Researchers have found significant associations between early-life diseases, including mental-behavioural disorders, and the chances of being childless lifelong in a new study.
The international study, led by the University of Oxford, UK, examined the link between 414 early-life diseases and lifetime involuntary childlessness in over 2.5 million individuals born in Finland and Sweden. It is published in the journal Nature Human Behaviour.
The researchers found that of the 74 early-life diseases significantly associated with childlessness in at least one sex, 33 were shared between men and women and more than half of these were mental-behavioural disorders. Their analysis also revealed new links between autoimmune and inflammatory diseases and childlessness.
The findings paved the way for better understanding how disease contributes to involuntary childlessness and the need for improved public health interventions, the researchers said.
Further, some of these diseases linked to childlessness were found to be gender-specific. For example, in men, schizophrenia and acute alcohol intoxication were more strongly linked with childlessness.
However, in women, diabetes-related diseases and congenital irregularities such as malformations in the digestive and musculoskeletal system were found to display stronger links with being childless.
“Various factors are driving an increase in childlessness worldwide, with postponed parenthood being a significant contributor that potentially heightens the risk of involuntary childlessness,” said Aoxing Liu, lead author of the study and postdoctoral researcher at the University of Helsinki’s Institute for Molecular Medicine in Finland.
The research team used the nationwide registers to analyse information on 414 early-life disease diagnoses for 1.4 million women born between 1956-1973 and 1.1 million men born between 1956-1968. They said that all were alive at 16 years of age, did not emigrate and had mostly finished their reproductive years by the end of 2018 (defined as age 45 for women, 50 for men).
About 25 per cent of these men were found to be childless compared to 16.6 per cent of the women, with individuals having lower education levels more likely to be childless compared to the general population.
The researchers also found gender-specific differences between the age of one receiving their initial diagnoses and their likelihood of being childless. For instance, they found that women initially diagnosed with obesity between the ages of 16-20 were more likely to remain childless than those initially diagnosed at later ages
“As well as reinforcing demographic research on assortative mating and other socioeconomic factors linked to childlessness, this paper underscores the necessity for interdisciplinary research and enhanced public health emphasis on addressing early-life diseases among both men and women in relation to childlessness,” said senior author Melinda Mills from the University of Oxford.
The researchers acknowledged the need for further research to be able to generalise the results beyond Nordic countries and to more recent cohorts with evolving treatments, reproductive and partnering practices.