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Biomedical subjects

R F Casper

Publications and source records attributed to R F Casper.

At least 55 records · Page 3Linked to original sources
PubMed1998

Reactive oxygen species: potential cause for DNA fragmentation in human spermatozoa.

The objective of this study was to evaluate the effect of the generation of reactive oxygen species (ROS) on the integrity of the DNA of human spermatozoa, and to determine if pretreatment with antioxidants can reduce DNA damage. Samples were obtained from 47 men undergoing infertility investigation. ROS were generated in the samples by the addition of xanthine/xanthine oxidase (X/XO) with or without antioxidants. After incubation at timed intervals (0-2 h) with X/XO, the percentage of spermatozoa with DNA fragmentation was determined using the method of TdT-mediated DNA end-labelling (TUNEL). Time intervals were selected to mimic the clinical situation in which spermatozoa are held for a period of time after swim-up while the oocytes are prepared for ICSI. A significant increase in sperm DNA damage was evident when samples were incubated in the presence of ROS for intervals of 1 and 2 h, but not when incubated with ROS for <1 h (P = 0.0001). The addition of antioxidants significantly decreased the amount of DNA damage induced by ROS generation (P < 0.04). ROS can cause an increase in DNA fragmentation and pretreatment with antioxidants can reduce DNA damage.

Antioxidants↗
PubMed1998

Effect of maternal age and conditions of fertilization on programmed cell death during murine preimplantation embryo development.

One of the major morphological anomalies observed in many human pre-embryos is extensive cellular fragmentation. Previously we confirmed that embryo fragmentation seemed to be associated with the activation of programmed cell death (PCD). The purpose of our experiments was to establish a rate for murine embryo fragmentation in vivo after hormonal stimulation in young versus older females and to compare it with the rate of embryo fragmentation during in-vitro fertilization (IVF). While murine maternal age beyond 40 weeks increased the rate of embryo fragmentation following in-vivo fertilization (P = 0.001), oocytes from females of all ages had a uniformly high rate of fragmentation when fertilized in vitro (33%). None of the fragmented murine embryos proceeded further in development. In the mouse, fragmentation occurs exclusively during the first cell cycle. Furthermore, IVF significantly reduced the rate of blastocyst formation (P = 0.0001) and decreased the mean cell number at the blastocyst stage in comparison with embryos produced in vivo (P < 0.0001). The cell death index was significantly affected by both maternal age (P = 0.005) and IVF (P = 0.0001). Identification of specific factors which trigger PCD, especially those associated with IVF, may enable us to lower the rates of fragmentation in preimplantation embryos and thereby increase pregnancy rates after human IVF.

Animals↗
PubMed1997

Effects of different estrogen and progestin regimens on the mechanical properties of rat femur.

The purpose of this study was to examine the effects of estrogen replacement, in concert with three different progestin regimens, on the mechanical properties of rat femoral cortical bone. Ninety-two 11-month-old female Sprague-Dawley rats were randomly divided into six groups and were treated for a duration of 6 months. Group-1 rats were intact controls, group-2 rats were ovariectomized controls, and groups 3-6 were ovariectomized and given continuous doses of estrogen with 5% estradiol 17B silicone-rubber implants. Groups 4, 5, and 6 were also given different doses of progestin (norethindrone): group 4 received a continuous dose of 3 micrograms per animal per day, group 5 received a cyclic dose of 6 micrograms per animal per day for 14 days of a 28-day cycle, and group 6 received an interrupted dose of 3 micrograms per animal per day for 3 days of a 6-day cycle. Femurs from each group were mechanically tested. Bending stiffness was measured by nondestructive three-point bending tests and maximum torque capacity, by destructive torsion tests. Geometrical properties and apparent density of cortical bone were also measured. The significant differences were: the increases in elastic modulus (measured from the three-point bending stiffness) of group 5 (cyclic norethindrone) compared with those of group 2 (ovariectomized controls) and group 3 (estrogen only); the increases in the size represented by the moment of inertia, the moment of the area, and medial-lateral width of group 2 compared with those of group 5; and the increases in apparent density and decreases in moment of inertia of group 6 (interrupted norethindrone) compared with those of group 2. Cyclic or interrupted treatment of progestin along with continuous treatment of estrogen after ovariectomy likely improves material properties of cortical bone, increases its density, and reduces the size of the bone compared with ovariectomized rats.

Animals↗
PubMed1997

An IVF fallacy: multiple pregnancy risk is lower for older women.

