The objective of the study was to determine if Preimplantation Genetic Diagnosis (PGD) and transfer of chromosomally normal embryos would decrease spontaneous abortion rates in patients suffering from recurrent pregnancy loss (RPL).   RPL patients having three or more prior lost pregnancies with no known etiology were recruited for the study. Biopsy of a single blastomere from each day-3 embryo was performed followed by chromosome analysis of the biopsied cell. Only embryos classified as chromosomally normal were replaced. The rate of spontaneous abortions in RPL subjects undergoing PGD were compared to 1) their own a priori expectations, based on Brigham et al. (1999) and 2) a "comparison" group of women undergoing PGD for advanced maternal age (35 y or older).

The results were that before PGD, RPL patients had lost 87% (262/301) of their pregnancies, with an expected loss rate of 36.5%.   After PGD they only lost 16.7% pregnancies, which was statistically significant.   This difference was mostly due to reduction in pregnancy loss in the >= 35-age subgroup, to 12% from an expected 44.5% (p=0.007).