Euploidy rates in donor egg cycles significantly differ between fertility centers.

Study question: Do external factors affect euploidy in egg donor cycles? Summary answer: The study demonstrates that during human assisted reproduction, embryonic chromosome abnormalities may be partly iatrogenic. What is known already: Chromosome abnormalities have been linked in the past to culture conditions such as temperature and Ph variations, as well as hormonal stimulation. Those reports were performed with older screening techniques (FISH), or ART methods no longer in use, and the subjects studied were not a homogeneous group. Study design, size, duration: A total of 1645 donor oocyte cycles and 13 282 blastocyst biopsies from 42 fertility clinics were included in this retrospective cohort study. Samples from donor cycles with PGS attempted between September 2011 and July 2015 were included. Participants/materials, setting, methods: PGS cycles from multiple fertility clinics referred to Reprogenetics (Livingston, NJ) that involved only oocyte donation were included in this study. Testing was performed by array comparative genomic hybridization (aCGH). Ploidy data were analyzed using Generalized Linear Mixed Models with logistic regression using a logit link function considering a number of variables that represent fixed and random effects. Main results and the role of chance: Euploidy rate was associated with the referring center and independent of almost all the parameters examined except donor age and testing technology. Average euploidy rate per center ranged from 39.5 to 82.5%. The mean expected rate of euploidy was 68.4%, but there are variations in this rate associated with the center effect. Limitations, reasons for caution: Data set does not include details of the donor selection process, donor race or ethnic origin, ovarian reserve or ovarian responsiveness. Due to the retrospective nature of the study, associations are apparent, however, causality cannot be established. Discrepancies in regard to completeness and homogeneity of data exist due to data collection from over 40 different clinics. Wider implications of the findings: This is the first study to show a strong association between center-specific ART treatment practices and the incidence of chromosome abnormality in human embryos, although the meiotic or mitotic origin of these abnormalities could not be determined using these technologies. Given the widespread applications of ART in both subfertile and fertile populations, our findings should be of interest to the medical community in general as well as the ART community in particular. Study funding/competing interest(s): No external funds were used for this study. S. Munne is a founding principle of Reprogenetics/current employee of Cooper Genomics. M Alikani's spouse is a founding principle of Reprogenetics/current consultant for Cooper Genomics. The remaining authors have no conflicts to declare.

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

OBJECTIVES: To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. METHODS: Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. RESULTS: IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). CONCLUSIONS: Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Assisted hatching facilitates earlier implantation.

OBJECTIVE: To examine whether opening of the zona pellucida (i.e., assisted hatching) accelerates implantation. DESIGN: In a controlled, randomized trial, patients were assigned to control and assisted hatching groups. SETTING: All patients studied were of the Center for Reproductive Medicine at Cornell University Medical College. INTERVENTION: All patients underwent stimulation with gonadotropins after luteal phase GnRH down regulation. Assisted hatching with zona drilling using acidic Tyrode's solution was performed on the assigned embryos. MAIN OUTCOME MEASURES: Luteal E2, P, and hCG on days +5, +6, +7, +8, +9, +11, +13, and +15 were measured. The implantation time, peak midluteal E2 and intervals between these two values were studied. RESULTS: Implantation occurred significantly earlier in the assisted hatching group. The interval between implantation and peak midluteal E2 was also significantly shorter in the assisted hatching group than in the controls. However, there was no significant difference in the day of the peak midluteal E2 between the assisted hatching and control groups. CONCLUSION: Assisted hatching may enhance embryo implantation not only by mechanically facilitating the hatching process but also by allowing earlier embryo-endometrium contact. Such early contact may enhance embryonic development potential and may optimize synchronization between embryo and endometrium, resulting in improved implantation efficiency.

Intracytoplasmic sperm injection: a novel treatment for all forms of male factor infertility.

