Correlation between human follicular diameter and oocyte outcomes in an ICSI program

Purpose: To determine the correlation between the follicular sizes and oocyte recovery, metaphase II oocyte recovery, fertilization rate and good embryo quality from mature and immature oocytes in an intracytoplasmic sperm injection (ICSI) program. Methods: 991 follicles obtained from 72 ICSI cycles were classified into three groups according to their diameters as measured by transvaginal ultrasound including group A (<10 mm), group B (10–14 mm), and group C (>14 mm). All obtained oocytes were classified according to their nuclear maturation: germinal vesicle (GV), metaphase I (MI) and metaphase II (MII). Mature oocytes underwent ICSI while immature oocytes were further cultured until maturity before ICSI was performed. The rates of fertilization and good quality embryos at day 3 were evaluated. Results: A progressive and significant increase in the rates of oocyte recovery and MII oocyte recovery were observed from group A follicles compared to the other groups (p < 0.001). The fertilization rate of mature and in vitro matured oocytes, as well as the rate of good quality embryos showed a tendency to increase from group A to group C follicles, but not significantly. The corresponding fertilization rates were 78 and 55.3% (p < 0.001) for mature and in vitro matured oocytes, respectively. Conclusion: Collection of oocytes from small follicles, especially with a mean diameter less than 10 mm, and in vitro maturation of immature oocytes before fertilization may allow the total number of good quality and transferable embryos to be increased.     

Intracytoplasmic Sperm Injection and Conventional In Vitro Fertilization Are Complementary Techniques in Management of Unexplained Infertility

Purpose : To evaluate the role of ICSI in unexplained infertility. Methods : In 125 cycles with six or more oocytes retrieved per cycle, sibling oocytes were randomly allocated to IVF or ICSI (group A). In 74 cycles with less than six oocytes retrieved per cycle, cycles were allocated to IVF or ICSI (group B). Results : In group A, ICSI fertilization rate of 61% per allocated oocyte was higher than IVF fertilization rate of 51.6% (P < 0.001). Complete fertilization failure occurred in 19.2 and 0.8% of cycles in IVF and ICSI, respectively (P < 0.001). In group B, fertilization rate in IVF cycles was 53.3% as compared to 60.7% per allocated oocyte in the ICSI cycles (P = 0.29). Complete fertilization failure was higher (P = 0.02) in conventional IVF (34.3%) than ICSI cycles (10.3%). Conclusions : Allocation of sibling oocytes to IVF and ICSI in the first cycle minimizes risk of fertilization failure. For patients with limited number of oocytes, ICSI technique is recommended.     

The Effect of Preincubation Period of Oocytes on Nuclear Maturity, Fertilization Rate, Embryo Quality, and Pregnancy Outcome in IVF and ICSI

Purpose : To clarify the effect of preincubation of oocytes on the results of IVF and ICSI. Methods : A total of 176 IVF and 64 ICSI cycles received long protocol ovarian stimulation. The oocytes were incubated for 1–8 h before insemination or sperm injection. Metaphase II (MII) percentage was evaluated in the ICSI arm; fertilization rates, embryo quality, and pregnancy outcomes were analyzed in both IVF and ICSI arms according to the preincubation period duration of oocytes. Results : The MII percentage of the ICSI arm was significantly lower (P < 0.05) in the group with preincubation period of <2.5 h. The fertilization rates in groups with preincubation for 2.5–5.5 h were significantly higher (P < 0.001) for IVF. Embryo quality and pregnancy outcomes were not significantly different between the IVF or ICSI arm. Conclusions : The preincubation of oocytes for at least 2.5 h is beneficial to both IVF and ICSI outcomes by increasing the nuclear maturity of oocytes.     

