Maternal use of hormonal contraception and rare cancer types in children: A nationwide PECH cohort study

Abstract Background Maternal hormonal contraception use has been associated with an increased risk of leukaemia and central nervous system (CNS) tumours in children. However, little is known about the association with other, less common childhood cancer types. We assessed associations between maternal hormonal contraceptive use and all main types of childhood cancer, excluding leukaemia and CNS tumours. Methods In this nationwide PECH cohort study, we followed all Danish children liveborn in 1996–2014 (n = 1 185 063) from birth until 2018. Registry information was extracted on maternal filled prescriptions of hormonal contraception and childhood cancer diagnoses (age at diagnosis