J.M. Franasiak

Detection of segmental aneuploidy and mosaicism in the human preimplantation embryo: technical considerations and limitations

Whole-chromosome aneuploidy screening has become a common practice to improve outcomes and decrease embryonic transfer order in patients undergoing treatment for infertility through inxa0vitro fertilization. Despite implementation of this powerful technology, a significant percentage of euploid embryos fail to result in successful deliveries. As technology has evolved, detection of subchromosomal imbalances and embryonic mosaicism has become possible, and these serve as potential explanations for euploid embryo transfer failures. Cases involving a parent with a balanced translocation provide a unique opportunity to characterize the capabilities and limitations of detecting segmental imbalances with a variety chromosome screening platforms. Adaptation of these methods to de novo imbalances now represent an ongoing challenge in the field of preimplantation genetic screening as additional factors including mosaicism, clinical predictive value, and distinguishing true imbalances from technical artifacts must be more carefully considered.

Endometrial microbiota—new player in town

Detection of bacteria with molecular techniques has enabled the study of low biomass microbiomes in tissues and organs previously considered sterile, such as the endometrium. Subsequently, an abnormal endometrial microbiota has been associated with implantation failure, pregnancy loss, and other gynecological and obstetrical conditions. Further investigation of the reproductive tract microbiome will allow for a better understanding of bacterial communities role in both physiology and pathophysiology, which in turn impacts the ability to achieve pregnancy and maintain a healthy pregnancy. Here we review the current literature that surrounds the endometrial microbiome and highlight the importance of assessing it as a future tool for improving reproductive outcomes in infertile patients.

High relative deoxyribonucleic acid content of trophectoderm biopsy adversely affects pregnancy outcomes

OBJECTIVEnTo evaluate the association between relative DNA content of the trophectoderm biopsy and pregnancy outcomes.nnnDESIGNnRetrospective cohort study.nnnSETTINGnAcademic-affiliated private practice.nnnPATIENT(S)nThis study included patients undergoing their first single embryo transfer after trophectoderm biopsy and comprehensive chromosome screening (CCS) at a single center between January 2010 and Februaryxa02014.nnnINTERVENTION(S)nIn phase 1 of the study, a standard curve was developed to estimate the relative DNA content of trophectoderm biopsies. Phase 2 of the study examined reproductive outcomes in patients undergoing single embryo transfer after trophectoderm biopsy and CCS. Samples were divided into quartiles according to their relative DNA content, and clinical outcomes were compared.nnnMAIN OUTCOME MEASURE(S)nChemical pregnancy rate, clinical implantation rate, ongoing pregnancy rate, live birth rate.nnnRESULT(S)nThe quartile of highest relative DNA content had a significantly lower live birth rate when compared with the other three quartiles (relative risk 0.84, 95% confidence interval 0.75-0.95). There was no difference between the quartiles regarding age, body mass index, ovarian response, or endometrial thickness. Among those patients who had a live birth, there was no difference in hCG levels, gestational age at delivery, or birth weight with respect to biopsy DNA content.nnnCONCLUSION(S)nTrophectoderm biopsies with the highest relative DNA content are associated with lower live birth rates after single embryo transfer. Possible explanations for this phenomenon include diminished accuracy of the euploid diagnosis vs. a mechanical impact of the biopsy. Regardless of the cause, the outcomes emphasize the importance of obtaining appropriately sized trophectoderm biopsies for CCS.

