Bobbi
Hi, Janet:
I cannot answer all of your questions, but I can give you some facts to digest to help your daughter make her decisions (or you, if your daughter is a minor).
Your daughter’s thyroid is permanently diseased. While it is possible for remissions to occur (in 20-30% of patients who go on ATDs), these are, by definition, temporary and of predictable duration.
Whether or not there is a flare-up during a pregnancy is not predictable. Pregnancy is one of the times when it is more common for Graves to appear, so it is always possible for a woman who already has Graves to experience a flare-up. If there IS a flare-up during a pregnancy , both your daughter and the baby are put at increased risk. It might be a slight risk, or it might be a greater risk — no one can tell you in advance. Women have had successful pregnancies while on PTU, but whether or not it is safe for the baby depends upon the dose the woman needs to keep her thyroid levels in check. PTU does cross the placental barrier. And it exists in breast milk is small quantities as well. THe levels might be tolerable for the child, or they might not.
Assessing the potential level of risk to mother and child needs to be done by your daughters’ doctors, and perhaps a pediatrician. No one online can give you those "best guesses."
I wish you and your daughter good health,
Bobbi — NGDF Online Facilitator