P-384 Efficacy of endometrial microbiome metagenomic analysis with recurrent implantation failure and recurrent pregnancy loss: multicenter study in Japan

Study question

Does the result of endometrial microbiome metagenomic analysis (EMMA), a next generation sequencing (NGS)-based test of the intrauterine microbiome, have an impact on pregnancy rate after the test?

Summary answer

After recommend treatment with antimicrobial and probiotic therapy, the group diagnosed as dysbiosis by EMMA achieved pregnancy significantly earlier than the group with Normal result.

What is known already

Using NGS technology, EMMA testing can determine the composition of the endometrial microbiome by analysing bacterial 16S ribosomal RNA with a focus on the lactobacillus population. Endometrial flora in patients undergoing in vitro fertilization (IVF) is often composed of pathogenic microorganisms which decrease implantation rates, such as the Enterobacteriaceae family, Staphylococcus spp., Escherichia coli and Gram-negative bacteria. Other studies also indicate that Lactobacillus spp. is a major microorganism in the endometrium. Especially, lactobacillus-dominated microbiota (LDM, defined as > 90% Lactobacillus spp.) in the endometrium has been reported to lead to better pregnancy outcomes than non-LDM (<90% Lactobacillus spp.).

Study design, size, duration

This study was a prospective, multicenter cohort study of 527 patients (under 42 years old) with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) at 14 IVF treatment facilities in Japan from June 2019 to August 2021. Defining RIF as three or more failed implantation attempts and RPL as two or more miscarriages, we examined the prognosis of two additional embryo transfers (ETs) after the EMMA test in patients who underwent the test.

Participants/materials, setting, methods

Endometrial tissue was obtained by aspiration from patients in day 15-25 of their menstrual cycles, and sample tissues were analyzed by NGS for EMMA. Participant centers treated patients according to the therapies specified in the reports, including antibiotic treatments, probiotic treatments, re-analysis, and embryo transfer. Multivariate analysis was performed using a generalized linear model with the endpoint of ongoing pregnancy. For the time-to-event analyses, we used Kaplan-Meier survival analysis to compare time to ongoing pregnancy.

Main results and the role of chance

The results of the first EMMA were as follows: 229 patients (43.4%) were normal with Lactobacillus spp. >90% (Normal group), 110 patients (20.9%) were abnormal with less than 90% Lactobacillus spp. and predominantly pathogenic bacteria (Abnormal group), and 188 patients (35.7%) were mild with low absolute amounts of bacteria and ultralow biomass indicating almost sterile (Mild + Ultralow group). There were no significant differences in background factors such as age, duration of infertility, number of previous ETs, or history of deliveries among the three groups. Gardnerella was the most pathogenic bacteria detected in patients with Abnormal EMMA results. All patients in the Abnormal group were treated with antimicrobials and probiotics, and those in Mild + Ultralow group were treated with probiotics. Odds ratio for ongoing pregnancy rate was 1.10(95%CI 0.67-1.82, p = 0.699) in Abnormal group and 1.23(95%CI 0.80-1.89, p = 0.342) in Mild + Ultralow group, respectively. After the intervention, ongoing pregnancies were comparable to those in Normal group.Analysis of time to pregnancy using Kaplan-Meier survival curves showed that Abnormal group had a significantly higher rate of ongoing pregnancies during the observation period than the other groups (p = 0.031).

Limitations, reasons for caution

Since this study was not necessarily limited to euploid embryos transferred after testing, an aging bias cannot be excluded. Since this study was conducted with all patients receiving EMMA, the effectiveness of the test needs to be further validated by comparison to patients without EMMA testing.

Wider implications of the findings

This study is the first multicenter study to demonstrate that the intervention based on EMMA reports improve pregnancy outcome in the patients with RIF and RPL. We suggest that the EMMA procedure, which aims at establishing an appropriate uterine microbiome, may be important for implantation and pregnancy continuation.

Trial registration number

UMIN000036917

P–193 First cleavage division perpendicular to the pronuclear axis adversely affects the clinical outcome in human embryos

Study question

Does the direction of formation for the first cleavage plane relative to the pronuclear axis affect clinical outcome?

Summary answer

A first cleavage division perpendicular to the pronuclear axis adversely affects the rate of embryo utilization for transfer or cryopreservation and the pregnancy outcome.

What is known already

It remains unclear how the first cleavage plane is determined in human embryos. By using time-lapse monitoring, our previous study (presented in ESHRE 2019) suggested that both the axis and locations of male and female pronuclei are involved in determining the first embryonic cleavage plane. Furthermore, by using immunofluorescence analysis, it was also revealed that most analyzed zygotes showed two pericentrin signals aligned around the interface between the male and female pronuclei. Our findings suggest that the pronuclear axis strongly influences the positions of the centrosomes, which become mitotic spindle poles and define the first cleavage plane. Study design, size, duration: From January 2015 to December 2017, time-lapse imaging (EmbryoScope®) of 3397 intracytoplasmic sperm injection (ICSI) oocytes was conducted. Of those, the relationship between the pronuclear axis and the first cleavage plane was analyzed in 607 normally fertilized embryos that cleaved to two cells and were obtained in 2015. Furthermore, of 3397 ICSI oocytes, 749 transferred embryos were classified based on the first cleavage patterns relative to the pronuclear axis, and the pregnancy rate was examined.

Participants/materials, setting, methods

A straight line connecting the centers of the pronuclei was defined as the 2PN axis. Based on the direction of the first cleavage relative to the 2PN axis, embryos were classified into three groups: parallel, perpendicular and intermediate. Fresh embryos were transferred on Day 2/3 (fresh-ET). Frozen and thawed embryos were transferred on Day 2/3 or Day 5 (F/T-ET). Clinical pregnancy was defined as confirmed gestational sac in the uterine cavity.

Main results and the role of chance

Of 607 analyzed embryos, 506 produced suitable images and were assigned to one of three groups: parallel (84.4%, n = 427), perpendicular (9.7%, n = 49) and intermediate (5.9%, n = 30). Embryos that formed a cleavage furrow parallel to the 2PN axis were significantly more frequent than others (perpendicular, intermediate) (P < 0.001). The embryo utilization rate for transfer or cryopreservation was significantly lower in the perpendicular group than in the parallel group (30.7% vs. 69.3%, P < 0.01). Furthermore, of 749 transferred embryos, 504 assigned to the parallel and perpendicular groups were selected (n = 470 and n = 34, respectively), and the pregnancy outcome was analyzed. The mean maternal age was not significantly different between groups. The pregnancy rate of embryos was 24.2% (n = 45/186) from fresh-ET and 39.4% (n = 112/284) from F/T-ET in the parallel group, and 0% (n = 0/14) from fresh-ET and 15.0% (n = 3/20) from F/T-ET in the perpendicular group. Regardless of the types of embryo transfer (fresh or F/T), the pregnancy rate was significantly lower in the perpendicular group than in the parallel group (P < 0.01). In addition, one of three patients who became pregnant from the transfer of an embryo in the perpendicular group had a miscarriage.

