ESPEYB18 3. Thyroid Thyroid and pregnancy (1 abstracts)
Lancet Diabetes Endocrinol. 2021;9:94105. doi: 10.1016/S2213-8587(20)30399-5.
This population based nested case-control study integrated registry data from Denmark, Norway, Sweden and Finland over 40 years to investigate the association of maternal, in-utero, and postnatal factors with thyroid cancer risk in offspring. Each patient with thyroid cancer (cases n=2437) was matched with 10 controls without thyroid cancer (n=24362).
As expected, there was a predominance of papillary thyroid carcinoma (81% of cases) and female sex (77% of cases). Mean age at diagnosis was 27.5 years. Although only available from the Danish registry, maternal thyroid disease diagnosed before or during pregnancy were associated with highest odds ratio (OR) for offspring thyroid cancer: maternal goitre OR 67, benign thyroid neoplasm OR 22, hypothyroidism OR 18, hyperthyroidism OR 12, thyroiditis OR 3. Thyroid-independent maternal conditions associated with increased offspring thyroid cancer risk were: diabetes OR 1.7, and postpartum haemorrhage OR 1.3. Interestingly, congenital hypothyroidism was associated with a relevant OR of 4.5 although occurring in only 5 patients with thyroid cancer vs. 11 controls.
In summary, this extensive case-control study identified maternal and neonatal thyroid disorders associated with increased thyroid cancer risk. The underlying mechanisms remain unknown. Nevertheless, these results might be helpful for clinical decision making in paediatric and young adult patients with thyroid nodules.