HLA-A,B compatibility in parents of offspring with neural-tube defects or couples experiencing involuntary fetal wastage.

To test the contribution of a putative human analogue of the murine T locus to neural-tube defects (N.T.D.) and involuntary fetal wastage, HLA-A, B compatibility between husband and wife was studied in a group of 77 couples with known obstetric histories. The frequency of sharing of HLA-A,B antigens was significantly higher in 13 couples with recurrent fetal loss at one gestational age and in 11 couples whose offspring had had a lethal N.T.D. than in 17 couples with three or more normal pregnancies. The extent of HLA compatibility--that is, the number of antigens shared by husbands and wives--was significantly higher in 16 couples with one spontaneous abortion, 23 couples with recurrent spontaneous abortions, and 21 couples with N.T.D. offspring than in controls. These data are consistent with a contribution of a locus in or near the HLA complex to N.T.D. and involuntary fetal wastage.