RESUMEN
BACKGROUND: Gestational thyrotoxicosis may be more prevalent in Asian women. METHODS: We have measured thyroid function, ferritin and bone specific alkaline phosphatase (BALP) as peripheral markers of thyroid function and hCG in Asian and western Caucasian women in non-pregnant and early pregnancy. RESULTS: TSH was lower in Asian women in non-pregnancy but not during normal pregnancy and this may reflect increased sensitivity of the thyroid gland to thyroid stimulation in the Asian population. No ethnic difference was found in FT3, FT4 or hCG but ferritin was lower and BALP higher in Asian women whether pregnant or not and this may be a reflection of iron balance and vitamin D status. CONCLUSIONS: We found during normal pregnancy that dynamic patterns of change for thyroid hormones and hCG are not different in Asian and western Caucasian women. We have developed gestation related reference intervals, which are a pre-requisite to the study of ethnic differences in gestation thyrotoxicosis in pregnancy.