Whether Using Sequential pH Would Improve Human Blastocyst Formation

Any drift in extracellular pH (pHe) from the intercellular pH (pHi) could alter the mechanism regulating transporters and exchangers through the plasma membrane. This could lead to difficulty in restoring the physiological level of pHi. The critical stages that lack robust mechanism of regulating the pHi are the denuded oocyte, early stage of fertilization or a thawed embryo. This, in turn, could lead to a significant effect of the perturbations on embryo development. Convincing evidence regarding the optimal pHe for culturing human embryo is, so far, scanty and mostly anecdotal. The embryo has been reported to have a compensatory mechanism to grow at pHe between 7.0-7.4. Others have recommended that embryo need a sequential pH to viably grow suggesting that the post-genomic activation stage needs a slightly alkaline range of pH. However, whether this holds true remains to be examined.