Limitations, reasons for caution

Since only ICSI embryos were analyzed in this study, the influence of fertilization methods on subsequent development could not be investigated. Further studies including preimplantation genetic testing for aneuploidy may help determine the reasons why pregnancy rates differ between groups.

Wider implications of the findings: We suggest that the 2PN axis is essential for determining the first cleavage plane because it seems to be involved in positioning the mitotic spindle poles. The direction of the first cleavage plane relative to the 2PN axis can be an important indicator for predicting embryo development and pregnancy outcome

Trial registration number

none

P–215 The degree of perivitelline space (PS) at the pronuclear stage affects subsequent embryonic development in human zygotes

Study question

Was embryonic development affected by the degree of perivitelline space (PS) at the pronuclear stage in human zygotes?

Summary answer

Zygotes with a fully surrounding PS showed less cytoplasmic fragmentation and a higher blastocyst development rate (BDR) than zygotes with a partially surrounding PS.

What is known already

We previously used abnormally-fertilized oocytes (zygotes with three pronuclei; 3PN), donated by ART patients in our clinic who gave written consent for the research. The zona pellucida (ZP) was artificially removed from these oocytes at the pronuclear stage, termed ZP-free culture. The resultant ZP-free 3PN embryos showed less cytoplasmic fragmentation and a higher rate of good-quality embryos (GQE) compared with ZP-intact embryos. Furthermore, in our clinical setting, the rate of GQE and BDR of normally-fertilized embryos were clearly improved by ZP-free culture in patients with recurrent failure of ART treatments due to severe cytoplasmic fragmentation at the early cleavage stage.

Study design, size, duration

This study included 49 patients who gave written informed consent for our study and were treated with ART in our clinic between March and December 2020. Embryonic development was compared between zygotes with a fully surrounding PS [PS(+)] with those with a partially surrounding PS [PS(-)] at the pronuclear stage. Furthermore, the ZP of PS(-) embryos were artificially removed at the pronuclear stage, and the rate of GQE and BDR were compared with ZP-intact embryos.

Participants/materials, setting, methods

The degree of PS in 128 zygotes was confirmed by hypertonic preparation using 0.125M sucrose-containing HEPES medium. PS(+) and PS(-) embryos were both cultured as ZP-intact, and the rate of GQE was compared. Furthermore, 223 zygotes were divided into three groups: 1) PS(-)/ZP-intact, 2) PS(-)/ZP-free, and 3) PS(+)/ZP-intact, and cultured in an incubator equipped with time-lapse monitoring up to Day 7, and the rate of GQE, BDR and useable embryos were compared between each groups.

Main results and the role of chance

The degree of PS was confirmed by a hypertonic preparation (shrinkage of the ooplasm) in 128 normally-fertilized zygotes obtained from 44 cases. There were 86 PS(-) (67.2%) and 42 PS(+) (32.8%) zygotes. The mean maternal age was 35.9 in PS(-) and 40.5 in PS(+) (P < 0.01), and the rate of GQE was significantly higher in PS(+) [64.3% (27/42)] than in PS(-)[38.4% (33/86)] (P < 0.01). In addition, of 223 normally-fertilized zygotes obtained from 41 cases, there were 51 PS(-)/ZP-intact (Group 1), 132 PS(-)/ZP-free (Group 2) and 40 PS(+)/ZP-intact (Group 3) zygotes. The rate of GQE was significantly lower in Group 1 [29.4% (15/51)] compared with Group 2 [59.8% (79/132)] and Group 3 [62.5% (25/40)] (P < 0.01). BDR was also significantly lower in Group 1 [51.3% (10/39)] compared with Group 2 [75.0% (99/132)] and Group 3 [65.0% (13/20) (P < 0.01).

Limitations, reasons for caution

Although the artificial removal of ZP at the pronuclear stage (ZP-free culture) clearly increased the rate of GQE, embryonic development was not improved in all cases. It seems that this procedure is only effective in embryos with a viable ooplasm.

Wider implications of the findings: The degree of PS at the pronuclear stage affects subsequent embryonic development in human zygotes. The artificial removal of ZP at the pronuclear stage (ZP-free culture) helps to suppress fragmentation and leads to an increase in GQE and BDR, and eventually, improves pregnancy rate in cases with severe fragmentation.

Trial registration number

non

P–201 The beneficial effects of ZP-free culture on cytoplasmic fragmentation in human embryos. : An innovative trial using 3PN zygotes

Study question

Is it possible to culture ZP-free embryos to eliminate perivitelline threads, which are known to be involved in generating cytoplasmic fragments at the first cleavage?

Summary answer

ZP-free culturing, an innovative system that decreases the amount of cytoplasmic fragments without disrupting the blastomeres, using incubators with time-lapse imaging.

What is known already

A study in 2017 observed perivitelline threads in more than 50% of cleavage-stage human embryos using time-lapse imaging, and the rate of cytoplasmic fragmentation (at the first cleavage) was significantly decreased in embryos without perivitelline threads (P < 0.001). While it has been proposed that perivitelline threads play an important role in crosslinking the cumulus cells and oocyte during maturation, the mechanism underlying such a role remains unclear. It is also unknown whether the threads still function in mature MII oocytes.

Study design, size, duration

A prospective study was conducted using 2,852 normal (2PN/2PB) embryos from c-IVF/ICSI and 113 abnormal (3PN) embryos obtained from c-IVF between 2017 and 2019. The zona pellucida (ZP) of 71 abnormal embryos was removed at the pronuclear stage (“ZP-free”), and the rest (n = 42) were cultured as “ZP-intact”. Normal and abnormal embryos were cultured for five days in bench-top incubators (MINC, COOK) and an incubator equipped with a time-lapse imaging system.

Participants/materials, setting, methods

Embryos used in this study were donated by 412 couples who underwent c-IVF cycles in our clinic between 2017 and 2019. For ZP removal, 3PN embryos were placed in 0.125M sucrose-containing HEPES media drops to reduce the ooplasm size. Then, ooplasms were completely separated from ZPs by a laser and pipetting. Embryo development and morphology of the three groups (normal, ZP-intact and ZP-free abnormal) were compared based on the degree of cytoplasmic fragmentation.

