Management of Hyperthyroidism in Pregnancy: Comparison of Recommendations of American Thyroid Association and Endocrine Society

Table 3

Comparison of recommendations of American Thyroid Association and Endocrine Society on the fetal aspects of hyperthyroidism in pregnancy.

Topic	Recommendations
	American Thyroid Association (2011)	Endocrine Society (2012)
Thyroid receptor antibodies (TRAb)	If the patient has a past or present history of Graves’ disease, a maternal serum determination of TRAb should be obtained at 20–24 weeks gestation.	TRAb should be measured by 22-week gestational age in mothers with (1) current Graves’ disease; or (2) a history of Graves’ disease and treatment with 131I or thyroidectomy before pregnancy; (3) a previous neonate with Graves’ disease; or (4) previously elevated TRAb
Fetal Surveillance	Fetal surveillance with serial ultrasounds should be performed in women who have uncontrolled hyperthyroidism and/or women with high TRAb levels (greater than three times the upper limit of normal). A consultation with an experienced obstetrician or maternal-fetal medicine specialist is optimal. Such monitoring may include ultrasound for heart rate, growth, amniotic fluid volume, and fetal goiter.	In women with TRAb or thyroid-stimulating Ig elevated at least 2- to 3-fold the normal level and in women treated with ATD, maternal free T4, and fetal thyroid dysfunction should be screened for during the fetal anatomy ultrasound done in the 18th–22nd week and repeated every 4–6 weeks or as clinically indicated. Evidence of fetal thyroid dysfunction could include thyroid enlargement, growth restriction, hydrops, presence of goiter, advanced bone age, tachycardia, or cardiac failure, if fetal hyperthyroidism is diagnosed and thought to endanger the pregnancy, treatment using MMI or PTU should be given with frequent clinical, laboratory, and ultrasound monitoring.
Umbilical blood sampling	Cordocentesis should be used in extremely rare circumstances and performed in an appropriate setting. It may occasionally be of use when fetal goiter is detected in women taking ATDs to help determine whether the fetus is hyperthyroid or hypothyroid.	Same (R)
Evaluation of newborn	Same (T)	All newborns of mothers with Graves’ disease (except those with negative TRAb and not requiring ATD) should be evaluated by a medical care provider for thyroid dysfunction and treated if necessary.