It is important to have iodine sufficiency before becoming pregnant because the brain and neurological system are formed during the first trimester. Inadequate maternal iodine can leave the child with permanent neurological damage and a lowered IQ.  A meta-analysis of 18 studies of children and adolescents found iodine deficiency was associated with a 13.5 point lower IQ score in those children.

In the latest NHANES (2009-2010) data, it was shown that the iodine level in  US pregnant women was low enough to cause thyroid dysfunction and neurological deterioration. Children born to mothers with inadequate iodine also have poorer educational outcomes.

In-utero iodine insufficiency has been associated with a host of ailments in children, including ADHD, autism, depression, and decreased learning ability, also  poor height and bone maturation as well as decreased neonatal survival rate in iodine-deficient areas of the country.

It's not difficult to achieve iodine sufficiency - the RDA for iodine before and during pregnancy is only 220ug/per day.  This can be achieved if taking a multi-vitamin/mineral supplement containing at least 150ug.  We can't rely on our food supply anymore because iodine was removed from most food products about 50 years ago, especially baked products/bread, and replaced with a toxic halogen, bromide.  Also the other toxic halogens now prevalent in our food supply (esp from pesticides on our food) replace the iodine we might have in our tissues because they all compete for the same cell receptor sites.  These include bromide, fluoride, and chloride.

In Japan, the country with the lowest level of breast, prostate, uterine, and ovarian cancer in developed countries, the normal daily intake of iodine is 100x the RDA for our country.  That works out to about 12 - 13 mg from certain seaweeds common in their daily diet. 

For those wishing for greater protection from these cancers, as well as a better functioning thyroid gland, I recommend doing the urine-analysis test to see how much iodine you have in your storage tank.  If you'd like info on this test, shoot me an email.  I now carry the test kits in my office.