Normal development and metabolic activity of preimplantation embryos in vitro from patients with polycystic ovaries

Polycystic ovary syndrome (PCOS) is closely associated with high miscarriage rates and, following in-vitro fertilization (IVF), with decreased fertilization rates, suggesting that oocytes and embryos are of poor quality. In this prospective study, we examined the development, metabolic activity and blastocyst cell number of embryos following IVF from 51 patients with either anovulatory PCOS, ovulatory PCOS or tubal disease. The number of oocytes retrieved and the fertilization rates were similar for patients with PCOS and tubal disease. Following embryo transfer, 46% of the patients with PCOS and 36% of patients with tubal disease became pregnant. A similar proportion of surplus embryos from patients with PCOS and tubal disease developed to the blastocyst stage (38% and 43% respectively). Patients with anovulatory PCOS had embryos with less fragmentation which cleaved faster, cavitated earlier and had more cells at the blastocyst stage than embryos from patients with tubal disease. While the profile of glucose uptake and lactate production was similar for all groups throughout preimplantation development, patients with tubal disease who underwent ovulation induction using the 'titrated' regimen optimized for PCOS patients resulted in embryos with reduced pyruvate uptake, in addition to low blastocyst cell numbers. This study demonstrates that with an optimized ovulation induction regimen, embryos from PCOS patients are of good quality and developmental potential.     

Oocyte morphology does not affect fertilization rate, embryo quality and implantation rate after intracytoplasmic sperm injection

In this study, we compared the fertilization rate and embryo quality after intracytoplasmic sperm injection (ICSI) as they relate to oocyte morphology. A total of 654 ICSI cycles yielding 5903 metaphase II oocytes were observed. The oocytes retrieved in these cycles were divided into (i) normal oocytes, (ii) oocytes with extracytoplasmic abnormalities (dark zona pellucida and large perivitelline space), (iii) oocytes with cytoplasmic abnormalities (dark cytoplasm, granular cytoplasm, and refractile body), (iv) oocytes with shape abnormalities, and (v) oocytes with more than one abnormality (double and triple abnormalities). Intracytoplasmic vacuoles and aggregates of smooth endoplasmic reticulum were not recorded separately. The fertilization rate and quality of morphologically graded embryos did not differ between the groups. There were 77 cycles where all transferred embryos were derived from abnormal oocytes, and 164 cycles where all embryos were derived from normal oocytes. These cycles were studied further. The two groups were comparable regarding mean female age, duration of infertility, duration of ovarian stimulation, number of ampoules of gonadotrophin injected, and number of oocytes retrieved. Two clinical pregnancy rates (44.4 versus 42.1%) and implantation rates per embryo (10.3 versus 13.2%) were similar. In conclusion, in couples undergoing ICSI, abnormal oocyte morphology is not associated with a decreased fertilization rate or unfavourable embryo quality. Furthermore, embryos derived from abnormal oocytes yield similar clinical pregnancy and implantation rates when transferred compared with embryos derived from normal oocytes.     

The effects of coculture with autologous cryopreserved endometrial cells on human in vitro fertilization and early embryo morphology: a randomized study

PURPOSE: The aim of this study was to examine the influence of endometrial cells on the fertilization rate and early embryonic morphology following routine in vitro fertilization (IVF). Cryopreservation with subsequent thawing allowed the use of autologous somatic cells, thus minimizing the risk of transmission of infective agents. Interpatient variability was eliminated by randomizing oocytes from each cycle into the control or coculture group. RESULTS: Two hundred ninety-four oocytes from 24 IVF cycles (21 patients) were included in the study (145 coculture and 149 control). The normal fertilization rate of control oocytes (56.4%) was not significantly different from that of oocytes cocultured with endometrial cells (61.4%). The mean number of blastomeres in cocultured embryos (3.65) was not significantly different from the number in control embryos (3.46) 2 days after insemination, but the proportion of embryos with minimal or no fragmentation was significantly higher in the coculture group [34/84 (40.5%) vs. 17/80 (21.3%); P < 0.01]. CONCLUSIONS: The inclusion of cryopreserved autologous endometrial cells in routine clinical IVF procedures does not influence fertilization or the early cleavage rate but may reduce the extent of embryo fragmentation during the early cleavage divisions.     

