Infertility treatments tied to developmental delays at age 2 years

Infants conceived with the help of infertility treatments, such as ovulation induction (OI) and artificial insemination with the husband’s sperm (AIH), are more likely to experience developmental delays at 2 years of age, according to a recent Japan study. However, such delays appear to grow nonsignificant by 3.5 years of age.

“Our longitudinal study demonstrated that at 2 and 3.5 years of age, the neurodevelopmental status of children conceived through infertility treatment, especially artificial reproductive technology (ART), might eventually catch up with that of those conceived naturally,” the researchers said.

The prospective cohort study included 9,655 mother-child dyads, of whom 2.8 percent and 5.0 percent were exposed to OI/AIH or ART, respectively. Study outcomes were neurodevelopment at 2 and 3.5 years of age, as assessed by the third edition of the Ages and Stages Questionnaire (ASQ-3). Data were retrieved from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study.

At 2 years of age, 1,437 children showed developmental delays according to ASQ-3 screening, yielding a rate of 14.9 percent. Developmental delays were much more common in children conceived through OI/AIH and ART than in those who were conceived naturally (21.3 percent and 22.6 percent vs 14.3 percent, respectively). [BMJ Open 2022;12:e060944]

Multivariable logistic regression analysis revealed that these differences were statistically significant. Those conceived through OI/AIH (odds ratio [OR], 1.36, 95 percent confidence interval [CI], 1.00–1.85), and particularly through ART (OR, 1.36, 95 percent CI, 1.07–1.72), suffered from a significantly greater likelihood of developmental delays at this age.

In particular, OI/AIH significantly impaired communication development (OR, 1.93, 95 percent CI, 1.25–2.98), while ART exerted a similar effect on gross motor skills (OR, 1.50, 95 percent CI, 1.08–2.09).

However, by age 3.5 years, development appeared to normalize across all conception groups. Rates of developmental delays were 12.9 percent, 14.7 percent, and 14.0 percent in children conceived naturally, through OI/AIH, and ART, respectively.

These trends were reflected in the regression models, which showed that neither OI/AIH (OR, 1.13, 95 percent CI, 0.79–1.61) nor ART (OR, 1.03, 95 percent CI, 0.78–1.37) remained significantly correlated with a higher likelihood of developmental delays.

Stratified analysis according to the five ASQ-3 subgroups likewise found no significant impact of infertility treatment on child neurodevelopment at this age.

“This study was a large longitudinal birth cohort with detailed information from the participants, and although continued follow-up of children born after infertility treatment is needed, this study helps to increase the understanding of the association between infertility treatment and neurodevelopmental outcomes in Japanese children,” the researchers said.