Compared with children conceived via a fresh embryo transfer, those conceived using frozen embryos did not generally have an increased, long-term risk of neurodevelopmental disorders, according to a
study published in the
Journal of the American Academy of Child & Adolescent Psychiatry.
Children conceived using either approach did show modestly higher rates of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) than those who were naturally conceived.
Why It’s Relevant
Globally, children are increasingly born using assisted reproductive technology (ART), such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). The use of frozen embryos has grown more popular, as they offer more flexibility and are associated with some positive pregnancy outcomes, but few studies have assessed the neurodevelopment of children conceived via ART.
By the Numbers
- Researchers used Taiwanese national databases to identify 4,604 children born from frozen embryo transfers, 16,877 born from fresh embryo transfers, and 85,924 matched controls who were naturally conceived.
- Overall, the rates of ADHD, ASD, cerebral palsy, and intellectual disability did not significantly differ between single children born via fresh versus frozen embryo transfers.
- Similarly, single children born via ICSI did not have an additional risk of neurodevelopmental disorders compared with those born with IVF.
- Compared with children conceived naturally, those conceived via ART had a statistically higher incidence of ADHD (7.7 versus 6.3 per 1,000 person-years) and ASD (2.5 versus 1.9 per 1,000 person-years).
What’s More
Among multiple births, using frozen embryos was associated with a 32% increased risk of ADHD and a 65% increased risk of ASD compared with fresh embryo transfers. The researchers noted that frozen embryo transfer has been linked to higher rates of maternal hypertension, which may amplify the vascular stress that often occurs during a multiple pregnancy.
The Other Side
The databases used lacked ART procedural details such as freezing methods, as well as data on lifestyle factors like smoking that may have influenced outcomes. The increased ADHD and ASD risk among ART-conceived children may have been influenced by surveillance bias, as parents undergoing fertility treatments are often high health care utilizers; ART parents were also older on average and had a higher prevalence of psychiatric disorders compared with those conceived naturally.
Takeaway Message
“[O]ur findings support the long-term neurodevelopmental safety of frozen [embryo transfers] and ICSI,” the researchers wrote. “While ART overall was associated with a modestly elevated risk of ADHD and ASD compared to natural conception, the minimal absolute risk increase remains clinically reassuring for patients and providers.”
Related Information
Source
Jui-Chun Chang, et al. Neurodevelopmental outcomes in children born after fresh versus frozen embryo transfer. Journal of the American Academy of Child & Adolescent Psychiatry. Published September 29, 2026. doi:10.1016/j.jaac.2026.09.015
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