K.M. Ferry

In vitro fertilization with single euploid blastocyst transfer: a randomized controlled trial

OBJECTIVE To determine whether performing comprehensive chromosome screening (CCS) and transferring a single euploid blastocyst can result in an ongoing pregnancy rate that is equivalent to transferring two untested blastocysts while reducing the risk of multiple gestation. DESIGN Randomized, noninferiority trial. SETTING Academic center for reproductive medicine. PATIENT(S) Infertile couples (n = 205) with a female partner less than 43 years old having a serum anti-Müllerian hormone level ≥ 1.2 ng/mL and day 3 FSH <12 IU/L. INTERVENTION(S) Randomization occurred when at least two blastocysts were suitable for trophectoderm biopsy. The study group (n = 89) had all viable blastocysts biopsied for real-time, polymerase chain reaction-based CCS and single euploid blastocyst transfer. The control group (n = 86) had their two best-quality, untested blastocysts transferred. MAIN OUTCOME MEASURE(S) The ongoing pregnancy rate to ≥ 24 weeks (primary outcome) and the multiple gestation rate. RESULT(S) The ongoing pregnancy rate per randomized patient after the first ET was similar between groups (60.7% after single euploid blastocyst transfer vs. 65.1% after untested two-blastocyst transfer; relative risk [RR], 0.9; 95% confidence interval [CI], 0.7-1.2). A difference of greater than 20% in favor of two-blastocyst transfer was excluded. The risk of multiple gestation was reduced after single euploid blastocyst transfer (53.4% to 0%), and patients were nearly twice as likely to have an ongoing singleton pregnancy (60.7% vs. 33.7%; RR, 1.8; 95% CI, 1.3-2.5). CONCLUSION(S) In women ≤ 42 years old, transferring a single euploid blastocyst results in ongoing pregnancy rates that are the same as transferring two untested blastocysts while dramatically reducing the risk of twins.

Comprehensive chromosome screening is highly predictive of the reproductive potential of human embryos: a prospective, blinded, nonselection study.

OBJECTIVE To determine both the negative and positive predictive values of comprehensive chromosome screening (CCS) results for clinical outcome. DESIGN Data obtained from two prospective, double-blinded, nonselection studies. SETTING Academic center for reproductive medicine. PATIENT(S) One hundred forty-six couples with a mean maternal age of 34.0 ± 4.4 years and a mean paternal age of 37.3 ± 5.8 years. INTERVENTION(S) Embryo biopsy for DNA fingerprinting and aneuploidy assessment. MAIN OUTCOME MEASURE(S) Failure rate of embryos predicted aneuploid by CCS (negative predictive value) and success rate of embryos predicted euploid by CCS (positive predictive value). RESULT(S) A total of 255 IVF-derived human embryos were cultured and selected for transfer without influence from CCS analysis. Embryos were biopsied before transfer, including 113 blastomeres at the cleavage stage and 142 trophectoderm biopsies at the blastocyst stage. Comprehensive chromosome screening was highly predictive of clinical outcome, with 96% of aneuploid predicted embryos failing to sustain implantation and 41% sustained implantation from embryos predicted to be euploid. CONCLUSION(S) These nonselection data provide the first prospective, blinded, clinical study directly measuring the predictive value of aneuploidy screening for clinical outcome. The clinical error rate of an aneuploidy designation is very low (4%), whereas implantation and delivery rates of euploid embryos are increased relative to the entire cohort of transferred embryos.

Development and validation of an accurate quantitative real-time polymerase chain reaction–based assay for human blastocyst comprehensive chromosomal aneuploidy screening

OBJECTIVE To develop and validate a quantitative real-time polymerase chain reaction (qPCR)-based method for blastocyst trophectoderm comprehensive chromosome screening (CCS) of aneuploidy. DESIGN Prospective, randomized, and blinded. SETTING Academic center for reproductive medicine. PATIENT(S) Nine cell lines were obtained from a commercial cell line repository, and 71 discarded human blastocysts were obtained from 24 IVF patients that underwent preimplantation genetic screening. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Consistency of qPCR diagnosis of aneuploidy compared with either conventional karyotyping of cell lines or microarray-based diagnoses of human blastocysts. RESULT(S) Samples from nine cell lines with well characterized karyotypes were diagnosed by qPCR with 97.6% (41/42) consistency. After applying a minimum threshold for concurrence, 100% consistency was achieved. Developmentally normal blastocysts designated as aneuploid or arrested blastocysts designated as euploid by single-nucleotide polymorphism microarray analyses were assigned identical 24 chromosome diagnoses by qPCR in 98.6% of cases (70/71). Overall euploidy (n = 37) and aneuploidy (n = 34) were assigned with 100% consistency. Data was obtained for both sample types in 4 hours. CONCLUSION(S) These data demonstrate the first qPCR technology capable of accurate aneuploidy screening of all 24 chromosomes in 4 hours. This methodology provides an opportunity to evaluate trophectoderm biopsies with subsequent fresh euploid blastocyst transfer. Randomized controlled trials to investigate the clinical efficacy of qPCR-based CCS are currently underway.

