Clinical efficacy of therapeutic intervention for subclinical hypothyroidism during pregnancy

Abstract

ABSTRACT. This study explored the effects of levothyroxine (L-T4) replacement therapy on pregnancy outcomes in patients with subclinical hypothyroidism (SCH). We analyzed the effects on pregnancy outcomes with respect to gestational week when the desired thyroid-stimulating hormone (TSH) level was reached as well as the length of time required to reach the target level during L-T4 treatment. This study enrolled 457 patients diagnosed with SCH upon initial thyroid function screening. Subjects were assigned to the treatment group (N = 184), and the control group (N = 273). Two variables were analyzed in the treatment group: the gestational week when the target TSH level was achieved and the length of time required to reach the target level during treatment. Based on these criteria, the treatment group was further divided into subgroups, including three subgroups based on the time required to reach target levels (<4 weeks, 4-8 weeks, and >8 weeks) and gestational week when the target TSH level was achieved (before the 12th, between the 12th-28th, and after the 28th gestational week). The overall risk of complications in the control group was significantly higher than in the treatment group (P < 0.05). After L-T4 treatment, the incidences of premature rupture of fetal membranes (PROM), gestational diabetes mellitus, fetal macrosomia, and postpartum hemorrhage in the group with treatment duration <4 weeks were significantly lower than those in the groups with 4-8 and >8 weeks treatment duration (P < 0.05). L-T4 treatment can significantly reduce the risks of adverse pregnancy outcomes in pregnant women with SCH. The shorter the treatment duration required to reach the target TSH level and the earlier the gestational week when the target TSH level is achieved through treatment, the lower the incidence of complications.

The impact of levothyroxine therapy on the pregnancy, neonatal and childhood outcomes of subclinical hypothyroidism during pregnancy: An updated systematic review, meta-analysis and trial sequential analysis

“…A total of 3222 articles were identified by the initial search. After selection, 22 studies ( 17 – 38 ) met our inclusion criteria and were included in this systematic review. The literature screening process is shown in Figure 1 .…”

Effects of thyroid diseases on pregnancy outcomes

“…Hypothyroxinemia and subclinical hyperthyroidism significantly increases adverse pregnancy outcomes and complications (7). Furthermore, L-T4 administration in thyroid deficiency groups may improve pregnancy outcomes and decrease the odds of complications (33).…”

The role of levothyroxine in obstetric practice

“…Additionally, in recent years, we have witnessed different studies where screening strategies have been used and LT 4 therapy was administered in cases of SCH and/or TAI in order to assess its effectiveness in preventing obstetrical complications and trying to increase the rate of successful pregnancies (Table 3) [67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86].…”

“…LT 4 is the first option for the treatment of hypothyroidism because of its effectiveness, costs and safety profile [14,15]. An insufficient maternal thyroid function may, therefore, be optimized with the prescription of an inexpensive, available and well-established therapy [16,17]. Nevertheless, the findings of some recent interventional studies [18,19] highlight the potential benefits and risks of the use of LT 4 in pregnant women with subclinical thyroid conditions.…”