Main results and the role of chance

The first cleavage occurred in 97.8% (n = 2,790/2,852) of 2PN/2PB, 83.3% (n = 35/42) of ZP-intact 3PN and 97.2% (n = 69/71) of ZP-free 3PN. Normal (2PN/2PB), ZP-intact and ZP-free 3PN embryos were classified into three groups based on the modified Veeck’s criteria thus: <20% fragmented compared to the total volume of cytoplasm at the first cleavage (Grade 1 and 2, Good); 20–39% fragmented (Grade 3, Fair) and ≧40% fragmented (Grade 4, Poor). Of 69 cleaved ZP-free 3PN embryos, 68.1% (n = 47) showed less than 20% fragments which was significantly higher than 2PN/2PB (43.7%, n = 1,218/2,790) and ZP-intact 3PN (45.7%, n = 16/35; P < 0.05). Furthermore, 24.6% (n = 17/69) of ZP-free 3PN embryos showed 20–39% fragments which was significantly lower than 2PN/2PB (45.9%, n = 1,281/2,790; P < 0.05). In addition, 50.7% of ZP-free 3PN embryos (n = 36) developed to the morula stage after the third cleavage, and 29.6% (n = 21) formed blastocoel and became blastocysts. Thus, removing the ZP before the first cleavage did not adversely affect embryo development and decreased the cytoplasmic fragmentation.

Limitations, reasons for caution

Due to ethical and clinical limitations, we only examined abnormally fertilized embryos in this study. Moreover, since the relationship between the perivitelline threads and cytoplasmic fragments is unclear, we plan to conduct molecular biological analysis of the perivitelline threads in further studies.

Wider implications of the findings: This study revealed that ZP is not always necessary after the pronuclear stage because ZP-free embryos studied herein developed normally and maintained cell adhesion well. This innovative culture method might provide the breakthrough needed for patients to improve embryo quality who obtain embryos with severe fragmentation caused by perivitelline threads.

Trial registration number

Not applicable

O-219 Detailed morpho-kinetic analysis of the first cleavage can help in evaluating the viability of direct-cleaved human zygotes

Study question

Why do some direct-cleaved human zygotes still lead to a live birth?

Summary answer

Direct-cleaved zygotes which have undergone the 2-cell stage can lead to a live birth, while zygotes cleaved from 1-cell to ≥ 3-cell do not.

What is known already

In recent years, zygotes that develop from 2-cell to 3-cell within 5 hours after the first cleavage have been evaluated as “direct-cleaved” zygotes, because normal cleavage takes approximately 12 hours to complete. It was reported that their implantation rate was significantly lower than zygotes with normal cleavage pattern, and eliminating direct-cleaved zygotes from transfer could improve the implantation rate. However, some direct-cleaved zygotes at the first cleavage could still lead to a live birth. Few reports have examined the difference between a cleavage from 1-cell to ≥ 3-cell and 2-cell to ≥ 3-cell within 5 hours after the first cleavage.

Study design, size, duration

A retrospective study involving 2,077 cycles of IVF/ICSI between July 2012 and July 2019. A total of 5,991 normally fertilized zygotes (2PN/2PB) were included. Of those, 3,508 were evaluated as usable good/fair quality embryos on Day2/3, and the rest (n = 2,483) were evaluated as poor quality and rejected from transfer or cryopreservation after 7 days of culture. Of 3,508 usable embryos, 884 were selected based on the availability of results of live birth for this study.

Participants/materials, setting, methods

Time-lapse imaging (5 slices along Z-axis every 10 minutes) was performed in EmbryoScopeTM. Zygotes were morphokinetically analyzed in detail and classified into four groups by their cleavage patterns: Group1 (1-cell→2-cell); Group 2 (1-cell→3-cell); Group 3 (1-cell→2-cell→≥3-cell within 5 hours after the first cleavage); and Group 4 (1-cell→2-cell→≥5-cell). The proportion, mean maternal age and live birth rate of each group were examined.

Main results and the role of chance

The proportion of Groups 1-4 was 83.6% (n = 739), 3.8% (n = 34), 5.9% (n = 52), and 6.7% (n = 59), respectively. 0f 884 zygotes examined in this study, the mean maternal age was significantly higher in Group 2 and 4 than in Group 1 (P < 0.05; 37.4±4.9 in Group1, 39.1±5.2 in Group 2, 38.6±6.0 in Group 3, and 38.7±5.1 in Group 4). The rate of confirmed gestational sac was significantly lower in Group 2 and 4 than in Group 1 [P < 0.01; 36.3% (n = 268/739), 0% (n = 0/34), 25.0% (n = 13/52), and 18.6% (n = 11/59) in Groups 1-4, respectively]. Furthermore, the live birth rate was significantly higher in Group 1 than in Groups 2, 3 and 4 [P < 0.01; 28.4% (n = 210/739), 0% (n = 0/34), 13.5% (n = 7/52), and 15.3% (n = 9/59) in Groups 1-4, respectively]. Above all, while zygotes in Group 2 showed no pregnancy and live birth at all, zygotes in Group 3 showed a live birth rate of 13.5%. However, they had a significantly higher miscarriage rate (42.9%, n = 6) compared to zygotes in Group 1 (19.5%, n = 55).

Limitations, reasons for caution

It is very difficult to capture cleavage patterns by routine observations because the timings of developmental events are different between embryos. A time-lapse imaging and culturing system is essential to solve this problem, however, it cannot visualize the distribution of chromosomes, and no chromosomal analysis was conducted in this study.

Wider implications of the findings

This study revealed that zygotes previously classified as “direct-cleaved” and eliminated from transfer included viable zygotes which could lead to a live birth. Therefore, it is crucial to optimize the use of time-lapse imaging of human zygotes in order to precisely evaluate the first cleavage.

Trial registration number

not applicable

P–216 Successful pregnancies and deliveries in patients with a recurrent failure of ART treatments following artificial removal of the zona pellucida (ZP) at the pronuclear stage

Study question

Can a novel embryo culture method that artificially removes the ZP at the pronuclear stage yield successful pregnancy in patients with poor-quality embryos and/or blastocysts?

Summary answer

A blastocyst transfer after ZP-free culture can result in pregnancy for patients who cannot obtain good quality blastocysts from conventional culture methods.

What is known already

Perivitelline threads are been associated with the formation of cytoplasmic fragments. We had previously observed perivitelline threads in the adhesive region between the ooplasm and the ZP at the first cleavage in human embryos. We removed the ZP at the pronuclear stage in 71 abnormally fertilized oocytes (zygotes with three pronuclei), donated after conventional IVF (c-IVF), and termed them ZP-free 3PN. We found ZP-free 3PN embryos could be cultured without losing blastomere adhesions. Furthermore, the rate of good quality embryos was significantly higher in ZP-free 3PN embryos compared with ZP-intact embryos (ZP-intact 2PN/2PB and 3PN embryos; P < 0.05).

Study design, size, duration

This study was conducted in two cases selected among patients who underwent ART treatment in our clinic between 2018 and 2019. Cases were selected if they lacked good quality blastocysts in previous c-IVF/Intracytoplasmic Sperm Injection (ICSI) cycles due to massive cytoplasmic fragmentation at the first and second cleavage. We performed a clinical trial of ZP-free culture from December 2019 to March 2020.

