In vitro fertilization: Four decades of reflections and promises

Expression of vascular endothelial growth factor A (VEGFA), placental growth factor (PlGF) and insulin-like growth factor 1 (IGF-1) in serum from women undergoing frozen embryo transfer

VEGFA, PlGF and IGF-1 are three main angiogenic factors which play significant roles in embryo implantation. However, the relationship between serum expressions of VEGFA, PlGF and IGF-1 and pregnancy outcomes has not been fully illustrated. In this study, serum specimens were collected precisely on day 7 after the LH surge in a natural non-conception cycle from 38 infertile patients who underwent frozen embryo transfer (FET) treatment. ELISA was used to determine the concentrations of VEGFA, PlGF and IGF-1. Serum levels of VEGFA, PlGF and IGF-1 were compared between patients who conceived (n=25) and who did not (n=13). Correlation and linear regression analyses were used to investigate the correlations of serum angiogenic factors and β-hCG MoM levels in the pregnant group. The results demonstrated that no significant difference was found in serum VEGFA, PlGF or IGF-1 concentration between pregnant and non-pregnant women. Spearman correlation analysis revealed a positive correlation between IGF-1 concentration and β-hCG level in pregnant participants (rs = 0.490, p = 0.013). In conclusion, serum IGF-1 level correlated positively with β-hCG level in pregnant women, which may provide information on the prognostic value of IGF-1 in this group of women.

Danish milk consumers are critical of advanced breeding methods in dairy production, but only 1 in 5 is unwilling to drink milk from dairy cows bred with semen derived from such methods

Assisted reproductive technologies and genetic technologies can accelerate progress in breeding programs in dairy farming, but it is unclear how consumers will react to the use of these technologies. Using representative questionnaire data on Danish citizens (n = 2,036) this cross-sectional study examined consumer attitudes to the application of advanced technologies in dairy cattle breeding. Attitudes were examined in 2 ways. First, we prompted about general attitudes to assisted reproductive technologies and genetic technologies in dairy cow breeding. Here we found that most of the participants were critical of cow impregnation involving hormone therapy and the insertion of cloned fetuses. Second, we used a vignette experiment to study whether acceptance of and willingness to drink milk varies with the type of technique that farmers use for their breeding work, as well as the traits being bred for. We included 5 breeding methods with differing degrees of technological complexity. Participants were randomly assigned to receive tailored information about 1 of the 5 breeding methods. The information specified that dairy farmers' own use of advanced technologies is limited to using semen in artificial insemination on the farm. The potentially concerning technologies are here not applied at farm level but are represented in the semen used in artificial insemination because they were used by breeders on earlier generations of cows and bulls to develop semen with higher genetic merit. There was much less concern about this indirect use of the technologies. Only 1 in 5 participants thought the most advanced method we prompted about (use of semen from breeding methods involving genetic engineering and cloning) was unacceptable. Unwillingness to drink milk from cows produced through such a breeding method was also modest (18%) and not much higher than the unwillingness to drink milk from a cow produced by natural fertilization (10%). A likely reason for the unexpectedly low level of unwillingness to drink milk is that people regard the genetic engineering as distant from the final product. We also found that high-frequency organic milk consumers were more critical of advanced breeding methods. Thus, 28% within this group were unwilling to drink milk from cows impregnated with semen derived from earlier generations of cows and bulls bred using gene editing and cloning. Further, this share rose if the high-frequency organic consumers were very averse to the manipulation of nature. The organic sector may need to cater to this subgroup (e.g., by ensuring the traceability of the semen that organic farmers use to artificially inseminate their cows).