Pregnancies and births resulting from in vitro matured oocytes fertilized with testicular spermatozoa

Purpose: In vitro maturation (IVM) of immature human oocytes is an attractive option for the treatment of infertility. Similarly, intracytoplasmic sperm injection (ICSI) followed by testicular fine needle aspiration (TEFNA) is an important treatment for primarily male-factor infertility. This report highlights the combination of these two advanced assisted reproduction techniques, namely IVM and fertilization with TEFNA-retrieved spermatozoa by ICSI to overcome both of male and female infertility problems.Methods: Before immature oocyte retrieval (IOR), gonadotropin stimulation was given for 3 or 5 days. Following IVM, and mature oocytes were inseminated by ICSI followed by TEFNA.Results: Four couples with five completed treatment cycles were performed, and total of 36 immature oocytes were retrieved. Following 36 to 48 h of culture, 32 (88.89%, 32/36) oocytes became mature. The mature oocytes were inseminated with TEFNA-retrieved sperm, and 18 (56.25%, 18/32) oocytes were fertilized normally following ICSI. Eleven embryos were transferred in five cycles and two pregnancies and two singleton births were achieved in two patients.Conclusions: This result demonstrates that the successful pregnancies and live births can be established from embryos produced from {in vitro} matured oocytes that fertilized with testicular sperm.     

Pronuclear abnormalities and cytoskeletal organization during assisted fertilization in a patient with multifollicular ovarian response

Purpose : To analyze the distribution of tubulins and acetylated tubulins and the chromatin configuration in abnormally fertilized zygotes from a patient with a multifollicular ovarian response after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Methods : Immunofluorescence and phase contrast microscopy was performed in abnormally fertilized zygotes. Results : After phase contrast microscopy analysis, immunofluorescence staining was performed in 20 oocytes that developed 3 pronuclei (PN) and karyomeres after IVF–ICSI. Around 80% of the abnormal zygotes from IVF were the consequence of monospermic fertilizations. Retention of the second polar body (PB) and the presumptive split of 1 PN within the cytoplasm were the main events present in most oocytes after IVF–ICSI. Conclusions : Fluorescence labeling of selected sperm and oocyte components affords a unique view of abnormal fertilized zygotes. Surprisingly, anomalies detected after IVF–ICSI showed similar etiologies in this special group of zygotes.     

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 intracytoplasmic 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.     

Intracytoplasmic sperm injection improving embryo quality: Comparison of the sibling oocytes of Non-Male-Factor couples

Objective: Our objective was to investigate whether the quality of embryos developed after intracytoplasmic sperm injection (ICSI) is better than that of conventional IVF embryos. Methods: Nine couples who previously achieved a normal rate of fertilization following IVF and four couples whose normal rate of fertilization was expected were involved in this study. The oocytes from those couples were randomly divided into two groups, group A by conventional insemination and group B by ICSI. The fertilization rate and quality of embryos were compared. Results: Normal fertilization was achieved in 61% of the oocytes (83/136) after conventional insemination. In group B, 69% of the oocytes (99/144) achieved normal fertilization, although only 127 metaphase II oocytes were injected using the ICSI technique. More grade A embryos were obtained when the ICSI technique was used for fertilization than by conventional IVF (35.4 and 24.3%, respectively;P=0.028). Conclusions: A similar fertilization rate can be achieved by ICSI in comparison with conventional IVF, when male factor is not involved. Embryos after ICSI have an improved quality.     

In Vitro Maturation and Fertilization of Immature Oocytes: A Comparative Study of Fertilization Techniques

Purpose: Our purpose was to investigate the factorsinfluencing maturation and fertilization of immature oocytes. Methods: Immature oocytes were obtained from womenundergoing cesarean section. They were cultured in thematuration medium either with or without cumulus cells. Aftermaturation to metaphase II, they were randomly fertilizedby in vitro fertilization (IVF) or intracytoplasmic sperminjection (ICSI). Results: After incubation for 48 hr, 441 oocytes (42.8%)reached metaphase II. Among them, 56.6% ofcumulus-enclosed oocytes, but only 29.2% of denuded oocytes,reached metaphase II. Of the 289 cumulus-enclosed oocytes,the fertilization rates by IVF and ICSI were 56.3 and 84.1%,respectively (P < 0.01). Of the 152 denuded oocytes, thefertilization rates by IVF and ICSI were 39.5 and 84.5%,respectively (P < 0.01). The cleavage rates, however,were similar. Conclusions: Cumulus cells are beneficial in the maturationof human oocytes in vitro and that ICSI increases thefertilization rate for the in vitro matured oocytes. Thedevelopmental potential of the fertilized oocytes, however, is similarirrespective of the fertilization method or the presence orabsence of cumulus cells.     

