diagnosed at birth or within the first year of life. The current population-based study looks at associations of cancers in mothers with congenital anomalies in their children. Children were followed up from birth to diagnosis of a congenital anomaly, death, emigration or end of follow-up (whichever occurred first). A total of 56,016 children (2.6%) were considered exposed to a maternal cancer of any type; and they had a hazard ratio (HR) of 1.04 (95% confidence interval [CI]: 1.00, 1.09) compared with unexposed children. The greatest HR was seen among children whose mothers had been diagnosed with cancers before or during pregnancy (HR: 1.37, 95% CI: 1.07, 1.75). Similar results were seen when paternal cancers were used as a 'negative control'. Statistically significant associations were seen for some specific congenital anomalies of organ systems (congenital anomalies of the musculoskeletal system [HR: 1.13, 95% CI: 1.02, 1.25]) and for some specific types of maternal cancer (leukaemia [HR: 1.31, 95% CI: 1.01, 1.61], The results of the main analyses suggest a small increase in risk of congenital anomalies in offspring of mothers diagnosed with cancer from 2 years before pregnancy, until the mother reaches 50 years of age; with the greatest increase seen for exposure in the pre-pregnancy and pregnancy period. These results may reflect shared causes for some cancers and some congenital anomalies. The similar results seen for paternal cancers indicate that the cause may be genetic or related to the families' social and environmental conditions.
authors.affiliation: Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus, Denmark.
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Momen
authors.affiliation: Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ernst
authors.affiliation: Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus, Denmark.
authors.forename: Linn Håkonsen
authors.initials: LH
authors.lastname: Arendt
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.|Department of Epidemiology, University of California Los Angeles, Los Angeles, CA, United States of America.
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.affiliation: THL National Institute for Health and Welfare, Helsinki, Finland.|Karolinska Institute, Department of Neurobiology, Care Sciences and Society, Division of Family Medicine, Stockholm, Sweden.
authors.forename: Mika
authors.initials: M
authors.lastname: Gissler
authors.affiliation: Department of Health Sciences, Lund University, Lund, Sweden.
authors.forename: Finn
authors.initials: F
authors.lastname: Rasmussen
authors.affiliation: Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus, Denmark.
authors.forename: Cecilia Høst
authors.initials: CH
authors.lastname: Ramlau-Hansen
mesh_terms: D000328:Adult; D002648:Child; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic; D011297:Prenatal Exposure Delayed Effects; D016016:Proportional Hazards Models; D012042:Registries; D012306:Risk; D055815:Young Adult