Effect of cytoplasmic fragmentation on embryo development, quality, and pregnancy outcome: a systematic review of the literature.

The role of cytoplasmic fragmentation in human embryo development and reproductive potential is widely recognized, albeit without standard definition nor agreed upon implication. While fragmentation is best understood to be a natural process across species, the origin of fragmentation remains incompletely understood and likely multifactorial. Several factors including embryo culture condition, gamete quality, aneuploidy, and abnormal cytokinesis seem to have important role in the etiology of cytoplasmic fragmentation. Fragmentation reduces the volume of cytoplasm and depletes embryo of essential organelles and regulatory proteins, compromising the developmental potential of the embryo. While it has been shown that degree of fragmentation and embryo implantation potential are inversely proportional, the degree, pattern, and distribution of fragmentation as it relates to pregnancy outcome is debated in the literature. This review highlights some of the challenges in analysis of fragmentation, while revealing trends in our evolving knowledge of how fragmentation may relate to functional development of the human embryos, implantation, and pregnancy outcome.

Increasing Endometrial Thickness Beyond 8 mm Does Not Alter Clinical Pregnancy Rate After Single Euploid Embryo Transfer.

The aim of this study was to investigate if variation in endometrial thickness affects clinical pregnancy and live birth rates among patients undergoing single euploid embryo transfer (SET). A retrospective review of IVF cycles performed at a single private fertility institution between 2015 and 2020 was performed. Patients with normal uterine anatomy undergoing their first SET of a euploid embryo undergoing their first cycle at the center were included, for a total of 796 cycles. Endometrial thickness was measured by transvaginal ultrasound following 10-14 days of estradiol exposure. Specific infertility diagnoses did not significantly impact endometrial lining thickness with means across diagnoses ranging from 9.3 to 11.0 mm. Endometrial thickness was grouped into five categories: < 8 mm, 8-10 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm. Using 8-10 mm as the reference group, the odds ratio of live birth was 0.5, 1.22, 1.05, and 1.05 for < 8 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm groups, respectively. Risk of first trimester miscarriage was equivalent across groups. There was a trend toward an increased rate of biochemical pregnancies in patients with a < 8 mm and ≥ 15 mm endometrium; however, this was not statistically significant. The clinical pregnancy and live birth rate were lowest in patients with < 8-mm endometrial thickness. For single euploid embryo transfers, an endometrial lining greater than or equal to 8 mm confers optimal live birth rates following a medicated FET cycle. These data confirm the findings of prior studies in fresh embryo transfers without the confounders of supraphysiologic ovarian hormone concentrations and genetically untested embryos.

Assisted Oocyte Activation following Intracytoplasmic Sperm Injection: A Sensible Option for Infertile Couples with Severe Teratozoospermia.

The intracytoplasmic sperm injection (ICSI) has significantly improved male factor infertility treatment; however, complete fertilization failure still occurs in 1-5% of ICSI treatment cycles mainly due to oocyte activation failure. It is estimated that around 40-70% of oocyte activation failure is associated with sperm factors after ICSI. Assisted oocyte activation (AOA) as an effective approach to avoid total fertilization failure (TFF) has been proposed following ICSI. In the literature, several procedures have been described to overcome failed oocyte activation. These include mechanical, electrical, or chemical stimuli initiating artificial Ca2+ rises in the cytoplasm of oocytes. AOA in couples with previous failed fertilization and those with globozoospermia has resulted in varying degrees of success. The aim of this review is to examine the available literature on AOA in teratozoospermic men undergoing ICSI-AOA and determine whether the ICSI-AOA should be considered as an adjunct fertility procedure for these patients.

Access to Fertility Care in Geographically Underserved Populations, a Second Look.

Infertility has a prevalence of up to 16% worldwide and is on the rise in developed nations, largely due to pursuing childbearing at advanced reproductive ages. Advances in assisted reproductive technology have benefitted socioeconomically advantaged patients disproportionately. High costs of fertility care are largely responsible for this disparity; however, patients in rural areas also face barriers in accessing both gynecology and reproductive endocrinology subspecialty care. Here, focusing on the USA, we discuss fertility care in geographically underserved areas and low-resource settings, and the impact on reproductive outcomes. Increased innovation to improve patient access to fertility care such as assisted reproductive technology is critical for ensuring equity. Remote monitoring is frequently performed by fertility centers, but partnership with local gynecologists has also been demonstrated to be an effective assisted reproductive technology monitoring method. Telehealth is now in mainstream use and the continued application to reduce geographic barriers to infertility patients is imperative. Partnership between local gynecologists and reproductive endocrinology and infertility specialists may improve patient access to fertility care and provide the unique benefits of continuity and ongoing local social support.

