An essay on research into the causation and prevention of spina bifida.

The curly-tail mouse is an animal model for human neural tube defects (NTD). Around 60% have either overt lesions of the neural tube or a curly tail. They were used to examine the gene/environment interaction which is implicated in the aetiology of human NTD. Both a fetal and a maternal genotype contribution to the cause, together with a triggering effect of an environmental component, could be demonstrated in the mice. The environmental limb of the cause appears to be relatively specific. Under certain conditions, administration of an environmental agent to the pregnant curly-tail mouse markedly reduced the incidence of NTD in her offspring. Primary prevention of NTD was thus shown to be possible. The apparent primary prevention of NTD in humans is also described. A multicentre collaborative project which supplemented women "at risk" for NTD with a standard multivitamin tablet with folic acid before they conceived again and in the early stages of pregnancy was associated with a recurrence of only 0.5% compared with 4.3% in unsupplemented controls at a comparable risk. The difference is statistically significant (p = less than 0.01).