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

Abstract

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 ≥36 years (n = 157), ≥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 ≥38 years and carriers of an altered karyotype.