Ovulation induction and intrauterine insemination in women of advanced reproductive age: a systematic review of the literature.

PURPOSE: The objective of this review is to define live birth rate (LBR) and clinical pregnancy rate (CPR) for women ≥ 40 undergoing ovulation induction (OI)/intrauterine insemination (IUI). METHODS: A systematic review was performed in accordance with PRISMA guidelines using PubMed and Google Scholar. The primary and secondary outcomes of interest were LBR and CPR, respectively. RESULTS: There were 636 studies screened of which 42 were included. In 8 studies which provided LBR for partner sperm, LBR/cycle ranged from 0 to 8.5% with majority being ≤ 4%. Cumulative LBR was 3.6 to 7.1% over 6 cycles with the majority of pregnancies in the first 4. In the four studies providing LBR for donor sperm cycles, LBR/cycle ranged from 3 to 7% with cumulative LBR of 12 to 24% over 6 cycles. The majority of pregnancies occurred in the first 6 cycles. There were three studies with LBR or CPR/cycle ≥ 1% for women ≥ 43. No studies provided data above this range for women ≥ 45. In 4 studies which compared OI/IUI and IVF, the LBR from IVF was 9.2 to 22% per cycle. In 7 studies which compared outcomes by stimulation protocol, no significant differences were seen. CONCLUSION: For women ≥ 40 using homologous sperm, the highest probability of live birth is via IVF. However, if IVF is not an option, OI/IUI may be considered for up to 4 cycles in those using partner sperm or 6 cycles with donor sperm. For women > 45, OI/IUI is likely futile but a limited trial may be considered for psychological benefit while encouraging consideration of donor oocyte IVF or adoption. Use of gonadotropins does not appear to be more effective than oral agents in this age group.

Catastrophic Human Error in Assisted Reproductive Technologies: A Systematic Review.

OBJECTIVE: Assisted reproductive technologies (ARTs) are complex processes with multiple and diverse opportunities for human error. Errors in ART are thought to be rare, but can have devastating consequences for patients and their offspring. The objectives of this article are to review known cases of human error in the ART laboratory and suggest preventative strategies. METHODS: We performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines using PubMed and Google Scholar databases. Studies were eligible for inclusion if they involved known cases of unintentional human error in the ART laboratory. Only full-text articles in English were included. References of the resulted studies were considered for inclusion. RESULTS: A total of 420 articles were screened and 37 articles were selected for inclusion. These largely included case reports and reviews in the medical and legal literature. Twenty-two adverse events due to human error in the ART laboratory were identified. Eight of these adverse events were the result of the insemination with the wrong sperm, 6 errors lead to the transfer of the wrong embryo, 3 lead to an error in preimplantation genetic testing, and 5 adverse events lead to the failure of gamete and embryo cryostorage. CONCLUSIONS: Since the advent of ART, there have been reports of catastrophic events occurring secondary to human error in the laboratory to include incidents of unintended parentage, and have resulted in the loss of embryos and gametes through cryostorage failure. Proposed solutions include the stringent implementation and adherence to safety protocols, adequate laboratory staffing and training, and novel methods for specimen labeling and tracking. Of utmost importance is having knowledge of these errors and the ability to determine cause so that future events can be prevented.

Early Serum hCG in IVF: Are We Trending in the Right Direction?

Human chorionic gonadotropin (hCG) measurements may be the earliest indicator of fertility cycle success, available several weeks before an ultrasound would be diagnostic for pregnancy. Outcomes of these cycles are high stakes for a couple, and the earliest reassurance of a normal pregnancy would be beneficial for their well-being. Additionally, earlier diagnosis can allow for more rapid management by providers in the case of abnormal pregnancies. Therefore, establishing normal values for initial hCG level and early hCG kinetics is of great interest. There are many factors involved in assisted reproductive techniques that may lead to alterations in hCG kinetics when compared with spontaneous pregnancies. We aim to characterize normal hCG values for in vitro fertilization (IVF) pregnancies and review how different aspects of the IVF process may alter these trends in order to establish how best to counsel patients during the waiting period.

