In vitro fertilization and long-term child health and development: nationwide birth cohort study in Japan

Area of Science:

• Reproductive Medicine
• Pediatric Health
• Public Health

Background:

• In vitro fertilization (IVF) is a widely used assisted reproductive technology.
• Japan has a strong policy favoring single embryo transfer (SET) to mitigate risks associated with multiple births.
• Long-term health outcomes for IVF-conceived children require ongoing investigation, particularly within specific national contexts.

Purpose of the Study:

• To compare long-term health and developmental outcomes in children conceived via IVF versus natural conception in Japan.
• To assess the safety of IVF, considering the prevalent use of SET, by examining outcomes up to nine years of age.

Main Methods:

• A nationwide birth cohort in Japan linked with perinatal data was utilized, analyzing 2140 children born in May 2010.
• Poisson regression with robust variance was employed to estimate risk ratios for associations between IVF conception and various health/developmental outcomes.
• Adjustments were made for potential confounding factors to ensure robust comparisons.

Main Results:

• No significant differences in most outcomes, including hospitalization, obesity, and developmental milestones, were observed between IVF-conceived and naturally conceived children.
• IVF-conceived children exhibited a slightly lower risk of attention problems at age eight (aRR: 0.73).
• Subgroup analyses revealed reduced risks of cognitive delays at age 5.5 in IVF-conceived term singletons (aRR: 0.31 and 0.37, respectively).

Conclusions:

• IVF conception in this Japanese cohort was not linked to adverse long-term health or developmental outcomes.
• The findings support the safety of IVF, particularly when SET is practiced, providing reassurance to patients and clinicians.
• Further research into specific IVF protocols and diverse subgroups is warranted to refine understanding.