Assisted Reproduction Treatment Outcome Research Articles

Increasing dehydration of human cleavage-stage embryos prior to slow cooling significantly increases cryosurvival

Increasing the proportions of embryos and blastomeres which survive cryopreservation would be expected to make a significant contribution to the outcome of assisted reproduction treatment. Despite this, the methodology used for slow cooling of human cleavage-stage embryos has remained largely unchanged for over two decades. Previous studies have demonstrated the value, in terms of cryosurvival, of increasing the extent of intracellular dehydration by increasing the concentration of non-permeating cryoprotectant prior to slow cooling of oocytes and embryos which have been biopsied for preimplantation genetic diagnosis. The present study extends the use of this approach to the slow cooling of non-biopsied day-2 embryos. Dehydration in the presence of 0.2 mol/l sucrose significantly increased the proportions of surviving embryos, surviving blastomeres and fully intact embryos (92.6%, 91.1%, and 80.4%, respectively) relative to those observed after dehydration in 0.1 mol/l sucrose (78.5%, 74.1%, and 54.6%, respectively, all P < 0.001). Post-thaw resumption of mitosis in vitro and implantation were not adversely affected by the increased prefreeze dehydration. This improved method for slow cooling of cleavage-stage embryos should have a major impact on clinical outcome.

Assisted reproductive treatment outcome in a large cohort of women with serum FSH above 15 IU/L

OBJECTIVE: To investigate the assisted reproductive treatment (ART) outcome of women with basal FSH higher than 15 IU/l and stratify the results according to woman age. DESIGN: Retrospective study. MATERIALS AND METHODS: Patient data during the period of January 2002 to October 2008 were reviewed to reveal women with basal FSH higher than 15 IU/l. A total of 454 patients were evaluated for cycle characteristics and the ART outcome. The results were further stratified according to the women age and four groups were formed as lower than 30 years, 30-34 years, 35-39 years and ≥40 years age groups. Values were expressed as mean±SD or percentages. For statistical evaluations chi-squared test and one-way ANOVA were used, as applicable. RESULTS: Overall implantation rate (IR), pregnancy rate per embryo transfer (PR/ET) and miscarriage rate in this group of women with basal FSH above 15 IU/l were found to be 15%, 25% and 33%, respectively. When the results were stratified according to the woman age, IR and PR/ET became significantly higher as the woman age became younger although the mean FSH values were similar among the groups.Table 1Cycle characteristics and the outcome of ART patients with basal FSH above 15 IU/l.<30 years30-34 years35-39 years≥40 yearsPCycles (n)3992138185Embryo transfers, n (%)32 (82)59 (64)103 (75)105 (57)0.001MII oocytes, n4.0 ± 3.13.6 ± 2.82.5 ± 1.92.2 ± 1.5<0.0001Fertilization, %86 ± 1971 ± 3680 ± 3271 ± 38NSImplantation, % (n)28 (17/60)18 (22/125)16 (31/200)7 (11/169)0.0003PR/ET, % (n)38 (12/32)31 (18/59)28 (29/103)15 (16/105)0.02Miscarriage rate, % (n)17 (2/12)28 (5/18)38 (11/29)44 (7/16)NSValues are mean±SD or percentages. Chi-squared test, one-way ANOVA. Open table in a new tab Values are mean±SD or percentages. Chi-squared test, one-way ANOVA. CONCLUSIONS: Basal FSH level above 15 IU/l may be a poor prognostic factor in ART, however woman age and ovarian response to the stimulation are more important determinants for the outcome.

The effect of a fall in the serum estradiol level prior to egg retrieval on the outcome of assisted reproductive treatment in poor responder women

