Universal screening detects two-times more thyroid disorders in early pregnancy than targeted high-risk case finding.
OBJECTIVE
Screening of thyroid disorders in pregnancy has been controversial. Recent recommendations favour targeted high-risk case finding, though this approach may miss a significant number of those affected. We aimed to assess the prevalence of accepted high-risk criteria in women with autoimmune thyroiditis and/or hypothyroidism detected from universal screening in an iodine-sufficient population.


METHODS
In 400 non-selected women in the 9-11th gestational week, thyroid-related tests were performed, and those with abnormalities were offered consultation.


METHODS
TSH was determined by IRMA, and the upper cut-off value for screening was set at 3.5 mIU/l. For free thyroxine (FT(4)) and thyroperoxidase antibodies (TPO-Ab), RIAs were used, with cut-offs of <10 pmol/l and >50 IU/ml respectively. Endocrinological consultation included Doppler ultrasonography and was aimed to confirm autoimmune thyroiditis and/or hypothyroidism. The prevalence of consensus high-risk criteria was assessed.


RESULTS
Among the 400 women, 65 (16.3%) had ≥1 abnormality: higher TSH was found in 10.3%, lower FT(4) in 2% and positive TPO-Ab in 8.3%. Fifty-one women were examined and followed up. Levo-T(4) treatment was initiated in 49 women for autoimmune thyroiditis (in 42), hypothyroidism (in 34) or both (in 27). Only 22 (45%) of 49 treated women fulfilled ≥1 high-risk criterion: most commonly family history (31%), history of miscarriage or preterm delivery (14%) and personal history (8%).


CONCLUSIONS
Over half (55%) of pregnant women with abnormalities suggestive of autoimmune thyroiditis and/or hypothyroidism would be missed if only those with high-risk criteria were examined. A more extensive screening of thyroid autoimmunity and dysfunction seems warranted.
Horacek
Jiri
J
Department of Internal Medicine, Faculty of Medicine and University Hospital in Hradec Kralove, Charles University in Prague, Sokolska 581, Hradec Kralove, Czech Republic. horacek@fnhk.cz
Spitalnikova
Sylvie
S
Dlabalova
Blanka
B
Malirova
Eva
E
Vizda
Jaroslav
J
Svilias
Ioannis
I
Cepkova
Jitka
J
Mc Grath
Catherine
C
Maly
Jaroslav
J
D001323:Autoantibodies / Q000097:blood; D005260:Female; D005865:Gestational Age; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood*; D011863:Radioimmunoassay; D013959:Thyroid Diseases / Q000097:blood* / Q000175:diagnosis*; D013967:Thyroiditis, Autoimmune / Q000097:blood / Q000175:diagnosis; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D001323:Autoantibodies; D013972:Thyrotropin; D013974:Thyroxine