Thirty-Four Fertilized Human Ova, Good, Bad and Indifferent, Recovered From 210 Women of Known Fertility

From a study of 34 early human ova (24 normal and 10 abnormal) recovered from a series of 107 patients known to be fertile whose conditions for conception were optimal it appears that the maximum fertility rate at implantation is 58%; the maximum normal fertility rate after the twelfth day of ovular development is 42%; the probable maximum fertility rate during the preimplantation stages is from 80 to 90%; the greatest ovular loss is in the preimplantation stage; the next greatest loss is during the week after implantation; the ovular loss after the first missed period may be as great as 28.6%, either with or without clinical signs and is therefore comparable to the clinical abortion rate; these defective human fertilized ova rise because of intrinsic defects rather than from defects of the local or endocrine environment, and, finally, the fertility rates and fate of fertilzed ova are roughly comparable in man and other mammals.