K.H. Hong

Blastocyst biopsy with comprehensive chromosome screening and fresh embryo transfer significantly increases in vitro fertilization implantation and delivery rates: a randomized controlled trial.

OBJECTIVE To determine whether blastocyst biopsy and rapid quantitative real-time polymerase chain reaction (qPCR)-based comprehensive chromosome screening (CCS) improves in vitro fertilization (IVF) implantation and delivery rates. DESIGN Randomized controlled trial. SETTING Academic reproductive medicine center. PATIENT(S) Infertile couples in whom the female partner (or oocyte donor) is between the ages of 21 and 42 years who are attempting conception through IVF. INTERVENTION(S) Embryonic aneuploidy screening. MAIN OUTCOME MEASURE(S) Sustained implantation and delivery rates. RESULT(S) We transferred 134 blastocysts to 72 patients in the study (CCS) group and 163 blastocysts to 83 patients in the routine care (control) group. Sustained implantation rates (probability that an embryo will implant and progress to delivery) were statistically significantly higher in the CCS group (89 of 134; 66.4%) compared with those from the control group (78 of 163; 47.9%). Delivery rates per cycle were also statistically significantly higher in the CCS group. Sixty one of 72 treatment cycles using CCS led to delivery (84.7%), and 56 of 83 (67.5%) control cycles ultimately delivered. Outcomes were excellent in both groups, but use of CCS clearly improved patient outcomes. CONCLUSION(S) Blastocyst biopsy with rapid qPCR-based comprehensive chromosomal screening results in statistically significantly improved IVF outcomes, as evidenced by meaningful increases in sustained implantation and delivery rates. CLINICAL TRIAL REGISTRATION NUMBER NCT01219283.

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.

The nature of aneuploidy with increasing age of the female partner: a review of 15,169 consecutive trophectoderm biopsies evaluated with comprehensive chromosomal screening

OBJECTIVE To determine the relationship between the age of the female partner and the prevalence and nature of human embryonic aneuploidy. DESIGN Retrospective. SETTING Academic. PATIENT(S) Trophectoderm biopsies. INTERVENTION(S) Comprehensive chromosomal screening performed on patients with blastocysts available for biopsy. MAIN OUTCOME MEASURE(S) Evaluation of the impact of maternal age on the prevalence of aneuploidy, the probability of having no euploid embryos within a cohort, the complexity of aneuploidy as gauged by the number of aneuploid chromosomes, and the trisomy/monosomy ratio. RESULT(S) Aneuploidy increased predictably after 26 years of age. A slightly increased prevalence was noted at younger ages, with >40% aneuploidy in women 23 years and under. The no euploid embryo rate was lowest (2% to 6%) in women aged 26 to 37, was 33% at age 42, and was 53% at age 44. Among the biopsies with aneuploidy, 64% involved a single chromosome, 20% two chromosomes, and 16% three chromosomes, with the proportion of more complex aneuploidy increasing with age. Finally, the trisomy/monosomy ratio approximated 1 and increased minimally with age. CONCLUSION(S) The lowest risk for embryonic aneuploidy was between ages 26 and 30. Both younger and older age groups had higher rates of aneuploidy and an increased risk for more complex aneuploidies. The overall risk did not measurably change after age 43. Trisomies and monosomies are equally prevalent.

Selecting the optimal time to perform biopsy for preimplantation genetic testing

A consistent requirement for all preimplantation genetic testing is the need to obtain DNA from the oocyte or embryo. Currently this sample is attained through biopsy of one or both polar bodies, blastomere biopsy at the cleavage stage, or trophectoderm biopsy after blastulation. Selecting the optimal time for biopsy requires careful consideration. Polar body biopsy is less invasive and provides more time for analysis but fails to capture as many as one in three embryonic aneuploidies. Additionally, the inability to readily distinguish nondysjunction from premature separation of sister chromatids greatly limits the predictive value of the technique and may lead to an overdiagnosis of aneuploidy in as many as 45% of cases with first polar-body errors. Cleavage-stage biopsy provides adequate samples but is detrimental to the embryo. The adverse effect of blastomere biopsy may result in approximately two of every five reproductively competent embryos losing their ability to implant and sustain development. Trophectoderm biopsy does not adversely impact the embryos. However, for the majority of clinical programs without a genetics laboratory, vitrification would be necessary to allow time for the genetic analysis. Although this extends the time required for treatment, clinical outcomes are equivalent after transfer of euploid blasts during fresh IVF and cryopreserved embryo transfer cycles, so that excellent outcomes are maintained. At present the blastocyst stage is the optimal time to perform biopsies for preimplantation genetic testing.

