Impact of High-normal Serum TSH with First Trimester Pregnancy Loss: A Case-control Study in Tertiary Care Hospitals in Bangladesh

Abstract

The relationship between existing thyroid autoimmunity and the probability of spontaneous abortion has been the subject of a number of studies. In this study, we evaluate the impact of `high normal' serum TSH levels (2.5-5.0 mlU/L) on first trimester pregnancy loss in anti-TPO Ab negative women in Bangladesh. Specifically, we wanted to know the average serum TSH levels for women who had a miscarriage (case group) and who did not have a miscarriage (control group) during the first trimester of pregnancy. Unmatched case-control study involving 119 women in their first trimester was conducted during July 2011 to June 2012 in three tertiary care hospitals in Bangladesh. We found average TSH level for the control group (1.42$\pm$0.86 mlU/L) to be lower than the average for the case group (1.74$\pm$1.15 mlU/L). However, we did not find statistically significant association between the serum TSH level and first-trimester pregnancy loss. The findings of this study will provide a baseline for future studies on this topic involving Bangladeshi women. In addition, our study adds to the growing discussion on redefining the lower limit for the `high normal' serum TSH level among the anti-TPO Ab negative women.