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Recommendations Table 17. ATD Treatment of Graves'
Disease Preconception and in Pregnancy
Strength
*
Level
#
Consider discontinuing ATD therapy for Graves' disease
upon confirmed pregnancy if the woman is euthyroid on low
dose ATD (MMI <5–10 mg/day or PTU <100–200 mg/
day) taken for >6 months pre-pregnancy (Figure 4).
Conditional Low
Following the discontinuation of ATD use in pregnancy,
serum TSH, FT4 and clinical examination may be
monitored every 1–2 weeks in the first trimester, then every
2–4 weeks in the second and third trimesters.
Conditional Low
In pregnant women with a new diagnosis of Graves'
hyperthyroidism or who have high risk of developing
thyrotoxicosis if ATDs were to be discontinued,
treatment with ATDs is advised as follows: Strength
*
Level
#
Pregnant women with active Graves' disease managed with
ATDs should have serum TSH, FT4, and TRAb and/or TSI
concentrations measured as soon as pregnancy is confirmed
and monitored with TSH and FT4 every 2–4 weeks thereaer.
Good Practice Statement
PTU may be used if initiating ATD for the treatment of
hyperthyroidism before 16 weeks of pregnancy.
Conditional Low
If a woman is taking MMI during pregnancy, switching to
PTU
a
may be considered until 16 weeks
b
depending on the
time of presentation and MMI dose (see text).
Good Practice Statement
If PTU is not available, MMI may be continued at the lowest
effective dose for the shortest duration possible.
Conditional Low
In case of thyrotoxicosis, propranolol may be used in routine
dosages to ameliorate hyperthyroidism-related symptoms.
Good Practice Statement
a
When switching from MMI to PTU, a dose ratio of approximately 1:20 should be used
(e.g., MMI 5 mg once daily= PTU 50 mg twice daily).
b
If ATD therapy continues to be required aer 16 weeks gestation, it remains unclear whether PTU
should be continued or switched to MMI.
* Strength of Recommendation;
#
Level of Evidence; Good Practice Statement.
