Preimplantation diagnosis for aneuploidies in patients undergoing in vitro fertilization with a poor prognosis: identification of the categories for which it should be proposed.

OBJECTIVE To verify whether advantages can derive from the implementation of preimplantation genetic diagnosis for aneuploidy in patients with a poor prognosis of full-term pregnancy, compared with conventional treatment procedures. DESIGN A randomized, controlled study. SETTING Reproductive Medicine Unit of the Società Italiana Studi Medicina della Riproduzione, Bologna, Italy. PATIENT(S) In a total of 262 stimulated cycles, women presented with the following poor-prognosis indications: maternal age of > or =36 years (n = 157), > or =3 previous IVF failures (n = 54), and an altered karyotype (n = 51). After giving consent, 127 patients underwent preimplantation genetic diagnosis for aneuploidy, whereas 135 controls underwent assisted zona hatching. INTERVENTION(S) Analysis of chromosomes XY, 13, 14, 15, 16, 18, 21, and 22 was carried out with the fluorescence in situ hybridization technique in a blastomere biopsied from day 3 embryos. Assisted zona hatching was performed on day 3 embryos from the control group. MAIN OUTCOME MEASURE(S) Embryo morphology and chromosomal status, number of transferred embryos, clinical pregnancies, implantation rates, and abortions. RESULT(S) In the study group, 717 embryos were analyzed by fluorescence in situ hybridization, and 60% were chromosomally abnormal. A mean of 2.3+/-0.9 euploid embryos were transferred in 99 cycles, resulting in 37 clinical pregnancies (37%) and a 22.5% ongoing implantation rate. In the control group, 126 cycles were performed with 3.2+/-1.3 embryos transferred, yielding 34 clinical pregnancies (27%) and a 10.2% ongoing implantation rate. CONCLUSION(S) The advantage of selecting embryos with a normal chromosome complement has an immediate impact on the ongoing implantation rate, especially in patients aged > or =38 years and carriers of an altered karyotype.