Pubertal development at age 12 in children born after fertility treatment: the Taiwan Birth Cohort Study

The increasing use of assisted reproductive technology has raised concerns about its long-term effects on offspring, including pubertal development. Evidence from large, population-based studies in non-Western countries remains limited. Using data from the Taiwan Birth Cohort Study, a nationally representative cohort of children born in 2005, we examined pubertal development at age 12 based on caregiver reports. Among 21,642 children with conception data, 172 were conceived via intrauterine insemination (IUI), 311 via in vitro fertilization (IVF), and 21,159 spontaneously (SC). Propensity score matching (1:1) yielded a final sample of 966 children. Ordinal logistic regression and parametric survival analysis assessed associations between conception method and pubertal milestones, including age at menarche. Among 966 matched children (546 boys, 420 girls), most associations between fertility treatments and pubertal development at age 12 were small and not statistically significant. Boys and girls conceived via IUI did not show a trend toward earlier or later puberty. In IVF-conceived children, odds ratios for pubertal development were near 1.0, not statistically significant and with wide 95% confidence intervals. No significant differences were found in age at menarche, either.

In this nationally representative cohort, we found no statistically significant differences in pubertal development or age at menarche by conception method at age 12. Continued follow-up is warranted to assess long-term reproductive outcomes.

• Children conceived through fertility treatment may be at risk for altered pubertal timing, but most existing evidence is from Western populations. • Prior large-scale studies suggest trends toward earlier puberty in IVF-conceived girls and later puberty in IVF-conceived boys.

• This study provides the first large-scale, nationally representative Asian evidence on the long-term pubertal outcomes of children conceived through fertility treatment, addressing a major geographic gap in the literature. • We did not detect statistically significant differences in pubertal stage or age at menarche at age 12 between children conceived via IUI/IVF and those conceived spontaneously.