Trimester specific reference intervals for thyroid function tests in normal Indian pregnant women.

Context: Accurate assessment of thyroid function during pregnancy is critical, for initiation of thyroid hormone therapy, as well as for adjustment of thyroid hormone dose in hypothyroid cases.

Aims: We evaluated pregnant women who had no past history of thyroid disorders and studied their thyroid function in each trimester.

Settings And Design: 86 normal pregnant women in the first trimester of pregnancy were selected for setting reference intervals.