Approximately 25% of men and 20% of women remain childless throughout their lives. While individual diseases have been linked to childlessness, particularly in women, a comprehensive understanding of early-life diseases' impact on lifetime childlessness is lacking. This study examined individuals born in Finland (n = 1,035,928) and Sweden (n = 1,509,092) between 1956-1973, following them to the end of their reproductive lifespan in 2018. Using nationwide registers, researchers associated sociodemographic and reproductive information with 414 diseases across 16 categories, employing population and matched-pair case-control designs of siblings discordant for childlessness. The strongest associations were found with mental-behavioral disorders (especially in men), congenital anomalies, and endocrine-nutritional-metabolic disorders (strongest in women). New associations were identified for inflammatory and autoimmune diseases. Associations were dependent on age at onset and mediated by singlehood and education. These findings contribute to understanding the role of disease in involuntary childlessness.

Aoxing Liu, Evelina T. Akimova, Xuejie Ding, Sakari Jukarainen, Pekka Vartiainen, Tuomo Kiiskinen, Sara Koskelainen, Aki S. Havulinna, Mika Gissler, Stefano Lombardi, Tove Fall, Melinda C. Mills, Andrea Ganna