Intracytoplasmic sperm injection as a treatment for unexplained total fertilization failure or low fertilization after conventional in vitro fertilization

OBJECTIVE: To determine whether IVF or intracytoplasmic sperm injection (ICSI) should be the choice of treatment in case of a previous IVF attempt with unexplained total fertilization failure or low fertilization (<25%). DESIGN: Prospective study. SETTING: Leiden University Medical Center. PATIENT(S): Thirty-eight couples undergoing IVF and ICSI on sibling oocytes after a first IVF attempt with total fertilization failure or with low fertilization (<25%). INTERVENTION(S): Performing IVF and ICSI on sibling oocytes. MAIN OUTCOME MEASURE(S): Fertilization and (ongoing) pregnancy rate. RESULT(S): A total of 271 oocytes were collected in 24 oocyte retrievals in the total fertilization failure group. Hundred nine oocytes were randomly allocated to IVF and 12 were fertilized (11%); 162 sibling oocytes were allocated to ICSI and 78 were fertilized (48%). In 8 of the 24 patients fertilization occurred after IVF. The pregnancy rate after transfer of 1 IVF and 1 ICSI embryo (n = 3) was 67% and after the transfer of 2 ICSI embryos (n = 21) this was 52%. In the low fertilization group 169 oocytes were collected in 14 oocyte retrievals. Seventy-two oocytes were randomly allocated to IVF and 16 were fertilized (22%). Ninety-seven sibling oocytes were allocated to ICSI and 58 were fertilized (60%). In 7 of 14 patients fertilization occurred after IVF. The pregnancy rate after the transfer of 1 IVF and 1 ICSI embryo (n = 5) was 80% and after the transfer of 2 ICSI embryos (n = 9) this was 33%. CONCLUSION(S): Performing ICSI on some oocytes of a cohort may avoid total fertilization failures both in patients with a history of total fertilization failure and in patients with a history of low fertilization, as the percentage of fertilization is higher after ICSI compared to IVF and the recurrence of total fertilization failure and low fertilization is high after IVF treatment.     

Cytogenetic analysis of spontaneously activated noninseminated oocytes and parthenogenetically activated failed fertilized human oocytes--implications for the use of primate parthenotes for stem cell production

Purpose: Spontaneous parthenogenetically activated noninseminated oocytes and failed fertilized oocytes after ART activated by puromycin were studied to assess cleavage ability and the cytogenetic constitution of the resulting embryos. Methods: Failed fertilized oocytes were exposed to puromycin, and whenever activation occurred, they were further cultured until arrest of development. FISH was used to assess the ploidy of spontaneous (group A) and induced parthenotes (group B). Results: The mean number of oocytes exposed to puromycin and the percentage and type of activation were identical in IVF and ICSI patients. The more frequent types of activation were one or two pronuclei and one polar body suggesting that retention of the second polar body is a common event after parthenogenetic activation. Conclusions: Retention of the second polar body and chromosome malsegregation were observed after parthenogenetic activation, either spontaneous or induced by puromycin. This means that using parthenogenetic embryos for stem cell research will require great care and attention.     

Early rescue oocyte activation for activation-impaired oocytes with no second polar body extrusion after intracytoplasmic sperm injection

PurposeWhen rescue artificial oocyte activation (ROA) is performed on the day after intracytoplasmic sperm injection (ICSI) or later, embryonic development is poor and seldom results in live births. The efficacy of an early ROA after ICSI is unclear. Is early ROA effective in rescuing unfertilized oocytes that have not undergone second polar body extrusion several hours after ICSI?MethodsWe performed retrospective cohort study between October 2016 and September 2019, targeting 2891 oocytes in 843 cycles when ICSI was performed. We performed ROA with calcium ionophore on 395 of the 475 oocytes with no second polar extrusion 2.5–6 h after ICSI.ResultsThe normal fertilization rate of ROA oocytes was significantly higher than non-ROA oocytes (65.8% vs 6.7%, P < 0.001). The blastocyst development rate in ROA oocytes was significantly lower than spontaneously activated oocytes (48.9% vs 67.2%, P < 0.001). The ROA oocyte implantation rate did not significantly differ from the spontaneously activated oocytes (36.0% vs 41.2%). We observed no differences in the implantation rates and blastocyst development rates over the 2.5–6 h from ICSI until ROA.ConclusionEarly ROA is effective, and the optimal timing appears to be 2.5–6 h after ICSI.     

