The Prevalence of Subclinical Hypothyroidism During Early Pregnancy in Pakistan: A Cross-Sectional Study.

Introduction Subclinical hypothyroidism (SCH) during early pregnancy is associated with an increased risk of miscarriage or premature birth. In Pakistan, the prevalence of SCH among pregnant women is not well documented. This multi-center study aims at identifying the prevalence of SCH among Pakistani pregnant women. Methods A cross-sectional multi-center study was conducted over a period of 12 months. Pregnant females in the first trimester of pregnancy were recruited from the antenatal clinics of seven centers from six Pakistani cities. We assessed the frequency of SCH in pregnant females and associated risk factors. Results A total of 500 pregnant women were enrolled in this study. Only eight women (1.6%) had a newly-diagnosed SCH. While 1.2% of women had hyperthyroidism, 6% had known hypothyroidism, and 1% had overt hypothyroidism. Ten females (33.3%) with known hypothyroidism were receiving an inadequate dose of thyroid replacement therapy. The association between BMI and SCH was not statistically significant (p = 0.69). Moreover, we could not find any significant difference between patients with or without SCH in terms of age (p > 0.90), dyslipidemia (p = 0.157), history of miscarriage (p > 0.90), the regularity of the cycle (p > 0.90), and history of infertility (p > 0.90). Conclusions The frequency of undiagnosed SCH in pregnant females in the study from Pakistan was 1.6%. The rate of uncontrolled hypothyroidism was high, which raises an alarm of the potential risks of untreated thyroid disorder.