Coculture of human embryos with buffalo rat liver cells for women with decreased prognosis in in vitro fertilization

OBJECTIVE: The coculture of human embryos with epithelial cells may improve both embryo quality and pregnancy rates. In this current study we tested the efficacy of coculture with the buffalo rat liver cell line on pregnancy rates in women with a potentially poor prognosis for success with in vitro fertilization (previous in vitro fertilization failure, advanced maternal age, increased early follicular follicle-stimulating hormone levels, and anovulation). STUDY DESIGN: This prospective controlled study evaluated a total of 203 women (135 coculture, 68 controls) undergoing in vitro fertilization. Implantation rates per embryo, clinical pregnancy rates, and continuing/delivered pregnancy rates were analyzed. RESULTS: Buffalo rat liver cells, which are commercially available, are stable in coculture. Implantation rates (number of sacs with fetal heart motion per embryos transferred) were similar for coculture (19%) and control (18%) embryos. No difference in the rate of continuing/delivered pregnancies per retrieval was noted (17% coculture vs 14% control) in the group with advanced maternal age, but coculture caused a trend toward improved pregnancy rates in the group with ovulatory dysfunction (43% coculture vs 14% control) and the group with previous in vitro fertilization failure (34% coculture vs 28% control). CONCLUSION: This is the first published controlled study to our knowledge that reports the use of the buffalo rat liver cell coculture for human in vitro fertilization in a large number of patients. Our data support consideration of buffalo rat liver coculture for in vitro fertilization for women with previous in vitro fertilization failure and possibly for patients with oocyte or ovulatory dysfunction.     

Long-term evaluation of implantation of fresh and cryopreserved human embryos following ovarian stimulation with buserelin acetate-human menopausal gonadotrophin (HMG) or clomiphene citrate-HMG

This study is a long-term evaluation of the total pregnancy potential of cohorts of fresh and cryopreserved sibling embryos from in-vitro fertilization (IVF) cycles stimulated with either the gonadotrophin-releasing hormone analogue buserelin (BUS) (long protocol) or clomiphene citrate (CC) both in combination with human menopausal gonadotrophin (HMG). Therefore a retrospective analysis was performed on patients who entered the IVF programme between January 1986 and July 1987 and who had triple embryo transfer in the collection cycle. Significantly more fertilized oocytes developed to good-quality embryos in the CC-HMG group (86.1%) than in the BUS-HMG group (80.8%). Transfer of the three morphologically best-looking embryos was performed in day 2 post-insemination in 106 CC-HMG and 80 BUS-HMG cycles. Supernumerary embryos were cultured for a further 24 h and multicellular embryos with up to 20% of fragments were frozen slowly with 1.5 M dimethylsulphoxide on day 3 post-insemination (162 embryos in CC-HMG cycles, 102 embryos in BUS- HMG cycles). Outcome was measured by embryo survival rate, embryo implantation rate and delivery rate in fresh and frozen embryo transfers. Delivery rates were 31.3 and 21.7% per fresh embryo transfer in BUS-HMG and CC- HMG cycles respectively. Fresh embryo implantation rates were significantly higher in collection cycles stimulated with BUS-HMG (17.9%) than in cycles stimulated with CC-HMG (11.3%). Implantation rates were significantly enhanced in embryos transferred in excess of one in cycles leading to pregnancy, perhaps indicative of higher embryo quality in BUS-HMG cycles. Almost all cryopreserved embryos have by now been thawed, so the contribution of frozen embryos to overall pregnancy rates can be evaluated. Overall morphological survival rates of frozen-thawed embryos have by now been thawed, so the contribution of frozen embryos to overall pregnancy rates can be evaluated Overall morphological survival rates of frozen-thawed embryos were similar for 140 embryos from CC-HMG cycles (50%) and 100 embryos from BUS-HMG cycles (46%). The percentage of fully intact embryos was, however, significantly lower in the BUS-HMG group (19%) than in the CC-HMG group (39.5%). Delivery rates were significantly lower following 30 transfers of frozen-thawed embryos from BUS-HMG-stimulated cycles (3.3%) than following 42 transfers of frozen-thawed embryos from CC-HMG cycles (19.1%). Embryo implantation rates were lower for frozen-thawed embryos from BUS-HMG cycles (2.3%) than from CC-HMG cycles (12.7%). Here we demonstrate that ovarian stimulation with the long protocol BUS-HMG instead of the CC-HMG protocol led to higher embryo implantation rates in collection cycles but to lower intact embryo survival rates and to lower embryo implantation rates for frozen sibling embryos. Despite the lower implantation rates with frozen embryos originating from the BUS-HMG protocol, there was no significant difference between total delivery rate per transfer from cycles stimulated with CC-HMG (30.2%) compared with BUS-HMG (33.8%).     