INTRODUCTION: Multiple pregnancy is one of the most important and preventable complications of in vitro fertilization (IVF) and embryo transfer. The general clinical practice in many IVF clinics is to transfer four or five embryos to older women if available, since pregnancy rates are lower in women older than 35 years of age. However, it is not clear whether the risk for multiple pregnancy is also lower. OBJECTIVE: Our objective was to investigate whether transferring a higher number of embryos actually improves pregnancy outcome in older women, without increasing the risk for multiple pregnancy and to investigate other factors that may affect the occurrence of multiple pregnancy. SETTING: The setting was university-based IVF program at The Toronto Hospital. DESIGN: The design was a retrospective case series. PATIENTS AND METHODS: The outcome of 1116 IVF cycles between January 1992 and December 1993 was investigated according to different age groups. MAIN OUTCOME MEASURE: The main outcome measure was multiple pregnancies. RESULTS: Seventy multiple pregnancies resulted from a total of 242 pregnancies. Overall pregnancy and multiple pregnancy rates were inversely correlated with age. However, when the data were adjusted for the number of embryos transferred, this trend disappeared. The result of multiple regression analysis showed that the multiple pregnancy rate was higher without improving the pregnancy rate when the number of embryos transferred exceeded three, regardless of the age of the patients, especially when more embryos were available than the number of transferred ones. CONCLUSIONS: The number of embryos transferred should be limited to a maximum of three regardless of the age of patients, to reduce the high frequency of multiple gestations in an IVF program.

Analysis of Variance↗
PubMed1997

Effects of cigarette smoking and age on the maturation of human oocytes.

We investigated whether cigarette smoking, measured by follicular fluid concentrations of cotinine (a major metabolite of nicotine), affects the maturity of oocytes from women undergoing in-vitro fertilization (IVF) and embryo transfer. In 234 women, follicular fluid samples were assessed for cotinine and their 2020 oocytes were assessed for maturity stage. Data on individual proportions of oocytes which were mature (OM) and were fertilized (OF) were analysed by regression in relation to age and follicular fluid cotinine. OF gave an independent assessment of oocyte maturity. Both age and follicular fluid cotinine entered the OM and OF regressions and were significant. The age-adjusted regression coefficients for log cotinine were positive; greater cotinine concentrations usually accompanied greater OM and OF. The cotinine effect on OM was positive in younger women, but it became negative (decreased OM with increasing cotinine concentrations) in older women (> or = 40 years). We further found in older women an average reduction of approximately 50% in the number of mature oocytes; this reduced number was lower than the number of embryos usually transferred. Smoking can reduce the number of mature oocytes even further, therefore risking a negative IVF-embryo transfer outcome. This may be the reason why the negative effects of smoking become clinically detectable in older women.

Adult↗
PubMed1997

Detection of deoxyribonucleic acid fragmentation in human sperm: correlation with fertilization in vitro.

The objective of this study was to determine the incidence of DNA fragmentation in human sperm, and to correlate any detected DNA damage with semen analysis parameters and fertilization rates in in vitro fertilization (IVF). A total of 298 semen samples were collected from men in the infertility program at The Toronto Hospital. For each sample, the percentage of sperm with DNA fragmentation was determined using the method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin end-labeling (TUNEL) and fluorescence-activated cell sorting. The percentage of sperm with fragmented DNA was less than 4% in the majority of samples but ranged from 5% to 40% in approximately 27% of the samples. A negative correlation was found between the percentage of DNA fragmentation and the motility, morphology, and concentration of the ejaculated sperm. In 143 IVF samples, a significant negative association was also found between the percentage of sperm with DNA fragmentation and fertilization rate (p = 0.008) and embryo cleavage rate (p = 0.01). In addition, 35 men who smoked demonstrated an increased percentage of sperm with fragmented DNA (4.7 +/- 1.2%) as compared to 78 nonsmokers (1.1 +/- 0.2%; p = 0.01). These results demonstrate a negative association between semen analysis parameters and sperm with fragmented DNA. Since extremely poor semen samples are the indication for intracytoplasmic sperm injection, there is a high likelihood that sperm with fragmented DNA may be selected by chance and used for oocyte injection, resulting in poor fertilization and/or cleavage rates.

Adult↗
PubMed1996

HLA-G expression during preimplantation human embryo development.

