A Comparison of Oocyte Yield between Ultrasound-Guided and Laparoscopic Oocyte Retrieval in Rhesus Macaques.

Obtaining quality oocytes is a prerequisite for ART-based studies. Here we describe a method for transabdominal ultrasound-guided (US) oocyte retrieval in rhesus macaques (Macaca mullata) and compare it to the standard surgical approach using laparoscopy (LAP). We analyzed oocyte yield from six continuous reproductive seasons (2017-2023) that included n = 177 US-guided and n = 136 laparoscopic oocyte retrievals. While the ultrasound-guided technique retrieved significantly fewer oocytes on average (LAP: 40 ± 2 vs. US: 27 ± 1), there was no difference in the number of mature metaphase II oocytes (MII) between the two techniques (LAP: 17 ± 1 vs. US: 15 ± 1). We show that oocytes retrieved by the ultrasound-guided approach fertilize at the same rates as those obtained via the laparoscopic procedure (LAP Fert Rate: 84% ± 2% vs. US Fert Rate: 83% ± 2%). In conclusion, minimally invasive ultrasound-guided oocyte retrieval improves animal welfare while delivering equivalent numbers of mature oocytes, which are ideal for ART. Furthermore, we show that oocyte competency, as represented by fertilization rate, is not affected by retrieval technique. Therefore, the Oregon National Primate Research Center (ONPRC) has adopted the ultrasound-guided approach as the standard technique for oocyte retrieval.

Limitations of gene editing assessments in human preimplantation embryos.

Range of DNA repair in response to double-strand breaks induced in human preimplantation embryos remains uncertain due to the complexity of analyzing single- or few-cell samples. Sequencing of such minute DNA input requires a whole genome amplification that can introduce artifacts, including coverage nonuniformity, amplification biases, and allelic dropouts at the target site. We show here that, on average, 26.6% of preexisting heterozygous loci in control single blastomere samples appear as homozygous after whole genome amplification indicative of allelic dropouts. To overcome these limitations, we validate on-target modifications seen in gene edited human embryos in embryonic stem cells. We show that, in addition to frequent indel mutations, biallelic double-strand breaks can also produce large deletions at the target site. Moreover, some embryonic stem cells show copy-neutral loss of heterozygosity at the cleavage site which is likely caused by interallelic gene conversion. However, the frequency of loss of heterozygosity in embryonic stem cells is lower than in blastomeres, suggesting that allelic dropouts is a common whole genome amplification outcome limiting genotyping accuracy in human preimplantation embryos.

In vitro fertilization with preimplantation genetic testing for monogenetic diseases versus unassisted conception with prenatal diagnosis for Huntington disease: a cost-effectiveness analysis.

OBJECTIVE: To investigate if in vitro fertilization (IVF) with preimplantation genetic testing for monogenic disease is cost effective for heterozygous individuals with Huntington disease vs. unassisted conception with prenatal diagnosis. DESIGN: Cost-effectiveness analysis in a theoretical cohort of 3,851 couples, where one individual is heterozygous for Huntington disease. SETTING: N/A. PATIENTS/ANIMALS: None. INTERVENTION: In vitro fertilization preimplantation genetic testing for couples attempting conception. MAIN OUTCOME MEASURES: Outcomes included cost and quality-adjusted life years (QALYs) for both parents in addition to secondary outcomes of procedure-related loss, spontaneous abortion, termination of pregnancy, and early/normal/late-onset Huntington disease. A willingness-to-pay threshold was set at $100,000/QALY. RESULTS: In vitro fertilization preimplantation genetic testing is lower in cost and higher in effectiveness compared to unassisted conception with prenatal diagnosis among couples with one heterozygous Huntington disease individual, making it the dominant strategy. In vitro fertilization preimplantation genetic testing was associated with 77 more QALYs and a cost savings of $46,394,268. All measured outcomes were lower in the IVF preimplantation genetic testing strategy, including 39 fewer procedure-related losses, 39 fewer spontaneous abortions, and 462 fewer terminations of pregnancy. Most notably, in our theoretical cohort of couples, IVF preimplantation genetic testing resulted in 1,079 fewer Huntington disease-affected offspring. Our results were robust over a wide range of assumptions. CONCLUSION: In vitro fertilization preimplantation genetic testing is a cost-effective conception strategy compared to unassisted conception with prenatal diagnosis when one individual is heterozygous for Huntington disease. Not only can morbidity and mortality incurred by Huntington disease be mitigated for the offspring with the use of IVF preimplantation genetic testing, but this study demonstrates the cost-effectiveness of using IVF preimplantation genetic testing for those with Huntington disease.