Cryopreservation of mouse spermatozoa from inbred and F1 hybrid strains

Mouse epididymal spermatozoa from inbred(BALB/c, C3H/He, C57BL/6N, CBA/JN and DBA/2N) and F1 hybrid (B6C3F1, BDF1 and CDF1) strains suspended in cryopreservation solution (18% raffinose and 3% skim milk in distilled water) were frozen and stored at -196 degrees C. After thawing at room temperature, sperm motility and fertilizing ability were examined. Spermatozoa from all of the strains were successfully frozen, although the motility and the fertilization rates of frozen-thawed spermatozoa (the proportions of the fresh oocytes from Jcl:ICR strain which developed to pronuclear oocytes and 2-cell embryos after insemination by frozen-thawed spermatozoa) varied among strains (motility: 23% for C57BL/6N to 62% for DBA/2N; fertilization rates: 26% for C57BL/6N to 89% for DBA/2N). Nearly all 2-cell embryos fertilized by frozen-thawed spermatozoa were transferred to the oviducts of pseudopregnant recipients and 35-62% of 2-cell embryos developed into normal young.     

Current and future methodology for monitoring sleep

The present study examined the effect of follicular shell pieces (FSP) during in vitro maturation (IVM) of porcine oocytes on 1) in vitro fertilization (IVF) parameters, 2) subsequent embryo development, 3) oocyte glutathione (GSH) concentration, and 4) viability after embryo transfer. Cumulus-oocyte complexes were cultured in North Carolina State University (NCSU) 23 medium containing porcine follicular fluid, cysteine, and hormonal supplements and with or without FSP for 20-22 h. They were then cultured in the same medium but without hormonal supplements for an additional 20-22 h. After culture, cumulus-free oocytes were coincubated with frozen-thawed spermatozoa for 5-6 h. Putative zygotes were transferred to NCSU 23 containing 0.4% BSA and cultured for 144 h. In comparisons between the presence and absence of FSP, no differences were observed in fertilization parameters. At 48 h, no mean differences were found in cleavage rates. However, at 144 h, the proportion of embryos that developed to the blastocyst stage was significantly (p < 0.01) higher (18% vs. 36%) for oocytes cocultured with FSP. A significantly (p < 0.05) higher GSH concentration was found in oocytes matured with FSP as determined by dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. Transfer of embryos to 9 recipients resulted in 5 pregnancies with the birth of 18 live piglets. The results provide clear evidence of the beneficial effect of FSP during IVM of pig oocytes cultured in the presence of cysteine on subsequent embryo development to the blastocyst stage. The birth of piglets confirms the viability of IVM-IVF-derived embryos.     

