Hey Mamas, I'm totally DDC-crashing here. I noticed the iodine thread because I guess I never officially left this group and the posts still come up.
Iodine and thyroid is so very, very complicated and especially so if you're pregnant or nursing. Our environment is so polluted with bromides (from flame retardants) and fluoride (from everywhere) and perchlorate (from rocket fuel, etc.) and chlorine (water - ingested, topically and inhaled) that compete with iodine in our bodies. We take in these other halides and they bind to our receptors blocking iodine from being absorbed. Dr. Brownstein tests all of his patients as they walk in the door and over 96% are iodine deficient. If you start supplementing iodine, you'll detox bromides (and other toxic halides) that are bound to your receptors and in your cells. Every cell in our bodies need iodine, not just our thyroid - breasts especially!
Seaweeds (like kelp) have waaaay more bromides than iodine anymore and are contaminated with heavy metals. You can Google the safety (recent stuff) about sea veggies.
One can absolutely be hypothyroid while having "normal" blood results. TSH is really useless in determining how your thyroid is functioning. It's true that how our thyroids function impacts the IQ of our babies plus their thyroid function and neurological development. Iodine deficiency in the mother also impacts the baby.
This is heavy stuff, I know, and I still haven't figured out what I'd do if I found out I was pregnant (I'm like 5 days late but am afraid of jinxing anything by testing..) I know there's an iodine receptor in the placenta but I don't know which is worse, being iodine deficient while pregnant or risking dumping toxic halides into your baby. I'm far from an expert on this, just something I've been reading a lot about lately and this is what I've learned so far.
Anything written by any of these guys is great: Dr. Guy Abraham, Dr. David Brownstein and Dr. Jorge Flechas
Here are some links:
http://www.mothering.com/community/t/780908/iodine-its-role-and-why-its-important <---- Nice long thread here on MDC
http://www.stopthethyroidmadness.com/ <--- Lots of info about thyroid and discussion of iodine in the blog - GREAT source!