OBJECTIVE: To demonstrate the effectiveness of intracytoplasmic sperm injection to treat male factor infertility and to report on the achievement of fertilization and pregnancy compared with standard in vitro insemination. DESIGN: Controlled clinical study. SETTING: Couples suffering from male factor infertility treated in an academic research environment. PATIENTS: Two hundred twenty-seven couples in whom the male partners were presumed to be the cause of repeated failed attempts at IVF or whose semen parameters were unacceptable for conventional IVF. INTERVENTIONS: Oocytes for this study were harvested after superovulation with GnRH agonist and gonadotropins. After removing the cumulus cells, a single spermatozoon was injected directly into the cytoplasm of metaphase II oocytes, and the outcome was analyzed in terms of semen parameters and origin of semen sample. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates (PRs) in relation to sperm parameters and origin of semen sample. RESULTS: Two hundred twenty-seven couples were treated by intracytoplasmic sperm injection resulting in an ongoing pregnancy rate of 37.0% per retrieval (84/227). There were 47 singleton pregnancies (5 of which were vanishing twin pregnancies), 30 twin gestations, 6 triplet pregnancies, and 1 quadruplet pregnancy. The concentration of the total motile spermatozoa present in the ejaculate as well as the origin of the samples influenced the fertilization rate but not the pregnancy outcome. CONCLUSIONS: Intracytoplasmic sperm injection can be used successfully to treat couples who have failed IVF or who have too few spermatozoa for conventional methods of in vitro insemination. Sperm parameters do not clearly affect the outcome of this technique.

A model for the incorporation of intracytoplasmic sperm injection into a private practice in vitro fertilization program.

OBJECTIVE: To describe a method for the training of personnel and the implementation of intracytoplasmic sperm injection (ICSI) into an IVF program. The results of the first 75 cycles are reviewed. DESIGN: Retrospective review of the first 75 consecutive ICSI procedures. SETTING: Private, community-based IVF program. MAIN OUTCOME MEASURES: The fertilization rate, damage rate, ongoing pregnancy rate (PR), and implantation rate were measured. RESULTS: Nine percent of the injected oocytes were damaged. The fertilization rate was 60%, and the cleavage rate was 98%. Fifty-nine percent of the cycles resulted in an ongoing pregnancy, and the implantation rate per embryo was 26%. CONCLUSIONS: A high initial PR can be obtained with ICSI using a systematic training regimen.

Embryo morphology, developmental rates, and maternal age are correlated with chromosome abnormalities.

OBJECTIVE: To determine some of the unresolved questions related to chromosome anomalies in early human embryos, such are the detection of any advanced maternal age effect; the complete assessment of mosaicism, which requires analysis of all cells; and the relationship with embryonic dysmorphism. Fluorescence in situ hybridization has been used in this study to answer these issues. DESIGN: Fluorescence in situ hybridization analysis of human embryos using simultaneously probes for three or five chromosomes. Five hundred twenty-four cleavage-stage human embryos obtained by IVF were analyzed by fluorescence in situ hybridization. Embryos were allocated into three groups according to morphological and developmental characteristics (arrested; slow and/or fragmented; morphologically and developmentally normal). The embryos also were analyzed according to maternal age. RESULTS: Dysmorphic embryos had higher rates of polyploidy and diploid mosaicism. Aneuploidy increased with maternal age in nonarrested embryos. Preimplantation genetic diagnosis successfully detected these abnormalities. CONCLUSION: This study demonstrates that, in morphologically and developmentally normal human embryos, cleavage-stage aneuploidy significantly increases with maternal age. The results suggest that implantation failure in older women largely could be due to aneuploidy.

Chromosome abnormalities in embryos obtained after conventional in vitro fertilization and intracytoplasmic sperm injection.

OBJECTIVE: To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated zygotes produced by intracytoplasmic sperm injection (ICSI) and conventional IVF. DESIGN: Embryos were classified by maternal age and morphological and developmental characteristics to avoid bias when comparing chromosome abnormalities in ICSI and IVF embryos. SETTING: The Institute for Reproductive Medicine and Science of Saint Barnabas Medical Center, West Orange, New Jersey. PATIENT(S): Seventy-nine couples undergoing IVF and 53 couples undergoing ICSI. INTERVENTION(S): Embryos donated for research were fully biopsied, and their cells were analyzed by fluorescence in situ hybridization with specific probes for chromosomes X, Y, 13, 18, and 21 and some with also a probe for chromosome 16. MAIN OUTCOME MEASURE(S): Embryo chromosome abnormalities. RESULT(S): A total of 245 embryos obtained through conventional IVF and 136 embryos obtained through ICSI were analyzed. There were no statistical differences between the rates of numerical chromosomal abnormalities detected in the IVF (61%) and ICSI (52%) embryos analyzed. Regarding gonosomal aneuploidy, the same rate was found in both ICSI (1%) and IVF groups (2%). CONCLUSION(S): If the parents are chromosomally normal, the results indicate that, at the embryo level and before any embryo selection has occurred in utero, ICSI does not produce more numerical chromosomal abnormalities than conventional IVF.

