Periconceptional folate supplementation reduces the risk of neural tube defect in a dose-dependent way in women without clinical folate deficiency. A possible explanation for the dissociation between therapeutic effect and clinical deficiency is provided by work in New York (

). They tested serum from 12 women whose current or previous pregnancy had been complicated by neural tube defect in the fetus and 20 controls who had had only normal pregnancies. They found autoantibodies against human placental folate receptors in the sera of nine of the 12 study subjects and two of the 20 controls. The antibodies blocked cellular uptake of folate and bound to folate receptors on placental membrane cells and on cultured human cells. More work is needed to establish the clinical importance of this finding.

In the November 2003 issue of Archives Lucina commented on a reported family link between neural tube defects or isolated hydrocephalus and Down’s syndrome. Now a large study in 10 countries of South America (

) has not shown a link. The study included a total of 1 583 838 live births and stillbirths with 2421 cases of neural tube defect, 952 of hydrocephalus, and 3095 of Down’s syndrome. There was no excess of Down’s syndrome in pregnancies prior to the birth of a child with neural tube defect or hydrocephalus and no excess of neural tube …