OBJECTIVE: To investigate the impact of serum E2 decrease following HCG administration on the outcome of ART in poor responder (PR) women. DESIGN: A retrospective study. MATERIALS AND METHODS: Patient files were reviewed to reveal PR women in whom serum E2 level was observed to decrease on the day after HCG administration. A total of 315 PR women treated between 2003 and 2008 were included in the study. Poor response was considered when lower than five oocytes were retrieved. Three groups of patients were formed according to the rate of E2 decrease between the day of HCG administration and the day after HCG administration: group 1 (n=162) <10% decrease, group 2 (n=128) 10-30% decrease and group 3 (n=25) ≥30% decrease. Primary outcome measures were implantation, pregnancy and miscarriage rates. Chi-squared test and one-way ANOVA were used for statistical evaluation. RESULTS: No significant difference was found in implantation rate (14%, 12% and 11%), pregnancy rate per embryo transfer (24%, 20% and 16%) and miscarriage rate (49%, 46% and 25%) between <10%, 10-30% and ≥30% E2 decrease groups.Table 1Cycle characteristics and the outcome of poor responder women undergoing ART compared according to the rate of decrease between serum E2 level on the day of HCG administration and the day after HCG administration.<10% decrease10-30% decrease≥30% decreasePAge (years)37.1 ± 4.837.0 ± 5.337.6 ± 4.8NSE2 on the day of HCG administration (pg/ml)785 ± 334 f897 ± 529 g704 ± 6480.045Total oocytes, n2.6 ± 0.9 a2.6 ± 1.1 a1.9 ± 0.9 b0.005Fertilization, %83 ± 2485 ± 2586 ± 27NSImplantation, % (n)14 (37/267)12 (24/203)11 (3/28)NSβHCG positive PR/ET, % (n)24 (39/162)20 (26/128)16 (4/25)NSMiscarriage rate, % (n)49 (19/39)46 (12/26)25 (1/4)NSa vs. b; p=0.002, f vs. g; p=0.038. Open table in a new tab a vs. b; p=0.002, f vs. g; p=0.038. CONCLUSIONS: There is no significant effect of a decrease in the serum E2 level prior to egg retrieval on implantation and pregnancy outcome in poor responder women undergoing ART.

Comparing assisted reproductive technology (ART) patient characteristics and treatment outcomes for US residents and non-residents with poor prognoses: an analysis of US surveillance data, 2004-2007

OBJECTIVE: The number of assisted reproductive technology (ART) cycles undertaken by US non-residents (NRs) at US ART clinics increased 79%, 980 in 2004 to 1758 in 2007. Little is known about NRs who seek ART treatment in the US. We examined differences in patient characteristics and treatment outcomes between NR and US ART users with poor prognoses.

Cytokine and nitric oxide concentrations in follicular fluid and blood serum of patients undergoing assisted reproductive treatment: relationship to outcome

OBJECTIVE: The role of cytokines and nitric oxide (NO) in ovarian folliculogenesis and the development of mature and fertilizable oocytes is controversial. The aim of this study is to determine the concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-12, tumor necrosis factor (TNF)-α and NO in the follicular fluid (FF) and blood serum (S) of patients undergoing assisted reproductive treatment (ART) and to investigate whether these cytokines could be used as a predictive parameter for ART outcome.

Timing of oocyte maturation and egg collection during controlled ovarian stimulation: a randomized controlled trial evaluating manual and automated measurements of follicle diameter

To evaluate the effect of a new automated technique of follicle measurement (Sono automated volume calculation [SonoAVC]) on the timing of oocyte maturation and subsequent oocyte retrieval. Prospective randomized controlled trial. University-based Assisted Conception Unit. Seventy-two women undergoing their first cycle of assisted reproduction treatment. The timing of final follicle maturation and oocyte retrieval based on follicle tracking with use of either conventional two-dimensional (2D) ultrasound or SonoAVC. The number of mature oocytes retrieved and clinical pregnancy rate. The number of the mature oocytes collected (10.70 +/- 6.08 vs. 11.43 +/- 6.17), the number of fertilized oocytes (7.27 +/- 4.78 vs. 7.97 +/- 5.25), and the clinical pregnancy rates (42% vs. 43%) were similar with both 2D ultrasound and SonoAVC methods. Automated follicle tracking using SonoAVC identifies a comparable number of follicles to real-time 2D ultrasound in this preliminary study. Timing final follicle maturation and egg retrieval on the basis of these automated measures does not appear to improve the clinical outcome of assisted reproduction treatment.

Outcome of assisted reproduction treatment in patients with endometrial thickness less than 7 mm

Endometrial thickness is one of the parameters contributing to the outcome of assisted reproduction treatment. The aim of the current study was to investigate the pregnancy rate and the outcome when the endometrial thickness was <7 mm during a treatment cycle. Treatments conducted between January 2000 and December 2004 at the German Hospital in Istanbul were reviewed retrospectively. A total of 175 embryo transfer cycles with an endometrial thickness of <7 mm on the day of oocyte retrieval were assessed. The 175 oocyte retrieval-embryo transfer cycles resulted in 53 pregnancies (30%), of which 11% were biochemical pregnancies, 26% were miscarriages and 58% were delivered. The clinical pregnancy rate was 26%, miscarriage rate was 31% and live birth rate was 17%. However, the results were quite good when the patient age was <35 years or the number of oocytes retrieved was over five or the number of available embryos to transfer was three or more. In conclusion, when the endometrial thickness is <7 mm during an treatment cycle, the couple should be informed about the chance of pregnancy and the outcome. In a young normoresponder woman with at least three embryos available for transfer, transfer could be carried out, otherwise embryo freezing should be recommended.

