Systematic review and meta-analysis of the efficacy and pregnancy outcomes of levothyroxine sodium tablet administration in pregnant women complicated with hypothyroidism.

BACKGROUND: In recent years, the detection rate of pregnancy complicated with hypothyroidism [subclinical hypothyroidism (SCH) during pregnancy] has increased significantly. Levothyroxine sodium tablet is the main drug for the treatment of SCH during pregnancy, but its effect on the treatment of SCH during pregnancy and the effect of pregnancy outcome are still controversial.

METHODS: PubMed, Web of Science, Medline, and Embase databases were screened to retrieve clinical studies on levothyroxine sodium tablets in the treatment of pregnancy complicated with hypothyroidism from the date of establishment to June 2021. Meta-analysis was performed with RevMan5.3 software. The differences in the incidence of preterm birth, miscarriage, gestational hypertension, postpartum hemorrhage, placental abruption, and abnormal neonatal weight were compared between the observation group and the control group. Heterogeneity of results was assessed with chi-square test and I2 in RevMan5.3 software.

RESULTS: Nine articles with a total of 2,873 pregnant women were included. The Cochrane assessments were all grade B and above, and the Jadad scale scores were all >3 points. The incidences of preterm birth, abortion, postpartum hemorrhage, and low birth weight infants in the pregnant women treated with levothyroxine sodium were lower than those in the control group [odds ratio (OR) =0.42, 0.34, 0.40, and 0.08, respectively; 95% confidence interval (CI): 0.30-0.58, 0.23-0.52, 0.22-0.74, and 0.01-0.51, respectively; Z=5.23, 5.08, 2.97, and 2.70, respectively; P<0.00001, <0.00001, =0.003, and =0.007, respectively].

DISCUSSION: Levothyroxine sodium in the treatment of SCH can significantly reduce the incidence of premature birth, miscarriage, postpartum hemorrhage, and low birth weight infants. Due to the limited number of included studies, it remained to be further verified whether levothyroxine sodium treatment in SCH patients would affect the incidence of gestational hypertension.