Patients with endometriosis have aneuploidy rates equivalent to their age-matched peers in the in vitro fertilization population

OBJECTIVEnTo determine whether endometriosis ultimately results in an increased risk of embryonic aneuploidy.nnnDESIGNnRetrospective cohort.nnnSETTINGnInfertility clinic.nnnPATIENT(S)nPatients participating in an inxa0vitro fertilization (IVF) cycle from 2009-2015 using preimplantation genetic screening (PGS) who had endometriosis identified by surgical diagnosis or by ultrasound findings consistent with a persistent space-occupying disease whose sonographic appearance was consistent with endometriosis.nnnINTERVENTION(S)nNone.nnnMAIN OUTCOME MEASURE(S)nRate of aneuploidy in endometriosis patients undergoing IVF compared to controls without endometriosis undergoing IVF.nnnRESULT(S)nThere were 305 patients with endometriosis who produced 1,880 blastocysts that met the criteria for inclusion in the endometriosis group. The mean age of the patients with endometriosis was 36.1 ± 3.9xa0years. When the aneuploidy rates in patients with endometriosis and aneuploidy rates in patients without endometriosis were stratified by Society for Assisted Reproductive Technology age groups and compared, there were no statistically significant differences in the rate of aneuploidy (odds ratio 0.85; 95% confidence interval, 0.84-0.85).nnnCONCLUSION(S)nPatients with endometriosis undergoing IVF have aneuploidy rates equivalent to their age-matched peers in IVF population who do not have endometriosis.

Contribution of immunology to implantation failure of euploid embryos

Outcomes in assisted reproduction have seen marked improvement. With increased ability in the embryology laboratory to use extended embryo culture which in turn enables other selective techniques, such as trophectoderm biopsy and comprehensive chromosome screening, the chance of success per embryo transfer is increased. However, even the selection of a euploid blastocyst, which selects out many embryonic factors, does not yield successful implantation and ultimately delivery in all cases. Among the factors that affect implantation failure of apparently reproductively competent embryos, the immune system has been perhaps both the most plausible and the most debated. There are data on T-helper cells, in particular the TH1-TH2 balance, peripheral and uterine natural killer cells, and autoantibodies, all of which have been shown to have variable effects on implantation. Many investigators have developed and used a wide range of immune tests and treatments aimed at manipulating the milieu to favor implantation. Although it is certain that the immune system plays a role in implantation, our understanding of the physiology, letxa0alone the pathophysiology, remains incomplete. It is imperative that we gain more clear evidence of causes and test and implement treatment paradigms. In the meantime, immune testing or empirical treatment with the use of immune modulators must be approached with caution.

Preimplantation genetic testing for aneuploidy is cost-effective, shortens treatment time, and reduces the risk of failed embryo transfer and clinical miscarriage

OBJECTIVEnTo determine if preimplantation genetic testing for aneuploidy (PGT-A) is cost-effective for patients undergoing inxa0vitro fertilization (IVF).nnnDESIGNnDecision analytic model comparing costs and clinical outcomes of two strategies: IVF with and without PGT-A.nnnSETTINGnGenetics laboratory.nnnPATIENTSnWomen ≤ 42xa0years of age undergoing IVF.nnnINTERVENTION(S)nDecision analytic model applied to the above patient population utilizing a combination of actual clinical data and assumptions from the literature regarding the outcomes of IVF with and without PGT-A.nnnMAIN OUTCOME MEASURE(S)nThe primary outcome was cumulative IVF-related costs to achieve a live birth or exhaust the embryo cohort from a single oocyte retrieval. The secondary outcomes were time from retrieval to the embryo transfer resulting in live birth or completion of treatment, cumulative live birth rate, failed embryo transfers, and clinical losses.nnnRESULTSn8,998 patients from 74 IVF centers were included. For patients with greater than one embryo, the cost differential favored the use of PGT-A, ranging from

Cumulus cell transcriptome profiling is not predictive of live birth after in vitro fertilization: a paired analysis of euploid sibling blastocysts

931-2411 and depending upon number of embryos screened. As expected, the cumulative live birth rate was equivalent for both groups once all embryos were exhausted. However, PGT-A reduced time in treatment by up to four months. In addition, patients undergoing PGT-A experienced fewer failed embryo transfers and clinical miscarriages.nnnCONCLUSIONnFor patients with > 1 embryo, IVF with PGT-A reduces healthcare costs, shortens treatment time, and reduces the risk of failed embryo transfer and clinical miscarriage when compared to IVF alone.

