Natalie A Cekleniak

Maternal age, morphology, development and chromosome abnormalities in over 6000 cleavage-stage embryos

Previous studies assessing the relationship between embryo development, maternal age and chromosome abnormalities were either small or analysed mostly embryos not suitable for replacement. The present study includes >6000 embryos, including many suitable for replacement. Embryos with the best morphology and development were 44% euploid in patients younger than 35, decreasing to 21% in patients 41 and older. The worst morphology group had only 30% normal embryos from patients younger than 35, and 12% in embryos from patients 41 and older. Thus morphological analysis was able to improve the population of normal embryos only from 30 to 44% in the best of cases. Regarding specific abnormalities, 20% of embryos were aneuploid, 32% aneuploid plus other abnormalities, and the rest had post-meiotic abnormalities. Of those, only aneuploidy increased with maternal age. There were no big differences in the frequency of chromosome abnormalities depending on patient indication, within a similar age group. In summary, previous trends detected in suboptimal embryos were also confirmed in the best embryos for replacement. Although dysmorphism and advanced maternal age are both related to chromosome abnormalities, these parameters can yield at most <50% euploid embryos, and other techniques such as preimplantation diagnosis are required to ensure that only euploid embryos are replaced.

The number of eight-cell embryos is a key determinant for selecting day 3 or day 5 transfer

OBJECTIVE To select patients for day 3 vs. day 5 embryo transfer. DESIGN Retrospective analysis of assisted reproduction technology (ART) cycles comparing outcomes of day 3 and day 5 transfers. SETTING ART program of Brigham and Womens Hospital. PATIENT(S) Patients with day 3 or day 5 embryo transfers (n = 221 and 141, respectively). INTERVENTION(S) Cycles with eight or more zygotes were stratified by the number of eight-cell embryos available on day 3 (none, one or two, or three or more). MAIN OUTCOME MEASURE(S) Number of blastocysts, implantation rates, ongoing pregnancy rates, and number of fetal heart beats. RESULT(S) With no eight-cell embryos on day 3, 0% and 33% pregnancies resulted from day 5 vs. day 3 transfers. With one or two eight-cell embryos on day 3, ongoing and high order multiple rates were not different between day 3 and day 5 transfers. With three or more eight-cell embryos, day 5 transfer resulted in a decrease in multiple gestations but no difference in ongoing pregnancy rates compared with day 3 transfer. CONCLUSION(S) With no eight-cell embryos on day 3, a day 3 transfer is warranted. With one or two eight-cell embryos, any benefit of day 5 transfer appears to be equivocal. With three or more eight-cell embryos, day 5 transfer is recommended.

A novel system for in vitro maturation of human oocytes

OBJECTIVE To compare in vitro maturation of cumulus-free oocytes in glucose-free medium (P1) and standard medium (TC199). DESIGN Prospective, cohort study. SETTING Assisted reproductive technology program. PATIENT(S) One hundred eight patients undergoing ICSI. INTERVENTION(S) Germinal vesicle-stage or metaphase I--stage oocytes were allocated to culture with P1 or TC199. Metaphase II oocytes were fixed for immunofluorescence analysis or fluorescence in situ hybridization at 24 or 48 hours (or both). Media were compared by performing conditional logistic regression analysis that controlled for egg-specific factors. MAIN OUTCOME MEASURE(S) Proportion of mature oocytes and appearance of normal spindle-chromosome cytoarchitecture. RESULT(S) At 24 hours, more P1 oocytes than TC199 oocytes reached metaphase II (59.7% vs. 44.9%). At 48 hours, 71.7% of P1 oocytes and 61.0% of TC199 oocytes reached metaphase II, but this difference was not significant. Metaphase II oocytes in P1 were 34.3% more likely than those in TC199 to have a bipolar spindle with aligned chromosomes. Compared with oocytes at the germinal vesicle stage at 0 hour, those at metaphase I at 0 hour were more likely to progress to metaphase II (72.6% vs. 46.1% at 24 hours; 84.1% vs. 60.6% at 48 hours). CONCLUSION(S) P1 is superior to TC199 for in vitro maturation of granulosa-free human oocytes.

Validation of array comparative genome hybridization for diagnosis of translocations in preimplantation human embryos

Fluorescent in-situ hybridization (FISH) for preimplantation genetic diagnosis (PGD) of structural chromosome abnormalities has limitations, including carrier testing, inconclusive results and limited aneuploidy screening. Array comparative genome hybridization (CGH) was used in PGD cases for translocations. Unbalances could be identified if three fragments were detectable. Smallest detectable fragments were ∼6 Mbp and ∼5 Mbp for blastomeres and trophectoderm, respectively. Cases in which three or more fragments were detectable by array CGH underwent PGD by FISH and concordance was obtained in 53/54 (98.1%). The error rate for array CGH was 1.9% (1/54). Of 402 embryos analysed, 81 were normal or balanced, 92 unbalanced but euploid, 123 unbalanced and aneuploid and 106 balanced but aneuploid. FISH with additional probes to detect other aneuploidies would have missed 28 abnormal embryos in the reciprocal group and 10 in the Robertsonian group. PGD cases (926) were retrospectively reviewed for reciprocal translocations performed by FISH to identify which could have been analysed by array CGH. This study validates array CGH in PGD for translocations and shows that it can identify all embryos with unbalanced reciprocal and Robertsonian translocations. Array CGH is a better approach than FISH since it allows simultaneous screening of all chromosomes for aneuploidy.