Intracytoplasmic sperm injection as a routine indication in low responder patients

The aim of this study was to determine if a low response to gonadotrophin stimulation could be considered as an indication for intracytoplasmic sperm injection (ICSI). This prospective study included a total of 96 non-male infertile couples with six or fewer retrieved oocytes, who underwent 104 in-vitro fertilization (IVF) cycles between January 1996 and April 1997. They were randomly divided into two groups for fertilization, one by IVF and the other by ICSI. Groups were compared in terms of fertilization rates, fertilization failure, embryo quality, embryos transferred and reproductive outcome. ICSI provided similar fertilization rates per inseminated oocyte (77.7 versus 70.2%) and per obtained oocyte (56.5 versus 58.8%) as IVF. Furthermore, equal numbers (2.2 versus 2.5) and quality of embryos were obtained and comparable pregnancy (21.1 versus 17.3%) and implantation (14.0 versus 11.1%) rates. Neither the number of retrieved oocytes, nor patient age was relevant for the fertilization rates obtained with both techniques. The number of cases with complete fertilization failure was similar in both procedures. We conclude that the technique of fertilization is not related to the reproductive outcome of low responders, and the routine use of ICSI is not indicated.     

In vitro fertilization in women age 40 and older: the impact of assisted hatching

PURPOSE: To assess the impact of assisted hatching on in vitro fertilization (IVF) outcome in women age 40 and older. METHODS: A retrospective analysis was performed to compare 28 cycles of IVF without assisted hatching to 38 cycles of IVF with assisted hatching. All patients in both groups were age 40 or older and the mean age was similar. RESULTS: The delivery rate per oocyte retrieval was significantly higher in the assisted hatching group (18/38; 48%) compared to the nonhatched controls (3/28; 11%, P = 0.0003). The implantation rate of hatched embryos (40/175; 22%) was clearly enhanced, compared to the nonhatched embryos (7/126; 6%, P < 0.001). The fertilization rate, number of oocytes and the number of embryos per patient were comparable in the two groups. CONCLUSIONS: Assisted hatching dramatically improves embryonic implantation and term pregnancy rates in women age 40 and older undergoing IVF.     

Low blastocyst formation rates in day-2 fertilized oocytes

PURPOSE: To examine the blastocyst formation rates of day-2 fertilized oocytes. METHODS: A retrospective study of the outcomes/blastocyst formation of day-2 fertilized oocytes was undertaken. RESULTS: Fertilization rates of day-1 and -2 oocytes by intra-cytoplasmic sperm injection were similar. The development frequencies to four cells were similar. However, the blastulation rates were significantly lower from the day-2 fertilized eggs. The fertilization rates from day-2 conventional in vitro fertilization reinsemination were lower than the fertilization rates of day-1 oocytes. The blastulation rates from day-2 fertilized eggs were also lower than the rates from day-1 fertilized eggs in the in vitro fertilization group. CONCLUSIONS: Fertilization is not a good indicator to predict the viability of fertilized oocytes. Day-2 fertilized oocytes had significantly lower blastocyst formation rates than the rates from day-1 fertilized oocytes.     

Preimplantation adoption: establishing pregnancy using donated oocytes and spermatozoa

The experience of transferring embryos produced through in-vitro fertilization (IVF) utilizing donated oocytes and spermatozoa is described. Recipients (n = 28; aged 38-59 years) received oral micronized oestradiol and i.m. progesterone and were synchronized to donors undergoing ovarian stimulation. Reasons for selecting therapy included advanced reproductive age (> 42 years; n = 21) or hypergonadotrophic hypogonadism (n = 7), combined with severe male factor infertility in 23 couples. Five women were single and without partners. Oocytes were fertilized by cryopreserved spermatozoa designated for use by the recipient. Up to five embryos were transferred transcervically. Supernumerary embryos were cryopreserved. A total of 36 aspirations produced 15.6 +/- 7.3 oocytes per retrieval. In 10/36 cycles (27.8%), embryos were available for cryopreservation. Using fresh embryos, the overall pregnancy rate was 38.9% (14/36), clinical pregnancy rate 33.3% (12/36), and ongoing/delivered pregnancy rate 30.6% (11/36). Three ongoing pregnancies were later established by transferring cryopreserved embryos. Adjusting for these events, the per aspiration overall pregnancy rate per retrieval was 47.2%, clinical pregnancy rate 41.7%, and ongoing/delivered pregnancy rate 38.9%. Implantation rates per individual embryo transferred were 16.6% following fresh embryo transfer. A viable pregnancy was achieved by 14 of 28 women (50% cumulative pregnancy rate). We conclude that using donor oocytes and donor spermatozoa is efficacious and allows couples of whom both members suffer from severe gamete abnormalities and single functionally agonadal women an effective means of achieving pregnancy.     