Participants/materials, setting, methods

Two cases were selected for this trial. Normally fertilized oocytes were grouped as ZP-free or ZP-intact. For the ZP-free group, 2PN embryos were placed in 0.125M sucrose-containing HEPES to reduce ooplasm size, then ooplasms were completely separated from ZPs by a laser and pipetting. ZP-free and ZP-intact embryos were cultured with time-lapse imaging for up to seven days. Resultant blastocysts were either transferred into uterus or cryopreserved on Day5/6/7 for future embryo transfer cycles.

Main results and the role of chance

The ZP-free culture method was applied to two patients (patient A and B) with recurrent failure of ART in our clinic due to poor-quality embryos and/or difficulties in obtaining good quality blastocysts. In both cases, blastocysts were successfully obtained and cryopreserved for all ZP-free culture cycles. In patient A, one good quality ZP-free blastocyst was freshly transferred five days after oocyte retrieval, and a live male baby (2925g) was delivered at 40 weeks of gestation by caesarean section). In patient B, a frozen/thawed ZP-free blastocyst transfer was conducted, and a live female baby (3225g) was delivered at 39 weeks of gestation by vaginal delivery. This shows ZP-free culturing may help obtain viable embryos in patients for which conventional in vitro culturing methods result in embryos characterized with severe cytoplasmic fragmentation and poor quality in the early cleavage stage.

Limitations, reasons for caution

Although successful pregnancies and deliveries were confirmed in two cases, postnatal evaluations will be absolutely necessary for infants derived from ZP-free culture. In addition, the number of trial cases needs to be expanded, however careful selection of suitable patients is necessary for this novel culture method.

Wider implications of the findings: We found removing the ZP at the pronuclear stage improved embryo development and led to successful pregnancies and deliveries after blastocyst transfer. This indicates ZP-free culturing may be an effective method for decreasing cytoplasmic fragmentation caused by perivitelline threads or adhesion between the ooplasm and the zona pellucida.

Trial registration number

Not applicable

A multi-centre, retrospective case series of oocyte cryopreservation in unmarried women diagnosed with haematological malignancies

STUDY QUESTION

Is oocyte cryopreservation an applicable option for fertility preservation in unmarried patients with haematological malignancies?

SUMMARY ANSWER

Oocyte cryopreservation via the vitrification method is accessible and may be considered an option for fertility preservation in unmarried patients with haematological malignancies.

WHAT IS KNOWN ALREADY

Haematological malignancies are most commonly observed amongst adolescent and young adult women. Although the survival rate and life expectancy of those with haematological malignancies have improved, chemotherapy and radiotherapy may impair their reproductive potential. Oocyte cryopreservation is thus an ideal option to preserve their fertility.

STUDY DESIGN SIZE DURATION

This study retrospectively evaluated 193 unmarried patients (age: 26.2 ± 0.4 years) with haematological malignancies, who consulted for oocyte cryopreservation across 20 different fertility centres in Japan between February 2007 and January 2015. The primary outcome measures were the oocyte retrievals and oocyte cryopreservation outcomes. The secondary outcome measures were the outcomes following oocyte warming for IVF.

PARTICIPANTS/MATERIALS SETTING METHODS

The patients had commenced ovarian stimulation cycles via antagonist, agonist, natural and minimal methods for oocyte retrievals, defined according to the treatment strategy of each respective fertility centre. A vitrification method using the Cryotop safety kit was used for oocyte cryopreservation. ICSIs were used for insemination of warmed oocytes. The endometrial preparation method for embryo transfer was hormonal replacement therapy, except in the case of a patient who underwent a spontaneous ovulatory cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 193 patients, acute myeloid leukaemia (n = 45, 23.3%) was most common, followed by acute lymphoid leukaemia (n = 38, 19.7%) and Hodgkin's lymphoma (n = 30, 15.5%). In total, 162 patients (83.9%) underwent oocyte retrieval, and oocytes were successfully cryopreserved for 155 patients (80.3%). The mean number of oocyte retrieval cycles and cryopreserved oocytes were 1.7 ± 0.2 and 6.3 ± 0.4, respectively. As of December 2019, 14 patients (9.2%) had requested oocyte warming for IVF. The survival rate of oocytes after vitrification-warming was 85.2% (75/88). The rates of fertilisation and embryo development were 80.0% (60/75) and 46.7% (28/60), respectively. Ten patients (71.4%) had successful embryo transfers, and seven live births (50.0%) were achieved.

LIMITATIONS REASONS FOR CAUTION

This study was limited by its retrospective nature. Additionally, there remains an insufficient number of cases regarding the warming of vitrified oocytes to reliably conclude whether oocyte cryopreservation is effective for patients with haematological malignancies. Further long-term follow-up study is required.

WIDER IMPLICATIONS OF THE FINDINGS

Oocyte retrieval and oocyte cryopreservation were accessible for patients with haematological malignancies; however, the number of oocyte retrievals may have been limited due to the initiation of cancer treatments. Acceptable embryonic and pregnancy outcomes could be achieved following oocyte warming; therefore, our results suggest that oocyte cryopreservation can be considered an option for fertility preservation in patients with haematological malignancies.

STUDY FUNDING/COMPETING INTERESTS

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Efforts to create an artificial testis: culture systems of male germ cells under biochemical conditions resembling the seminiferous tubular biochemical environment

Induction of meiotic and post-meiotic alterations of male germ cells in vitro has been the target of several research efforts since 1960. However, to date, the establishment of an ideal culture system in which spermatogonial stem cells can be maintained and directed to proliferate and undergo meiosis and complete spermiogenesis does not exist. This is attributed to the difficulties concerning the isolation and purification of defined subpopulations of germ cells and the establishment of male germ cell lines. In addition, there is no adequate knowledge regarding the optimal biochemical conditions that promote the survival and differentiation of germ cells in long-term cultures. This review focuses on the methodologies that have been proved sufficient to achieve differentiation of cultured male germ cells. Furthermore, the factors regulating spermatogenesis and the technical prerequisites to achieve differentiation of cultured male germ cells are described. Finally, the role of in vitro cultures of immature diploid germ cells in the therapeutic management of men negative for haploid cells in their testes and the subsequent potential genetic and epigenetic risks are discussed.

Germ cell transplantation: a review and progress report on ICSI from spermatozoa generated in xenogeneic testes

Results from the transplantation of donor male germ cells into xenogeneic recipient seminiferous tubules indicate that donor spermatogonia are capable of differentiating to form spermatozoa morphologically characteristic of the donor species. Germ cell transplantation procedures combined with developments in freezing, culturing or enriching germ cell populations have applications of paramount importance in medicine, basic sciences and animal reproduction. Additionally, these techniques can serve as an alternative approach for gonadal protection and fertility preservation in patients with cancer. This article is a chronological critical review of the technological advances that followed the initial successful transplantation of mouse germ cells into recipient mice. Furthermore, the factors responsible for the immunological privilege properties of the testis and the parameters influencing the potential of mammalian germ cells to undergo mitosis and meiosis within a xenogeneic testis are described. Finally, the role of human germ cell transplantation procedures in the therapeutic management of non-obstructive azoospermia is discussed.