Ovarian Folliculogenesis and Uterine Endometrial Receptivity after Intermittent Vaginal Injection of Recombinant Human Follicle-Stimulating Hormone in Infertile Women Receiving In Vitro Fertilization and in Immature Female Rats

The uterine first-pass effect occurs when drugs are delivered vaginally. However, the effect of vaginally administered recombinant human follicle-stimulating hormone (rhFSH) on ovarian folliculogenesis and endometrial receptivity is not well established. We aimed to compare the efficacy of rhFSH administered vaginally and abdominally in clinical in vitro fertilization (IVF) treatment, pharmacokinetic study, and animal study. In IVF treatment, the number of oocytes retrieved, endometrial thickness and uterine artery blood perfusion were not different between women who received the rhFSH either vaginally or abdominally. For serum pharmacokinetic parameters, significantly lower Tmax, clearance, and higher AUC and T_1/2_elimination of rhFSH were observed in women who received rhFSH vaginally, but urine parameters were not different. Immature female rats that received daily abdominal or vaginal injections (1 IU twice daily for 4 days) or intermittent vaginal injections (4 IU every other day for two doses) of rhFSH had more total follicles than the control group. In addition, the serum progesterone and progesterone receptors in the local endometrium were significantly higher in the groups treated with intermittent abdominal or vaginal injection of rhFSH, compared with those who recieved daily injection. In summary, vaginal administration of rhFSH may provide an alternative treatment regimen in women receiving IVF.

The Effect of Using In Vitro Fertilization (IVF) on Increasing the Prevalence of Craniosynostosis

BACKGROUND

Craniosynostosis, a malformation caused by premature closure of one or more cranial sutures, is a rare congenital disability usually of unknown cause; however, it is often associated with assisted reproductive technology. Given the increasing prevalence of craniosynostosis and the use of the in vitro fertilization (IVF) method, the authors evaluated the association between IVF and the prevalence of craniosynostosis.

METHODS

This retrospective study reviewed records of patients with nonsyndromic craniosynostosis who underwent surgery in Mofid Hospital, a tertiary children's hospital affiliated to Shahid Beheshti University of Medical Sciences, between 2010 and 2019.

RESULTS

A total of 200 patients aged one month to 7 years old, were evaluated. Out of 200 patients, 43% were plagiocephalic, 39% trigonocephalic, 8.5% scaphocephalic, 8% brachiocephalic, and 1.5% were mixed. Nine (4.5%) patients had received clomiphene citrate. Eight (4%) mothers had become pregnant under IVF, and they all had used clomiphene citrate for ovulation stimulation. No use of artificial insemination was reported. Of the eight patients whose mother had become pregnant through IVF, three were trigonocephalic, and five were plagiocephalic.

CONCLUSIONS

Without a control group, we are not able report the statistical results confirming or denying a link between craniosynostosis and infertility treatment. However, 4% prevalence of IVF use among craniosynostosis patients is significant. Further studies with a broader statistical community are suggested in this regard.

Pregnancy outcomes among Asian Americans of advanced maternal age, 1992-2018

AIM

The trend of delayed childbearing has implications for the increasing national burden of adverse perinatal outcomes across vulnerable racial-ethnic groups. The objective of this study was to investigate age-adjusted risk for adverse maternal-fetal outcomes among Asian Americans of advanced maternal age (≥35 years).

METHODS

This was a retrospective cohort study using the 1992-2018 Natality data files. We calculated the prevalence of maternal-fetal outcomes: maternal diabetes, hypertensive disorders of pregnancy (HDP), C-section, small-for-gestational age (SGA), large-for-gestational age (LGA), and preterm birth. Adjusted binomial logistic regression was created to evaluate the association between maternal race/ethnicity and each of the maternal-fetal outcomes.

RESULTS

Compared with non-Hispanic Whites, Asian American women had reduced odds of diabetes, HDP, and LGA babies and increased odds of preterm birth, C-section delivery, and SGA, irrespective of the advanced maternal age group. The odds of developing specific adverse outcomes by advanced maternal age varied by Asian American ethnic subgrouping.

DISCUSSION

The risk of maternal-fetal outcomes varied among the ethnic subgroups of Asian Americans in the United States. Future studies should explore the sociocultural and environmental nuances that might explain these differences.

