Management of Subclinical Hypothyroidism in Pregnancy: A Comment from the Italian Society of Endocrinology and the Italian Thyroid Association to the 2017 American Thyroid Association Guidelines—“The Italian Way”

Abstract

The 2017 American Thyroid Association guidelines for the diagnosis and management of thyroid disease during pregnancy and the postpartum were published six years after the previous ones. They provide comprehensive clinical recommendations for the whole spectrum of thyroid diseases, as well as for optimal iodine intake during pregnancy, postpartum, and lactation. The present position statement mainly regards the recommended flow chart for therapeutic decision making in pregnant women being diagnosed with subclinical hypothyroidism. Here, we comment on the major biochemical and clinical situations and the corresponding therapeutic recommendations. In particular, we welcome the critical revision of the thyrotropin (TSH) reference range in pregnancy, and we agree that there is no need to treat thyroid peroxidase antibody-negative women with a serum TSH ranging from 2.5 μIU/mL to the upper limit of the reference range. This recommendation will hopefully reduce the huge proportion of healthy pregnant women in whom, according to the previous guidelines, levothyroxine therapy had to be initiated. On the other hand, we are concerned with the recommendation to only "consider treatment" in thyroid peroxidase antibody-negative pregnant women with a serum TSH ranging from the upper limit of the reference range to 10.0 μIU/mL. This is because thyroid antibodies may be falsely negative during gestation, and serum negative chronic autoimmune thyroiditis is a well-known clinical entity even outside pregnancy. Based on these and other arguments, we recommend treatment with levothyroxine in pregnant women with TSH levels ranging between the upper limit of the reference range and 10.0 μIU/mL independently from their thyroid antibody status.

Effects of Maternal Subclinical Hypothyroidism in Early Pregnancy Diagnosed by Different Criteria on Adverse Perinatal Outcomes in Chinese Women With Negative TPOAb

“…In addition, our findings were obtained from Chinese pregnant women with negative TPOAb, which provided robust evidence to support the opinion from Rotondi et al ( 34 ). They thought the 2017 ATA guidelines overemphasized thyroid autoantibodies status and recommended treatment with LT4 in pregnant women with TSH levels ranging between the upper limit of the reference range and 10.0 μIU/mL independent from their thyroid antibody status.…”

Practice Variation in the Care of Subclinical Hypothyroidism During Pregnancy: A National Survey of Physicians in the United States

“…Interventional studies [13, 27, 28] have been unable to document the same benefits of LT4 treatment of SCH in pregnancy as seen in observational studies [29–32]. In this uncertain context, the ATA issued an updated version of its guidelines encompassing major changes in clinical practices for the management of SCH during pregnancy [1, 33]. The new recommendations have been partially accepted [33–35]; as demonstrated here, practice is only partially concordant with ATA recommendations.…”

“…In this uncertain context, the ATA issued an updated version of its guidelines encompassing major changes in clinical practices for the management of SCH during pregnancy [1, 33]. The new recommendations have been partially accepted [33–35]; as demonstrated here, practice is only partially concordant with ATA recommendations. This could be due to low-grade recommendations according to the guideline-grading hierarchy, which could be perceived by health care providers as lacking certainty in the evidence.…”

The Follow-Up of Thyroid Disease in 188 Pregnant Women According to the Guidelines of ATA (American Thyroid Association) 2017

“…The most common cause of hypothyroidism in the pregnancy is autoimmune disorders such as Hashimoto's thyroiditis [2,7]. It is treated with a synthetic hormone (levothyroxine), and the dose is adjusted and monitored by thyroid function tests every 4-6 weeks during pregnancy (ATA recommendation) [5,6].…”