Fertilization after standard in vitro fertilization versus intracytoplasmic sperm injection in subfertile males using sibling oocytes

OBJECTIVE: To compare conventional IVF with ICSI in the subfertile male population using sibling oocytes. Results from males with isolated severe teratozoospermia also are analyzed. DESIGN: Prospective experimental study. SETTING: University based IVF clinic. PATIENT(S): Group A: 18 patients with one or more abnormalities in count, motility, or morphology. Group B: 20 patients with isolated severe teratozoospermia (< or = 4% Kruger Strict Criteria). INTERVENTION(S): Ovulation induction, random allocation of sibling oocytes, and IVF or ICSI. MAIN OUTCOME MEASURE(s): Fertilization rates (fertilization per cycle, fertilization per oocytes, and fertilization per couple) and embryo quality. RESULT(S): In group A, fertilization occurred in 13 of 18 (72%) of IVF cycles and 17 of 18 (94%) of ICSI cycles. Overall, 69 of 120 (58%) oocytes fertilized after IVF, whereas 80 of 131 (61%) fertilized after ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 44.6%+/-9.0% with IVF and 62.7%+/-5.6% with ICSI (not statistically significant). In group B, fertilization occurred in 18 of 20 (90%) cycles after IVF and 20 of 20 (100%) cycles with ICSI. Overall, 54 of 113 (48%) of the oocytes fertilized after IVF, whereas 82 of 124 (66%) fertilized with ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 50.9%+/-7.1 % with IVF and 66.6%+/-4.7% with ICSI. No statistically significant difference in embryo quality after IVF versus ICSI was demonstrated. CONCLUSION(S): With severe teratozoospermia, ICSI results in higher fertilization rates than conventional IVF, without altering embryo quality. In our subfertile male population, there is a trend toward improved fertilization with ICSI, with less failed fertilization.     

Are Cumulus Cells Necessary for the Spontaneous Maturation of Germinal Vesicle-Stage Oocytes to Metaphase II

Purpose: In this study we investigated the need of the support from cumulus cells for germinal-vesicle (GV) oocytes collected from stimulated ovaries to complete their maturation to metaphase II (MII). Methods: We compared the maturation rate of GV oocytes after coculture with cumulus cells (study group) with their spontaneous maturation in culture medium alone (control group). Results: Sixty-four and nine-tenths percent of the GV oocytes matured to metaphase II in the coculture group, and of these, 43.5% gave normal 2pn zygotes following intracytoplasmic sperm injection (ICSI), while 73.8% of the GV oocytes spontaneously matured to the MII stage and 30% of these reached the zygote stage after ICSI. Conclusions: It is probable that a follicular factor is responsible for this arrested maturation in the human and that maturation occurs spontaneously when the oocytes are separated from their follicular fluid environment after collection.     

Intracytoplasmic sperm injection using hyaluronic acid or polyvinylpyrrolidone: a time-lapse sibling oocyte study

This study evaluated the effect of sperm selection and intracytoplasmic sperm injection (ICSI) on subsequent fertilization and embryo development using the hyaluronic acid-based SpermSlow? (HA-ICSI) compared to injection with polyvinylpyrrolidone (PVP-ICSI). A total of 206 metaphase II oocytes were collected from 21 prospectively enrolled ICSI cycles at Fertility North between July 2014 and March 2015. Sibling oocytes were randomized into HA-ICSI and PVP-ICSI (n?=?103 per group). Subsequent fertilization outcomes and embryo development in terms of qualitative and quantitative time-lapse measures following three-day culture in the Embryoscope? were compared. HA-ICSI resulted in significantly lower abnormal fertilization rates (1.9% vs 9.7%, p?=?0.017), and a trend towards increased normal fertilization rates (73.8% vs 62.1%, p?=?0.073) with increased injection time (2.5 vs 2.1?min, p?=?0.001). No differences between HA-ICSI and PVP-ICSI were observed in (a) the proportion of good conventional morphology embryos (50% vs 53.1%, p?=?0.712), (b) time-lapse qualitative measures (p?>?0.05) and (c) time-lapse quantitative measures (p?>?0.05). In conclusion, HA-ICSI improves fertilization outcomes although sperm injection takes longer to complete. Subsequent embryo development up to day 3 is not affected.     