Use of time-lapse monitoring in medically assisted reproduction treatments: a mini-review

During human in vitro culture, a morphological microscope analysis is normally performed to select the best embryo to transfer, with the hope of obtaining a successful pregnancy. The morphological evaluation may combine number and size of blastomeres, fragmentation, multinucleation, blastocyst expansion, inner-cell mass and trophectoderm appearance. However, standard microscopy evaluation involves the removal of the embryos from the incubator, exposing them to changes in pH, temperature, and oxygen level. Additionally, morphological assessments might include high inter-observer variability. Recently, continuous embryo culture using time-lapse monitoring (TLM) has allowed embryologists to analyse the dynamic and morphokinetic events of embryo development and, based on that, the embryologist is able to scrutinize the complete sequence of embryonic evolution, from fertilization to the blastocyst formation. Therefore, TLM allows an uninterrupted culture condition, reducing the need to remove embryos from the incubator. The monitoring system is normally composed of a standard incubator with an integrated microscope coupled to a digital camera, which is able to collect images at regular times, and subsequently processed into video. These data can be annotated and analyzed using an integrated software, therefore this allows embryologists to facilitate the process of embryo selection for transfer. The main aim of this paper is to discuss the potential benefits and uses of the TLM in the embryology laboratory.

Genetics in human reproduction

Approximately 50% of the causes of infertility are of genetic origin. The objective of this study was to analyze the role of genetics in human reproduction by reviewing the main genetic causes of infertility and the use of preimplantation genetic testing in Brazil. This literature review comprised articles in English and Portuguese published on databases PubMed, Scielo, and Bireme from 1990 to 2019. Randomized clinical trials and specialized guidelines were given preference whenever possible. Genetic cause can be traced back to up to 20% of the cases of severe azoospermia or oligozoospermia. Subjects with these conditions are good candidates for genetic screening. In women, genetic causes of infertility (fragile X syndrome, X-trisomy, and Turner's syndrome, some of which diagnosed with karyotyping) culminate with premature ovarian failure. Genetic screening helps advise couples of the risk of experiencing early reproductive capacity loss and of the chances of their offspring carrying genetic disorders. In addition to enhancing the prevention of serious diseases in the offspring of couples at increased risk of genetic diseases, preimplantation genetic screening improves the success rates of assisted reproduction procedures by allowing the selection of euploid embryos for transfer. The interface between genetics and human reproduction has gained significant relevance, but discussions are still needed on which procedures are clinically and ethically acceptable and how they should be regulated.

Live birth following a single oocyte fertilized with ICSI and embryo transfer on day 2: a case report

In this report, we present a case of a couple who obtained a live birth with a single oocyte fertilized by intracytoplasmic sperm injection. The oocyte was collected at 36 h post trigger and was found to be at metaphase II when sperm injection was performed. At 18 h post injection, the oocyte was found to be fertilized with two clear pronuclei. The embryo divided and generated a four-cell embryo on day 2, which was replaced to the uterine cavity. Pregnancy test gave a positive β-human chorionic gonadotropin result, the scan performed at 7 weeks, revealed the presence of one amniotic sac with fetal heartbeat. Healthy live birth was obtained after 39 weeks of gestation.

Blastocyst collapse as an embryo marker of low implantation potential: a time-lapse multicentre study

Spontaneous blastocyst collapse during in vitro embryo development has been suggested as a novel marker of embryo quality. Therefore, the aim of this multicentre study was to carry out a retrospective multicentre analysis to investigate the correlation between blastocyst collapse and pregnancy outcome. Here, 1297 intracytoplasmic sperm injection (ICSI)/in vitro fertilization (IVF) fresh cycles, with an elective single blastocyst transfer (eSET) were included in this study. Embryos were cultured individually in 6.0% CO2, 5.0% O2, 89.0% N2, using single step medium (GTLTM VitroLife, Sweden) or sequential medium (CookTM, Cook Medical, Australia) and selected for transfer using standard morphological criteria. With the use of time-lapse monitoring (TLM), blastocysts were analyzed by measuring the maximum volume reduction and defined as having collapsed, if there was ≥ 50% volume reduction from the expanded blastocyst and the collapse event. Following embryo replacement, each blastocyst was retrospectively allocated to one of two groups (collapsed or not collapsed). Here, 259 blastocysts collapsed once or more during development (19.9%) and the remaining 1038 either contracted minimally or not collapsed (80.1%). A significantly higher ongoing pregnancy rate (OPR) of 51.9% (95% CI 48.9-59.9%) was observed when blastocysts that had not collapsed were replaced compared with cycles in which collapsed blastocysts were transferred 37.5% (95% CI 31.6-43.4%). This study suggests that human blastocysts that collapse spontaneously during development are less likely to implant and generate a pregnancy compared with embryos that do not. Although this is a retrospective study, the results demonstrated the utility of collapse episodes as new marker of embryo selection following eSET at blastocyst stage.