Advanced paternal age: effects on sperm parameters, assisted reproduction outcomes and offspring health.

Many factors, including postponement of marriage, increased life expectancy, and improved success with assisted reproductive technologies have been contributing to increased paternal age in developed nations. This increased average paternal age has led to concerns about adverse effects of advanced paternal age on sperm quality, assisted reproductive outcomes, and the health of the offspring conceived by older fathers. This review discusses the association between advanced paternal age and sperm parameters, assisted reproduction success rates, and offspring health.

Does sperm DNA fragmentation have negative impact on embryo morphology and morphokinetics in IVF programme?

Evaluation of sperm integrity may predict the in vitro fertilisation (IVF) outcomes. The aim was to evaluate the relationship between the sperm DNA fragmentation (sDNAf) with embryo morphology and morphokinetic using time-laps monitoring (TLM) and to select the best time points for normalisation in IVF setting. After evaluating the fertilisation and pronuclei (Z) scoring, 328 normally fertilised oocytes were assessed to time of pronuclei fading, time of 2 to 8 discrete cells (t2-t8) and abnormal cleavage patterns, such as multinucleation, direct cleavage, reverse cleavage and fragmentation. Sperm chromatin dispersion (SCD) assay was used for assessment of prepared sperm chromatin status. SCD was categorised into 4 groups of <6.5, 6.5-10.7, 10.7-20.1 and >20.1. The finding showed significant differences in t6 (p = .012), t7 (p = .045), t8 (p = .013) and s1 (p = .001) between 4 SCD groups. When morphokinetic variables were normalised to tPNf, this difference was observed in t2 (p = .003) and t6 (p = .017). Subsequently, the percentage of top quality embryos and Z1 scoring were dependent to the sDNAf rate. In conclusion, tPNf was the best reference time point in IVF cycles. Also, we found high sDNAf rate had no negative impact on embryo morphology and morphokinetics in conventional IVF.

Preimplantation genetic testing as a component of root cause analysis of errors and reassignment of embryos in IVF.

The risks of embryo/gamete mix-up are a threat to the integrity of the IVF process, with significant implications for affected families. The use of preimplantation genetic testing through single-nucleotide polymorphism array or next-generation sequencing technology can help to identify, characterize and ultimately help, in some cases, to find the root cause, and to mitigate the extent of these errors for a given patient or laboratory.

Mouse embryo assay for human in vitro fertilization quality control: a fresh look.

The mouse embryo assay (MEA) has been used in the field of human in vitro fertilization (IVF) for multiple purposes such as developing embryo culture media, quality control within the laboratory, and procedural training and proficiency testing for embryology staff. In addition, manufacturing companies use the MEA as a means of quality control for the development of embryo culture media and medical devices and to meet the standards of testing for FDA approval of new products. It has long been considered by embryologists and laboratory scientists whether the MEA is an accurate or sensitive test in the quality assessment of culture media and medical devices or if use of this testing is more an obligation. There is no uniformly accepted gold standard method for IVF lab quality control or FDA approval. This review aims to revisit the role of the use of mouse embryos in the formulation of IVF media for clinical use and the different methods of employing the mouse embryo assay for quality control. In addition, we will review the use of the MEA as an important adjunct in the training for embryology staff and fellows in training in reproductive endocrinology and infertility (REI), as well as alternatives to the use of the MEA for these purposes.

High prevalence of allergy in patients undergoing in vitro fertilization and embryo transfer.

