In the United States, boys are diagnosed with autism at significantly higher rates than girls, with three to four boys diagnosed for every one girl. Additionally, women and girls are often diagnosed later in life than their male counterparts. A new study led by the University of Minnesota has uncovered a gender bias in autism diagnostic practices, providing evidence that many girls are missed in early screenings and suggesting an urgent need to implement new diagnostic strategies.
To determine if sex-based differences exist in the structure and level of autism symptoms, the authors leveraged 18 years of data on more than 4,500 participants in the Baby Siblings Research Consortium. About 3,100 of the children who participated in the study had an older sibling with autism (high familial likelihood), while the other 1,400 children did not (low familial likelihood). Among the HFL group with autism diagnostic information, about 26.5 percent of males and 13.4 percent of girls received an autism diagnosis, equating to a diagnosis ratio of two boys for every one girl – significantly lower than the four-to-one ratio observed in prior studies.
Aligned with girls in the general population, girls in the HFL group demonstrated stronger language and social skills than their male counterparts. Notably, girls in this cohort had fewer challenges with eye contact – one of the best-known autism symptoms. Thus, by not accounting for well-known, sex-based differences in social skills among the general population, traditional autism diagnostic practices could be preventing early identification for girls. By implementing sex-specific thresholds in autism measurements, girls with the condition could be diagnosed earlier, leading to better outcomes for autistic women and girls.
In addition to the University of Minnesota, the research team included scholars from universities across the United States, Korea, and Canada.