Sibling oocyte submission to IVF and ICSI in unexplained infertility patients: a potential assay for gamete quality

In order to reduce total fertilization failure in unexplained infertility, sibling oocytes were submitted to both conventional IVF and intracytoplasmic sperm injection (ICSI). Two groups of ICSI embryos were compared in unexplained infertility patients: those derived from ICSI when IVF had failed to fertilize, and those derived from ICSI while their sibling oocytes were fertilized by IVF. The outcome of oocytes fertilized exclusively by ICSI (essential ICSI, n = 749) was compared with those fertilized both by IVF and ICSI (non-essential ICSI, n = 957) in all IVF patients treated for unexplained infertility at the Hadassah Hospital (1999-2002). The latter group was further subdivided into ICSI and IVF embryos. Total fertilization rate was 54%. Fertilization rates by ICSI were lower in the essential ICSI compared with the non-essential ICSI group, at 65 and 73% (P < 0.025). Pregnancy rates per embryo transfer in the essential ICSI group (49%), ICSI derived embryos group (55%) and IVF derived embryos (44%) from the non-essential ICSI group, were similar. Implantation rates were lower in the essential ICSI group as compared with the non-essential ICSI group (21 versus 32% respectively; P < 0.05) and 26% for IVF embryos. In conclusion, essential ICSI was associated with lower fertilization and implantation rates.     

Embryological indicators in cycles with HCG or different doses of GnRH-a for the final oocyte maturation in IVF–ICSI patients

Abstract

So far there is no consensus on the optimal dosage of GnRH-a when using it as a trigger for final oocyte maturation in in vitro fertilization (IVF) cycles. We compared embryological characteristics in IVF–intra-cytoplasmic sperm injection (ICSI) cycles when applying triptorelin at a dose of 0.2?mg (test group 2), 0.5?mg (test group 3) and human chorionic gonadotropin (HCG) at a dose of 10?000?IU (test group 1). In group 1, the average number of oocytes per oocyte retrieval (11.7?±?4.8) was lower in comparison with groups 2 and 3, which can be explained by the differences in the selection of the patients’. The number of oocytes per retrieval in group 3 (20.2?±?6.3) was significantly higher (p?=?0.02) compared to group 2 (17.0?±?6.2). The percentage of mature oocytes (MII) and fertilization rate did not differ between the groups. The rate of blastocyst formation in group 3 (71.9?±?17.1%) was significantly higher (p?=?0.02) in comparison with group 2 (57.9?±?24%). We conclude that the application of triptorelin at a dose of 0.5?mg may be more effective for triggering final oocyte maturation in IVF cycles in comparison with the dose of 0.2?mg, due to the increase in the number of retrieved oocytes and the improved rate of the blastocyst formation.     

Effect of normal sperm morphology rate (NSMR) on clinical outcomes and fertilization methods selection in the ultra-short-term GnRH-a protocol

Purpose: To investigate whether intracytoplasmic sperm injection (ICSI) can improve the clinical outcomes of the male patients with teratozoospermia in the ultra-short term GnRH-a protocol.

Methods: Based on different normal sperm morphology rate (NSMR), the patients were divided into three groups as follows: NSMR?=?0% group, 1% ≤NSMR <4% group and NSMR ≥4% group. Each group was compared with two fertilization type of in-vitro fertilization (IVF) and ICSI separately. Main outcomes compared were normal fertilization, high-quality embryo, transferrable embryo, implantation, pregnancy and abortion rate.

Results: We observed that the total clinical pregnancy rate in single cleavage-stage embryo transfer (SET) group was significantly lower compared with double cleavage-stage embryo transfer (DET) group (23.87% versus 40.08%; p?p?>?0.05). The normal fertilization, high-quality embryo, transferrable embryo, implantation, pregnancy and abortion rate of IVF and ICSI showed no significant difference among three groups (p?>?0.05).