Histone demethylase KDM4A and KDM4B expression in granulosa cells from women undergoing in vitro fertilization.

PURPOSE: To assess expression of the histone demethylases KDM4A and KDM4B in granulosa collected from women undergoing oocyte retrieval and to determine if expression was related to pregnancy outcome. METHODS: Cumulus and mural granulosa cells were obtained from women undergoing oocyte retrieval. KDM4A and KDM4B mRNA expression was determined by qRT-PCR. KDM4A and KDM4B proteins were immunohistochemically localized in ovarian tissue sections obtained from archival specimens. RESULTS: KDM4A and KDM4B protein was localized to oocytes, granulosa cells, and theca and luteal cells in ovaries from reproductive-aged women. KDM4A and KDM4B mRNA expression was overall higher in cumulus compared to mural granulosa. When comparing granulosa demethylase gene expression, KDM4A and KDM4B mRNA expression was higher in both cumulus and mural granulosa from not pregnant patients compared to patients in the pregnant-live birth group. CONCLUSIONS: Histone demethylases KDM4A and KDM4B mRNA are differentially expressed in cumulus and mural granulosa. Expression of both KDM4A and KDM4B mRNA was lower in cumulus granulosa and mural granulosa from pregnant compared to not pregnant patients. These findings suggest that altered expression of histone demethylases may impact epigenetic changes in granulosa cells associated with pregnancy.

Correction of a pathogenic gene mutation in human embryos.

Genome editing has potential for the targeted correction of germline mutations. Here we describe the correction of the heterozygous MYBPC3 mutation in human preimplantation embryos with precise CRISPR-Cas9-based targeting accuracy and high homology-directed repair efficiency by activating an endogenous, germline-specific DNA repair response. Induced double-strand breaks (DSBs) at the mutant paternal allele were predominantly repaired using the homologous wild-type maternal gene instead of a synthetic DNA template. By modulating the cell cycle stage at which the DSB was induced, we were able to avoid mosaicism in cleaving embryos and achieve a high yield of homozygous embryos carrying the wild-type MYBPC3 gene without evidence of off-target mutations. The efficiency, accuracy and safety of the approach presented suggest that it has potential to be used for the correction of heritable mutations in human embryos by complementing preimplantation genetic diagnosis. However, much remains to be considered before clinical applications, including the reproducibility of the technique with other heterozygous mutations.

Environmental exposure to endocrine-disrupting chemicals and miscarriage.

Establishment of early pregnancy is the result of complex biochemical interactions between the decidua and blastocyst. Any alteration in this chemical dialogue has the potential to result in adverse pregnancy outcomes including miscarriage. Sporadic miscarriage is the most common complication of pregnancy and can be caused by multiple factors. While the most common cause of miscarriage is genetic abnormalities in the fetus, other contributing factors certainly can play a role in early loss. One such factor is environmental exposure, in particular to endocrine-disrupting chemicals, which has the potential to interfere with endogenous hormone action. These effects can be deleterious, especially in early pregnancy when the hormonal milieu surrounding implantation is in delicate balance. The purpose of this paper is to review the current evidence on the role of environmental toxins in reproduction.

Clinical guidelines for sperm cryopreservation in cancer patients.

No clear clinical guidelines exist on how to counsel male cancer patients about fertility preservation. Detailed counseling is recommended before treatment when issues of collection and storage need to be highlighted. Concern about the quality of sperm collected before and/or after treatment in terms of assisted reproduction is needed, and the potential outcomes should be discussed early as part of cancer survivorship. The discussion should be sensitive and tailored to the ethical situation based on the age of the patient, the severity of the illness, the need to initiate treatment, and genetic risk. Cryopreservation should be attempted/achieved before cancer treatment is initiated. Cryopreservation should not be performed during treatment or for some time after treatment because of the chromosomal and structural damage to sperm from cancer treatment. Contraception should be instigated during this period.

Normal pregnancy after tetraploid karyotype on trophectoderm biopsy.