Obstetrical and neonatal outcomes from the BEST Trial: single embryo transfer with aneuploidy screening improves outcomes after in vitro fertilization without compromising delivery rates

OBJECTIVE We sought to determine whether performing elective single embryo transfer (eSET) after trophectoderm biopsy and rapid aneuploidy screening results in improved obstetrical and neonatal outcomes compared with transferring 2 untested embryos. STUDY DESIGN The Blastocyst Euploid Selective Transfer (BEST) Trial enrolled infertile couples with a female partner up to age 42 years who were undergoing in vitro fertilization. They were randomized to receive transfer of a single euploid embryo (eSET) or to the standard of care with transfer of 2 embryos that were not biopsied for aneuploidy screening (untested 2-embryo transfer). Gestational age at delivery, birthweight, and neonatal intensive care unit (NICU) lengths of stay were compared with Mann-Whitney U. The risk of preterm delivery, low birthweight, and NICU admission were compared with χ(2). RESULTS Among the 175 randomized patients, the delivery rates were similar (69% after euploid eSET vs 72% after untested 2-embryo transfer; P = .6) through the fresh cycle and up to 1 frozen transfer, with a dramatic difference in multiple births (1.6% vs 47%; P < .0001). The risk of preterm delivery (P = .03), low birthweight (P = .002), and NICU admission (P = .04) were significantly higher after untested 2-embryo transfer. Babies born after untested 2-embryo transfer spent >5 times as many days in the NICU (479 vs 93 days; P = .03). CONCLUSION By enhancing embryo selection with a validated method of aneuploidy screening, a single euploid embryo with high reproductive potential can be selected for transfer. Using this approach, eSET can be performed without compromising delivery rates and improving the chance of having a healthy, term singleton delivery after in vitro fertilization.

Delivery of a chromosomally normal child from an oocyte with reciprocal aneuploid polar bodies

PurposeTo demonstrate that a euploid embryo derived from an oocyte with reciprocal aneuploid polar bodies is capable of producing a chromosomally normal child.MethodsA case report of maternal MI error compensation where single nucleotide polymorphism (SNP) microarray based comprehensive chromosome screening (CCS) was performed on the 1st and 2nd polar body, the resulting embryo, and newborn DNA.ResultsCCS performed after embryo transfer identified a chromosomally normal embryo that resulted from an oocyte with reciprocal aneuploid polar bodies. The first polar body was found to be missing a single chromatid derived from chromosome 21 and the second polar body possessed an extra chromatid derived from chromosome 21. Compensation of the maternal meiotic error was verified by CCS analysis of a trophectoderm biopsy from the resulting blastocyst which was euploid for all 23 pairs of chromosomes. DNA fingerprinting and CCS of the resulting newborn confirmed a chromosomally normal child, demonstrating the developmental potential of an oocyte with reciprocal aneuploid polar bodies.ConclusionsThis is the first case report demonstrating the reproductive potential of a chromosomally normal embryo derived from an oocyte which had undergone meiosis I error. Systematic investigation into the frequency of meiosis I error compensation and the negative predictive value of polar body aneuploidy screening for reproductive potential should be conducted in order to confirm clinical relevance.

Comprehensive Chromosome Screening and Embryo Selection: Moving Toward Single Euploid Blastocyst Transfer

Interest in using aneuploidy screening to select embryos has been renewed with the introduction of new methods for comprehensive chromosome screening (CCS) that evaluate all 24 chromosomes. With a series of experiments providing level I evidence of accuracy, reliability, safety, predictive value, and clinical efficacy, CCS-based selection of a single euploid blastocyst may provide an opportunity to finally realize the potential benefits and practical application of elective single embryo transfer. Furthermore, by incorporating CCS into research and development to control for chromosomal contribution to reproductive potential, additional biomarkers may now be more readily identified that help to further enhance the efficacy of embryo selection technology. This review describes the critical components of a valid CCS embryo selection methodology and discusses the limitations and opportunities for future routine application in reproductive medicine.

