7912 Children's Neurodevelopmental Outcomes at School-Age After Conception with Hysterosalpingography Using Iodinated Contrast Media

Abstract Disclosure: S. Keestra: None. C. Kooper: None. N. van Welie: None. K. Dreyer: Grant Recipient; Self; research grants from Guerbet. Speaker; Self; travel and speaker fees Guerbet. R. van Eekelen: None. T. Roseboom: None. J. Oosterlaan: None. B. Mol: Consulting Fee; Self; Organon Laboratories, Norgine, Merck. Grant Recipient; Self; Merck. Stock Owner; Self; ObsEva. M. Finken: None. V. Mijatovic: Grant Recipient; Self; Guerbet, Merck, Ferring Pharmaceuticals. Speaker; Self; Guerbet, Merck, Ferring Pharmaceuticals. M. Königs: None. Thyroid hormone sufficiency in pregnancy is vital for children's neurodevelopment. Exposure to iodine excess can cause transient disruption of thyroid hormone synthesis through the Wolff-Chaikoff effect. Iodinated contrast media are commonly utilized in hysterosalpingography (HSG) as part of female fertility work-up. When conception occurs shortly after HSG with iodinated contrast, a temporary reduction of maternal and/or foetal thyroid hormone synthesis could jeopardize children's neurodevelopment. We compared the neurodevelopmental outcomes of 6-9-year-old children (n=69) conceived <6 months after HSG with 5-10 ml of oil-based contrast (iodine content: 480mg/ml) or water-based contrasts (iodine content: 250mg/ml) in the follow-up of a nationwide randomised controlled trial (H2Oil trial; Netherlands; 2012-2014; NCT05168228). A community sample of naturally-conceived children (n=44) with similar age, sex and parental education was used as a comparison group (NTR9574). Primary outcomes were intelligence (Wechsler’s Intelligence Scale for Children V), behaviour questionnaires for parents and teachers (Strengths and Difficulties Questionnaire (SDQ); Strengths and Weaknesses of ADHD Symptoms And Normal behaviour (SWAN)), and academic performance. Secondary outcomes were neurocognitive domains assessed in computerized tasks focussing on Processing & Control, Verbal Memory, Visual Memory, Verbal Working Memory, Visual Working Memory, and Visuomotor Integration (Emma Toolbox for Neurocognitive Functioning). We adjusted linear regression models for age, sex, and parental education, applying FDR correction for multiple comparisons. Additional analysis looked at children conceived within 4 weeks, 4-12 weeks, or >12 weeks after HSG. Children conceived <6 months after HSG had lower performance on intelligence tests (-6.81; 95%CI -10.97 to -2.65; p=0.02) and the neurocognitive domain Processing & Control (-0.52; 95%CI-0.84 to -0.19; p=0.02), with processing speed and consistency affected. No differences were found for other neurocognitive domains, behaviour or academic performance. In comparison to naturally-conceived children, children conceived <4 weeks after HSG had lower performance on intelligence tests, but there was no difference for children conceived 4-12 weeks and >12 weeks after HSG. Replication studies with higher power are needed to further evaluate the safety of iodinated contrast media use periconception, including their effects on thyroid function and children's neurodevelopment. Closer monitoring and treatment of thyroid dysfunction in the months following HSG may be warranted. Presentation: 6/1/2024