Use of a highly sensitive quantitative telomerase assay in intracytoplasmic sperm injection programmes for the treatment of 47,XXY non-mosaic Klinefelter men

We evaluated the role of the sensitive quantitative telomerase assay (SQTA) in the management of men with non-mosaic Klinefelter's syndrome (KS). Diagnostic testicular biopsy (DTB) was performed in 24 men with KS. A part of the DTB was stained and the remaining fragment was processed for the SQTA. After 3-18 months, a therapeutic testicular biopsy (TTB) was performed in the same testicle and the recovered specimens were processed to identify spermatozoa. Men with a SQTA outcome equal to 0.00 Units microg-1 protein (n = 7) demonstrated therapeutic testicular biopsy material that was negative for spermatogenic cells. In five men with a SQTA outcome of 8.11-38.03 Units microg-1, the most advanced germ cell was the spermatogonium/primary spermatocyte. In the remaining 12 men, the most advanced spermatogenic cell in the TTB was the spermatozoon. In these men, the SQTA outcome was equal to 25.76-92.68 Units microg-1 protein. Using 39.00 Units microg-1 protein as a cut-off value, the accuracy of the SQTA in identifying men positive for spermatozoa was 91.6%. It appears that the SQTA has a role for identifying non-mosaic KS men who have testicular spermatozoa.

Influence of sexual stimulation on sperm parameters in semen samples collected via masturbation from normozoospermic men or cryptozoospermic men participating in an assisted reproduction programme

To evaluate the influence of sexual stimulation via sexually stimulating videotaped visual images (VIM) on sperm function, two semen samples were collected from each of 19 normozoospermic men via masturbation with VIM. Two additional samples were collected from each man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, percentage of morphologically normal spermatozoa, outcome of hypo-osmotic swelling test and zona-free hamster oocyte sperm penetration assay, and markers of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM than masturbation without VIM. The improved sperm parameters in the samples collected via masturbation with VIM may reflect an enhanced prostatic secretory function and increased loading of the vas deferens at that time. In a similar protocol, two semen samples were collected via masturbation with VIM from each of 22 non-obstructed azoospermic men. Semen samples from these men had been occasionally positive in the past for a very small number of spermatozoa (cryptozoospermic men). Two additional samples were collected from each cryptozoospermic man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, and a marker of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM. Fourteen out of the 22 men were negative for spermatozoa in both samples collected via masturbation without VIM. These men demonstrated spermatozoa in both samples collected via masturbation with VIM. Six men with immotile spermatozoa in both samples collected via masturbation without VIM exposed motile spermatozoa in both samples collected via masturbation with VIM. High sexual stimulation during masturbation with VIM results in recovery of spermatozoa of greater fertilizing potential both in normozoospermic and cryptozoospermic men. The appearance of spermatozoa after masturbation with VIM in the vast majority of cryptozoospermic men is of clinical significance in programmes applying intracytoplasmic sperm injections for the management of severe male infertility and obviates the need for testicular biopsy.

Highly sensitive quantitative telomerase assay of diagnostic testicular biopsy material predicts the presence of haploid spermatogenic cells in therapeutic testicular biopsy in men with Sertoli cell-only syndrome

The role of a telomerase assay in the recognition of Sertoli cell-only syndrome with testicular foci of haploid cells was evaluated. Men with Sertoli cell-only syndrome (n = 23) were given a new diagnostic testicular biopsy. Part of the biopsy was stained and the remainder was processed for the quantitative telomerase assay. After 3-13 months, a therapeutic testicular biopsy was performed. This material was minced and then examined using confocal laser scanning microscopy and fluorescent in-situ hybridization. Histology of diagnostic testicular biopsy material confirmed the diagnosis of Sertoli cell-only syndrome in all the participants. All seven men with a telomerase assay value in their diagnostic testicular biopsy of >42 total product generated (TPG) U/microg protein had haploid cells (i.e. spermatozoa and/or spermatids) in their therapeutic testicular biopsy. Among participants with telomerase assay values <42 TPG U/microg protein, only one man had haploid cells in his therapeutic testicular biopsy. Thus, telomerase assay values >42 TPG U/microg protein in the diagnostic biopsy identified 87.5% of the Sertoli cell-only syndrome men with haploid cells in their therapeutic testicular biopsy. Significantly higher values of the telomerase assay were found in men with testicular foci of haploid cells than in men without these foci. The use of a quantitative telomerase assay biopsy appears to be important for identifying those men with Sertoli cell-only syndrome who have foci of haploid cells and can be candidates for assisted reproduction techniques.

Nitric oxide-dependent vasodilator mechanism is not impaired by hypertension but is diminished with aging in the rat aorta

This study was designed to elucidate the effects of hypertension and aging on nitric oxide (NO)-mediated relaxation response to acetylcholine in the rat aorta. NO-mediated relaxation response was assessed as the relaxation response to acetylcholine after treatment with cyclooxygenase inhibitor in KCl-precontracted aortic rings. The endothelium-dependent relaxation responses to acetylcholine were lower in aortic rings isolated from spontaneously hypertensive rats (SHRs) at ages 16-20 and 55-60 weeks compared with those seen in age-matched Wistar-Kyoto (WKY) rats. Aging induced a reduction of the relaxation response to acetylcholine in aortic rings from WKY rats but not from SHRs. Pretreatment with indomethacin enhanced the relaxation response to acetylcholine in only SHRs at ages 16-20 and 55-60 weeks, thereby cancelling the difference in the relaxation response between WKY rats and SHRs. Simultaneous administration of indomethacin and NG-nitro-L-arginine methyl ester abolished the relaxation response to acetylcholine in both strains. Thus NO-mediated relaxation response to acetylcholine was similar between WKY rats and SHRs at ages 16-20 and 55-60 weeks, respectively, and was attenuated with aging to the same degree in both strains. In conclusion, NO-mediated relaxation response to acetylcholine in the aorta is attenuated with aging but not impaired by hypertension.

Ooplasmic injection of elongating spermatids for the treatment of non-obstructive azoospermia

We applied the technique of ooplasmic elongating spermatid injection to the treatment of non-obstructive azoospermia. Mature oocytes were injected with elongating spermatids isolated from testicular biopsy material obtained from 13 non-obstructed azoospermic men. Seventy-three oocytes were successfully injected with elongating spermatids and were then cultured for 36 h. At 13 h post-injection 68 oocytes were found to be activated and 52 of them were fertilized. Forty-one 2- to 4-cell stage embryos developed from normally fertilized oocytes were transferred. At least two embryos were transferred to each female partner. Two pregnancies were achieved. Elongating spermatid injection may have a role in the treatment of non-obstructive azoospermia.