Defining the “sweet spot” for administered luteinizing hormone-to-follicle-stimulating hormone gonadotropin ratios during ovarian stimulation to protect against a clinically significant late follicular increase in progesterone: an analysis of 10,280 first in vitro fertilization cycles

OBJECTIVE To determine whether different ratios of administered LH-to-FSH influence the risk of clinically relevant late follicular P elevations and whether there is an optimal range of LH-to-FSH to mitigate this risk. DESIGN Retrospective cohort. SETTING Private academic center. PATIENT(S) A total of 10,280 patients undergoing their first IVF cycle. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) The ratio of exogenous LH-to-FSH throughout stimulation and association with absolute serum P level≥1.5 ng/mL on the day of hCG administration. RESULT(S) Stimulations using no administered LH (N=718) had the highest risk of P elevation≥1.5 ng/mL (relative risk [RR]=2.0; 95% confidence interval [CI] 1.8-2.2). The lowest risk of P increase occurred with an LH-to-FSH ratio of 0.30:0.60 (20%; N=4,732). In contrast, ratios<0.30, reflecting proportionally less administered LH (N=4,847) were at increased risk for premature P elevation (32%, RR=1.6; 95% CI 1.5-1.7) as were ratios>0.60 (23%, RR 1.1; 95% CI 1.0-1.3). This pattern of lowest risk in the 0.30-0.60 range held true for cycles characterized by low, normal, and high response. When performing a logistic regression to control for multiple confounding variables this relationship persisted. CONCLUSION(S) Absent or inadequate LH dosing is associated with a risk for a late follicular elevation in P sufficient to induce suboptimal outcomes. A total LH-to-FSH ratio of 0.30:0.60 was associated with the lowest risk of P elevation. Optimization of this parameter should be considered when making gonadotropin dosing decisions.

Blastocyst transfer is not associated with increased rates of monozygotic twins when controlling for embryo cohort quality

OBJECTIVE To compare monozygotic twinning (MZT) rates in patients undergoing blastocyst or cleavage-stage ET. DESIGN Retrospective cohort. SETTING Academic research center. PATIENT(S) Autologous, fresh IVF cycles resulting in a clinical pregnancy from 1999 to 2014. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Monozygotic twin pregnancy in blastocyst-stage transfer vs. cleavage-stage transfer when controlling for patient prognosis and embryo cohort quality factors. RESULT(S) There were a total of 9,969 fresh transfer cycles resulting in a pregnancy during the study period. Of these pregnancies, 234 monozygotic twin pregnancies were identified (2.4%). Of all transfers, 5,191 were cleavage-stage and 4,778 were blastocyst-stage transfers. There were a total of 99 MZT identified in the cleavage-stage group (1.9%) and 135 MZT in the blastocyst ET group (2.4%), which was significant. Multivariable logistic regression revealed that increasing age was associated with a significant reduction in MZT, regardless of transfer order. Embryo cohort quality factors, including the number and proportion of six- to eight-cell embryos and availability of supernumerary embryos, were also significant. When controlling for patient age, time period during which the cycle took place, the number and proportion of six- to eight-cell embryos, and availability of supernumerary embryos, there was no longer a difference in MZT rate between blastocyst and cleavage transfer. CONCLUSION(S) Patient prognosis and embryo cohort quality seem to be major factors in MZT rate in women undergoing blastocyst transfer. Although technology-based effects cannot be excluded, patient and embryo characteristics play an important role.

Aneuploidy across individual chromosomes at the embryonic level in trophectoderm biopsies: changes with patient age and chromosome structure

PurposeTo characterize each chromosome’s risk for being involved in embryonic aneuploidy.MethodsThis is a retrospective cohort study conducted at a single, academic center. The cohort consisted of 15,169 consecutive trophectoderm biopsies which then underwent comprehensive chromosome screening utilizing validated real-time polymerase chain reaction (RT-PCR) or single nucleotide polymosphism (SNP) array platforms. Analysis was done to determine probability of aneuploidy by chromosome, changes in that risk with increasing maternal age, and in relationship of aneuploidy to chromosomal structure as classified by prior cytogenetic literature.ResultsThe highest prevalence of imbalances leading to aneuploidy was seen for chromosomes 13, 15, 16, 18, 19, 21, and 22. While elevated in all age groups, there was a disproportionate rise in aneuploidy rates for these chromosomes with increasing maternal age. When classic cytogenetic karyotype groups were compared, the overall smaller groups D, E, and G were associated with the highest rates. Similarly, when grouped based upon structure, acrocentric chromosomes exhibited the highest rates of aneuploidy, followed by the metacentric chromosomes, with the lowest prevalence of error in those with submetacentric structures.ConclusionsThe highest rates of chromosomal aneuploidy were found in chromosomes known to be involved in clinically detectable, abnormal pregnancies, not just simply implantation failure. The rate of aneuploidy in these chromosomes rises disproportionately with age when compared to the other chromosomes which may provide information about chromosomal susceptibility to aging. The biological structure groupings did show varied aneuploidy rates which may provide insight into the biology of aneuploidy.