Association of pronuclear Z score with rates of aneuploidy in in vitro-fertilised embryos.

The present study aimed to correlate the Z-scoring system to outcomes in in vitro fertilisation (IVF) cycles performed in conjunction with preimplantation genetic diagnosis. In 178 cycles, a total of 468 pronuclear embryos was scored prospectively using the Z score before culture and biopsy on Day 3 to detect chromosomes 13, 16, 18, 21, 22, X and Y. The results showed significant differences between Z1 and Z4 scoring embryos, with Z1 giving an increased biopsy rate (83.3% v. 51.1%), embryo quality (> or = fair: 83.3% v. 57.8%) and embryo growth rate (> or = six cells: 87.0% v. 44.4%). The incidence of chromosomally normal embryos decreased from Z1 to Z4 (Z1: 40%; Z2: 29.7%; Z3: 22.7%; Z4: 13.6%; P < 0.04). Thus, the Z scoring, mainly Z1 and Z4, correlated significantly with the expected embryo outcomes and preimplantation genetic diagnosis findings. Further improvement of pronuclear scoring with the use of a two-stage assessment is proposed.

A study failing to determine significant benefits from assisted hatching: patients selected for advanced age, zonal thickness of embryos, and previous failed attempts.

PURPOSE: Pregnancy and implantation rates after mechanical assisted hatching (AH) in patients aged > or = 38 years, with embryos > or = 15 microns in zonal thickness and two or more failed attempts, were assessed at two infertility centers using fresh and frozen embryo transfer (FET) cycles. METHODS: AH was performed on 3-day-old embryos. Spare embryos cryopreserved at the two-pronucleus stage were subjected to AH after 2 days of culture and transferred to artificially prepared uteri. RESULTS: In fresh cycles, no significant differences in pregnancy rates (clinical and ongoing) and implantation rates were observed between the AH and the controls for all three selected patient groups (Centers 1 and 2). In FET cycles, AH tended to give poor results for > or = 38 year olds (clinical pregnancy rates of 0 and 5.0% with AH vs 13.3 and 16.7% for controls at Centers 1 and 2, respectively). With AH, embryos with thick zonae implanted to the same extent as those in the control group and achieved pregnancies for patients with multiple failures (four to six attempts for some) in both fresh and FET cycles. CONCLUSIONS: AH failed to show significant benefits in all three patient groups. A larger study group may confirm the effects of AH on frozen/thawed embryos and outcomes for multiple failure cases.

Cytogenetic analysis of unfertilized oocytes following intracytoplasmic sperm injection using spermatozoa from a globozoospermic man.

A man with globozoospermia was treated in our in-vitro fertilization-intracytoplasmic sperm injection (ICSI) programme. In the treatment cycle, 24 oocytes were collected from his wife. All the oocytes were at metaphase II stage. The semen sample produced on the day had a normal sperm count, good motility, but with 100% globozoospermia. All oocytes were injected with randomly selected spermatozoa and of these, two oocytes showed two pronuclei and another contained a single pronucleus. The remainder were unfertilized. The normally fertilized oocytes (two pronuclear) cleaved to the four-cell stage and were transferred to the patient. At 48 h after ICSI, the 21 unfertilized oocytes were processed for cytogenetic analysis. All oocytes contained a haploid chromosome set. The only abnormality seen was a chromosome fragment in one metaphase. Eighteen oocytes contained decondensed sperm nuclei and of these, 14 nuclei were beginning to show signs of premature chromatin condensation (PCC) and the other four showed strong signs of PCC. Thus it appears that in some forms of globozoospermia, arrest of nuclear decondensation and/or PCC are another cause of fertilization failure. The most likely cause for this is the absence or down-regulation of spermatozoa associated activating factor in round-headed spermatozoa.

Evidence that male smoking affects the likelihood of a pregnancy following IVF treatment: application of the modified cumulative embryo score.