Clinical utility of freeze-all approach in ART treatment: A mini-review

A significant proportion of couples at reproductive age rely on assisted reproductive technology to overcome infertility. In vitro fertilisation (IVF) involves typically the use of exogenous gonadotropins to stimulate the ovary to produce oocytes, which are collected surgically. After fertilization by conventional IVF or intracytoplasmic sperm injection (ICSI), embryos are cultured in the embryology laboratory for a few days before being replaced into the uterus (fresh embryo transfer). Spare embryos can be vitrified and stored in liquid nitrogen to be transferred in a subsequent cycle. Over the years, concerns have arisen about possible adverse outcomes of transferring embryos back to the uterus immediately after controlled ovarian stimulation (COS) as regards to obstetrical and perinatal outcomes. It has been suggested that high hormonal levels during COS could create a relatively hostile environment for embryo implantation whilst increasing the risk of ovarian hyperstimulation syndrome (OHSS). With the remarkable improvement of vitrification as an alternative to the slow-freezing technique for human embryos, a new strategy the so-called "freeze-all" (FA) or "elective frozen embryo transfer" (eFET) was introduced. This approach involves COS, followed by the elective cryopreservation of the entire cohort of viable embryos to be transferred to the uterus in subsequent cycles in a possibly more physiological environment, thus avoiding the supra-physiologic hormonal levels observed during COS. The initial reports suggested that this policy could lead to improved pregnancy rates and reduced perinatal complications, which resulted in a steady increase and widespread use of FA globally. However, as data accumulated, it became clear that the use of FA to unselected couples undergoing ART offered no additional benefits over the conventional approach. Nonetheless, current evidence based on randomized controlled trials and observational studies indicates that FA might be justified in selected clinical scenarios, such as those involving the risk of OHSS. By contrast, there is a lack of evidence to support the FA policy for other indications, such as implantation failure or high progesterone levels on the trigger day. This review summarizes the clinical effectiveness of FA with the main focus on the health of offspring.

The fertilization-induced zinc spark is a novel biomarker of mouse embryo quality and early development

Upon activation, mammalian eggs release billions of zinc ions in an exocytotic event termed the “zinc spark.” The zinc spark is dependent on and occurs coordinately with intracellular calcium transients, which are tightly associated with embryonic development. Thus, we hypothesized that the zinc spark represents an early extracellular physicochemical marker of the developmental potential of the zygote. To test this hypothesis, we monitored zinc exocytosis in individual mouse eggs following parthenogenetic activation or in vitro fertilization (IVF) and tracked their development. Retrospective analysis of zinc spark profiles revealed that parthenotes and zygotes that developed into blastocysts released more zinc than those that failed to develop. Prospective selection of embryos based on their zinc spark profile significantly improved developmental outcomes and more than doubled the percentage of embryos that reached the blastocyst stage. Moreover, the zinc spark profile was also associated with embryo quality as the total cell number in the resulting morulae and blastocysts positively correlated with the zinc spark amplitude (R = 0.9209). Zinc sparks can thus serve as an early biomarker of zygote quality in mouse model.

Matrix metalloproteinases 2 and 9 and e-cadherin expression in the endometrium during the implantation window of infertile women before in vitro fertilization treatment

OBJECTIVE

To evaluate the expression of endometrial matrix metalloproteinases (MMPs) 2 and 9 and E-cadherin in peri-implantation phase of infertile women who have undergone in vitro fertilization (IVF) cycles.

METHODS

This prospective study included 51 patients who underwent endometrial biopsy during the receptive phase in a menstrual cycle prior to IVF treatment. The samples were evaluated by tissue microarray for immunohistochemical study.

RESULTS

The expression of MMP-2, MMP-9, and E-cadherin in the endometrium prior to IVF treatment was not associated with pregnancy. There was a decrease in E-cadherin immunodetection, the higher the age of the patients, a negative relationship between E-cadherin and MMP-2, and a positive association between MMP-9 and E-cadherin.