PURPOSE: To determine the prevalence of allergy in couples undergoing in vitro fertilization (IVF) and the relationship between having allergy and IVF treatment outcomes. DESIGN: A retrospective cohort study of female infertility patients aged 20-49 years and their male partners undergoing IVF cycles from August 2010 to December 2016 in an academic fertility program. RESULTS: Prevalence data was collected for 493 couples (935 cycles). Over half of the female patients (54%) had at least one reported allergy versus the cited US prevalence of 10-30%. Antibiotic (54.7%) and non-antibiotic medication (39.2%) were the most common female allergy subtypes. Fewer male patients reported allergy (21.7%). Data on ß-hCG outcomes were calculated for 841 cycles from 458 couples with no significant relationship found except for number of cycles including ICSI and number of embryos transferred per cycle (1.81 for those without allergy vs 2.07 for those with allergy, p = 0.07). Female patients with allergy were marginally statistically more likely to have a negative ß-hCG (p = 0.07) and less likely to have a successful cycle (p = 0.06). When allergy subgroups were evaluated, there were no significant differences between groups except for a higher number of embryos transferred in women with environmental/other allergies (p = 0.02). CONCLUSION: The prevalence of allergy among patients seeking infertility treatment is high compared with the general population. However, allergy was not found to be associated with IVF cycle outcomes. These findings are likely primarily limited by difficulty in defining specific allergy types within a retrospective study.

Co-Enzyme Q10 Supplementation Rescues Cumulus Cells Dysfunction in a Maternal Aging Model.

Over the past four decades, due to cultural and social changes, women in the developed world have significantly delayed childbirth. This trend is even worse for patients who attend infertility clinics. It is well-known that live birth rates in women older than 35 are significantly lower than in those younger, both naturally and with assisted reproduction. Fertility decline is, in part, due to an increase in oocyte aneuploidy that leads to a reduced embryo quality, as well as an increased incidence of miscarriages and birth defects. Here we show that aging-associated malfunction is not restricted to the oocyte, as cumulus granulosa cells also display a series of defects linked to mitochondrial activity. In, both, human and mouse model, a decline in cumulus cell function due to increased maternal age is accompanied by a decreased expression of enzymes responsible for Coenzyme Q (CoQ) production, particularly Pdss2 and CoQ6. In an aged mouse model supplementation with Coenzyme Q10-a potent stimulator of mitochondrial function-restored cumulus cell number, stimulated glucose uptake, and increased progesterone production. CoQ10 supplementation might, thus, improve oocyte and cumulus cells quantity and quality, by improving the mitochondrial metabolism in females of advanced maternal age.

Egg freezing for fertility preservation and family planning: a nationwide survey of US Obstetrics and Gynecology residents.

BACKGROUND: Little is known about resident attitudes toward elective egg freezing (EF) or how educational exposure to EF affects residents' views and ability to counsel patients. This study aimed to evaluate US OB/GYN residents' views on elective EF, decisions regarding family planning, and whether education on EF affects these views and self-reported comfort discussing EF with patients. METHODS: A 32 question survey was emailed to program directors at all US residency programs for distribution to residents. Chi-square tests were used to evaluate the relationship between educational factors and views on EF and comfort counselling patients. RESULTS: Of those surveyed, 106 residents and 7 fellows completed the survey (103 female). Almost three quarters of female respondents reported postponing pregnancy due to residency (71.8%). Non-exclusive reasons for this choice included career plans (54.4%) and concern for childcare (51.5%) and for fellow residents and their program (50.5%). Of the male and female residents who reported educational exposure to EF (57.5%), almost all of them (95.4%) received this in an REI rotation. Only half of female residents reported being comfortable counseling a patient on EF (49.5%). For female residents, education on EF (p = 0.03) and more advanced level of residency (p = 0.02) were significantly associated with comfort counseling a patient on EF. CONCLUSIONS: Female OB/GYN residents are choosing to delay pregnancy during residency for career and social support reasons. Few residents feel comfortable counseling patients on EF, but appropriate curricular content on EF during residency could improve residents' comfort in assisting patients with reproductive planning.

Birthweight in infants conceived through in vitro fertilization following blastocyst or cleavage-stage embryo transfer: a national registry study.