The impact of LH-containing gonadotropins on diploidy rates in preimplantation embryos: long protocol stimulation

BACKGROUND The aim of this study was to evaluate the effect of ovarian stimulation with LH-containing gonadotropins (human menopausal gonadotropin, hMG), on ploidy of human cleavage-stage-embryos. METHODS A total of 104 women, at ages 27-43 years, undergoing one cycle of controlled ovarian hyperstimulation for IVF in combination with preimplantation genetic diagnosis, were eligible for enrollment in this retrospective, controlled cohort study. Ovarian stimulation included down-regulation with long agonist and stimulation with either recombinant FSH or hMG. Since the ploidy of embryos changes with female age, patients were matched for age and dosage of the respective gonadotropin. RESULTS Despite similar numbers of chromosomally normal embryos in both groups, women undergoing hMG stimulation demonstrated significantly higher percentages of diploid embryos than did the FSH-stimulated patients (69.8 versus 45.3%; P < 0.01). CONCLUSIONS Long protocol LH-containing ovarian stimulation improves embryonic ploidy in comparison to pure FSH stimulation. This observation may explain higher IVF pregnancy rates, reported for hMG stimulation in some studies.

Factors associated with disposition of cryopreserved reproductive tissue

OBJECTIVE To study patient characteristics associated with the preferences for the disposition of cryopreserved semen and embryos in the event of death or divorce. DESIGN Retrospective exploratory study. SETTING Tertiary care academic medical center. PATIENT(S) One hundred twelve men banking sperm, 54 female patients (partners of men banking sperm) undergoing in vitro fertilization (IVF), and 112 women undergoing IVF who were not partners of men banking sperm. INTERVENTION(S) Male patients banking sperm and couples undergoing IVF completed a standard consent form detailing their desired dispositions (disposal or release to a surviving party) of cryopreserved sperm and embryos in the event of death or divorce. MAIN OUTCOME MEASURE(S) Effect of marital status, age, reason for sperm banking, infertility diagnosis, partner status (single or significant-other partner) on sperm, and embryo disposition choice. RESULT(S) In the event of death, married men were 5.5 times more likely to release banked sperm to a surviving party than were single men. The estimated odds of giving sperm to a survivor were 1.07 times greater with every 1-year increase in age. The choice of sperm disposal was significantly related to the banking reason for the case of banking prior to chemotherapy and/or radiation for malignancy. In the case of male death, the decisions of couples undergoing IVF for embryo disposition agreed with choices of male patients for sperm disposition approximately 33% of the time more often than by chance alone. CONCLUSION(S) Decisions surrounding disposition of cryopreserved sperm are significantly associated with marital status, age, and reason for banking sperm. Respective choices of sperm and embryo disposition in couples undergoing IVF were similar in the situation of male death.

First clinical application of comparative genomic hybridization (CGH) and polar body testing for preimplantation genetic diagnosis (PGD) of aneuploidy

OBJECTIVE To develop a preimplantation genetic diagnosis (PGD) protocol that allows any form of chromosome imbalance to be detected. DESIGN Case report employing a method based on whole-genome amplification and comparative genomic hybridization (CGH). SETTING Clinical IVF laboratory. PATIENT(S) A 40-year-old IVF patient. INTERVENTION(S) Polar body and blastomere biopsy. MAIN OUTCOME MEASURE(S) Detection of aneuploidy. RESULT(S) Chromosome imbalance was detected in 9 of 10 polar bodies. A variety of chromosomes were aneuploid, but chromosomal size was found to be an important predisposing factor. In three cases, the resulting embryos could be tested using fluorescence in situ hybridization, and in each case the CGH diagnosis was confirmed. A single embryo could be recommended for transfer on the basis of the CGH data, but no pregnancy ensued. CONCLUSION(S) Evidence suggests that preferential transfer of chromosomally normal embryos can improve IVF outcomes. However, current PGD protocols do not allow analysis of every chromosome, and therefore a proportion of abnormal embryos remains undetected. We describe a method that allows every chromosome to be assessed in polar bodies and oocytes. The technique was accurate and allowed identification of aneuploid embryos that would have been diagnosed as normal by standard PGD techniques. As well as comprehensive cytogenetic analysis, this protocol permits simultaneous testing for multiple single-gene disorders.