Female cigarette smoking has been implicated as having a detrimental effect on in-vitro fertilization (IVF) outcomes mediated through: (i) a diminished ovarian reserve (DOR), and (ii) an elevated pregnancy loss. Research is sparse regarding the effect of male smoking. The objective of this retrospective cohort study was to investigate the effect of male and female smoking on: (i) the collective quality of embryos selected for uterine transfer, and (ii) the likelihood of achieving an ongoing pregnancy at 12 weeks. A total of 498 consecutive IVF treatment cycles were analysed. Female smokers were significantly younger (P < 0.05) and achieved a better modified cumulative embryo score (mCES) (P < 0.05) than female non-smokers. Female age correlated inversely with the number of oocytes collected (r = -0.42, P < 0.01) and the number of oocytes in turn was important in terms of predicting mCES. The decreasing number of oocytes aspirated with increasing age was of a significantly stronger magnitude for female smokers than for female non-smokers (P < 0.05). Multiple logistic regression was used to determine whether smoking affected the likelihood of achieving a 12-week pregnancy. The mCES, tubal infertility and male smoking were found to be significant. Male smoking interacted with male age (P = 0.0164), indicating for male smokers a decrease of 2.4% in the likelihood of achieving a 12-week pregnancy with every 1-year increase in age. This is the first study to show that male smoking has a deleterious effect on pregnancy outcome among IVF patients. Our study supports the increased risk of DOR but fails to support the elevated incidence of pregnancy loss among female smokers. A reduced pregnancy rate was associated with male smoking possibly through pre-zygotic genetic damage. The growing realization of a paternal component of reproductive impairment suggests that studying the male is necessary.

Cryopreservation of oocytes and embryos: use of a mouse model to investigate effects upon zona hardness and formulate treatment strategies in an in-vitro fertilization programme.

Mouse oocytes and embryos were obtained following ovulation induction of (C57B16 x CBA) F1 animals. Zonae pellucidae were exposed to alpha-chymotrypsin in phosphate-buffered medium (PB1) supplemented with 3 mg/ml bovine serum albumin upon a heated stage (37 degrees C) and were observed constantly through an inverted microscope. The endpoint of the bioassay was the limits of the zona no longer being seen clearly at x 200 magnification, and the time taken for each zona to dissolve was recorded. A dose-dependent response in dissolution time was clearly seen, with 1% alpha-chymotrypsin being chosen as the routine working solution. Cryopreservation of 2-cell mouse embryos using propanediol did not cause zona hardening but induced a small and significant softening, as gauged by the time taken for zona dissolution (2181 +/- 167 versus 1864 +/- 82 s). Zona hardening was not suspected to occur after the freezing of human embryos as there was no difference in implantation rates per embryo for in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles between fresh [IVF: 63/644 (9.7%); ICSI: 51/330 (15.5%)] and frozen embryos [IVF: 36/458 (7.9%); ICSI: 18/112 (16.1%)]. Conversely, significant hardening of the zonae of mature oocytes was seen following cryopreservation (747 +/- 393 s) compared with freshly ovulated oocytes (151 +/- 68 s). It is concluded that (i) the freezing of murine oocytes with propanediol results in zona hardening, implying a possible benefit of ICSI after the cryopreservation of human oocytes, and (ii) the cryopreservation of embryos is not associated with zona hardening or reduced implantation, making microdissection of the zona in such cases generally unwarranted.

Birth from cryopreserved embryos following in-vitro maturation of oocytes and intracytoplasmic sperm injection.

This case report describes the birth of a baby following the transfer of cryopreserved embryos generated from intracytoplasmic sperm injection (ICSI) carried out on the second day after oocyte pick-up of in-vitro-matured metaphase I and germinal vesicle stage oocytes. The couple had a history of three failed intrauterine insemination attempts and reduced fertilization rates in two previous in-vitro fertilization (IVF) cycles. In the IVF-ICSI treatment cycle, 6/11 mature oocytes became fertilized following ICSI on the first day. However, the patient failed to conceive following the transfer of three embryos. Five oocytes were immature (two at metaphase I stage and three with a germinal vesicle) and these were cultured overnight. All had extruded a polar body by the following day and ICSI was therefore performed; four oocytes became fertilized, and were cryopreserved at the pronulear stage in propanediol. In the next treatment cycle, transfer of frozen embryos was planned. The pronuclear zygotes were thawed and cultured for 24 h prior to the transfer of two embryos in a cycle stimulated with low doses of follicle stimulating hormone. This resulted in a pregnancy and the delivery of a healthy baby boy. In-vitro maturation of metaphase I and germinal vesicle oocytes which are routinely collected in IVF-ICSI cycles, followed by second day ICSI fertilization, may provide a valuable source of embryos for infertile couples.