Partial zona dissection or subzonal sperm insertion: microsurgical fertilization alternatives based on evaluation of sperm and embryo morphology.

OBJECTIVE: To establish guidelines for application of partial zona dissection, subzonal sperm insertion, and regular in vitro fertilization (IVF) in severe male factor patients. DESIGN: Two studies were performed: partial zona dissection and IVF was applied in 57 couples during the first period, and subzonal sperm insertion was also applied in a second group of 47 couples. SETTING: Procedures were performed in an academic research environment. PATIENTS, PARTICIPANTS: Couples who failed fertilization previously, others not acceptable for IVF, and a third group in whom IVF was expected to fail. INTERVENTIONS: Oocytes were micromanipulated with either partial zona dissection or subzonal sperm insertion, or the zona pellucida was left intact. Embryos were replaced in patients prophylactically treated with methylprednisolone and antibiotics. MAIN OUTCOME MEASURES: Because several microsurgical fertilization techniques are now available, this study was performed to compare sperm parameters, embryo morphology, fertilization, and implantation rates after application of two successful micromanipulation procedures. RESULTS: Twenty-one pregnancies were established in 104 patients, 5 definitely from subzonal sperm insertion and 4 from partial zona dissection. Patients who failed IVF before had a similar chance of pregnancy after the use of micromanipulation, as first time patients (9/53 versus 12/51). In a subgroup of 15 patients who failed IVF with insufficient numbers of motile sperm, fertilization was significantly higher after subzonal sperm insertion. Partially zona-dissected embryos from couples with severe teratozoospermia (less than or equal to 5% normal forms; strict criteria) had significantly more morphological abnormalities than those from patients with moderate teratozoospermia (6% to 10% normal forms). In severely teratozoospermic patients, significantly fewer partially zona-dissected than subzonally inserted embryos implanted. CONCLUSIONS: The decision of which micromanipulation method to perform can possibly be based on careful analysis of sperm morphology.

Human embryo fragmentation in vitro and its implications for pregnancy and implantation.

OBJECTIVE: To evaluate the effects of fragmentation and fragment removal in day 3 human embryos on implantation and pregnancy. DESIGN: Retrospective analysis of ETs homogeneous with respect to embryo fragmentation. SETTING: A program of IVF-ET. PATIENT(S): The study population consisted of 2,410 patients. INTERVENTION(S): The degree and pattern of fragmentation were evaluated on days 2 and 3; microsurgical fragment removal was performed after assisted hatching on day 3. MAIN OUTCOME MEASURE(S): Clinical pregnancy and implantation rates. RESULT(S): The degree and pattern of fragmentation significantly impact pregnancy and implantation. With the application of microsurgical fragment removal before ET, embryos with 6%-35% fragmentation implant with similar frequency. The presence of large fragments (type IV) is detrimental to the developing embryo, whereas localized or small and scattered fragments do not significantly affect implantation. CONCLUSION(S): The potential of fragmented embryos for implantation is determined partly by the distribution of fragments. Adoption of an embryo classification system reflecting types of fragmentation is advisable. The use of microsurgical fragment removal significantly alters the course of development for some embryos and improves their implanting potential.

Epididymal micropuncture with in vitro fertilization and oocyte micromanipulation for the treatment of unreconstructable obstructive azoospermia.

