Association of hemoglobin level with thyroid-stimulating hormone in different trimester pregnant women with subclinical hypothyroidism

Abstract

To investigate the association between hemoglobin (Hb) and thyroid-stimulating hormone (TSH) levels in different trimester pregnant women with subclinical hypothyroidism (SCH). 62 pregnant women, who were diagnosed as SCH when they had their first antenatal care and eventually delivered in the Affiliated Quanzhou First Hospital of Fujian Medical University from March 2013 to December 2014, were enrolled in this study. These subjects were divided into three groups according to weeks of gestation when they had their first prenatal care: including first trimester (n=24), second trimester (n=17), and third trimester (n=21) groups. All SCH pregnant women were treated with levothyroxine (L-T4). The clinical and laboratory data in the first antenatal care and antepartum period were collected. Association of Hb level with other clinical and laboratory data were analyzed. Compared to baseline, the levels of TSH, γ-glutamyl transpeptidase, alanine aminotransferase, and total cholesterol were lower (all P<0.05), and the levels of Hb were higher (P<0.05), after treated with L-T4 in three groups. Pearson correlation analysis showed that the level of Hb was negativly correlated with TSH in all pregnancies or in third trimester groups (r=-0.394, -0.308, -0.537 and -0.453 respectivly, all P<0.05). Multivariate regression analysis indicated that the level of Hb was independently associated with TSH and body mass index in pregnant women with SCH. In pregnant women with SCH, the higher TSH and body mass index levels are correlated with increased risk of anemia. L-T4 treatment may ameliorate anemia during pregnancy. (Chin J Endocrinol Metab, 2018, 34: 505-508) Key words: Pregnancy; Subclinical hypothyroidism; Hemoglobin; Levothyroxine