Aggressive behavior of psychiatric patients among geriatric population

The effects of protein supplements and culture dish type on in vitro fertilization (IVF) and embryo development in culture were examined in the domestic cat. In Experiment I, follicular oocytes were fertilized and cultured in either 1) modified Earle's balanced salt solution, designated MK-1, supplemented with one of the following: 10% human serum (HS), 10% FCS or 0.4% BSA, or 2) Medium 199 (M-199) supplemented with 10% FCS. Fertilization rates were lower (P < 0.01) in MK-1 + BSA (74.4%), MK-1 + FCS (56.1%), and M-199 + FCS (51.4%) than in MK-1 + HS (94.7%). A greater (P < 0.01) percentage of blastocysts was obtained in MK-1 + HS (50.0%) than in other treatment groups (range, 4.3-17.2%). In Experiment II, the effect of dish type (tissue culture dish, TCD, versus suspension culture dish, SCD) on embryo development was evaluated in MK-1 supplemented with either HS or BSA. Significantly higher proportions of IVF-derived embryos developed to blastocysts at 120 and 144 hr post-insemination, respectively, when cultured in HS/SCD (47.2 and 71.7%) than in BSA/SCD (11.4 and 27.3%) or BSA/TCD (10.4 and 25.0%). At 120 hr post-insemination, there was a lower (P < 0.01) percentage of blastocysts in HS/TCD (22.2%) than in HS/SCD. In Experiment III, six embryos per cat were transferred to the uterine horns of 17 recipients at 144 hr after hCG treatment. Five of 7 recipients which received late morulae cultured in MK-1 + BSA (SCD) for 120 hr became pregnant (71.4%). Eight of 10 recipients which received early blastocysts cultured in MK-1 + HS (SCD) for 120 hr became pregnant (80.0%). We conclude that MK-1 containing HS is highly beneficial for overcoming the in vitro developmental block of IVF-derived feline embryos and increasing the success rate of IVF/ET.     

The selection criteria on an IVF program can remove the association between maternal age and implantation

BACKGROUND: 1190 consecutive in vitro fertilization (IVF) treatment cycles from the Southampton University/BUPA Chalybeate unit, spanning a four year period, were studied retrospectively in order to assess the relationship between maternal age and implantation. Our aim was to evaluate the hypothesis that the number of transferred embryos can be determined by age alone. METHOD: The cases were allocated to two age groups, Group 1 was composed of patients of less than or equal to 35 years of age and Group 2 of patients greater than 35 years of age. RESULTS: We found that the selection criteria used in our programme for abandoning treatment cycles led to significantly more older patients being excluded from oocyte collection (p < 0.001). The patients from both groups that progressed to oocyte collection and embryo transfer showed no significant difference in embryo implantation. The overall implantation rate (12.4%) and clinical pregnancy rate per embryo transfer (22.8%) were achieved by being able to transfer comparable numbers of embryos in both age groups and in spite of the younger age group having a significantly better quality of transferred embryos. CONCLUSION: Although advancing maternal age predisposes to a reduced chance of success from IVF treatment, maternal age alone was not a useful predictor of embryo implantation or endometrial receptivity in completed IVF treatment cycles.     

