New guidance for managing neonates born to mothers with Graves' disease

By Anne Harding

NEW YORK - A new literature-based algorithm provides guidance for physicians on managing neonates born to mothers with Graves' disease (GD).

Maternal hypothyroidism due to GD occurs in up to 2.7% of pregnancies, Dr. Danielle van der Kaay, currently working in the Haga Hospital/Juliana Children's Hospital in Hague, the Netherlands, and her colleagues from the Hospital for Sick Children in Toronto, Canada, noted in their March 15 Pediatrics report. Infants born to these mothers are at risk of developing transient GD, they added, with prevalence estimates ranging from 1.5% to 20%.

Dr. van der Kaay decided to develop the algorithm during her fellowship in pediatric endocrinology at the Hospital for Sick Children in Toronto, after observing that many physicians would call for advice on how to manage patients born to mothers with GD.

"Sometimes we had multiple phone calls a week, and we couldn't really find any good clinical guidelines," she explained. "In Toronto I was working with several pediatric endocrinologists, and if you asked everyone's opinion you would get different answers."

The algorithm is based on case reports, case series, and observational cohort studies, Dr. van der Kaay said, so the quality of evidence is low to moderate. "There is no good-quality, evidence-based research done in these infants, but I think this algorithm can help guide clinicians and physicians," she added.

Dr. van der Kaay and her colleagues from the Netherlands and Canada are now planning to test the algorithm in a multicenter study.

The algorithm includes the following eight suggestions:

1. Assess risk based on maternal thyroid stimulating hormone (TSH)-receptor antibodies. If levels are negative, there is no need for follow-up; if they are positive, or not available, newborns should be considered "at risk" for hypothyroidism.

2. Test cord blood for TSH-receptor antibodies, if possible. Newborns who test negative can be discharged from follow-up.

3. Measurement of fT4 and TSH levels in cord blood is not indicated.

4. Test fT4 and TSH levels at day 3 to 5; repeat at day 10 to 14; and follow clinically until two to three months of age.

5. Schedule should be the same for infants born to mothers with treated or untreated GD.

6. Methimazole (MMI) is the treatment of choice when warranted. Beta blockers can be added for sympathetic hyperactivity. Patients with refractory symptoms can also be given potassium iodide along with MMI. It is not clear whether asymptomatic infants with biochemical hyperthyroidism should be treated.

7. Newborns on MMI should be assessed weekly until their condition is stable, and then every one or two weeks, with medications decreased as tolerated. MMI treatment typically lasts one to two months.

8. Be aware that these infants can develop central or primary hypothyroidism.

The authors reported no funding or disclosures.

SOURCE: http://bit.ly/1VahneJ

Pediatrics 2016.

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