I was taking too much synthroid (thyroxine) when i conceived. could this cause chromosonal abnormalities in the fetus?

Unlikely: Although possible, it is highly unlikely that synthroid (thyroxine) would cause chromosomal damage. It would more likely suppress the fetal thyroid temporarily.

NO!: Thyroid function is critical for fertility and embryonic development but cannot cause or prevent chromosomal defects. Those are caused by genetic accidents in the male or female gonads prior to conception or at the time of conception; your synthroid (thyroxine) dose has nothing to do with it.

No: Synthroid (thyroxine) level does not cause chromosomal abnormalities but it does affect the health of the fetus and the ability to carry through the pregnancy. If your level is too high, please see your doctor to get it readjusted during this critical time. Good luck.