Impact of intracytoplasmic morphologically selected sperm injection on assisted reproduction outcome: a review

To date, several publications have focused their attention on a new method for observing spermatozoa called ‘motile sperm organelle morphology examination’ (MSOME), which enables the evaluation of the fine nuclear morphology of motile spermatozoa in real time at high magnification (>×6000). As a consequence, a new microinjection procedure called intracytoplasmic morphologically selected sperm injection (IMSI) has been developed. The aim of the present work is therefore to evaluate the efficacy of the IMSI technique in the light of the current literature, focusing attention on the potential clinical application of the selection of strictly morphologically normal spermatozoa in patients undergoing conventional intracytoplasmic sperm injection treatments. In addition, a brief analysis of preliminary data regarding the relationship between IMSI and assisted reproduction treatment outcome is presented.

Management of prestimulation ovarian cysts during assisted reproductive treatments: impact of aspiration on the outcome

To evaluate the effect of basal ovarian cysts and also the impact of aspiration of those cysts at the onset of an assisted reproductive treatment (ART) cycle on stimulation characteristics and treatment outcome. A retrospective study of 162 normoresponder patients with basal cysts from whom at least five oocytes were retrieved was performed. They all received mid-luteal GnRH-a long protocol. Of 162 patients, 79 with basal cysts of 29.4 +/- 9.0 mm and initial estradiol (E2) of 221.2 +/- 24.3 pg/ml underwent cyst aspiration on day 3 and stimulation was initiated when E2 fell to <70 pg/ml. In the remaining 83 patients with basal cysts of 16.9 +/- 6.4 mm and initial E2 of 39.9 +/- 5.7 pg/ml, the stimulation was started with gonadotropins immediately. The cycle characteristics and the treatment outcomes were compared between those two groups. Further comparison was made between the two groups when initial E2 concentrations were <70 pg/ml. No significant differences were found between the two compared groups regarding stimulation parameters and treatment outcomes. Implantation rates (IR) were 27 and 23%, pregnancy rates (PR) were 64 and 54% and live birth rates were 47 and 41% in the cyst positive and cyst aspirated groups, respectively (P > 0.05). Basal ovarian cysts should not be considered a contraindication to gonadotropin initiation in normoresponder ART patients, provided serum E2 levels indicate down-regulation. Moreover, aspiration of basal cysts does not improve ART outcome when E2 levels are suppressed.

Laparoscopic proximal tubal division can preserve ovarian reserve for infertility patients with hydrosalpinges

To investigate whether laparoscopic proximal tubal division for the treatment of hydrosalpinges could preserve ovarian function. From June 2002 to October 2006, before assisted reproductive treatment (ART), a total of 17 infertile patients with bilateral hydrosalpinges were studied--11 patients underwent laparoscopic proximal tubal division (PTD group), and six underwent laparoscopic salpingectomy (salpingectomy group). In both groups, the basal follicle-stimulating hormone (FSH) values before and after surgery, the operation time and outcome of ART treatment were retrospectively evaluated. The mean FSH value before laparoscopic PTD was similar to that after surgery. The FSH value before laparoscopic salpingectomy significantly increased after surgery (6.8 +/- 1.1 vs 14.1 +/- 9.3). The operation time in the PTD group was significantly shorter than in the salpingectomy group. The outcomes of ART were similar in both groups. The pregnancy rate per patient in the PTD and salpingectomy groups were 45.5% and 50%, respectively. Laparoscopic proximal tubal division preserved ovarian function and was an optimal operation method for infertility patients with hydrosalpinges. The basal FSH values after laparoscopic proximal tubal division were comparable to those before surgery.