OBJECTIVE: To provide fertility to couples in whom the man has surgically unreconstructable obstructive azoospermia. DESIGN: Prospective. SETTING: Hospital-based IVF unit, including associated division of urologic microsurgery. PATIENTS: Couples referred to our fertility unit for treatment of men with surgically unreconstructable reproductive tract obstruction, including congenital absence of the vas deferens. MAIN OUTCOME MEASURES: Fertilization, pregnancies, and live births. RESULTS: Of 51 cycles in which sperm and eggs were retrieved, 67% (34/51) resulted in fertilization and 27.5% (14/51) developed clinical pregnancy. Clinical pregnancy rate per couple was 33% (14/43). A total of 15 live births have been obtained in 11 couples with one ongoing pregnancy. Epididymal length was the best predictor of sperm quality and pregnancy results. For couples with at least the corpus epididymis present, 41% (9/22) of cycles resulted in clinical pregnancies. CONCLUSIONS: Pregnancy rates are optimized using sperm retrieved from the epididymis by micropuncture and when micromanipulation is available for use during IVF.

Cystic fibrosis gene mutations do not affect sperm function during in vitro fertilization with micromanipulation for men with bilateral congenital absence of vas deferens.

OBJECTIVE: To assess the effects of cystic fibrosis transmembrane-conductance regulator (CFTR) gene mutations on sperm function and fertility in men with bilateral congenital absence of the vas deferens. DESIGN: Prospective. SETTING: Division of urologic microsurgery and associated hospital-based IVF unit. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates. PATIENTS: Men referred to our fertility unit for treatment of bilateral congenital absence of the vas deferens, using sperm surgically retrieved from the epididymis with IVF and micromanipulation. RESULTS: Of 45 men with bilateral congenital absence of the vas, 54% (19/35) tested were found to be carriers of CFTR gene mutations, with one compound heterozygote. Epididymal sperm from men affected with CFTR mutations fertilized 19% (29/152) of oocytes, whereas men without mutations fertilized 22% (44/204) of oocytes. Pregnancy rates (PRs) were 36% (5/14) for cycles involving men with CFTR mutations and 33% (5/15) for other patients with congenital absence of the vas deferens but without detectable CFTR mutations. CONCLUSIONS: The presence of detectable CFTR mutations does not affect fertilization rates or PRs for men with bilateral congenital absence of the vas deferens when IVF and micromanipulation are applied.

Development and implementation of intracytoplasmic sperm injection (ICSI).

The purpose of this paper is to elucidate the experimental steps that led to the development of intracytoplasmic sperm injection (ICSI) and its application in the human. ICSI has become the most successful micromanipulation procedure for treating male infertility. A total of 355 in vitro fertilization (IVF) cycles utilizing ICSI are described; 180 couples were previously treated in 509 IVF cycles but achieved no fertilization and 175 couples could not be treated by IVF because of extremely poor semen parameters. Of the 3063 metaphase II (M II) oocytes retrieved, 2970 were injected with a survival rate of 93.6%, yielding 1917 bipronuclear zygotes (64.5%). In 148 patients, a foetal heart was evidenced by ultrasound; 11 of these patients miscarried between 7 and 13 weeks of gestation. The ongoing pregnancy rate was 38.6% (137/355) per retrieval and 40.5% (137/338) per embryo replacement. At the time of writing, there were 22 deliveries and one therapeutic abortion for a trisomy 21 chromosomal abnormality. In addition, 66 singleton, 37 twin, 10 triplet and 1 quadruplet pregnancies were ongoing. The concentration of motile spermatozoa in the ejaculate only slightly influenced the fertilization rate (P < 0.001) and the pregnancy outcome (P < 0.01). A preliminary injection procedure utilizing intracytoplasmic injection of isolated sperm heads was performed in 35 M II human oocytes with resultant fertilization and cleavage rates of 74% and 73% respectively. Skills in ICSI were acquired by injecting hamster and unfertilized human oocytes with human sperm. ICSI can be used to successfully treat couples who have failed IVF or who have too few spermatozoa for conventional in vitro insemination.(ABSTRACT TRUNCATED AT 250 WORDS)

Advances in clinical micromanipulation of gametes and embryos. Assisted fertilization and hatching.