The effect of a propofol-based sedation technique on cumulative embryo scores, clinical pregnancy rates, and implantation rates in patients undergoing embryo transfers with donor oocytes

STUDY OBJECTIVE: To determine the effect, if any, of a propofol-based sedation technique on the reproductive outcomes of patients undergoing embryo transfers with donor oocytes. These ova recipients form a unique subgroup, whose clinical outcomes are unrelated to direct anesthetic effects on their reproductive tracts. DESIGN: Retrospective chart review. SETTING: A 1200-bed university medical center. PATIENTS: 117 patients who received fresh embryo transfer cycles between January 1991 and December 1995. MEASUREMENTS AND MAIN RESULTS: The anesthesia records of 106 women who donated ova were reviewed for propofol usage during the transvaginal needle aspiration of the ova. The medical records of the 117 patients who received these donated embryos were reviewed for cumulative embryo scores, clinical pregnancy rates, and implantation rates. Fourteen patients received ova from women who were sedated with fentanyl and midazolam during ovum retrievals, while 103 patients received ova from women who had been given fentanyl, midazolam, and propofol in doses of 1.87 mg/kg to 8 mg/kg. The pregnancy rate among all patients who received ova from women who received propofol (44 of 103 = 42.7%) was 14.1% greater than those whose ovum donors did not receive propofol (4 of 14 = 28.6). 78.6% of both propofol and non propofol-exposed groups had cumulative embryo scores of greater than 50. Among patients who became pregnant, 52.3% of propofol-exposed and 50% of nonpropofol-exposed cases had greater than 20% implantation rates. CONCLUSION: There is no evidence from our data that the administration of propofol during the aspiration of ovarian follicles for oocyte donation had a negative impact on the oocytes as measured by cumulative embryo scores, probability of a clinical pregnancy, or implantation rate.     

A comparative analysis of embryos derived from routine in-vitro fertilization and subzonal microinsemination

Embryos obtained from patients undergoing routine in-vitro fertilization (IVF) and embryo transfer were compared with those undergoing subzonal microinsemination (SUZI) for male factor infertility. Overall, the proportion of cleaved embryos was significantly higher in the IVF group in comparison with the SUZI group at 48 h post-insemination [1533 out of 1609 (95.3%) versus 776 out of 952 (81.5%)]. The mean +/- SD grading score of the IVF-derived embryos of 3.61 +/- 0.50 was significantly better than that for SUZI of 2.97 +/- 0.86 (P < 0.0005) at the same time. The implantation rates following the replacement of IVF or SUZI embryos at 48 h were comparable: 14.3 and 10.0% respectively. However, the IVF embryo implantation rate of 15.1% at 72 h was significantly better than that following the replacement of SUZI embryos at either 48 (10.0%) or 72 h (8.0%). The replacement of SUZI-derived embryos at 48 h resulted in significantly higher pregnancy (25.0%) and implantation rates (10.0%) than at 72 h, with rates of 10.8 and 8.0% respectively. Similarly, the overall embryo quality deteriorated following in-vitro culture for up to 72 h. The clinical pregnancy loss rate (33.0%) was highest following the replacement of SUZI embryos at 72 h, although the data were limited. It is suggested that these data indicate that a combination of in-vitro manipulation, the injection of multiple spermatozoa into the subzonal space and probably the genomic capacity of spermatozoa derived from poor-quality semen may contribute to the poorer outcome of embryo development following SUZI. Prolonged in-vitro culture beyond 48 h appears to be deleterious to the development of SUZI cleaved embryos and the subsequent outcome of treatment, and hence should be avoided.     