Oocyte vitrification does not increase the risk of embryonic aneuploidy or diminish the implantation potential of blastocysts created after intracytoplasmic sperm injection: a novel, paired randomized controlled trial using DNA fingerprinting

OBJECTIVE To assess the impact of oocyte vitrification on aneuploidy and reproductive potential by comparing vitrified and control oocytes from a single patient within a single cycle and a single fresh transfer. DESIGN Paired randomized controlled trial in which each patients cohort of mature oocytes was divided into two even groups with half undergoing Cryotop vitrification and rapid warming and half serving as controls. SETTING Academic center for reproductive medicine. PATIENT(S) Forty-four patients with a mean age of 29.9 ± 2.3 years and normal ovarian reserve. INTERVENTION(S) Cryotop vitrification of half of mature oocytes. Trophectoderm biopsy with single nucleotide polymorphism microarray analysis for ploidy and DNA fingerprinting. MAIN OUTCOME MEASURE(S) Rate of aneuploidy (primary outcome), fertilization, cleavage, blastulation, and implantation in embryos derived from vitrified and control oocytes. RESULT(S) A total of 588 mature oocytes were randomized, with 240/294 (81.6%) surviving vitrification. Among surviving vitrified oocytes, there was a lower fertilization rate with intracytoplasmic sperm injection (77.9% vs. 90.5%; relative risk [RR], 0.86; 95% confidence interval [CI], 0.80-0.93), a lower cleavage rate (90.9% vs. 99.2%; RR, 0.92; 95% CI, 0.87-0.96), and a lower usable blastocyst formation rate per two pronuclei (34.8% vs. 50.8%; RR, 0.68; 95% CI, 0.54-0.86). There was no difference in the rate of embryonic aneuploidy (vitrified, 29.1% vs. control, 26.4%). In paired blastocyst transfers, the ongoing pregnancy rate per embryo transferred was similar (vitrified, 53.9% vs. control, 57.7%). CONCLUSION(S) Although the IVF process is less efficient after oocyte vitrification, implantation rates are equivalent and there is no increased risk of aneuploidy. Given the lack of other viable options, this study provides great reassurance to patients and clinicians applying oocyte vitrification for fertility preservation.

Blastocyst preimplantation genetic diagnosis (PGD) of a mitochondrial DNA disorder.

OBJECTIVE To evaluate the utility of trophectoderm biopsy for preimplantation genetic diagnosis (PGD) of mitochondrial (mt) DNA mutation load. DESIGN A PGD case and analysis of blastocyst mosaicism. SETTING Academic center for reproductive medicine. PATIENT(S) A 30-year-old carrier of 35% 3243A>G mtDNA mutation load with a daughter affected by mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. INTERVENTION(S) Blastocyst biopsy for PGD of mutation load and gender. MAIN OUTCOME MEASURE(S) Variation in mutation load within and among embryos, and newborn mutation load after PGD-based selection. RESULT(S) Oocytes and embryos were found to possess a variety of 3243A>G mutation loads from 9% to 90% in oocytes and 7% to 91% in embryos, demonstrating that PGD would be a relevant procedure. Highly consistent results were obtained within multiple biopsies of both cleavage- and blastocyst-stage embryos. Importantly, mutation loads observed in trophectoderm were predictive of the inner cell mass (r(2) = 0.97). Transfer of a male embryo, predicted to possess 12% mutation load by analysis of a trophectoderm biopsy, resulted in the delivery of a boy with tissue-specific mutation loads ranging from undetectable to 15%. CONCLUSION(S) This study represents the first successful clinical application of PGD to reduce the transgenerational risk of transmitting an mtDNA disorder and supports the applicability of blastocyst trophectoderm PGD for carriers of mtDNA mutations attempting reproduction.