RAT EMBRYO CULTURE TO DETECT NUTRITIONAL DEFICIENCY IN WOMEN WITH POOR REPRODUCTIVE HISTORIES

The cause of habitual early pregnancy loss is not known for most affec ted couples. It has been proposed that a deficiency of amino acids or other nutrients may contribute to early embryo loss, and an assay base d on culture of rat embryos in human serum has been proposed to evalua te women with poor reproductive histories. We tested this assay in wom en with unexplained infertility (n = 27), habitual abortion (n = 15), and normal midtrimester pregnancies (n = 10) by examining the ability of subject's serum to support the normal development of rat embryos in culture with and without supplemental vitamins and amino acids. Nonpr egnant women with nutrient deficiencies identified in this manner were given oral supplements or placebo and were retested. A similar propor tion of women in each group had serum that was unable to support the n ormal development of rat embryos without supplemental vitamins and ami no acids. When oral supplements were used, most sera were able to supp ort normal embryo growth. There were no seroconversions on placebo. In spite of the apparent success in producing seroconversions on oral su pplementation, only two women conceived, one on the placebo treatment and one on nutritional supplements. Because serum nutrient deficiencie s identified by rat embryo culture could not distinguish normal pregna nt women from women with unexplained infertility or habitual abortion, and because of the low pregnancy rates, we could not confirm the util ity of this assay for the general population of women with habitual ab ortion. If subtle nutritional deficiencies play a role in early pregna ncy loss, it may require a more homogeneous population of women with, for example, a history of five or more spontaneous pregnancy losses.