Management of Graves' disease during pregnancy: the key role of fetal thyroid gland monitoring.
BACKGROUND
Fetuses from mothers with Graves' disease may experience hypothyroidism or hyperthyroidism due to transplacental transfer of antithyroid drugs (ATD) or anti-TSH receptor antibodies, respectively. Little is known about the fetal consequences. Early diagnosis is essential to successful management. We investigated a new approach to the fetal diagnosis of thyroid dysfunction and validated the usefulness of fetal thyroid ultrasonograms.


METHODS
Seventy-two mothers with past or present Graves' disease and their fetuses were monitored monthly from 22 wk gestation. Fetal thyroid size and Doppler signals, and fetal bone maturation were determined on ultrasonograms, and thyroid function was evaluated at birth. Thyroid function and ATD dosage were monitored in the mothers.


RESULTS
The 31 fetuses whose mothers were anti-TSH receptor antibody negative and took no ATDs during late pregnancy had normal test results. Of the 41 other fetuses, 30 had normal test results at 32 wk, 29 were euthyroid at birth, and one had moderate hypothyroidism on cord blood tests. In the remaining 11 fetuses, goiter was visualized by ultrasonography at 32 wk, and fetal thyroid dysfunction was diagnosed and treated; there was one death, in a late referral, and 10 good outcomes with normal or slightly altered thyroid function at birth. The sensitivity and specificity of fetal thyroid ultrasound at 32 wk for the diagnosis of clinically relevant fetal thyroid dysfunction were 92 and 100%, respectively.


CONCLUSIONS
In pregnant women with past or current Graves' disease, ultrasonography of the fetal thyroid gland by an experienced ultrasonographer is an excellent diagnostic tool. This tool in conjunction with close teamwork among internists, endocrinologists, obstetricians, echographists, and pediatricians can ensure normal fetal thyroid function.
Luton
Dominique
D
Department of Perinatology, Multidisciplinary Center for Prenatal Diagnosis, Robert Debré Hospital, 75019 Paris, France.
Le Gac
Isabelle
I
Vuillard
Edith
E
Castanet
Mireille
M
Guibourdenche
Jean
J
Noel
Michèle
M
Toubert
Marie-Elisabeth
ME
Léger
Juliane
J
Boissinot
Christine
C
Schlageter
Marie-Hélène
MH
Garel
Catherine
C
Tébeka
Brigitte
B
Oury
Jean-François
JF
Czernichow
Paul
P
Polak
Michel
M
D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use*; D001323:Autoantibodies / Q000097:blood; D005260:Female; D005333:Fetus / Q000502:physiology*; D006111:Graves Disease / Q000188:drug therapy*; D006801:Humans; D018828:Immunoglobulins, Thyroid-Stimulating; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy*; D011446:Prospective Studies; D011989:Receptors, Thyrotropin / Q000097:blood; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000502:physiology; D013974:Thyroxine / Q000097:blood; D016216:Ultrasonography, Prenatal
D013956:Antithyroid Agents; D001323:Autoantibodies; D018828:Immunoglobulins, Thyroid-Stimulating; D011989:Receptors, Thyrotropin; C094372:thyrotropin-binding inhibitory immunoglobulin; D013974:Thyroxine