Researchers from Odense University Hospital report a surprising link between the hormone cortisol and early language development. Their latest observations suggest that higher levels of cortisol in the final stage of pregnancy may influence how children acquire speech and language skills in the first few years of life. The findings were presented at the 25th European Congress of Endocrinologists held in Istanbul, where the team outlined a growing body of evidence about how prenatal biology shapes childhood outcomes.
Cortisol is a steroid hormone that plays a central role in the body’s response to stress. Beyond this immediate function, cortisol has a broader influence during pregnancy: it appears to participate in steering fetal growth and shaping the developing brain. This dual role makes the hormone a key focus for researchers who want to understand both normal development and the roots of variability in cognitive and language outcomes among children.
In this study, scientists examined cortisol measurements from 1,093 Danish pregnant individuals during the third trimester and connected these data to the subsequent speech and language performance of their children, evaluated between ages 12 and 37 months. The analysis revealed gender-specific associations. Male offspring tended to say a greater number of words within the age range of 12 to 37 months when their mothers had higher cortisol levels during late pregnancy. Female offspring, on the other hand, showed improvements in receptive language, with better word comprehension occurring more rapidly between 12 and 21 months. These patterns highlight potential differences in how prenatal hormone exposure may shape language pathways differently in boys and girls.
The researchers emphasize that these observations do not establish a direct cause effect but point to a meaningful association worthy of further exploration. The study uses a robust, population-based sample and longitudinal tracking to map early language milestones in relation to prenatal cortisol exposure. The team notes that a number of biological and environmental factors contribute to language development, and cortisol is likely one piece of a larger puzzle. They also acknowledge the need to replicate findings across diverse populations and to examine potential mechanisms, such as cortisol’s influence on brain regions involved in language processing and on the maturation of neural networks during critical periods of development.
Looking ahead, the investigators plan additional work to determine whether higher prenatal cortisol levels are connected to differences in general cognitive function in later childhood. A key aim is to assess whether these early language patterns predict intelligence scores at later ages, including potential correlations with IQ benchmarks around school age. By expanding follow-up to longer timeframes, researchers hope to better understand how prenatal hormonal environments relate to broader cognitive trajectories across childhood. The broader goal is to translate these insights into guidance for expecting families and healthcare providers, while continuing to refine the scientific model with replication studies and cross-cohort analyses. The ongoing effort reflects a cautious but hopeful stance about the potential predictive value of prenatal cortisol for later developmental milestones, and it underscores the importance of considering sex-specific effects in developmental research. [Citation: Odense University Hospital, study presented at the European Congress of Endocrinologists]