Euthyroid hyperthyrotropinemia in children born after in vitro fertilization

Area of Science:

• Endocrinology
• Reproductive Medicine
• Pediatrics

Background:

• Assisted reproduction techniques, including in vitro fertilization (IVF), are widely used.
• Long-term prospective studies on children conceived via assisted reproduction are limited.

Purpose of the Study:

• To investigate thyroid function in children conceived after IVF compared to naturally conceived controls.
• To assess serum thyroid hormone levels and thyroid autoantibodies in these children.

Main Methods:

• A cohort of 106 children conceived via classic IVF and 68 naturally conceived controls (aged 4-14 years) were studied.
• Serum T3, T4, TSH, anti-thyroid peroxidase, and anti-thyroglobulin antibodies were measured.
• Persistent hyperthyrotropinemia was confirmed with a second TSH measurement and thyroid ultrasound if initial TSH was elevated.

Main Results:

• Seven IVF children exhibited persistent elevated TSH, unlike controls, indicating euthyroid hyperthyrotropinemia or subclinical hypothyroidism (P=0.044).
• The IVF group had significantly higher TSH levels than controls (P=0.046).
• No significant differences in T3 or T4 levels were found, and no antithyroid antibodies were detected in either group.

Conclusions:

• IVF children showed elevated serum TSH, suggesting mild thyroid resistance not linked to autoantibodies.
• This may indicate a subtle epigenetic developmental abnormality from preimplantation embryo manipulation.
• Further research is needed to confirm these findings and clarify their clinical significance and cause.