HLA-G is a nonclassical class I major histocompatibility complex molecule with a restricted pattern of expression that includes the placental extravillus cytotrophoblast cells in direct contact with maternal tissues. Circumstantial evidence suggests that HLA-G may play a role in protection of the semiallogeneic human fetus. We examined whether HLA-G is expressed during the critical period of preimplantation human development and whether expression of this molecule could be correlated with the cleavage rate of embryos. Using reverse transcription PCR on surplus human embryos and unfertilized oocytes from patients undergoing in vitro fertilization we detected HLA-G heavy chain mRNA in 40% of 148 of blastocysts tested. The presence of HLA-G mRNA was also detected in unfertilized oocytes and in early embryos, but not in control cumulus oophorus cells. beta 2-Microglobulin mRNA was also found in those embryos expressing HLA-G. In concordance with our mRNA data, a similar proportion of embryos stained positive for HLA-G utilizing a specific monoclonal antibody. Interestingly, expression of HLA-G mRNA was associated with an increased cleavage rate, as compared to embryos lacking HLA-G transcript. Thus, HLA-G could be a functional homologue of the mouse Qa-2 antigen, which has been implicated in differences in the rate of preimplantation embryo development. To our knowledge, the presence of HLA-G mRNA and protein in human preimplantation embryos and oocytes has not been reported previously. The correlation of HLA-G mRNA expression with cleavage rate suggests that this molecule may play an important role in human pre-embryo development.

Antibodies, Monoclonal↗
PubMed1996

Fine-needle aspiration cytology of ovarian cysts in in vitro fertilization patients: a study of 125 cases.

Fine-needle aspiration (FNA) cytology of ovarian cysts, especially in in vitro fertilization (IVF) patients, has been only rarely reported. The aim of this study was to describe the spectrum of cytological findings seen in FNA specimens of 125 ovarian cysts obtained from 84 IVF patients at our institution from 1989-1993. The Papanicolaou-stained slides made following cytocentrifuge or membrane-filter preparation were reviewed blindly by two independent pathologists, and the consensus diagnoses were compiled and correlated with clinical and radiological findings as well as surgical pathology when available. Eight aspirates derived from 4 different patients contained neoplastic cells and, of these, one patient was later found to have a serous cystadenocarcinoma of low malignant potential, while another had a serous cystadenoma. The other 2 patients with neoplastic cells in their ovarian aspirates have persistent ovarian cysts that are being followed clinically for preservation of fertility. The breakdown of the cytological diagnoses of the other aspirates is as follows: 30 follicular cysts, 5 corpus luteum cysts, and 16 endometriotic cysts. The exact underlying nature of 66 cysts could not be determined as the aspirates consisted of foamy macrophages only. This study demonstrates that the nature of ovarian cysts in IVF patients can be determined in many cases by their cytological features, information that may help in defining an unsuspected cause for infertility (such as endometriosis), and in choosing the most appropriate therapy. This study also illustrates that FNA cytology of ovarian cysts can play a role in the detection of occult ovarian neoplasms in the IVF patients population.

Adult↗
PubMed1996

The hypo-osmotic swelling test for selection of viable sperm for intracytoplasmic sperm injection in men with complete asthenozoospermia.

OBJECTIVE: To determine the ability of the hypo-osmotic swelling test to select viable sperm from nonmotile sperm samples for intracytoplasmic sperm injection (ICSI). DESIGN: Nonrandomized, sequential comparative study. PATIENTS: Thirteen couples enrolled in our ICSI program had 16 cycles in which sperm preparations with 0% motility were obtained. Five cycles used cryopreserved epididymal sperm with complete asthenozoospermia. INTERVENTIONS: In eight cycles, the semen samples were washed through a Percoll gradient and sperm were selected randomly for ICSI. In another eight cycles, the washed sperm were placed in a hypo-osmotic solution (75 mM fructose; 25 mM sodium citrate dihydrate) and the sperm with curled tails taken up with the microinjection needle, rinsed, and used ICSI. MAIN OUTCOME MEASURES: Fertilization rate per oocyte injected as determined by the presence of two pronuclei at 18 hours after retrieval and embryo cleavage rate per oocyte injected at 48 hours after retrieval. RESULTS: With random sperm injection, the fertilization and cleavage rates were 26% and 23%, respectively. In contrast, after injection of sperm selected using the hypo-osmotic swelling test, fertilization and cleavage rates were significantly greater (43% and 39%, respectively). There were three pregnancies in the eight cycles with the hypo-osmotic swelling test-selected sperm, including two from frozen epididymal sperm. CONCLUSION: Based on these preliminary observations, we believe that the hypo-osmotic swelling test will prove to be valuable for increasing fertilization and cleavage rates and pregnancy rates in ICSI cycles where no motile sperm are recovered.