Oxidized LDLs but not native LDLs augment Ba2+ currents through L-type Ca2+ channels of the A7r5 smooth muscle-derived cell line

The whole-cell patch-clamp method was used on A7r5 smooth muscle-derived cell line, and Ba2+ currents through Ca2+ channels were recorded. The A7r5 cells showed voltage-dependent, long-lasting Ba2+ currents which were markedly inhibited by nifedipine (10 microM). The magnitude of the maximum Ba2+ current (IBa(max)) was augmented by an application of dbcAMP (1 mM), but not affected by TPA (80 nM). Noradrenaline (NA) at 100 microM caused an increase in the IBa(max) by 19.7% in the presence of phentolamine (10 microM). This effect was cancelled by Rp-cAMPs (10 microM). In the presence of propranolol (10 microM), NA tended to reduce the IBa(max). Application of Ox-LDLs at 100 microg protein/ml caused an increase in the IBa(max) by 15.7%, whereas native LDLs did not change the IBa(max). Rp-cAMPs was ineffective to the Ox-LDL action on the IBa(max). In the presence of Ox-LDLs, NA augmented the IBa(max) by 21.4% in the presence of phentolamine. These results suggest that Ox-LDLs activate L-type Ca2+ channels of A7r5 cells by a mechanism independent of cAMP/PKA signalling.

Differentiation and morphogenesis in pellet cultures of developing rat retinal cells

We previously developed a reaggregate cell culture system (pellet cultures) in which retinal neuroepithelial cells proliferate and give rise to rod photoreceptor cells (rods) in vitro (Watanabe and Raff, 1990, Neuron 4:461-467). In the present study, we analyzed cell differentiation and morphogenesis in pellet cultures by using both cell-type-specific markers with immunofluorescence and electron microscopy. We demonstrated that, in addition to rods, the other major retinal cell types, including amacrine cells, bipolar cells, Müller cells, and ganglion cells were all present in the pellets, where most were able to develop from dividing precursor cells in vitro. The different cell types in the pellets became organized into two distinct structures: dark rosettes and pale rosettes. The cellular composition of these structures indicated that the dark rosettes correspond to the outer nuclear layer and the pale rosettes to the inner nuclear layer of the normal retina. Ultrastructural studies have indicated that the thin layer of neuronal processes surrounding the dark rosettes correspond to the outer plexiform layer, and the central region of the pale rosettes correspond to the inner plexiform layer of the normal retina. Other features of normal retinal development also occurred in the pellets, including programmed cell death and the formation of inner and outer rod cell segments and synapses. Thus, pellet cultures provide a convenient way to study different aspects of retinal development where one can control the size and the cellular composition of the initial reaggregate.

Congenital chylothorax in a patient with 21 trisomy syndrome

A female infant with 21 trisomy syndrome associated with congenital chylothorax was reported. She was born at a gestational age of 34 weeks by Cesarean section because of fetal hydrothorax and hydrops fetus, confirmed by ultrasonography at 32 weeks. Emergent resuscitation and immediate thoracentesis were performed soon after birth. After beginning breast feeding, the serous pleural fluid became opalescent and a diagnosis of congenital chylothorax was made. Feeding was changed to medium-chain triglyceride (MCT) feeding and the production of pleural effusion disappeared after thoracentesis was performed several times. Accumulating evidence suggested that MCT feeding and intermittent thoracentesis under echo guide were effective. Some reports on patients, including this one, suggest that there may be more patients with 21 trisomy associated with congenital hydrothorax. Therefore, congenital hydrothorax might be listed as a complication of 21 trisomy.

Excitatory and inhibitory actions of norepinephrine on the Ba2+ current through L-type Ca2+ channels of smooth muscle cells of guinea-pig vas deferens

The effect of norepinephrine (NE) was examined on the whole-cell Ba2+ current through L-type Ca2+ channels of freshly isolated smooth muscle cells of guinea-pig vas deferens. The magnitude of maximum Ba2+ current [1Ba(max)] varied in different cells, although the capacitance of the cell membrane was similar (approximately 50 pF). Application of dbcAMP augmented 1Ba(max) by 37%, which was canceled by Rp-cAMPs, while PMA decreased the current by 32%, which was canceled by staurosporine. NE increased 1Ba(max) of the cells which originally showed relatively small 1Ba(max), and decreased the current of the cells which showed larger 1Ba(max). In the presence of phentolamine, NE increased 1Ba(max), and this effect was remarkable in cells showed smaller 1Ba(max). In the presence of propranolol, NE decreased 1Ba(max). The excitatory beta-adrenoceptor activation was canceled by Rp-cAMPs, and the inhibitory alpha-adrenoceptor effect was canceled by staurosporine. It is suggested that NE shows dual (excitatory and inhibitory) actions on the L-type Ca2+ channels of smooth muscle of guinea-pig vas deferens. The excitatory beta-adrenoceptor action mediated through cAMP/PKA is predominant in cells with lower density of the Ca2+ channels, while inhibitory alpha-adrenoceptor action mediated through PKC is predominant in cells with higher channel density.

Role of extracellular Ca2+ in acetylcholine-induced repetitive Ca2+ release in submandibular gland acinar cells of the rat

Acetylcholine (ACh) caused repetitive transient Cl- currents activated by intracellular Ca2+ in single rat submandibular grand acinar cells. As the concentration of ACh increased the amplitude and the frequency of the transient Cl- currents increased. These responses occurred also in the absence of extracellular Ca2+ but disappeared after several minutes. Repetitive transient Cl- currents were restored by readmission of Ca2+ to the extracellular solution. The higher the concentration of extracellular Ca2+ readmitted, the larger the amplitude of the transient Cl- currents. Ca2+ entry through a store-coupled pathway was detected by application of Ca2+ to the extracellular solution during a brief cessation of stimulation with ACh. In these experiments too, the higher the concentration of Ca2+, the larger the transient Cl- currents activated by Ca2+ released from the stores. The time course of decrease in total charge movements of repetitive transient responses to ACh with removal of extracellular Ca2+ depended on a decrease in charge movements of each transient event rather than a decrease in frequency of the repetitive events. The decrease of charge movements of each transient event was due to a decrease in its amplitude rather than its duration. The results suggest that in this cell type and amplitude-modulated mechanism is involved in repetitive Ca2+ release and that Ca2+ entry is essential to maintain the repetitive release of Ca2+. The results further suggest that the magnitude of Ca2+ entry determines the number of unitary stores filled with Ca2+ which can synchronously respond to ACh.