Cytogenetic abnormalities of unfertilized oocytes generated from in-vitro fertilization and intracytoplasmic sperm injection: a double-blind study.

In the present study we have assessed the cytogenetic abnormalities of unfertilized oocytes from in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) programmes during a one year period (July 1995 to July 1996) with the cytogenetic analysis being carried out in a double-blind manner. A total of 88 unfertilized ICSI and 85 unfertilized IVF oocytes were used for the study and of these 51 and 62 oocytes, in each respective group, were suitable for analysis. The haploidy, diploidy and aneuploidy rates between ICSI (62.7, 7.8 and 5.9%) and IVF (61.3, 9.7 and 14.5%) groups were similar. A significant inter-patient variation in the incidence of hypohaploidy was observed within the IVF group. Chromosomal fragmentation or breakage was observed at a similar rate in both groups of unfertilized oocytes (23.5 and 14.5% for ICSI and IVF respectively). A significantly higher proportion of ICSI oocytes contained sperm nuclei (27/51, 52.9%) than did IVF oocytes (20/62, 32.3%, P < 0.01). The distribution and state of sperm head chromatin in relation to oocyte chromosomal complement was studied in both groups. ICSI oocytes contained decondensed or swollen sperm nuclei in association with haploid oocyte chromosomes (12/27, 44.4%) or condensed sperm heads in oocytes showing no chromosomal complements (7/27, 25.9%). In IVF oocytes sperm heads were either arrested in the condensed state (5/20, 25%), metaphase stage (3/20, 15%) or had undergone premature chromosome condensation (PCC; 6/20, 30%) in association with haploid oocyte chromosomes. The incidence of PCC was similar in the two groups. A marked variation in the incidence of total chromosomal abnormality was observed between patients within both ICSI (0-75%) and IVF (0-71%) groups indicating a possible similarity in oocyte quality between the majority of male factor and tubal infertility patients. The type of sperm used in the two fertilization procedures showed an increased incidence of chromosomal breakage with ICSI-MESA (microepididymal sperm aspiration) spermatozoa (4/6, 67%) compared to the ICSI-ejaculated (6/35, 17.1%; P < 0.05), ICSI-testicular biopsy (2/10, 20%) and IVF-normospermic (9/62, 14.5%; P < 0.01) spermatozoa. Chromosomal fragmentation may be associated with the degree of difficulty experienced at sperm injection, especially with sperm retrieved from the reproductive tract. Thus chromosomal fragmentation in ICSI may need further investigation using a larger sample size in order to assess the possible causative factors.

Changes in motility patterns during in-vitro culture of fresh and frozen/thawed testicular and epididymal spermatozoa: implications for planning treatment by intracytoplasmic sperm injection.

The present report describes the motility changes in vitro (percentage motile and progressively motile) of freshly collected testicular and epididymal spermatozoa and following freeze/thaw of the same spermatozoa from a man with obstructive azoospermia. Washed spermatozoa were cultured in micro droplets under paraffin oil or in test tubes using HEPES-buffered or bicarbonate-buffered medium containing 10% human serum. In fresh testicular sperm cultures 60-65% of the sperm cells became motile within 2 days of culture; the motility was maintained for a further 4-5 days before a decline was observed. The progressive motility improved markedly on the third day of culture and it peaked around day 5. Only a small number of frozen/thawed testicular spermatozoa became motile during in-vitro culture (15-20%) and the motility was maintained for only 2-3 days before it declined. Furthermore, only 10-12% of the spermatozoa showed progressive motility. Spermatozoa recovered from micro-epididymal sperm aspiration (MESA) showed a gradual decrease in progressive motility and in 5 days all sperm cells were found to be immotile in both freshly collected and frozen/thawed spermatozoa. All culture systems supported sperm motility. It is clear that testicular spermatozoa, particularly from men with obstructive azoospermia, can be collected and maintained in vitro for up to 1 week before the oocyte retrieval but when frozen testicular or epididymal spermatozoa are used it is more reliable to thaw these spermatozoa on the day of intracytoplasmic sperm injection.