Adult↗
PubMed1996

Programmed cell death and human embryo fragmentation.

The quality of embryos produced by in-vitro fertilization (IVF) is variable. Many embryos contain unequal sized blastomeres and multiple cellular fragments. Embryos with excessive fragmentation have limited developmental potential both in vitro and in vivo. Histologically, some blastomeres of fragmented embryos resemble cells undergoing apoptosis as a result of programmed cell death (PCD). The objective of the present study was to determine if the morphological features of apoptosis are observed in fragmented human preimplantation embryos, supporting the possible involvement of PCD in early human embryo arrest and demise. Using combined nuclear and terminal transferase-mediated DNA end labelling (TUNEL) on arrested, fragmented human embryos, we were able to detect extensive condensation and degradation of chromatin, compatible with apoptosis. Electron microscopy confirmed the typical morphological features of apoptosis. No such abnormalities were observed in spare embryos with regular sized blastomeres without fragmentation. The high incidence of condensed chromatin, TUNEL detection of degraded DNA, cell corpses and apoptotic bodies in fragmented human embryos strongly suggest that PCD is triggered in human embryos at a stage prior to blastocyst formation. At such early stages, occurrence of apoptosis seemed to be detrimental, leading to preimplantation embryo death.

Apoptosis↗
PubMed1996

Intracytoplasmic sperm injection for treatment of infertility due to acrosomal enzyme deficiency.

OBJECTIVE: To determine whether absence of fertilization in IVF associated with an acrosomal enzyme defect (hyaluronidase deficiency) results from a simple mechanical block to sperm penetration or from a more serious sperm abnormality. DESIGN: Nonrandomized, prospective study. SETTING: Toronto Center for Advanced Reproductive Technology, a tertiary referral center for infertility associated with The University of Toronto. PATIENTS: One hundred twenty-two couples about to undergo intracytoplasmic sperm injection (ICSI) were selected. Thirty-six of the studied couples had failed to fertilize in prior IVF cycles. INTERVENTIONS: Hyaluronidase activity was measured in the semen samples provided for ICSI using a zymogenic assay. Intracytoplasmic sperm injection was performed in all couples using standard techniques. RESULTS: Forty-eight of 122 semen samples had poor of absent semen hyaluronidase activity. All 48 samples resulted in successful fertilization with ICSI in the present study. The average fertilization rate per oocyte was 59.43% in couples in whom the partner had low semen hyaluronidase activity and 55.85% in whom the male had normal hyaluronidase activity. The ET rate per cycle was 100% and 95% and pregnancy rates per cycles were 26% and 25% in cycles with poor and normal semen hyaluronidase activity, respectively. Unlike routine IVF, no statistical correlation was found between semen hyaluronidase activity and the fertilization rate in ICSI. CONCLUSION: Our results indicates that semen hyaluronidase deficiency is associated with a simple mechanical block to fertilization. In addition, the measurement of semen hyaluronidase activity can provide a reliable means for selecting couples who would benefit from ICSI.

Acrosome↗
PubMed1996

Embryonic human leukocyte antigen-G expression: possible implications for human preimplantation development.

OBJECTIVE: To investigate further the association between human leukocyte antigen G (HLA-G) expression in human embryos and other factors known to influence IVF pregnancy outcome. SETTING: A university-based tertiary referral center (The Toronto Hospital). INTERVENTIONS: Nontransferred embryos at the two- to four-cell stage were obtained from patients undergoing IVF and were cultured in Ham's F-10 medium supplemented with 10% human sera or cocultured with ovarian cancer cells in the same medium. Embryos that reached blastocyst stage (n = 148) were analyzed by reverse transcriptase-polymerase chain reaction for HLA-G and beta 2 microglobulin (beta 2m) expression. Statistical analysis was performed to identify possible factors associated with variability of expression. RESULTS: Approximately 40% of studied blastocysts had detectable expression of both HLA-G and beta 2m messenger RNA. In 46% of blastocysts, beta 2m alone was observed. Interestingly, sibling embryos from patients that became pregnant were significantly more likely to express HLA-G than embryos from patients that did not conceive as a result of their IVF cycles. No association was found between HLA-G expression and culture conditions, patients age, or infertility diagnosis. CONCLUSION: The population of embryos obtained through IVF is heterogeneous in expression of HLA-G and beta 2m, which may reflect overall health of the embryos. Blastocysts showing positive HLA-G expression may have increased viability and implantation potential, although the underlying mechanisms remain to be elucidated.

