Langerhans cell histiocytosis in children born 1982-2005 after in vitro fertilization

Aim: In a recent Swedish study, comparing data from the Swedish Cancer Register with the Medical Birth Register including data on IVF, an increased risk of Langerhans cell histiocytosis (LCH) was found in children born 19822005 after IVF. Here, we aimed to verify the LCH diagnoses and examine whether any special forms of the disease were overrepresented in this population. Methods: Medical records for all children with LCH conceived by IVF were acquired and the diagnosis confirmed or discarded. Disease characteristics were compared with data from children diagnosed with LCH 19922001 in the Stockholm County. Results: We verified LCH in seven children born after IVF, all born prior to 2002. These children did not have milder disease forms. The odds ratio (OR) to develop LCH for the whole group born after IVF was 3.2 [95% confidence interval (CI), 1.47.3] and for children born before 2002, 5.2 [95% CI, 2.311.9], compared with children in Stockholm County 19922001. Conclusion: LCH was overrepresented in children born after IVF prior to 2002. Affected children did not have milder disease forms. These findings may be valuable to understand LCH aetiology. Additional studies on a putative correlation between IVF and LCH in the offspring are encouraged.