“Will my hyperactive thyroid create complications in my pregnancy?”

Yes

Yes, hyperactive thyroid can create complications in pregnancy if it's not treated. You can prevent complications by getting it treated to normal levels.

Not if your obstetrician and the doctor who is treating the problem work together. You DO have an obstetrician, don't you? Have you asked him or her about this? Some of the antithyroid meds are perfectly safe in pregnancy; a thyroid ultrasound test is safe, but most doctors postpone the nuclear scan until after delivery.

Hi. I do hope you have been seen for your hyperactive thyroid condition as this increased thyroxine level will directly affect your unborn child during the pregnancy. Control will require medical management in most cases.
Kindly see your obstetrician / internal physician and let him/her deal with this matter for the duration of your pregnancy. After pregnancy you will still need to be followed through until you have settled.

Yes, it can adversely affect the fetus so it must be treated. Surgery has been shown to have a higher spontaneous abortion rate than medical Rx. Medical treatment can be with radioactive iodine or anti-thyroid medications. There is a danger with RI that some of the radiation can effect the baby so it is nor recommended. (I did have a patient who was given RI by another DR. during a pregnancy with diabetes & hyperthyroid. There was no damage to the baby.) I would recommend treatment with an anti-thyroid drug as safest. These drugs can cross the placenta & enter the fetus thus blocking their thyroid. The baby's Dr. then must know of the treatment so the baby can be treated with thyroid until the gland recovers from the blockage (usually a few months).