Higher levels of thyrotropin in pregnancy and adverse pregnancy outcomes

Abstract

Objective: To determine the frequency of subclinical hypothyroidism in women with pathological pregnancies and the association between elevated thyroid-stimulating hormone (TSH) and pregnancy outcome. Subjects and methods: A cross-sectional prospective study investigated value of TSH and free thyroxine (FT4) in (1) pregnant women with hypertension (HTA) (N = 62) or preeclampsia (PE) (N = 50), (2) women with gestational diabetes mellitus (GDM) (N = 92) in pregnancy, and (3) women with normal pregnancies (control) (N = 201). The level of statistical significance was set at p < .05. Results: Of the total 404 respondents, the highest incidence of subclinical hypothyroidism was in the group with preeclampsia 22%, followed HTA group 9.6%; GDM group 10.9% and in the control group 9% (p < .001). Higher levels of TSH were in the preeclampsia (2.5 ± 1.54 mIU/L) and in the HTA (2.03 ± 0.97 mIU/L) compared with the control group (1.95 ± 0.86 mIU/L); (p < .001). Weight gain in pregnancy was significantly higher in women with TSH >3 mIU/L (p = .003). There were no differences in the average TSH value between GDM (1.93 ± 1.03 mIU/L) and control group (p = .962). Conclusions: Early detection and optimal treatment of thyroid dysfunction before and in the first trimester of pregnancy reduces the risk of adverse pregnancy outcomes.

Keywords: Complications in pregnancy; hypothyroidism; pregnancy outcomes; screening; thyrotropin.