Bridging Evidence and Practice: Recent Advances in Hypothyroidism Management during Pregnancy

Deficiency of thyroid hormones, primarily thyroxine and triiodothyronine, results in the clinical condition known as hypothyroidism, a prevalent endocrine disorder globally, particularly in women of childbearing age. Dynamic changes occur in thyroid function during pregnancy to provide adequate levels of thyroid hormones to the mother and the fetus. Hashimoto thyroiditis remains the most widespread reason for gestational hypothyroidism in iodine-sufficient regions and in mildly iodine deficient populations. Iodine plays a vital role in the synthesis and regulation of thyroid hormones; therefore, during pregnancy, iodine consumption must be increased by 50% to produce the required amount of maternal thyroid hormones and meet the increased demand of the developing fetus. Evidence-based studies have shown that even minor alteration in maternal thyroid function can cause pregnancy-related complications and adverse pregnancy outcomes (e.g. miscarriage, perinatal death, pre-eclampsia, pregnancy-induced hypertension, low birth weight and postpartum hemorrhage). Therefore, the timely assessment and appropriate management of gestational hypothyroidism is crucial to ensure optimal maternal and fetal outcomes. Levothyroxine remains the standard treatment for hypothyroidism, significantly reducing the risk of adverse pregnancy outcomes in women with hypothyroidism. The present review provides an update on the diagnosis and management of hypothyroidism in pregnant women, highlighting the different types, causes, signs and symptoms of hypothyroidism, and the obstetric outcomes of each type of hypothyroidism along with the treatment strategy. Current key recommendations based on clinical evidence by health practitioners are also provided to assist in planning and choosing the individualized treatment regimen for patients with hypothyroidism before and during pregnancy.