Prospective randomized trial of the effect of two flushing media on oocyte collection and fertilization rates after in vitro fertilization

OBJECTIVE: To assess the value of heparinized saline as a flushing medium for oocyte recovery. DESIGN: Prospective randomized study. SETTING: Academic tertiary referral center for fertility treatment. PATIENT(S): Thirty-five patients, with both ovaries intact having IVF-ET. INTERVENTION(S): Patients were randomized either to have the follicles of the left or right ovary flushed with heparinized normal saline at the time of oocyte recovery for IVF-ET. The contralateral ovary was flushed with heparinized culture medium. Oocytes obtained from each side were cultured separately and assessed for fertilization 18-21 hours after insemination. MAIN OUTCOME MEASURE(S): Collection and fertilization rates. RESULT(S): A total of 481 follicles were aspirated yielding 366 oocytes. Of these, 240 fertilized. From the side flushed with saline 185 oocytes were collected from 237 follicles, which was not significantly different from 181 oocytes collected from 244 follicles on the side flushed with culture medium (odds ratio = 1.23; 95% confidence interval = 0.79-1.92). Similarly, there was no significant difference observed in fertilization rates between oocytes obtained after saline (median 71.4%) and culture medium flush (median 75.0%) (odds ratio = 1.08; 95% confidence interval = 0.68-1.72). CONCLUSION(S): Heparinized normal saline is an equally good but cheaper and more convenient medium than standard heparinized culture medium and could replace it for flushing follicles during oocyte recovery for IVF-ET procedures.     

Reproductive wastage in the androstenedione-immune ewe

An experiment was carried out using 320 adult Merino ewes to examine the effects of immunization against an androstenedione human serum albumin conjugate (Fecundin) on ovulation rate, fertilization rate and embryo viability at days 2, 9 and 13-14 after fertilization. The ovulation rate of immunized ewes (2.19 +/- 0.06) was greater (P < 0.001) than that of control ewes (1.43 +/- 0.04). The recovery rate of embryos or of unfertilized oocytes on day 2 was reduced in immunized ewes, but fertilization rate of recovered oocytes was unaffected by immunization. The mean number of normal embryos per ewe pregnant (prolificacy) was higher and the proportion of ewes pregnant (fertility) was lower in immunized than in the control ewes. The distribution of the number of cells per embryo showed no differences in developmental age over the period of sampling, the majority of embryos at this time being at the two- to four-cell stage of development. At day 9 of pregnancy, blastocyst recovery rates were lower in immunized than in control ewes. About 90% of blastocysts recovered were developing normally in control ewes compared with 64% in immunized ewes. The majority of blastocysts recovered on day 9 had hatched from the zona pellucida prior to recovery (mean values were 94.2% and 87.8% for control and immunized groups, respectively). In control ewes single blastocysts were larger than twin blastocysts, but for the immunized ewes this difference was not significant. Both single blastocysts (P < 0.01) and twin blastocysts (P < 0.05) from immunized ewes were smaller than those from control ewes.(ABSTRACT TRUNCATED AT 250 WORDS)     

The presence of a sponsoring embryo in a batch of poor quality thawed embryos significantly increases pregnancy and implantation rate

OBJECTIVE: To evaluate quantitatively the effect of one good-quality (sponsoring) embryo in a batch of low-quality thawed embryos on the implantation and pregnancy rates (PR). DESIGN: Retrospective analysis of data. SETTING: Tertiary care center IVF clinic affiliated with a university medical school. PATIENT(S): Between March 1988 and April 1995, 392 IVF patients underwent a total of 440 thawing and ET cycles of 1,436 multicellular embryos. MAIN OUTCOME MEASURE(S): Implantation, clinical pregnancy, and multiple pregnancy rates. RESULT(S): In the absence of sponsoring embryos in the thawed batch of embryos, a PR of 9.8% with an implantation rate of 3.1% was achieved. In the presence of a single sponsoring embryo, the PR nearly doubled (18.2%), with a significantly higher implantation rate of 7.0%. Only singleton pregnancies were achieved in the absence of sponsoring embryos compared with 21.7% multiple pregnancies in the single sponsoring embryo group. CONCLUSION(S): The presence of a sponsoring embryo in a batch of poor quality thawed embryos is an important factor that significantly increased pregnancy and implantation rates. The optimal strategy for planning batches of multicellular frozen embryos is to include at least one sponsoring embryo in each batch when possible. We speculate that the sponsoring embryo may favorably influence the chances of low-quality embryos to undergo successful implantation.     

