Objectives: The objective of our study was to find the prevalence of subclinical hypothyroidism in pregnant females of Kashmir. This was done so as to assess the magnitude of the problem in the valley and to formulate a strategy based on its results.

Methods: The study was done over a period of one year from July 2009 to July 2010 in Government Medical College, Srinagar. Pregnant females attending the out-patient department of Gynecology and Obstetrics, for their routine antenatal check-ups, formed our study population. Their blood samples were taken for estimation of serum FT3, FT4 and TSH levels.

Results: Most of our patients were in the age group of 25-29 years, comprising 45.3% of the total subjects. Out of the total 902 patients, TSH was within range in 788 (87.4%) and elevated in 114(12.6%). In control group (age matched non pregnant females), 91.4% had TSH in normal range while 8.6% had elevated levels. FT4 was within range in 96.2%, low in 3.2% and raised in 0.6% in cases, while as in controls, the percentages were 92.5%, 5.4% and 2.2% respectively. Hence the prevalence of subclinical hypothyroidism (Increased TSH within normal FT4) was 12.6% in cases and 8.6% in controls.

Conclusion: A high prevalence of subclinical hypothyroidism was found in pregnant females. Therefore, thyroid screening should be made important in pregnancy and threshold for treating subclinical hypothyroidism should be kept low.