Altering the timing of human chorionic gonadotropin injection according to serum progesterone (P) concentrations improves embryo quality in cycles with subtle P rise

OBJECTIVE

To investigate the effect of earlier administration of hCG according to serum concentrations of P on the outcome of IVF-ET in cycles in which a subtle rise in serum P (1.0 to 2.0 ng/mL; conversion factor to SI unit, 3.180) occurred during the follicular phase.

DESIGN

Retrospective study.

PATIENTS

A total of 110 infertile women underwent 124 cycles of IVF-ET at Tottori University Hospital.

MAIN OUTCOME MEASURES

Serum was obtained daily or every 12 hours from day 7 until the administration of hCG. Serum E2 and P concentrations were measured by RIA. In 19 of 36 subtle P rise cycles, hCG injection was given when the levels of serum P exceeded 1.0 ng/mL ("rescued" subtle P rise). Parameters of IVF outcomes for the no P rise, the subtle P rise, and the rescued subtle P rise cycles were compared.

RESULTS

The mean day of hCG administration in the rescued cycles was 1 day earlier than those of the subtle P rise and no P rise cycles. The mean number of oocytes collected was significantly higher in the subtle P rise and rescued P rise cycles than in the no P rise cycles. The mean follicular diameter on the day of hCG administration was 13.9 mm in the rescued cycles, significantly smaller than those of the no P rise and subtle P rise cycles. However, there was no significant difference in the cleavage rates between the three groups. The rate of embryonic development beyond four-cell stage was increased significantly in the rescued cycles and no P rise cycles versus the subtle P rise cycles. Embryos obtained in the no P rise and rescued cycles were of better morphological quality than those obtained in the P rise cycles. The implantation rate was significantly higher in the rescued cycles than in the P rise cycles.

CONCLUSION

The data suggest that, if hCG is administered when a subtle P rise is detected, embryo quality and subsequent implantation rate can be improved.

Ca2+ entry through the store-mediated pathway directly activates only the K+ current but the subsequent Ca2+ release from the store activates both K+ and Cl- currents in submandibular gland acinar cells of the rat

The store-mediated Ca2+ entry was detected in single and cluster of rat submandibular acinar cells by measuring the Ca2+ activated ionic membrane currents. In the cells where intracellular Ca2+ was partly depleted by stimulation with submaximal concentration of acetylcholine (ACh) under a Ca2(+)-free extracellular condition, an employment of external Ca2+ in the absence of ACh caused a sustained increase of the K+ current without affecting the Cl- current. A renewed ACh challenge without external Ca2+ caused repetitive spikes of both K+ and Cl- currents due to the Ca2+ release. SK & F 96365 inhibited the generation of the sustained K+ current and refilling of the Ca2+ store following the Ca2+ readmission. It is suggested that the Ca2+ enters the cell through the store-mediated pathway new the K+ channels and is taken up by the store. Thus, only Ca2+ released from the store can activate both the K+ and Cl- currents.

Reduced implantation rate associated with a subtle rise in serum progesterone concentration during the follicular phase of cycles stimulated with a combination of a gonadotrophin-releasing hormone agonist and gonadotrophin

Our objective was to assess the effects of subtle increases in serum progesterone concentration (1.0-2.0 ng/ml) on the outcome of in-vitro fertilization (IVF), particularly on the quality of embryos, during the follicular phase of cycles stimulated with gonadotrophin-releasing hormone agonist (GnRHa) and human menopausal gonadotrophin (HMG). A total of 97 patients underwent 116 cycles of IVF and were stimulated with a combination of HMG and GnRHa. They were divided into two groups: those with a subtle progesterone rise and those with no progesterone rise. The two groups were compared with respect to serum oestradiol, progesterone, immunoreactive luteinizing hormone (I-LH), bioactive LH (B-LH), and results of IVF. The groups did not differ significantly in mean age or in total dose of HMG received. On the day that human chorionic gonadotrophin was administered, concentrations of oestradiol and progesterone were significantly higher in the subtle progesterone rise cycles than in the no progesterone rise cycles. In the no progesterone rise cycles, the percentages for embryos beyond the 4-cell stage, grade 1 embryos, and implantation rates were significantly higher than those in subtle progesterone rise cycles. The combination of GnRHa and HMG eliminated any significant rise in serum I-LH or B-LH concentration during the follicular phase, but did not suppress the subtle rise in progesterone. These results confirm our previous finding that a subtle progesterone rise adversely affects the outcome of IVF. It is also suggested that a reduction in embryo quality may influence the lower rate of implantation in subtle progesterone rise cycles.

Stimulated Ca2+ entry activates Cl- currents after releasing Ca2+ from the intracellular store in submandibular gland cells of the rat

In order to examine whether Ca2+ entry is directly involved in controlling exocrine secretion, the Ca(2+)-activated Cl- currents were recorded in single and clusters of rat submandibular gland cells using the whole-cell patch-clamp method. Extracellularly applied acetylcholine (ACh, 10 nM) as well as intracellularly applied GTP gamma S and InsP3 caused repetitive transients of the Cl- currents activated by intracellular Ca2+. These responses occurred also in the absence of external Ca2+, but disappeared after several minutes. Readmission of Ca2+ to the extracellular solution restored the repetitive current transients, while introduction of Sr2+ failed to restore the current signals in spite of the presence of Sr2+ entry detected by microfluorimetry. On the other hand, direct application of Sr2+ to the cell inside caused activation of the Cl- currents although less effectively than Ca2+. When Ca2+ was introduced to the extracellular solution during an interruption of ACh stimulation after the ACh-induced depletion of intracellular Ca2+ store, the Cl- current was not elicited. However, a subsequent challenge with ACh at the same concentration in the absence of extracellular Ca2+ caused repetitive transient Cl- currents. The results suggest that in this cell type the stimulated Ca2+ entry does not by itself activate the Cl- currents but activates them indirectly by triggering Ca2+ release from the intracellular Ca2+ store which may take up Ca2+ soon after the Ca2+ entry.

GLUT2 expression in the rat retina: localization at the apical ends of Müller cells

In order to understand the molecular basis of glucose regulation supporting visual function, this study examined the presence of GLUT2, a facilitated-diffusion glucose transporter isoform, and delineated its localization in the rat retina. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated the presence of GLUT2 mRNA, and immunoblot analysis using polyclonal antibody specific to rat GLUT2 revealed a band at a molecular weight of approximately 60 kDa, indicating the presence of GLUT2 protein in the rat retina. Fluorescence and electron microscopy localized GLUT2 expression to the apical ends of Müller cells that face the inter-photoreceptor space. These findings suggest that GLUT2 on Müller cells may control intra-retinal glucose homeostasis by performing both anterior and posterior glucose transport within the rat retina. This is the first study to provide evidence that GLUT2 is present in the mammalian central nervous system and indicates that GLUT2 may have local glucose homeostatic functions within the retina in addition to its role in the regulation of systemic blood glucose level.

