A correlation of the outcome of clinical in vitro fertilization with the inositol content and embryotrophic properties of human serum.

PURPOSE: This study was designed to investigate whether the level of myo-inositol (MI) in human serum is critical for embryotrophic activity.

METHODS

The embryotrophic properties of human serum were evaluated by the development of postimplantation mouse embryos [in vitro assay of Tam et al. (Fertil Steril 48:834-839, 1987)]. An enzymatic spectrophotometric method using myo-inositol dehydrogenase was used for determination of serum MI. The level of MI detected in serum was compared with the embryotrophic properties and the pregnancy outcome. The effect of MI on the embryotrophic activity of human serum was studied by supplementing the suboptimal serum samples that were unsupportive of embryo growth with extra MI.

RESULTS

Serum obtained from patients having successful IVF pregnancies generally supported better development of postimplantation mouse embryos and contained higher levels of inositol, particularly if the serum sample was collected during the IVF treatment cycle. Serum samples obtained from patients with aborted pregnancies, though supporting mouse embryo development, contained significantly lower concentrations of inositol. An improvement of the embryotrophic properties with exogenous inositol supplement was achieved in some but not all of the suboptimal serum samples studied.

CONCLUSIONS

It is possible that other factors in addition to inositol are crucial in promoting better embryonic development.