Are we overtreating subclinical hypothyroidism in pregnancy?

  title={Are we overtreating subclinical hypothyroidism in pregnancy?},
  author={Kate Wiles and Sheba Jarvis and Catherine Nelson-Piercy},
  journal={BMJ : British Medical Journal},
#### The bottom line Overt hypothyroidism is diagnosed with a high serum thyroid stimulating hormone (TSH) concentration in conjunction with a low serum thyroxine concentration or an isolated TSH concentration above 10 mU/L. Subclinical hypothyroidism is a biochemical diagnosis based on a high TSH concentration with normal thyroxine. The benefits of treating overt hypothyroidism during pregnancy include improved obstetric and neonatal outcomes. However, evidence for the management of… 

Management for women with subclinical hypothyroidism in pregnancy

  • K. Wiles
  • Medicine, Biology
    Drug and Therapeutics Bulletin
  • 2019
Pregnancy outcomes in SCH are discussed and the evidence for thyroxine replacement is detailed and reference intervals for thyroid function are outlined including the new upper limit for TSH defined by the American Thyroid Association in 2017.

Identifying and treating subclinical thyroid dysfunction in pregnancy: emerging controversies.

It is essential to reconsider how thyroid dysfunction should be identified in pregnant women and highlight the arguments for and against the use of levothyroxine in obstetric practices to reach agreements between both endocrinologists and obstetricians.

Impact of TPOAb-negative maternal subclinical hypothyroidism in early pregnancy on adverse pregnancy outcomes

A mildly elevated thyroid-stimulating hormone level or maternal subclinical hypothyroidism diagnosed by 2011 American Thyroid Association guidelines during early pregnancy in thyroid peroxidase antibody–negative women was not associated with adverse pregnancy outcomes, however, maternal sub clinical hyp Timothyroidism identified by the 2017 American Thyroxine Association guidelines increased the risks of several adverseregnancy outcomes in women untreated with levothyroxine.

Diagnosis and Management of Subclinical Hypothyroidism in Pregnancy: A Retrospective Review Study

Early diagnosis and treatment of SCH during pregnancy is cost effective in reducing the preterm labour, miscarriage and its complications and screening should include not only high risk cases but patients in countries with high prevalence of SCH.

Prevalence of subclinical and overt hypothyroidism in antenatal women: A study from tertiary care center in North India

Timely management of HT and SCH is required to achieve a successful pregnancy outcome and serum TSH level is a simple and reliable indicator of thyroid status in pregnancy.

Current challenges in the pharmacological management of thyroid dysfunction in pregnancy

Key challenges and areas of uncertainty in the management of thyroid dysfunction in pregnancy are addressed including uncertainties in optimal thresholds for correction of hypothyroidism and strategies for pharmacological management of hyperthyroidism.

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

Maternal SCH diagnosed by the 2017 ATA guidelines was more likely to develop PIH, preeclampsia, cesarean delivery, preterm delivery, placenta previa, and total adverse maternal and neonatal outcomes, while a mildly elevated TSH level was significantly associated with PIH after adjustment for confounding factors.

Managing thyroid disease in general practice

  • J. Walsh
  • Medicine, Biology
    The Medical journal of Australia
  • 2016
Thyroxine remains standard treatment for hypothyroidism, with optimal dosage determined by clinical response and serum TSH, and positive TSH‐receptor antibodies indicate Graves' disease.

Thyroid stimulating hormone (TSH) ≥2.5mU/l in early pregnancy: Prevalence and subsequent outcomes.

Effects of Levothyroxine Therapy on Pregnancy Outcomes in Women with Subclinical Hypothyroidism.

LT4 therapy is associated with a decreased risk of LBW and a low Apgar score among women with SCH, and this association awaits confirmation in randomized trials before the widespread use of LT4 therapy in pregnantWomen with SCH.



Diagnosis and management of subclinical hypothyroidism in pregnancy

O Ongoing prospective trials that are evaluating the impact of levothyroxine therapy on adverse outcomes in the mother and fetus in women with subclinical hypothyroidism will provide crucial data on the role of thyroid hormone replacement in pregnancy.

2014 European Thyroid Association Guidelines for the Management of Subclinical Hypothyroidism in Pregnancy and in Children

This guideline has been produced as the official statement of the European Thyroid Association guideline committee and indicates that targeted antenatal screening for thyroid function will miss a substantial percentage of women with thyroid dysfunction.

The magnitude of increased levothyroxine requirements in hypothyroid pregnant women depends upon the etiology of the hypothyroidism.

The etiology of hypothyroidism plays a pivotal role in determining the timing and magnitude of thyroid hormone adjustments during pregnancy, and patients require vigilant monitoring of thyroid function upon confirmation of conception and anticipatory adjustments to LT(4) dosing based on the etiology.

Perinatal Significance of Isolated Maternal Hypothyroxinemia Identified in the First Half of Pregnancy

There was a low prevalence of thyroid peroxidase antibodies and no correlation between TSH and free T4 levels in women with hypothyroxinemia, leading us to question its biological significance.

Interventions for clinical and subclinical hypothyroidism pre-pregnancy and during pregnancy.

There is insufficient evidence to recommend the use of one intervention for clinical or subclinical hypothyroidism pre-pregnancy or during pregnancy over another, for improving maternal, fetal, neonatal and childhood outcomes.

Maternal Thyroid Hypofunction and Pregnancy Outcome

Maternal thyroid hypofunction is not associated with a consistent pattern of adverse outcomes, and there was an increased risk for preterm premature rupture of membranes when both antibodies were positive in either trimester.

Significance of (sub)clinical thyroid dysfunction and thyroid autoimmunity before conception and in early pregnancy: a systematic review.

Pregnant women with subclinical hypothyroidism or thyroid antibodies have an increased risk of complications, especially pre-eclampsia, perinatal mortality and (recurrent) miscarriage.

Maternal thyroid deficiency and pregnancy complications: implications for population screening

From the second trimester onward, the major adverse obstetrical outcome associated with raised TSH in the general population is an increased rate of fetal death, which would be another reason to consider population screening.

Does the thyroid-stimulating hormone measured concurrently with first trimester biochemical screening tests predict adverse pregnancy outcomes occurring after 20 weeks gestation?

Testing maternal TSH as part of first trimester screening does not predict adverse pregnancy outcomes, which may be because in the community setting, mainly mild abnormalities in thyroid function are detected.

Assessment of thyroid function during first-trimester pregnancy: what is the rational upper limit of serum TSH during the first trimester in Chinese pregnant women?

The reference range for nonpregnant women can be used for the assessment of pregnant women at 4 to 6 weeks of gestation and the upper limit of serum TSH in the first trimester was much higher than 2.5 mIU/L in Chinese pregnant women.