Base Sequence↗
PubMed1996

Ovarian response to recombinant human follicle-stimulating hormone in luteinizing hormone-depleted women: examination of the two cell, two gonadotropin theory.

OBJECTIVE: To evaluate the relative contribution of FSH to ovarian estrogen production. DESIGN: Nonrandomized, prospective study. SETTING: University of Toronto teaching hospital reproductive biology unit. PATIENTS: Five women who had been treated with depot GnRH agonist with hormonal add-back for 4 to 48 months and who were confirmed to be gonadotropin depleted by both bioassay and RIA. INTERVENTIONS: Subjects received 75 IU SC recombinant human FSH daily for 7 days followed by 150 IU daily for 7 days and 225 IU daily for the third week. MAIN OUTCOME MEASURE: Serum steroid determination and vaginal sonography for follicle size and endometrial thickness were performed serially and follicular fluid hormone levels were measured in two subjects. RESULTS: Bioactive LH and FSH activity were less than the detection limit of the assay (0.1 mIU/mL; conversion factor to SI units, 1.00 for LH and FSH) before recombinant FSH treatment in all five women. In all subjects, at least one preovulatory follicle developed by the end of two to three weeks. Endometrial thickness increased to between 7 and 9 mm in four women. Mean serum E2 in the five subjects increased from 17 pg/mL (range: 5 to 33 pg/mL; conversion factor to SI unit, 3.671) at baseline to 230 pg/mL (range: 37 to 489 pg/mL) at the end of the study. Follicular fluid E2 concentrations ranged from 44,296 to 69,367 pg/mL in the four follicles aspirated. CONCLUSION: Our results indicate that LH is not necessary for ovarian E2 production. We speculate that the granulosa cells, in the absence of detectable LH bioactivity, can use circulating adrenal androgens or constitutive or FSH-stimulated thecal androgens, to produce intrafollicular E2.

Adult↗
PubMed1996

Coculture with ovarian cancer cell enhances human blastocyst formation in vitro.

OBJECTIVE: To examine the effect of human embryo coculture with an ovarian cancer cell line. DESIGN: Prospective, randomized in vitro study. SETTING: University of Toronto IVF clinic at The Toronto Hospital. PATIENTS: Couples undergoing IVF who chose not to cryopreserve their spare embryos and were willing to donate spare embryos for research. INTERVENTION: Spare embryos were cultured randomly either under regular conditions with Ham's F-10 medium supplemented with 10% heat inactivated human serum (n = 189) or were cocultured in the same medium, with human ovarian epithelial cancer cells (n = 173). MAIN OUTCOME MEASURE: Blastocyst formation. RESULTS: Coculture with the cancer cell line improved the preimplantation embryo development to the blastocyst stage. There was a significant increase in the number of cavitating morulae (68%) and the proportion of embryos reaching the fully expanded blastocyst stage (39%) compared with those in standard culture medium (34% and 23%, respectively). CONCLUSION: Coculture of early cleavage stage human embryos with epithelial cancer cells markedly improves in vitro human blastocyst formation compared with standard culture conditions.

Blastocyst↗
PubMed1995

The effect of different hormone replacement therapy regimens on the mechanical properties of rat vertebrae.

The purpose of this study was to examine the effects of estrogen replacement, in concert with three different progestin regimens, on the mechanical properties of rat lumbar vertebrae. Ninety-two Sprague-Dawley rats (11 months old) were divided into six groups for treatment. The first group was an intact control, the second group (OVX) was ovariectomized only, and the third group (estrogen-only) was ovariectomized and received continuous estrogen through a 17 beta-estradiol implant. The remaining groups were ovariectomized and received estrogen and progestin (norethindrone, NET) therapy; 3 micrograms of NET was injected daily (estrogen plus continuous NET), or 6 micrograms of NET was injected for 14 consecutive days of a 28-day cycle (estrogen plus cyclic NET), or for 3 consecutive days of a 6-day cycle (estrogen plus interrupted NET). The animals were sacrificed after 6 months, and the vertebrae were dissected out. The vertebral processes of the fourth lumbar vertebrae were removed, and the density of the vertebral bodies was determined. They were then subjected to compression testing. We found that all three estrogen/progestin regimens maintain bone density and all mechanical properties at a level indistinguishable from the control. However, the cyclic and continuous NET treatment results were, with the exception of density, also indistinguishable from those of the ovariectomized group. The estrogen plus interrupted NET group on the other hand, has a significantly greater compressive modulus and density than the ovariectomized group. In conclusion, with respect to the ovariectomized group, the estrogen plus interrupted NET treatment resulted in a superior density and compressive modulus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Lumbar vertebral density and mechanical properties in aged ovariectomized rats treated with estrogen and norethindrone or norgestimate.

