Pregnancy and PTU

[Amy555]

Dear experts of the forum,

I am 30 years old and was diagnosed with Graves Disease this past May 2007 (TSH less than 0.01, elevated T3, T4, and antithyroid antibodies, ultrasound revealed no nodules). Since July 25, 2007 I have been taking 300mg propylthiouracil (PTU) per day, and when tested on September 6, 2007, my T3 and T4 were in the normal range and my TSH was still low (0.01). I was instructed to continue the dose of 300mg PTU per day, which I am currently taking. I just found out I am pregnant (a few days shy of 4 weeks along). Unfortunately I am also now away in a country whose language I do not speak, unable to consult directly with my doctor back home, and need to figure out ASAP the urgency of my situation. My questions are:

1) How high is the risk of the current PTU dose for the normal develoment of the embryo/fetus, and from which stage in fetal development does this become important?

2) Can the medical therapy be optimised so that the risks of medication/antibodies are lowered profoundly?

3) At this point, are there alternatives to my current treatment that pose lower risks to the fetus?

-and a related question:
4) Are there specialists who deal together with issues of reproduction and endocrinology problems such as Graves Disease?

Thank you for your help, and I would be glad to hear from you soon.

[Amy555]

Many, many thanks for your quick response! What is your professional opinion on breastfeeding with Grave's Disease, 1) if I am taking PTU simultaneously, and 2) in regards to having anti-thyroid antibodies (i.e. do they cross into breast milk and affect the baby)? There seems to be some controversy among medical professionals, but I am not aware of the current consensus, if there is one.

[Mark Lupo, M.D.]

Graves disease complicating a pregnancy is not uncommon.  PTU is still the preferred treatment, if treatment is necessary.  Things tend to improve on their own in the 2nd/3rd trimester.  We keep the T4 and T3 in the upper range of normal and tend to pay less attention to the TSH -- the risk of hypothyroidism is more than mild hyperthyroidism in this setting.  

Try to minimize the PTU does (which should be taken in divided doses -- ie, if 300mg/day total dose then take 100mg with breakfast, lunch and dinner) -- but likely you will need less than 300mg.

Working with a high-risk obstetrician and an endocrinologist is the best combination.