Comparing Blood Pressure in Pregnant Women with Subclinical Hypothyroidism Using Levothyroxine to those with...

Subclinical hypothyroidism (SCH) is a common condition during pregnancy that can be treated with levothyroxine at a dosage of 0.5-1 mcg/kg/day. If left untreated, the risk of hypertensive disorders of pregnancy increases. However, we did not find any studies examining the impact of levothyroxine on blood pressure levels in pregnancy. Therefore, we decided to assess blood pressure levels in pregnant women with SCH who are using levothyroxine, as well as in euthyroid subjects.

This prospective cohort study involved 245 primiparous women. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were collected from pregnancy records at weeks 6-10, 18, 26, 33, 36, and 37-41. Using generalized estimating equations, we analyzed the relationship between levothyroxine dosage and mean SBP and DBP, as well as compared blood pressures between women receiving levothyroxine and those who were euthyroid.

The correlation between levothyroxine dosage and both SBP (P = 0.313) and DBP (P = 0.553) was not significant at a 0.05 significance level. Additionally, the mean SBP and DBP values did not differ significantly between women with SCH and those who were euthyroid.

Out of 245 pregnant women, 31% in their first trimester were diagnosed with SCH and treated with levothyroxine, with an average dosage of 49.46 (35.24) µg per day. The average SBP and DBP levels did not differ significantly between the SCH group and the euthyroid group.