Trophoblast antigen levels in the first trimester of a trisomy 22 pregnancy.

We report trophoblast antigen (pregnancy-associated plasma protein-A, PAPP-A; free beta-human chorionic gonadotrophin, F beta hCG) expression in a trimosy 22 pregnancy. Maternal concentrations of these antigens were depressed prior to detection of abnormalities by ultrasonography. Immunohistochemical findings were consistent with depressed marker expression.

An argument for the past and continued use of pentoxifylline in assisted reproductive technology.

Pentoxifylline was first used within an in-vitro fertilization (IVF) programme before the advent of alternative treatment strategies such as oocyte micromanipulation. Over the years, it has continued to be useful in aiding fertilization in selected IVF cases, with a beneficial effect also being seen in certain cases treated by intrauterine insemination. In both instances, the acrosome reaction to ionophore challenge test appears to have been invaluable in identifying suitable patients. The stimulation of spermatozoa by pentoxifylline should remain a therapeutic option in the treatment of couples with a male factor present. As an adjunct to IVF, it has the advantage of being simpler and less costly to perform compared with micromanipulation. However, its use should be restricted to selected cases, and the merits over and above those of invasive procedures such as intracytoplasmic sperm injection should be discussed with the individual patients. The pretreatment of spermatozoa prior to intrauterine insemination in selected cases gives an alternative therapeutic strategy to those patients not wishing or unable to undertake IVF.

Sperm stimulants can improve fertilization rates in male-factor cases undergoing IVF to the same extent as micromanipulation by partial zona dissection (PZD) or subzonal sperm insemination (SUZI): a randomized controlled study.

PURPOSE: Our purpose was to evaluate the efficacy of direct insemination (IVF), micromanipulation by partial zona dissection (PZD), and subzonal sperm insemination (SUZI) using sperm-treated with pentoxifylline (PF) +/- 2-deoxyadenosine (2DA). RESULTS: The overall fertilization rate achieved was similar for all three fertilization techniques (33.1, 30.2, and 26.9% for IVF, SUZI, and PZD, respectively). Patients who had reduced fertilization in previous IVF attempts showed improved fertilization with sperm stimulants, either PF alone or PF in combination with 2DA in standard IVF. In certain cases, SUZI or PZD gave significantly improved fertilization rates in comparison to IVF. CONCLUSION: Selective use of sperm stimulants in IVF can achieve fertilization for the majority of male-factor cases. However, PZD and SUZI techniques are useful, especially when sperm stimulants fail to achieve fertilization or achieve poor fertilization in direct insemination.

Use of the acrosome reaction to ionophore challenge test in managing patients in an assisted reproduction program: a prospective, double-blind, randomized controlled study.