Involvement of cystic fibrosis transmembrane conductance regulator (CFTR) in the pathogenesis of hydrosalpinx induced by Chlamydia trachomatis infection

Genital Chlamydia (C) trachomatis infection has been recognized as the single most common cause of pelvic inflammatory disease leading to severe tubal damage, ectopic pregnancy, infertility and hydrosalpinx. However, the mechanism underlying the formation of hydrosalpinx induced by C. trachomatis infection remains largely unknown. We performed this study to determine the involvement of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel that regulates epithelial electrolyte and fluid secretion, in hydrosalpinx fluid formation. Western blot analysis was used to determine CFTR expression in the hydrosalpinges that were seen on the ultrasound scans of infertile assisted reproduction treatment patients. Correlation with C. trachomatis infection was done by testing patients' sera for C. trachomatis immunoglobulin G antibody titer using a Capita enzyme-linked immunosorbent assay based kit. CFTR involvement was further verified in a rat C. trachomatis infection model and confirmed using CFTR mutant (CFTR(tm1Unc)) mice. Here we report on the up-regulated expression of CFTR in the hydrosalpinx tissues of infertile patients with detectable serum levels of C. trachomatis antibody (immunoglobulin G). In a rat model, increased CFTR expression and fluid accumulation could be observed in the uterine horns infected with C. trachomatis elementary bodies, which was reversed by antibiotics treatment. In C. trachomatis-infected CFTR(tm1Unc) mice, however, no detectable fluid accumulation was observed. These findings suggest the involvement of CFTR in the pathogenesis of hydrosalpinx fluid formation and may provide grounds for a better treatment strategy to improve assisted reproduction treatment outcome in infertile patients with hydrosalpinx.

Implantation is apparently unaffected by the dopamine agonist Cabergoline when administered to prevent ovarian hyperstimulation syndrome in women undergoing assisted reproduction treatment: a pilot study

Ovarian hyperstimulation syndrome (OHSS) is a result of ovarian overexpression of vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2). VEGF/VEGFR2 binding disrupts cellular junctions and increases vascular permeability (VP), a characteristic of OHSS, but enhances angiogenesis, which is a fundamental step in implantation. In animals, the dopamine agonist Cabergoline (Cb2) prevents VP without affecting angiogenesis. In humans, Cb2 averts OHSS, but a possible detrimental effect on angiogenesis and implantation has not been explored. A pilot study was designed to analyze whether or not Cb2 administration, as a procedure for preventing OHSS, affects the outcome of assisted reproduction treatment (ART). A retrospective study with endpoints of implantation and ongoing/term pregnancy rates. Women (n = 35) at risk of OHSS (20-30 follicles developed and >20 oocytes collected) took a daily oral dose of 0.5 mg Cb2 for 8 days, beginning on the day of hCG. They were matched with controls treated during the same period and who were similar with respect to age, number and quality of the embryos replaced, embryonic stage at transfer and sperm quality. No difference was detected between the groups in fertilization, implantation or pregnancy rates. A total of 14 ongoing (beyond 32 weeks) or full term pregnancies were registered in each group. No major problem was detected during pregnancy or after delivery in any of these babies. Administration of Cb2 in order to prevent OHSS is safe and does not appear to affect ART outcome.

Association of body mass index with treatment outcomes on assisted reproduction treatment in korea

Obesity may adversely effect reproduction, but the effects of obesity on assisted reproduction treatment (ART) outcome are controversial . The distribution of body mass index (BMI) in Asians differs from Whites, however, most of the previous studies of the effects of BMI on ART were based on the Whites. We examined the distribution of BMI in Korean women who underwent in vitro fertilization (IVF) and the independent effect of BMI on ART.

The influence of body mass index to in-vitro fertilisation treatment outcome, risk of miscarriage and pregnancy outcome

SummaryThe aim of this work was to evaluate the effects of extreme body mass index (BMI) on assisted reproductive treatment outcome and pregnancy outcome. This is a descriptive cohort study that evaluated 8,145 consecutive in-vitro fertilisation/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles in which BMI were known, from July 1997 to June 2005 in an inner London major fertility clinic. The data were collected prospectively and analysed retrospectively on women undergoing IVF/ICSI and ET. Patients' weight and height were established prior to treatment. IVF/ICSI treatment was then started using either a long or an antagonist protocol. Patients were divided into five groups: Group A (BMI < 19); Group B (BMI between 19 and 25.9); Group C (BMI between 26 and 30.9); Group D (BMI between 31 and 35.9); Group E (BMI > 36). The main outcomes measured were number of eggs collected, fertilisation rate, number of embryos available for transfer, pregnancy rate (PR), live-birth rate (LBR) and miscarriage rate (MR). The results showed no significant difference in the average number of days taking follicle stimulating hormone (FSH) for ovarian stimulation, the average amount of gonadotrophin used for stimulation, number of eggs collected and fertilisation rate. The pregnancy rate, miscarriage rate and the live-birth rate were not statistically different between all groups. However, in group E the miscarriage rate was significantly higher and the LBR was statistically lower compared with group B. We concluded that extreme BMI did not affect the super-ovulation outcome fertilisation rate and pregnancy rate. Women with a BMI > 35 had a higher miscarriage rate and hence a lower live-birth rate, but a reasonable pregnancy and live-birth rate can be achieved. For women with a BMI < 20 there was no difference in assisted reproduction treatment (ART) outcome and pregnancy outcome when compared with women with a normal BMI. This information should be used to advise patients who wish to embark on ART with extreme BMI.

