Preimplantation genetic diagnosis for aneuploidy screening is superior compared with controls not only in clinical outcome at the first ET but also in dramatically decreasing miscarriage rates and shortening the time to pregnancy.

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BackgroundIt has been reported that a natural cycle (NC) is similar to or even better than hormone replacement therapy (HRT) in patients with regular cycles who undergo frozen embryo transfer (FET). Hundreds of FETs are managed yearly in our clinic. Scheduling these cycles is critical in a busy unit like ours. This is why we have to prove if a NC really shows a better outcome than other endometrium preparation protocols.MethodsHence we carried out a prospective study between June 2011 and June 2012, which included 530 patients (570 FET cycles) randomly allocated to two study groups: Group 1 (n=280 cycles), artificial cycle (HRT); or group 2 (n=290 cycles), natural cycle. Natural cycles were later divided into two groups: 169 patients scheduled with human chorionic gonadotropin (hCG) and 121 with endogenous luteinizing hormone (LH) surge. The inclusion criteria were: age <39 years, regular menstrual cycles (26–35 days), and previous IVF cycle with embryo cryopreservation. The exclusion criteria were polycystic ovarian syndrome and endometriosis stage III/IV.ResultsNo statistical differences were found in the baseline characteristics among groups, nor between implantation or ongoing pregnancy rates (30.8% HRT group; 32.7% hCG group; 34.5% LH surge group). However, a higher miscarriage rate was observed in the HRT group when compared to hCG or LH surge (21.2% versus 12.9% versus 11.1%, P<0.01). Live birth rates were similar among groups, as were perinatal outcomes, for rates of natural delivery and weight and length of newborns.ConclusionsWe conclude that scheduling FET with HRT on weekdays and avoiding work overload at weekends prove efficient and safe in cycle outcome terms. Another reason for the convenience of an HRT protocol is having fewer visits to the clinic compared to natural cycle protocols.

Chromosome abnormalities in embryos obtained through in-vitro maturation (IVM) of oocytes from 11 oocyte donors were compared with embryos from women undergoing fluorescence in-situ hybridization (FISH) analysis for sex selection. Thirty-three oocytes had reached metaphase II stage at 28-30 h (65%) and 27 were successfully fertilized by intracytoplasmic sperm injection. Blastomere biopsy was performed in 20 embryos (74%). For five embryos, two blastomeres were analysed, three of which were mosaic. FISH study revealed aneuploidies of chromosomes 13, 15, 16, 18, 21, 22, X and Y in 12 embryos (60%) and euploidy in the remaining eight (40%). The percentage of aneuploidies in the control group was 33%. Differences between IVM and control embryos were not statistically significant. The high incidence of chromosome abnormalities in embryos resulting from the IVM protocol may account for the low implantation rates reported by others. Although a greater incidence of miscarriage or congenital abnormalities in babies born alive following IVM versus conventional IVF has not been observed in previous studies, preimplantation genetic aneuploidy screening or prenatal chromosome studies may be recommended to these patients on the basis of the present results.

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