Screening for thyroid disease in pregnancy remains a contentious issue. This review presents these diverging views and discusses their reasons as well as the relevant facts. The final aim is to establish the information gaps and limitations - technological or otherwise - which still need to be eliminated in order to settle the debate conclusively. The prevalence of the more common thyroid dysfunctions that occur in and after pregnancy is discussed. The subsequent impact of these disorders on mother and offspring is also described. Special focus is placed on the benefits and setbacks of currently available and newly proposed investigations, which assay serum hormone levels, serum autoantibody levels, and/or use clinical data. It is pointed out that the relevance of screening varies from one region of the world to the other, based on the content of iodine and selenium in food and water. The review then discusses the current major arguments for and against screening, as well as recommendations and proposed alternatives.