CONCLUSIONS

The MMP-2, MMP-9, and E-cadherin are expressed in the endometrium of infertile patients during the receptive phase of the natural menstrual cycle. However, there is no correlation between the expression of these molecules and the clinical IVF outcomes.

First births with a simplified culture system for clinical IVF and embryo transfer

This study reports the outcome results from a pilot clinical trial using a simplified laboratory method for human IVF. This system reproducibly generates de novo the atmospheric and culture conditions that support normal fertilization and preimplantation embryogenesis to the hatched blastocyst stage without the need for specialized medical-grade gases or equipment. Development from insemination to the hatched blastocyst stage occurs undisturbed in a completely closed system that enables timed performance assessments for embryo selection in situ that, in this study, involved single-embryo transfers on day 3. With the simplified culture system, 8/23 embryos implanted, one miscarried at 8weeks of gestation and seven healthy babies have been born. The methodology and results are discussed with regard to how this simplified system can be adopted worldwide to meet the growing need for accessible and affordable IVF. A common notion concerning the demographics of infertility is that it is largely a phenomenon associated with developed countries, where infertility treatments are commonplace. In fact, most infertile couples reside in developing/low-resource countries where infertility diagnosis and treatment is nonexistent, inaccessible or unaffordable by the vast majority of young men and women in need. The irony of this situation is that bilateral tubal occlusions, for which IVF was originally indicated and is the most effective treatment, is by far the most common cause of their infertility. We have addressed one aspect of this issue, the IVF laboratory, as part of a wider effort by the Walking Egg Project to design and establish small, dedicated centres in developing countries to provide assisted reproduction technologies that are affordable and accessible to a wider proportion of the population in need. The methods for conventional IVF designed to addresses tubal obstructions are relatively simple and free of complex instrumentation and the highly developed infrastructure common to high-resource centres. This simplified IVF system self-generates culture conditions in a closed system. After prolonged preclinical testing, a pilot clinical study was initiated in 2012 in Genk, Belgium. The findings suggest that a significant first step has been achieved in the effort to bring advanced assisted reproduction to developed countries using a low-resource but highly effective IVF system capable of bringing modern reproductive medicine to infertile couples in low-resource societies.

Preimplantation genetic testing in the 21st century: uncharted territory

The past hundred years have given birth to arguably the most profound changes in society, medicine, and technology the world has ever witnessed. Genetics is one such field that has enjoyed a meteoric rise during this time. Progressing from Mendelian genetics to the discovery of DNA to the ability to sequence the human genome, perhaps no other discipline holds more promise to affect future change than genetics. Technology currently exists to evaluate some of the genetic information held by developing embryos in the context of an in vitro fertilization (IVF) cycle. This information is then used to determine which embryos are selected for uterine transfer. Many societies have enacted legislation to protect against possible abuses utilizing this technology. However, it is incumbent upon society to continue ensuring that preimplantation genetic diagnosis (PGD)—and genetic testing in general—is applied in a way that utilizes its potential in a responsible manner to improve health care.

The impact of luteal phase support on endometrial estrogen and progesterone receptor expression: a randomized control trial

BACKGROUND

To assess the impact of luteal phase support on the expression of estrogen receptor (ER) alpha and progesterone receptors B (PR-B) on the endometrium of oocyte donors undergoing controlled ovarian hyperstimulation (COH).

METHODS

A prospective, randomized study was conducted in women undergoing controlled ovarian hyperstimulation for oocyte donation. Participants were randomized to receive no luteal support, vaginal progesterone alone, or vaginal progesterone plus orally administered 17 Beta estradiol. Endometrial biopsies were obtained at 4 time points in the luteal phase and evaluated by tissue microarray for expression of ER alpha and PR-B.

RESULTS

One-hundred and eight endometrial tissue samples were obtained from 12 patients. No differences were found in expression of ER alpha and PR-B among all the specimens with the exception of one sample value.

CONCLUSIONS

The administration of progesterone during the luteal phase of COH for oocyte donor cycles, either with or without estrogen, does not significantly affect the endometrial expression of ER alpha and PR.