OBJECTIVE: To assess the utility of the acrosome reaction (AR) to ionophore challenge test in determining the sperm treatment protocols for patients undergoing assisted reproduction. DESIGN, SETTING, PATIENTS: One hundred twenty-one couples undergoing an IVF-ET or GIFT procedure from January to July 1992 were included in this prospective study. All cases had a preliminary semen analysis within the previous 3 months and an AR to ionophore challenge test was carried out unless an acceptable fertilization rate occurred on previous IVF. For those patients whose AR to ionophore challenge score was below the accepted fertile range of > or = 10%, a second AR to ionophore challenge test was performed after exposure of sperm to the stimulant pentoxifylline. Couples then were managed by assisted reproduction with randomized allocation of oocytes for fertilization with a standard sperm preparation or with added sperm stimulants, either 3.6 mM pentoxifylline alone or combined with 3.0 mM 2-deoxyadenosine. The study was double-blind with neither the patients nor the embryologist knowing the AR to ionophore challenge result at the time of the IVF procedure. MAIN OUTCOME MEASURES: Data from the preliminary semen analyses and AR to ionophore challenge scores were correlated with the fertilization rates achieved using control and treated sperm preparations. The rates of total fertilization failure and the numbers of clinical pregnancies occurring in each subgroup were also recorded. RESULTS: All AR to ionophore challenge groups showed normal sperm counts except the groups with poor AR to ionophore challenge, which demonstrated reduced sperm counts. The group with normal AR to ionophore challenge scores or previous normal fertilization showed satisfactory fertilization rates with either control or treated sperm, although some individual cases showed reduced fertilization with treated sperm. The fertilization rate for the group with low AR to ionophore challenge scores improved significantly with pentoxifylline, and the benefit was greatest when this had been predicted from the AR to ionophore challenge studies. Cases with persisting poor AR to ionophore challenge despite pentoxifylline showed no significant improvement in fertilization rates with sperm exposed to either sperm stimulant regimens. Poor AR to ionophore challenge scores were also predictive of total fertilization failure, but this problem was reduced by sperm stimulation. The AR to ionophore challenge score at 10% cutoff level showed optimal levels of sensitivity (82.1%), highest negative predictive value (82.1%), and lowest false negative rate (17.9%). CONCLUSIONS: The AR to ionophore challenge test is useful in the assessment and management of the male factor in assisted reproduction. It can be used to identify the majority of cases who will benefit from the use of sperm stimulants.

Cytogenetic analysis of human oocytes and embryos in an in-vitro fertilization programme.

Oocytes (unfertilized and preovulatory) and embryos (normal and polypronuclear), which were donated to research by patients undergoing procedures of assisted reproductive treatment, were analysed for cytogenetic abnormalities. A total of 362 oocytes and embryos were analysed. The unfertilized oocytes with readable metaphases (53.4%) gave 25.2% chromosomal abnormality with diploidy being the main aberration observed. A high incidence of premature chromosome condensation (PCC) was observed and the incidence of PCC in oocytes exposed to colcemid was significantly higher (14/62, 22.6%) than in those not exposed to this treatment (3/41, 7.3%, P less than 0.05). When chromosomal anomalies and PCC in the unfertilized oocytes were correlated to various patient criteria such as stimulation regimen, number of human menopausal gonadotrophin ampoules, peak oestradiol levels, age of patient and number of previous attempts, none of the criteria tested had any significant relationship to the incidence of chromosomal abnormality. However a significant increase in the incidence of PCC was noted in the gonadotrophin-releasing hormone (GnRH) 'flare' group (6/15, 40.0%) compared to the GnRH 'down-regulation' group (11/88, 12.5%). The incidence of chromosomal abnormalities among preovulatory oocytes was 16.7% and diploidy was the only abnormality noted. For embryos arising from two-pronuclear oocytes, the chromosomal constitution related mainly to embryo quality. The rate of chromosomal abnormality for apparently good quality embryos was 23.5% and for poor or fragmented embryos 83.3%. The majority (77.3%) of the readable metaphase plates for polypronuclear 1-cell and cleaved embryos showed grossly abnormal chromosome complements but 19% of the cleaved embryos contained sets of normal diploid chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Assisted fertilization of mouse oocytes and preliminary results for human oocytes using zona drilling.

The zona-drilling procedure was investigated in mouse oocytes prior to a study on human oocytes. The procedure involved the injection of 5-nl volumes of acidic Hepes-buffered medium at pH 2.5 using a microinjection instrument. Zona-drilled mouse oocytes had significantly higher rates of fertilization (60/99; 61%) than zona-intact oocytes (6/103; 6%) at an insemination concentration of 1 x 10(4) sperm/ml (P less than 0.001). The procedure did not induce parthenogenetic activation of oocytes and more than 97% of zygotes developed to the blastocyst stage. A similar rate of live progeny was observed when zona-drilled (38.0%) and control embryos (38.5%) were transferred to pseudopregnant recipients. Chromosome analyses were performed on zona-intact, zona-free, and zona-drilled oocytes inseminated with varying concentrations of sperm and analysed at the first cleavage division. Zona-free oocytes had high rates of polyploidy (greater than or equal to 40%) with varying insemination numbers but the zona-drilled oocytes did not reveal significant increases in the rate of polyploidy or aneuploidy when compared to controls. In the human studies, zona-drilled oocytes achieved higher rates of fertilization than zona-intact oocytes, with sperm numbers as low as 1 x 10(4)/ml (6/8; 75%). Polyspermic fertilization was observed in 1/2 and 2/6 of fertilized oocytes inseminated with 1 x 10(5) and 1 x 10(4) sperm/ml, respectively. With the low sperm concentration 2/4 of those which were normally fertilized developed to healthy blastocysts. These studies suggest that the zona-drilling technique as described can be performed without apparent harm to oocytes and generate normal embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of luteal support therapy in a randomized controlled study within a gamete intrafallopian transfer program.

