Embryo selection versus natural selection: how do outcomes of comprehensive chromosome screening of blastocysts compare with the analysis of products of conception from early pregnancy loss (dilation and curettage) among an assisted reproductive technology population?

Objective: To compare the incidence of numerical chromosomal abnormalities (NCAs) reported after preimplantation genetic screening (PGS) analysis compared with that reported after cytogenetic analysis of products of conception after spontaneous abortion.

Design: Retrospective study.

Setting: Private academic in vitro fertilization center.

Optimizing human oocyte cryopreservation for fertility preservation patients: should we mature then freeze or freeze then mature?

Objective: To evaluate the maturation and post-thaw survival rates of immature oocytes to determine whether in vitro maturation (IVM) should be attempted prior to or after cryopreservation.

Design: Nonrandomized observational study.

Setting: Private academic and clinical reproductive center.

Commercially available enhanced in vitro maturation medium does not improve maturation of germinal vesicle and metaphase I oocytes in standard in vitro fertilization cases.

Improvements in in vitro maturation techniques have focused on culture optimization to increase oocyte maturation rates. Specialized culture media, now commercially available, did not perform significantly better than standard IVF culture media for maturation of immature oocytes in our normal IVF cases.

High pregnancy rates can be achieved after freezing and thawing human blastocysts.

Objective: To examine the results of a 3-year trial using blastocyst cryopreservation to limit multiple pregnancy and optimize overall pregnancy per cycle.

Design: Retrospective clinical evaluation of pregnancy rates after freezing and thawing human blastocysts.

Setting: Tertiary-care academic center.