Thyroid function in neonates conceived after hysterosalpingography with iodinated contrast

Area of Science:

• Reproductive Endocrinology
• Neonatal Health
• Diagnostic Imaging

Background:

• Hysterosalpingography (HSG) is a common fertility test using oil- or water-based contrast.
• Oil-based contrast has higher iodine content than water-based contrast.
• Previous studies suggested a potential risk of congenital hypothyroidism (CH) with oil-based contrast exposure.

Purpose of the Study:

• To investigate if preconceptional hysterosalpingography (HSG) with iodinated oil-based contrast affects neonatal thyroid function compared to iodinated water-based contrast.
• To assess the safety of oil-based contrast in HSG for neonatal thyroid health.

Main Methods:

• Retrospective data analysis of the H2Oil randomized controlled trial.
• Collected thyroid function test data from 140 neonates (76 oil-based, 64 water-based contrast).
• Analyzed T4 and TSH levels from neonatal screening programs, comparing groups and contrast volume.

Main Results:

• No significant difference in median T4 concentrations between neonates exposed to oil-based (87.0 nmol/l) versus water-based (90.0 nmol/l) contrast (P=0.13).
• No neonates in either group screened positive for congenital hypothyroidism (CH).
• No influence of contrast amount on T4 concentrations was observed.

Conclusions:

• Preconceptional HSG with iodinated oil-based contrast does not adversely affect neonatal thyroid function.
• The use of oil-based contrast in HSG is considered safe for offspring thyroid health.
• Further research is recommended on maternal thyroid function and neurodevelopmental outcomes.