Outcomes of natural cycles versus programmed cycles for 1677 frozen-thawed embryo transfers.

The study compares outcomes for patients with frozen embryos who had frozen-thawed embryo transfer (FET) timed to their natural ovulation cycle versus cycles in which endometrial timing was programmed with oestrogen and progesterone. A total of 1205 patients undergoing 1677 FET cycles between 1 January 2000 and 31 December 2006 were analysed. Comparisons were made for patients undergoing modified natural versus programmed FET cycles, as well as between patients using their own eggs for frozen embryos versus those using donor-egg-derived embryos. Clinical pregnancy (gestational sac on 7 week ultrasound) rates (CPR), as well as miscarriage rates, were significantly higher in programmed FET cycles in patients using their own eggs (106/262, 40.5% per embryo transfer, P = 0.015) However, there was not a difference in delivered pregnancies between cycle types in own egg patients (natural cycle delivery rate 245/862, 28.4%; programmed cycle delivery rate 77/262, 29.4%). Furthermore, CPR were not different in natural (38/129, 29.5%) versus programmed cycles (144/424, 34.0%) for ovum donor recipients, nor were delivered pregnancy rates different in natural (33/129, 25.6%) versus programmed cycles (114/424, 26.9%) for ovum donor recipients. In conclusion, there is no significant difference in delivery rates for FET in natural (278/991, 28.1%) versus programmed (191/686, 27.8%) cycles using both own embryos and donor-egg-derived embryos.

Pregnancy outcomes from more than 1,800 in vitro fertilization cycles with the use of 24-chromosome single-nucleotide polymorphism-based preimplantation genetic testing for aneuploidy.

OBJECTIVE: To measure in vitro fertilization (IVF) outcomes following 24-chromosome single‒nucleotide-polymorphism (SNP)-based preimplantation genetic testing for aneuploidy (PGT-A) and euploid embryo transfer. DESIGN: Retrospective. SETTING: Fertility clinics and laboratory. PATIENT(S): Women 20-46 years of age undergoing IVF treatment. INTERVENTION(S): Twenty-four-chromosome SNP-based PGT-A of day 5/6 embryo biopsies. MAIN OUTCOME MEASURE(S): Maternal age-stratified implantation, clinical pregnancy, and live birth rates per embryo transfer; miscarriage rates; and number of embryo transfers per patient needed to achieve a live birth. RESULT(S): An implantation rate of 69.9%, clinical pregnancy rate per transfer of 70.6%, and live birth rate per transfer of 64.5% were observed in 1,621 nondonor frozen cycles with the use of SNP-based PGT-A. In addition, SNP-based PGT-A outcomes, when measured per cycle with transfer, remained relatively constant across all maternal ages; when measured per cycle initiated, they decreased as maternal age increased. Miscarriage rates were ∼5% in women ≤40 years old. No statistically significant differences in pregnancy outcomes were found for single-embryo transfers (SET) versus double-embryo transfers with SNP-based PGT-A. On average, 1.38 embryo transfers per patient were needed to achieve a live birth in nondonor cycles. CONCLUSION(S): Our findings that SNP-based PGT-A can mitigate the negative effects of maternal age on IVF outcomes in cycles with transfer, and that pregnancy outcomes from SET cycles are not significantly different from those of double-embryo transfer cycles, support the use of SET when transfers are combined with SNP-based PGT-A.