Several methods for micromanipulation of human gametes have been proposed to enhance fertilization in cases of male infertility. Of these methods, two have been successful in producing pregnancies and live births worldwide; these include partial zona dissection and subzonal sperm insertion. During the period between October 1989 and July 1991, 251 patients with male infertility due to impaired sperm function were treated with in vitro fertilization in conjunction with gamete micromanipulation at our center. Sixty pregnancies (24% per cycle, 42% per replacement) resulted in 144 patients. The details of these treatments are discussed. In another study, in an attempt to increase the incidence of implantation, we have conducted three clinical trials of assisted hatching and selected assisted hatching. The combined results of the trials indicate a clinical pregnancy rate of 51% in the control group and 60% in the micromanipulated group (P less than .05). Moreover, while 20% of the embryos replaced in the control group implanted the implantation rate was increased to 28% in the experimental group (P less than .05). Methodologies and possible implications of these treatments are discussed.

Selective assisted hatching of human embryos.

Overall results of assisted hatching by zona drilling using acidic Tyrode's solution performed during three randomised trials in 330 in vitro fertilisation (IVF) patients are presented. It was demonstrated retrospectively and prospectively that assisted hatching by zona drilling was effective in embryos with thick zonae (> 15 microns). This procedure is called selective assisted hatching. In order to investigate whether the success rate of embryos with thin zonae (< 13 microns) can be improved further, a fourth trial was executed in 40 consenting patients. Embryos with thin zonae were left intact in one group (control), while the outside of zonae of similar embryos were thinned with acidic Tyrode's solution. Results thus far indicate that embryos with thin zonae do not benefit from this technique. Embryonic implantation (fetal heartbeat per embryo) was high (26%-27%) in both arms of the trial, probably as a result of selective zona drilling of low prognosis embryos with thick zonae. A method is presented for quantifying zona hardening in human embryos. The exposure to acidic Tyrode's solution of each embryo was expressed as a function of the duration to pierce the zona and the diameter of the needle. Preliminary findings suggested that embryonic viability is correlated with zona hardening. In order to test the hypothesis that extracellular fragments may affect embryonic viability, small amounts of fragments were removed from embryos during assisted hatching. The pregnancy rate in 36 patients with extracted fragments was relatively high (41%) considering the poor morphology of the embryos involved.

Micromanipulation of human gametes for assisted fertilization.

The techniques of partial zona dissection, subzonal sperm insertion, and intracytoplasmic sperm injection have been clinically employed to alleviate aberrations of human gamete interaction. This article reviews the current status of assisted fertilization technology and its relevance in treating male infertility. Indications for the application of each technique and factors affecting outcome are discussed.

Micromanipulation of cleaved embryos cultured in protein-free medium: a mouse model for assisted hatching.

A mouse model for studying anomalies of human embryonic hatching following micromanipulation is proposed. Initiation and completion of mouse blastocyst hatching was severely impaired (34/292; 12% and 28/292; 10%, respectively) with protein deprivation, resembling the situation in human in vitro fertilization. Hatching ability was restored when an artificial gap was introduced in the zona pellucida by micromanipulation at the cleaved embryo stage. This enabled 77% (285/371) and 36% (134/371) of the embryos to initiate and complete hatching in protein-free medium. No differences were found in overall cell counts between the two groups of embryos. Transfer of micromanipulated blastocysts to pseudopregnant females resulted in development of healthy fetuses.

Laboratory techniques for handling gametes and embryos.

This review describes some basic and novel principles pertaining to the science of in vitro fertilization and embryo culture. Several systems for cell-free culture of gametes and embryos are described. The advantages of a coculture or helper cell system was investigated in several clinical trials using bovine cells from the reproductive tract. Improved embryonic morphology and implantation indicate that standard IVF culture provides suboptimal conditions. Microsurgical methods for assisting in vitro fertilization in cases of severe male factor infertility are also discussed. Thus far, it has been demonstrated that mechanical opening of the zona pellucida by methods such as partial zona dissection enhances fertilization. In addition, the introduction of a limited gap in the zona seems to facilitate hatching of the blastocyst, which may benefit all patients undergoing in vitro fertilization.