Of these, approximately 450 full-length papers were
reviewed. Of these, 27 original studies and two metaanalyses
were included in this review. It was decided
not to attempt to perform a meta-analysis of the pregnancy
studies because: (i) the number of randomised
controlled intervention trials of iodine in pregnancy
and/or infancy is small; (ii) in many, blinding is
uncertain, drop-outs were high and follow-up was
inconsistent; and (iii) the studies vary widely in their
designs (oral vs. intramuscular delivery of high doses
of iodised oil; daily low dose potassium iodide; iodisation
of irrigation water; timing of intervention).