Send to

Choose Destination
Gynecol Endocrinol. 2017 Jan;33(1):16-18. doi: 10.1080/09513590.2016.1240773. Epub 2016 Nov 4.

Onset of Graves' disease during pregnancy in a woman with established hypothyroidism.

Author information

a Servicio de Endocrinología y Nutrición, Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria, Instituto Universitario de Investigaciones Biomédicas y Sanitarias, Universidad de Las Palmas de Gran Canaria , Las Palmas de Gran Canaria , Spain.



Pregnancy strongly influences the thyroid gland and its function. Thyroid guidelines recommend a 30 to 50% increase of the preconceptional levothyroxine dose in women with hypothyroidism, when pregnancy is diagnosed.


A 33 year-old, 8-week pregnant woman with hypothyroidism, presents with a 2-week history of palpitations, sweating, nervousness and fatigue. Physical examination shows tachycardia (108 bpm), distal tremors and diffuse goiter. After biochemical confirmation of hyperthyroidism, her levothyroxine dose is reduced and finally interrupted. Propylthiouracil is started and maintained until after the delivery of a healthy baby at week 40. Two weeks postpartum, hyperthyroidism worsens and propylthiouracil is replaced by methimazole. Eighteen months after delivery 7.5 mCi 131Iodine was given. Two months later, hypothyroidism developed and levothyroxine was initiated.


Although conversion of Hashimoto's hypothyroidism into Graves' disease is exceptional in pregnancy, pregnant women with autoimmune hypothyroidism should ideally have their TSH concentrations measured before empirically increasing their levothyroxine dose.


Hyperthyroidism; hypothyroidism; pregnancy

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center