Assessment of functional integrity of frozen-thawed mouse embryos by albumin and leucine uptake

To assess the effects of freezing-thawing on metabolic functions of embryos prior to implantation, we measured the uptake of [125I]bovine serum albumin (BSA) and [3H]leucine in 2-cell mouse embryos, that were freshly collected (control), exposed to cryoprotectants (non-frozen), and frozen-thawed, and in morulae and blastocysts cultured from these 2-cell embryos. No significant difference in [125I]BSA uptake by 2-cell embryos was observed among the three groups. However, [125I]BSA uptake by blastocysts in the frozen-thawed group was significantly reduced compared with the control and non-frozen groups. [3H]leucine uptake by 2-cell embryos in the frozen-thawed and non-frozen groups was significantly less than in the control group. Fluorescein diacetate staining was performed in the control and frozen-thawed 2-cell embryos. The intensity of fluorescence after fluorescein diacetate exposure did not differ between the control and frozen-thawed embryos. The present study with mouse embryos suggests that freezing-thawing procedures impair the metabolic functions, in particular the membrane transport system, of embryos. Measurements of BSA and leucine uptake in embryos may be useful for evaluating the quality of frozen-thawed embryos.

Measurement of uptake and incorporation of nucleic acid precursors by preimplantation mouse embryos after development in vivo and in vitro

PURPOSE

To assay DNA and RNA synthesis by developing mouse embryos in vitro and in vivo, we measured the uptake and incorporation of 3H-thymidine and 3H-uridine by morulae and blastocysts. We also evaluated the effect of adding EDTA to the culture medium on the uptake and incorporation of nucleic acid precursors by blastocysts.

RESULTS

Thymidine and uridine incorporation increased after morulae developed into early blastocysts both in vitro and in vivo. However, the rates of uptake and incorporation were significantly lower by embryos grown in vitro than by those grown in vivo. The ratios of incorporation to total uptake were similar in embryos grown in vitro and in vivo. EDTA (100 microM) added to the culture medium significantly increased the incorporation of uridine into RNA by blastocysts grown in vitro (P < 0.01) but did not increase the total uptake of uridine.

CONCLUSION

These observations showed that both DNA and RNA synthesis increased during the early development of preimplantation embryos and that those activities were reduced in embryos undergoing development in vitro. The results also suggested that through the mechanism of EDTA effect in embryo culture remains unknown, it appeared to reduce the retardation of RNA synthesis by embryos cultured in vitro through a selective stimulation of uridine incorporation.

The importance of the hypoosmotic swelling test and acrosin activity assay for identifying subpopulations of idiopathic infertile men

Semen samples collected from fertile donors (n = 13) and pooled samples from idiopathic infertile men (n = 19) were used in this study. Measurements of the total sperm acrosin activity and the hypoosmotic swelling test (HOST) were performed in all the samples. The percentage of swollen spermatozoa and acrosin profiles were significantly lower in the infertile men than in the fertile donors. Considering the lowest values of the outcome of the HOST and the acrosin activity assay in the group of fertile men as the lowest normal values, it was proven that HOST and acrosin activity assay could identify subpopulations of infertile men of 37 and 26%, respectively. The results tend to support the employment of the HOST and the acrosin activity assay in the evaluation of idiopathic infertile men.

Evaluation of measurement of fetal crown-rump length from ultrasonically timed ovulation and fertilization in vitro

To assess with accuracy the development and maturity of the fetus, we evaluated fetal growth in 46 pregnant women who had conceived subsequent to ultrasonically timed ovulation. Fetal crown-rump length (CRL) was measured at gestational ages that differed by about 1 day from those previously reported. The variance in CRL measurements at each gestational age was small, and the data were normally distributed. The CRL growth curves of this and previous studies were tested using measurements from 7 pregnancies derived from in vitro fertilization (IVF). The data from IVF pregnancies were consistent with our curve, having 1 day difference to those previously reported. The gender of the fetus did not influence the CRL during the first trimester. The results suggest that fetal growth is uniform during the first trimester.

Subtle rise in serum progesterone during the follicular phase as a predictor of the outcome of in vitro fertilization

OBJECTIVE

To investigate the effects of subtle rises in serum progesterone (P) during the follicular phase on the outcome of in vitro fertilization and embryo transfer (IVF-ET).

DESIGN, PATIENTS

One hundred one patients underwent IVF-ET for 170 cycles and were stimulated with a combination of clomiphene citrate and human menopausal gonadotropin. Based on their hormonal data, we divided the patients into two groups: those who had a cycle with an increase in serum P concentration (1.0 to 2.0 ng/mL) that was not associated with a pituitary LH release (subtle P rise) and those who had a cycle without any increase in serum P concentration (no P rise).

MAIN OUTCOME MEASURES

The daily serum estradiol (E2) concentration and the results of IVF-ET (number of developed and collected oocytes, rates of mature oocytes, fertilization, and pregnancy) were compared between the two groups.

RESULTS

Subtle P rises were observed in 31.7% (32/101) of the patients and 20.5% (36/170) of the cycles evaluated during the IVF-ET programs. A significantly higher serum E2 concentration (P less than 0.001) and a greater number of developed and collected oocytes (P less than 0.001 and P less than 0.05, respectively) also were observed in those cycles with a subtle P rise. The rates of mature oocyte formation and fertilization were significantly lower in cycles with a subtle P rise (P less than 0.001 and P less than 0.05, respectively). A lower pregnancy rate was observed in cycles with a subtle P rise, and all 12 ongoing pregnancies occurred only in cycles with a no P rise.

CONCLUSION

These results suggest that the development of an increased number of follicles may not necessarily improve the outcome of IVF-ET and that the measurement of serum P may be a better predictor for successful pregnancy.

Luteinized unruptured follicle in the early stages of endometriosis as a cause of unexplained infertility

OBJECTIVE

We attempted to clarify the relationship between luteinized unruptured follicle, which occurs in the early stages of endometriosis, and unexplained infertility.

STUDY DESIGN

Seventy patients who had unexplained infertility were reviewed.

RESULTS

Laparoscopic examination showed that 47 patients (67%) had endometriosis; of these, 40 (85%) had minimal or mild disease. The incidence of luteinized unruptured follicle was higher (p < 0.05) in patients who had endometriosis (35%/patient and 25%/cycle) compared with patients who did not have endometriosis (11%/patient and 7%/cycle). Degenerated oocyte cumuli were collected in 6 (43%) of 14 luteinized unruptured follicles diagnosed by transvaginal ultrasound.

CONCLUSIONS

These results show that luteinized unruptured follicle is common in patients who have mild or minimal endometriosis and that it may be one of the causes of endometriosis-associated infertility. Transvaginal ultrasound-guided follicular puncture of luteinized unruptured follicle during the mid luteal phase may be useful in establishing a definitive diagnosis of luteinized unruptured follicle.