PURPOSE: In vitro fertilization (IVF) infants have lower birthweights than their peers, predisposing them to long-term health consequences. Blastocyst transfer (BT), at day 5-6 post-fertilization, is increasing in usage, partially due to improved pregnancy outcomes over cleavage-stage transfer (CT, day 2-3). Data to date, however, have been inconclusive regarding BT's effects on birthweight. METHODS: Participants included all US autologous, single-gestation, fresh embryo transfer cycles initiated from 2007 to 2014 that resulted in a term infant (N = 124,154) from the National Assisted Reproductive Technology Surveillance System. Generalized linear models including obstetric history, maternal demographics, and infant sex and gestational age were used to compare birthweight outcomes for infants born following BT (N = 67,169) with infants born following CT (N = 56,985) and to test for an interaction between transfer stage and single embryo transfer (SET). RESULTS: Infants born following BT were 6 g larger than those born following CT (p = 0.04), but rates of macrosomia (RR 1.00, 95% CI 0.96-1.04) and low birthweight (LBW, RR 1.00, 95% CI 0.93-1.06) were not different between the groups. The interaction between SET and transfer stage was significant (p = 0.02). Among SET infants, BT was associated with 19.26 g increased birthweight compared to CT (p = 0.008). CONCLUSIONS: The increase in birthweights identified following BT is unlikely to be clinically relevant, as there were no differences in rates of macrosomia or LBW. These findings are clinically reassuring and indicate that the increasing use of BT is unlikely to further decrease the on average lower birthweights seen in IVF infants compared to their naturally conceived peers.

Effect of frozen/thawed embryo transfer on birthweight, macrosomia, and low birthweight rates in US singleton infants.

BACKGROUND: Singleton infants conceived using assisted reproductive technology have lower average birthweights than naturally conceived infants and are more likely to be born low birthweight (<2500 gr). Lower birthweights are associated with increased infant and child mortality and poor adult health outcomes, including cardiovascular disease, hypertension, and diabetes. Data from registry and single-center studies suggest that frozen/thawed embryo transfer may be associated with larger birthweights. To date, however, a nationwide, full-population study on United States infants born using frozen/thawed embryo transfer has not been reported. OBJECTIVES: The objective of this study was to compare the effect of frozen/thawed vs fresh embryo transfer on birthweight outcomes for singleton, term infants conceived using in vitro fertilization in the United States between 2007 and 2014, including average birthweight and the risks of both macrosomia (>4000 g) and low birthweight (<2500 g). STUDY DESIGN: We used data from the Centers for Disease Control and Prevention's National Assisted Reproductive Technology Surveillance System to compare birthweight outcomes of live-born singleton, autologous oocyte, term (37-43 weeks) infants. Generalized linear models for all infants and stratified by infant sex were used to assess the relationship between frozen/thawed embryo transfer and birthweight, in grams. Infertility diagnosis, year of treatment, maternal age, maternal obstetric history, maternal and paternal race, and infant gestational age and sex were included in the models. Missing race data were imputed. The adjusted relative risks for macrosomia and low birthweight were evaluated using multivariable predicted marginal proportions from logistic regression models. RESULTS: In total, 180,184 singleton, term infants were included, with 55,898 (31.02%) having been conceived from frozen/thawed embryos. Frozen/thawed embryo transfer was associated with, on average, a 142 g increase in birthweight compared with infants born after fresh embryo transfer (P < .001). An interaction between infant sex and embryo transfer type was significant (P < .0001), with frozen/thawed embryo transfer having a larger effect on male infants by 16 g. The adjusted risk of a macrosomic infant was 1.70 times higher (95% confidence interval, 1.64-1.76) following frozen/thawed embryo transfer than fresh embryo transfer. However, adjusted risk of low birthweight following frozen/thawed embryo transfer was 0.52 (95% confidence interval, 0.48-0.56) compared with fresh embryo transfer. CONCLUSION: Frozen/thawed embryo transfer, in comparison with fresh embryo transfer, was associated with increased average birthweight in singleton, autologous oocytes, term infants born in the United States, with a significant interaction between frozen/thawed embryo transfer and infant sex. The risk of macrosomia following frozen/thawed embryo transfer was greater than that following fresh embryo transfer, but the risk of low birthweight among frozen/thawed embryo transfer infants was significantly decreased in comparison with fresh embryo transfer infants.

Ultrastructure of cytoplasmic fragments in human cleavage stage embryos.