Human menopausal gonadotropin during in vitro maturation of human oocytes retrieved from small follicles enhances in vitro fertilization and cleavage rates

OBJECTIVES: To compare the IVF rates of oocytes retrieved from small follicles (< 2 mL in volume) with those of oocytes retrieved from large follicles and to test the effect of adding gonadotropins to the IVF medium on the fertilization rates of oocytes from small follicles. DESIGN: Oocytes were retrieved with endovaginal ultrasound (US) guidance from patients undergoing infertility treatment in our IVF program. Oocytes were grouped according to the volume of the originating follicle and subjected to our routine procedure for IVF. HMG was added to the IVF medium for some of the oocytes from small follicles. SETTING: Toronto Fertility and Sterility Institute is affiliated with the University of Western Ontario and University of Toronto and is equipped for RIA, endovaginal US monitoring and oocyte retrieval, and for processing and culturing gametes and embryos. PATIENTS: Infertile patients admitted to our IVF program. INTERVENTIONS: Patients underwent ovarian stimulation with hMG before oocyte retrieval. No other interventions were introduced to the processing and culturing the gametes and embryos except the addition of hMG to the medium of some of the small follicle-originated oocytes with the informed consent from the patients. MAIN OUTCOME MEASURES: Rates of fertilization, cleavage of the fertilized embryos before replacement, and meiotic status of some of the oocytes from small follicles. RESULTS: Most of the oocytes from small follicles did not complete the first meiotic division; they had low rates of fertilization and cleavage compared with oocytes from large follicles, and these rates were improved by the addition of hMG to the IVF medium. CONCLUSIONS: Oocytes from small follicles are probably less mature and require a more physiological environment to achieve normal rates of fertilization and cleavage.     

In vitro fertilization treatment for severe male factor: a comparative study of intracytoplasmic sperm injection with testicular sperm extraction and with spermatozoa from ejaculate

PURPOSE: Our purpose was to evaluate whether the source of spermatozoa influences the results of intracytoplasmic sperm injection (ICSI) treatment in couples with severe male-factor infertility. METHODS: A retrospective analysis of 40 cases of ICSI with testicular-retrieved spermatozoa, matched with 40 cases of ICSI with ejaculated spermatozoa, was performed. We included only couples with normoovulatory females younger than 37 years who were matched according to the day of ovum pickup with the patients in the study group. RESULTS: Eighty cycles were analyzed: 40 cycles using testicular spermatozoa and 40 cycles using ejaculated spermatozoa. In 32 (80%) of the 40 ICSI transcutaneous needle aspiration cycles, we obtained enough spermatozoa to inject all the mature oocytes retrieved. In eight (20%) cases there were not enough spermatozoa to inject all the oocytes. Only 76 (54%) of 141 available oocytes were injected in these eight patients. The oocyte fertilization rates were 42% for the study group and 55.5% for the controls (P < 0.005). Thirty-six (90%) patients in the group with nonobstructive a zoospermia (NOA) and 37 (92.5%) patients in the oligoteratoasthenospermia (OTA) group had embryos for replacement. The mean cleavage rates per cycle (96% with testicular and 93% with ejaculated spermatozoa), the mean number of embryos per transfer (3.72 +/- 1.6 in the NOA group and 4.24 +/- 1.5 in the OTA group), the embryo quality (cumulative embryo scoring = 34.03 +/- 22.62 in the testicular sperm group and 36.08 +/- 19.28 in the ejaculated sperm group), and the clinical pregnancy rates (22.5% in the NOA patients and 20% in the ejaculate group) were not significantly different between groups. CONCLUSIONS: High fertilization, cleavage, and pregnancy rates can be achieved with intracytoplasmic testicular sperm injection from patients with NOA, reaching levels comparable with those of ICSI using ejaculated spermatozoa.