Do we need to assess the thyroid function in the infants of mothers with Hashimoto's thyroiditis?

Reducing unnecessary neonatal testing in infants of mothers with thyroid disease

AIM

To examine the numbers of asymptomatic infants <8 weeks who had appropriate thyroid function tests (TFTs) in addition to the newborn screening test, because of maternal thyroid disease, before and after the implementation of an updated institutional guideline and staff education.

METHODS

A medical record audit of infants <8 weeks born at a metropolitan teaching hospital, who had TFTs between 1 July 2017 and 31 October 2017 was performed as part of a quality improvement project. Records were reviewed to determine the indication for testing and whether this complied with the current 2011 institutional guideline. A multidisciplinary staff education package was developed to coincide with the publication of an updated guideline in August 2018. Staff education and resources were provided throughout July 2018. A post-intervention audit was repeated between 1 August 2018 and 1 December 2018, assessing compliance with the 2018 guideline.

RESULTS

In the baseline period, 40 of 457 infants born had TFTs performed, of which 26 of 40 (65%) were for maternal thyroid disease. Of these 10 of 26 (38%) met the 2011 criteria for testing; 1 of 26 (4%) met the updated 2018 criteria. In the post-intervention period, 14 of 412 infants born had TFTs of which 5 of 14 (36%) were tested due to maternal thyroid disease and all were compliant with the new guideline.

CONCLUSIONS

Baseline audit revealed unnecessary neonatal thyroid function testing of healthy babies. Implementation of an updated guideline and a brief, targeted education package successfully increased awareness of the updated recommendations, reduced unnecessary testing and led to improved practice.

Are thyroid function tests in neonates born to mothers with hypothyroidism clinically useful?

Thyroid function tests from all babies born to mothers with hypothyroidism (381 neonates) during a 6-year period, were collected and examined against findings of the universal screening test. No difference was found between the results of bloodspot test and later blood test. Additional blood tests for thyroid function in this population of neonates seem to be without clinical value and may be discontinued.

[Recommendations for the diagnosis and follow up of the foetus and newborn child born to mothers with autoimmune thyroid disease]

The objective of this document is to review the current recommendations in the management of the foetus and the newborn child born to mothers with autoimmune thyroid disease. In 2017, the American Thyroid Association published guidelines for the diagnosis and management of thyroid disease during pregnancy and post-partum. In this guide, 97 recommendations were made, and an algorithm for the diagnosis and treatment of gestational hypothyroidism was proposed. Also, in this last year, a wide review was been published on the foetal and neonatal approach of the child of a mother with Graves' disease. The importance of the determination of maternal antibodies against thyrotropin receptor in the second half of pregnancy is stressed, in order to adequately stratify the risk in the neonate.

Thyroid function testing in neonates born to women with hypothyroidism

Our aim was to assess the utility of serum thyroxine and thyroid stimulating hormone performed at 10-14 days of life in diagnosing congenital hypothyroidism (CH) in babies born to mothers with hypothyroidism. This was a retrospective study of all babies born in a tertiary referral centre for neonatology over a 12-month period. Infants who had thyroid function testing (TFT) checked at 10-14 days of life because of maternal hypothyroidism during the period of study were included. The results of the newborn bloodspot and day 10-14 TFT were recorded along with whether or not patients were subsequently treated. Of the 319 patients included in the study, only two patients were found to have CH and in both cases the newborn blood spot had been abnormal.

CONCLUSION

No extra cases of CH were detected from the thyroid test at 10-14 days and this practice should be discontinued due to the robust nature of existing newborn screening programmes. What is Known: • Congenital hypothyroidism(CH) is the commonest preventable cause of childhood intellectual impairment. • Family history of hypothyroidism has been implicated as a risk factor for CH. • CH has formed part of newborn screening since the 1970s. What is New: • There is no research recommending thyroid function testing at 10-14 days of life to detect CH in neonates born to mothers with hypothyroidism. • Thyroid function testing at 10-14 days of life does not improve diagnostic yield for CH in babies born to mothers with hypothyroidism. • Newborn blood spot remains the mainstay for accurate and timely diagnosis of CH.

Serum thyroid function tests in neonates of mothers with thyroid disease

Maternal thyroid disease can affect the newborn baby leading to neonatal hyperthyroidism or hypothyroidism. Babies born to mothers with thyroid disease get thyroid function tests (TFT) done randomly irrespective of the nature of maternal thyroid disease and medication .The aim of this study was to determine which babies are at-risk and need thyroid function monitoring besides a simple Newborn screening test and to produce a local guideline for management of this particular cohort of babies. This prospective study done on 30 newborn babies concluded that routine newborn screening test is enough to monitor majority of these babies. A new local guideline is formulated accordingly.