OBJECTIVE: This study was designed to investigate the effects of estrogen alone or combined with two different progestins, norethindrone or norgestimate, on bone density and compressive mechanical properties in an aged rat model. STUDY DESIGN: Twenty 11-month-old female Sprague-Dawley rats were sham operated (intact control) and 80 wee ovariectomized. Three groups of 20 ovariectomized rats were implanted with Silastic silicon rubber (Dow Corning, Midland, Mich.) capsules containing 5% estradiol (wt/wt) in cholesterol. All rats in the intact control (group 1) and the ovariectomized (group 2) and the first of the ovariectomized plus estrogen (group 3) groups were injected subcutaneously daily for 6 months with corn oil (vehicle). Two other groups of rats with estrogen capsules received daily injections of norethindrone (3 micrograms/rat/day) or norgestimate (1.5 micrograms/rat/day) in corn oil for 3 days out of every 6 days (interrupted progestin). The effects of these various treatments on bone mineral content and bone mineral density in the vertebrae were measured by dual energy x-ray absorptiometry. The L4 vertebral bodies were also tested to failure in compression. RESULTS: The ovariectomized rats receiving corn oil alone had the lowest bone mineral density compared with intact controls. Estrogen treatment alone resulted in a lower bone mineral density than in the intact controls. In contrast, both interrupted progestin regimens resulted in vertebral bone mass index at the same level as the intact controls. Compression tests revealed that ovariectomized controls also had the lowest modulus of elasticity of all groups. However, unlike bone mineral density, estrogen alone resulted in mechanical properties similar to intact controls, whereas the vertebrae in both interrupted progestin groups had variable mechanical properties compared with the ovariectomized and intact control groups. CONCLUSIONS: We conclude that in this experimental model hormone replacement therapy with estrogen and an androgenic (norethindrone) or nonadrogenic (norgestimate) progestin result in similar bone mineral density and mechanical properties. In addition, both interrupted progestin regimens had a better effect than estrogen alone on vertebral bone density.

Absorptiometry, Photon↗
PubMed1995

In vitro fertilization outcome in the presence of severe male factor infertility.

OBJECTIVE: To assess the outcome of standard IVF treatment (nonmicromanipulated) with respect to total motile sperm number recovered by swim-up, particularly for couples with severe male factor infertility defined as total motile sperm number < 0.5 x 10(6). DESIGN: Retrospective study of patients who underwent successful oocyte retrieval in an IVF program from August 10, 1992 to December 31, 1993. SETTING: A university-based tertiary referral center (The Toronto Hospital). PATIENTS: All cycles (n = 672) were divided into four groups according to total motile sperm number recovered using standard swim-up: group 1, total motile sperm number < or = 0.50 x 10(6); group 2, total motile sperm number between 0.51 and 1.00 x 10(6); group 3, total motile sperm number between 1.01 and 1.50 x 10(6); and group 4, total motile sperm number > or = 1.51 x 10(6). All patients received the same controlled ovarian hyperstimulation protocol, which consisted of a GnRH analog flare-up followed by parenteral menotropins. Clinical and cycle characteristics in the four groups were analyzed and outcome was evaluated. RESULTS: There was no significant difference in clinical and cycle characteristics between the groups. The uniformity of the groups justified analysis of their outcome. A fertilization rate of 21.5% was achieved in couples with severe male factor (group 1). Fertilization rate and number of embryos transferred increased directly with the total motile sperm number. There was no significant difference in implantation rate per embryo between the groups. CONCLUSIONS: The results in couples with severe male factor infertility compare favorably with monospermic fertilization rates reported in the literature using partial zona dissection and subzonal insertion but is lower than with intracytoplasmic sperm injection. Therefore, we believe that couples with severe male factor infertility should be considered for standard IVF, as long as adequate total motile sperm can be recovered (100 x 10(3) per dish). If intracytoplasmic sperm injection is available, it should be offered to these couples.

Embryo Transfer↗