Vitamin D binding protein is lower in infertile patients compared to fertile controls: a case control study

OBJECTIVEnTo compare the transcriptome of cumulus cells associated with a euploid embryo that resulted in live birth with that of a sibling euploid embryo without sustained implantation.nnnDESIGNnPaired analysis.nnnSETTINGnAcademic institution.nnnPATIENT(S)nCouples undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection with preimplantation genetic screening with female age ≤42xa0years and normal ovarian reserve.nnnINTERVENTION(S)nTranscriptome profiling of cumulus cells from sibling oocytes for correlation with live birth after euploid blastocyst transfer. Embryos were individually cultured to facilitate association with clinical outcomes. The cumulus cell transcriptome from the embryo resulting in live birth was compared with that of its sibling embryo without sustained implantation to investigate potential biomarkers that may aid in embryo selection.nnnMAIN OUTCOME MEASURE(S)nDifferential gene expression in cumulus cells associated with a euploid embryo resulting in live birth and its sibling euploid embryo without sustained implantation using next-generation RNA sequencing (RNAseq).nnnRESULT(S)nCumulus cell RNAseq of 34 samples (from 17 patients) generated an average of 10.4 ± 4 × 106 reads per sample. A total of 132 differentially expressed genes between sibling embryos that resulted in a live birth and those that did not were identified (P<.05). However, after correcting for multiple testing none of the genes remained significantly differentially expressed (false discovery rate <.05).nnnCONCLUSION(S)nThe RNAseq profiles were similar between cumulus cells associated with a euploid embryo resulting in live birth and its sibling embryo that did not sustain implantation. The cumulus cell transcriptome is not predictive of live birth within an individual patients cohort of euploid embryos.

Microbiome in Embryonic Implantation and Implantation Failure

BackgroundThe importance of vitamin D in general health as well as in human reproductive success has been an area of focus. A better understanding of vitamin D metabolism, particularly vitamin D binding protein, is important when elucidating this relationship.MethodsThis case control trial seeks to characterize vitamin D metabolism in infertile patients undergoing natural cycle IVF as compared to normally cycling premenopausal women with proven fertility matched for age and body mass index (BMI). A total of 68 subjects were examined; 39 were infertile premenopausal women and 29 were regularly cycling fertile controls. Their 25-hydroxy vitamin D (25OHD), vitamin D binding protein (DBP), and albumin were measured and free and bioavailable 25OHD calculated. Between group comparisons were conducted with an unpaired t-test. A stepwise regression using age, BMI, 25OHD, estradiol & albumin in the model were used to determine predictors of DBP.ResultsAge, BMI, and total 25OHD did not differ between the two groups. However, vitamin D binding protein, free and bioavailable vitamin D were significantly different in the infertile patients as compared to the regularly cycling fertile controls (pxa0<xa00.01). Stepwise Regression using age, BMI, 25OHD, estradiol & albumin in the model showed that only albumin was a predictor of DBP (β-coefficientxa0−xa00.310; pxa0=xa00.01).ConclusionThe implications of lower vitamin D binding protein associated with infertility is not clear from this pilot study, and requires further study.

Hematologic Disease in Implantation Failure

The latest advances in microbial detection with next-generation sequencing have enabled the study of low biomass microbiomes of tissues and organs previously considered sterile, such as the endometrium. Most recently an abnormal endometrial microbiota has been associated with implantation failure, pregnancy loss, as well as other gynecological and obstetrical conditions. Further investigation of the reproductive tract microbiome in physiological and pathological conditions will allow researchers to unravel the role of bacterial communities and its function in the uterine cavity before, during, and after pregnancy. As knowledge of the reproductive tract microbiome evolves, there are data which suggest this may be an effective future tool for improving reproductive outcomes in infertile patients.