PURPOSE: The goal of this study was to evaluate the ultrastructure of cytoplasmic fragments along with the effect of cytoplasmic fragment and perivitelline space coarse granulation removal (cosmetic microsurgery) from embryos before embryo transfer on ART outcomes. METHODS: One hundred and fifty intracytoplasmic sperm injection cycles with male factor infertility were included in this prospective study. Patients were divided into three groups of case (n = 50), sham (n = 50), and control (n = 50). Embryos with 10-50 % fragmentation were included in this study. Cosmetic microsurgery and zona assisted hatching were only performed in case and sham groups respectively. Extracted fragments were evaluated ultrastructurally by transmission electron microscopy (TEM). Rates of clinical pregnancy, live birth, miscarriage, multiple pregnancies, and congenital anomaly in the three groups were also compared. RESULTS: Micrographs from TEM showed that mitochondria were the most abundant structures found in the fragments along with mitochondria-vesicle complexes, Golgi apparatus, primary lysosomes, and vacuoles. There were no significant differences in demographic characteristics, laboratory and clinical data, or embryo morphological features between the groups. The rate of clinical pregnancy in control, sham, and case groups had no significant differences (24, 18, and 18 %, respectively). The rates of live birth, miscarriage, multiple pregnancy, and congenital anomaly were also similar between the different groups. CONCLUSIONS: Our data demonstrated that cosmetic microsurgery on preimplantation embryos had no beneficial effect on ART outcomes in unselected groups of patients. As mitochondria are the most abundant organelles found in cytoplasmic fragments, fragment removal should be performed with more caution in embryos with moderate fragmentation.

Human embryo mosaicism: did we drop the ball on chromosomal testing?

There are newly recognized challenges presented by the occurrence of mosaicism in the context of trophectoderm (TE) biopsy for pre-implantation genetic screening (PGS) in in vitro fertilization (IVF) embryos. Chromosomal mosaicism, known to be significantly higher in IVF embryos than in later prenatal samples, may contribute to errors in diagnosis. In particular, PGS may result in discarding embryos diagnosed as aneuploid but in which the inner cell mass may be completely or mainly euploid, thus representing a false positive diagnosis. Although less likely, some embryos diagnosed as euploid could be mosaic and contain some aneuploid cells, possibly impacting their implantation potential. The ability of current diagnostic techniques to detect mosaicism is limited by the number and location of TE cells in the biopsy and by the methodology used for chromosomal assessment. The clinical consequences of mosaicism are dependent on the chromosome(s) involved, the developmental stage at which the mosaicism evolved, and whether TE biopsy accurately reflects the status of the inner cell mass that forms the fetus. Consequently, in patients with no euploid embryos identified on PGS, it may be appropriate to consider the transfer of diagnosed aneuploid embryos if the TE biopsy result is a non-viable chromosomal monosomy or triploidy that could not result in a birth. It should be acknowledged in consent forms that mosaicism has the potential to impact test results and that its detection may be below the resolution of the genetic tests being used. This concept represents a major shift in current IVF practice and ought to be considered given the data, or lack thereof, of the impact of mosaicism on IVF/PGS outcomes.

Ongoing Pregnancies following Cosmetic Micromanipulation of Preimplantation Embryos in Patients with Implantation Failure.

Cosmetic micromanipulation is defined as fragment and coarse granulation removal from preimplantation embryos. We report two cases of pregnancies in patients with implantation failure following cosmetic micromanipulation.

A pilot study to evaluate a device for the intravaginal culture of embryos.

The aim of this comparative randomized embryology trial was to determine if an intravaginal culture device (IVC) can provide acceptable embryo development compared with conventional IVF. Ten women between the ages of 27 and 37 years with an indication for IVF treatment were included in this study. After ovarian stimulation, oocytes were randomized to fertilization in the IVC device or using conventional IVF. Fertilization rates were higher in the IVF group compared with the IVC device (68.7% ± 36 % versus 40.7% ± 27%), respectively, whereas cleavage rates were similar (93% ± 1.5% versus 97% ± 6%) for both groups. A significantly lower number of embryos of suitable quality for transfer was obtained from the IVC device compared with conventional IVF (OR, 0.47; 95% CI, 0.26 to 0.87). The clinical pregnancy rate from transfer of IVC device embryos was 30%. Satisfaction questionnaires were also completed by all participants. Most women (70%) placed high importance on having had fertilization and embryo development occur while carrying the device. Overall, the IVC device produced reasonable pregnancy rates suggesting this technology may have a place under certain circumstances. Cost-benefit analysis, psychological factors and future studies must be considered.