Conclusion: ICSI cannot improve clinical outcomes of the patients with teratozoospermia in the ultra-short term GnRH-a protocol.     

Second polar body extrusion is highly predictive for oocyte fertilization as soon as 3 hr after intracytoplasmic sperm injection (ICSI)

Objective Our objective was to evaluate the time course and the predictive value of the extrusion of the second polar body after intracytoplasmic injection (ICSI) related to the fertilization rate, embryo cleavage and quality.Setting The setting was the in vitro fertilization program of a university hospital.Patients Twenty-one patients were treated with intracytoplasmic single sperm injection either for fertilization failure in IVF, low fertilization in IVF (<5%), or severe male factors.Design One hundred thirty-five of 205 metaphase 2 oocytes treated with intracytoplasmic single sperm injection were observed 1, 2, and 3 hr after the assisted fertilization procedure. Extrusion of the second polar body was recorded. For each of these oocytes, fertilization was noted 18 hr after ICSI and cleavage and embryo quality were assessed 24 hr later. The 70 remaining oocytes were used to assess a possible negative effect of repeated exposure to light microscopy.Results The extrusion of the second polar body 3 hr after injection was an observation with a sensitivity of 0.87, a specificity of 0.58, and a high positive predictive value (0.90) toward oocyte fertilization. Twenty-nine and four-tenths percent of the oocytes extruded a second polar body within the first hour, 56.6% within the first 2 hr, and 78.3% had a second polar body 3 hr after injection. This time course was related neither to the speed of embryo cleavage nor to the embryo quality. Fertilization, cleavage, and embryo quality were not affected by repeated observation as deduced from comparison with the control group and confirmed by a high pregnancy (62% per oocyte retrieval) and implantation rate (22% per replaced embryo).Conclusion Oocytes can be checked, in all safety, 3 hr after a single sperm injection for the presence of a second polar to predict oocyte fertilization with a high certainty.     

Is Intracytoplasmic Sperm Injection Necessary for Couples Undergoing In Vitro Fertilization–Embryo Transfer with Normal Semen Analyses but Failing Hamster Egg Penetration Assays?

Purpose: Our purpose was to assess whether in vitro fertilization (IVF)–embryo transfer (ET) candidate couples with basically normal semen analyses but failing zona-free hamster egg penetration assay (HEPA) scares benefit from intracytoplasmic sperm injection (ICSI). Methods: Twenty consecutive IVF candidate couples with normal–borderline semen analyses and failing HEPA scores were recruited. Mature oocytes obtained from each woman were randomly divided between ICSI (group I; n = 126 oocytes) and standard insemination techniques (group II; 138 oocytes). Fertilization (two pronuclei) and cleavage (2–4 cells) rates were assessed for both groups. Results: There were no statistically significant differences between the two groups with respect to (mean ± standard error of the mean) fertilization (group I, 63.1 ± 7.75; group II, 77.8 ± 4.7%) or cleavage (group I, 87.3 ± 2.4%; group II, 91.2 ± 3.5%) rates. Conclusions: ICSI is not beneficial for IVF-ET when sperm samples demonstrate a failing HEPA score but have normal or minimally compromised semen analysis parameters.     

Intracytoplasmic sperm injection (ICSI) in unexplained and stage I endometriosis-associated infertility after fertilization failure with in vitro fertilization (IVF)

Purpose: To investigate possible differences between unexplained and stage I endometriosis-associated infertility in ICSI cycles conducted after low fertilization (<20%) in preceding IVF cycles with normal semen parameters. Methods: Retrospective cohort study consisting of patients with unexplained (n=48) and stage I endometriosis-associated infertility (n=43) with a minimum of one IVF cycle with <20% fertilized oocytes and normal semen quality, treated with ICSI from January 1997 to January 2006. Age matched male factor infertility patients (n=91) were used as controls. Results: Diploid fertilization rate was significantly lower in the stage I endometriosis-associated infertility group compared to the unexplained infertility group. Score of the transferred embryos, implantation rate, pregnancy rate and outcome were similar in the two groups. Conclusions: ICSI appears to be an efficient treatment option after fertilization failure with IVF in unexplained and stage I endometriosis-associated infertility.