OBJECTIVE: To report a case of successful pregnancy after trophectoderm biopsy and fluorescence in situ hybridization (FISH) revealed a tetraploid karyotype. DESIGN: Case report. SETTING: A university medical center. PATIENT(S): An infertility patient desiring trophectoderm biopsy on frozen blastocysts to facilitate preimplantation genetic screening. INTERVENTION(S): Frozen blastocysts were thawed on the evening before transfer. Trophectoderm biopsy was performed the following morning. FISH results were available the same day, and two embryos with tetraploid results were transferred. MAIN OUTCOME MEASURE(S): Chorionic villus sample (CVS) and newborn exam. RESULT(S): Normal diploid CVS result and a healthy male infant. CONCLUSION(S): Although multiple cells can be analyzed using trophectoderm biopsy, abnormalities in the trophectoderm may not be present in the inner cell mass.

Obstetric outcomes in donor oocyte pregnancies compared with advanced maternal age in in vitro fertilization pregnancies.

OBJECTIVE: To evaluate obstetric complications in women who conceived through donated oocytes compared with women who conceived through assisted reproduction using autologous oocytes. DESIGN: Retrospective cohort analysis. SETTING: Stanford Hospital and Clinics and Lucille Packard Children's hospital, both tertiary referral centers. PATIENT(S): A cohort of 71 oocyte recipients who underwent in vitro fertilization (IVF) were compared to all women over 38 years who conceived through IVF with autologous oocytes (n = 108) between January 1, 2001, and December 31, 2005, at Stanford University and subsequently delivered infants at Lucille Packard Children's Hospital. INTERVENTION(S): Assisted reproductive technology with donor oocytes. MAIN OUTCOME MEASURE(S): Obstetric charts of the donor-oocyte recipients were compared for all women over 38 years old who had conceived through IVF with autologous oocytes at the same center (n = 108) and delivered at the same hospital during the same time period. Perinatal complications including preeclampsia, diabetes, preterm labor, preterm premature rupture of membranes and placental abnormalities, mode of delivery, presentation, Apgar scores, gestational age at delivery, and weight were compared between the groups. RESULT(S): Oocyte recipients and autologous oocyte controls had similar rates of complications of prematurity, hypertensive disorders of pregnancy, gestational diabetes, and placental abnormalities. Infant birth weights and gestational age at time of delivery were similar between the two groups. CONCLUSION(S): This study suggests that women undergoing IVF with donor oocytes are not at increased risk for complications during pregnancy or at increased immediate neonatal complications compared with women of advanced maternal age undergoing IVF with autologous oocytes.

Interplay between estrogen response element sequence and ligands controls in vivo binding of estrogen receptor to regulated genes.

To examine the role of the estrogen response element (ERE) sequence in binding of liganded estrogen receptor (ER) to promoters, we analyzed in vivo interaction of liganded ER with the imperfect ERE in the pS2 gene and the composite estrogen-responsive unit (ERU) in the proteinase inhibitor 9 (PI-9) gene. In transient transfections of ER-positive HepG2-ER7 cells, PI-9 was strongly induced by estrogen, moxestrol (MOX), and 4-hydroxytamoxifen (OHT). PI-9 was not induced by raloxifene or ICI 182,780. Quantitative reverse transcriptase-PCR showed that moxestrol strongly induced cellular PI-9 and pS2 mRNAs, whereas OHT moderately induced PI-9 mRNA and weakly induced pS2 mRNA. Chromatin immunoprecipitation experiments demonstrated strong and similar association of 17beta-estradiol-hERalpha and MOX-hERalpha with the PI-9 ERU and with the pS2 ERE. Binding of MOX-hERalpha to the PI-9 ERU and the pS2 ERE was rapid and continuous. Although MOX-hERalpha bound strongly to the PI-9 ERU and less well to the pS2 ERE in chromatin immunoprecipitation, gel shift assays showed that estrogen-hERalpha binds with higher affinity to the deproteinized pS2 ERE than to the PI-9 ERU. Across a broad range of OHT concentrations, OHT-hERalpha associated strongly with the pS2 ERE and weakly with the PI-9 ERU. ICI-hERalpha bound poorly to the PI-9 ERU and effectively to the pS2 ERE. Raloxifene-hERalpha and MOX-hERalpha exhibited similar binding to the PI-9 ERU and the pS2 ERE. These studies demonstrate that ER ligand and ERE sequence work together to regulate in vivo binding of ER to estrogen-responsive promoters.