A randomized controlled study of luteal support therapy (using intramuscular injections of progesterone and/or human chorionic gonadotropin) was conducted in a trial designed to minimize variables that might adversely affect the change of pregnancy. After applying rigid selection criteria, 207 women were recruited into one of four groups. Mathematical modeling was applied to the results to determine if there were degrees of improvement in uterine receptivity relative to various grades of embryo quality ("E" factor). Although the trial size was insufficient to enable the detection of significant improvements in the pregnancy rates that ranged from 27.5% for non-treatment to 41.2% for those receiving combined treatment, the birth rates were significantly better with luteal support (11.8% versus 29.4%). Similarly, the overall implantation rate just failed to reach statistical significance for luteal support, but the ongoing implantations were significantly better (3.6% versus 9.0%). Data modeling indicated that luteal support, particularly with the combined regimen, could improve the ongoing implantation rate by up to 2.5-fold when the E factor was poorest.

Influence of pentoxifylline in severe male factor infertility.

Two in vitro fertilization sperm preparation protocols using pentoxifylline (long and short exposure before insemination) were studied in 57 couples (61 cycles) with male factor infertility. For each cycle, oocytes were divided into two groups for insemination using either pentoxifylline-treated or control semen. Fertilization rates improved over controls in the short protocol (P less than 0.001) and fewer couples experienced fertilization failure (P = 0.02). Sixteen pregnancies ensued (30% per collection with the short protocol), and 4 were from cases with less than 1.0 X 10(6) progressively motile sperm count per milliliter, 1 being as low as 0.2 X 10(6) progressively motile count per milliliter. Seventeen healthy infants have now delivered and pregnancy wastage is not increased. Pentoxifylline is thus a useful sperm treatment for cases of male factor infertility.

Pituitary down-regulation using leuprolide for the intensive ovulation management of poor prognosis patients having in vitro fertilization (IVF)-related treatments.

A review of 118 treatment cycles in 115 women under prolonged GnRH analogue (GnRHa; leuprolide) treatment is presented. Patients were selected for treatment primarily on the grounds of poor previous response to stimulation (n = 40), advanced age (greater than 35 years; n = 29), previous premature luteinizing hormone (LH) surge (n = 30), polycystic ovarian disease (PCO; n = 12), and elevated androgens without evidence of PCO (n = 5). An overall pregnancy rate of 28.8% per treatment cycle was attained, compared with a pregnancy rate of 6.2% (6/97, of which none went to term) in the previous completed treatment cycle for the same patients. Ovarian response, as measured by oocytes recovered and maximum estradiol levels observed, was significantly improved in all groups and this was associated with a prolonged follicular phase, significantly more human menopausal gonadotropin (hMG) stimulation and a relatively high incidence of ovarian hyperstimulation, particularly in pregnant patients. Of specific techniques in the GnRHa cycle, GIFT produced a pregnancy rate per treatment of 50% (10/20); IVF-ET, 22% (8/36); PROST, 28% (13/46); and TEST, 19% (3/16). No cycles were abandoned, compared with a cancellation rate of 24% in previous cycles without GnRHa. Patients with PCO performed particularly well on GnRHa management, with a pregnancy rate per treatment of 58% (7/12). Pregnancy rates per treatment for the other groups were as follows: elevated age, 27% (9/33), high androgens, 40% (2/5); premature LH surges, 32% (9/28); and poor responders, 17.5% (7/40).(ABSTRACT TRUNCATED AT 250 WORDS)