Acceptance of single-embryo transfer by patients

In New Zealand, patient motivation to accept single-embryo transfer can be measurably changed within a short period of time if patients are provided with credible clinical written and verbal communication, in addition to funding incentives from the Ministry of Health.

O-240: Sperm apoptosis compromises pronuclei morphology and pregnancy outcomes in ICSI cycles

Sperm DNA fragmentation has been used as a marker of male factor infertility and as a predictor of assisted reproduction treatment (ART) outcomes. Sperm DNA integrity has been shown to be necessary for achieving and sustaining embryo development. Several studies have suggested the relationship between DNA fragmentation and intrauterine insemination, in vitro fertilization (FIV) and intracytoplasmic sperm injection (ICSI) results. Furthermore, some studies have established statistical threshold levels for DNA fragmentation, which may influence ART success outcome. The present study aims to evaluate sperm DNA fragmentation, by necrosis and apoptosis and correlate it with sperm parameters and ICSI outcomes. Prospective study. This preliminary study included 10 ICSI cycles, in which women were younger than 35 years old, and had at least 4 oocytes recovered. Semen analysis had spermatozoa concentration ≥ 20 x 106 / mL and motility ≥ 50%. Semen samples were processed by swim-up and 200μL of supernatant were used to carry out the ICSI, and 300μL were used to flow cytometric analysis. The cells were fixed in 0.4% paraformaldehide and the DNA fragmentation was analyzed. Fluorescein isothiocyanate (FITC) labeled annexin-V was used to detect changes in membrane phospholipids distribution associated to apoptosis and Popidium Iodide (PI) to detect permeate damaged membranes and DNA fragmentation, associated to necrosis. Spermatozoa stained by annexin-V and PI was considered in advanced apoptosis process. The flow cytometry was adjusted to read 10.000 events and a negative control was included in all tests. The pre-embryo quality was assessed according to a cumulative score, since fertilization until transfer day. The statistical analysis was carried out by Pearson correlation and Mann-Whitney tests as appropriate. A p value <0.05 was considered statistically significant. Fifty one mature oocytes were injected and 41 (80.4%) had normal fertilization. There were no correlation between normal fertilization rate and apoptosis or necrosis incidence. When embryo morphology was evaluated, it was observed a positive correlation between presence of advanced apoptosis and abnormal pro-nucleus morphology (p=0,037). No correlation was found between embryo morphology in the second or third day of development and apoptosis or necrosis rates. Three couples had ongoing pregnancy in which the spermatozoa samples had in average 2.1% apoptosis, 23.1% advanced apoptosis and 21.6% necrosis. Among couples which achieved or not pregnancy, the total apoptosis rate was 26.1% ± 2.3 and 82.5% ± 16.5, respectively (p=0,014). These preliminary results show that the DNA fragmentation does not influence the fertilization rate, but does influence pre-embryo development and pregnancy rate. This study is to be continued to confirm the results.

The impact of endometrial polyps on assisted reproductive treatment outcome

The impact of endometrial polyps on assisted reproductive treatment outcome

Improvement of delivery and live birth rates after ICSI in women aged &gt;40 years by ovarian co-stimulation with growth hormone

Growth hormone (GH) is required for ovarian follicular development, and its administration during ovarian stimulation improves pregnancy rate in cow and sheep. Data on the use of exogenous GH in human assisted reproduction treatment are inconsistent. This prospective randomized study evaluates the usefulness of GH administration in women of >40 years undergoing ovarian stimulation for assisted reproduction treatment. One hundred women of >40 years undergoing assisted reproduction treatment were randomized between a GH treatment group and a placebo group. Assisted reproduction treatment outcomes were evaluated. In patients of the GH treatment group, a similar number of oocytes, embryos and pregnancies was achieved as compared with the placebo group. However, the patients treated with GH suffered fewer pregnancy losses, resulting in higher delivery and live birth rates. These patients also showed higher peak serum estradiol concentration and higher concentrations of GH and estradiol in pre-ovulatory follicular fluid as compared with the placebo group. Administration of GH during ovarian stimulation alleviates age-related decrease in assisted reproduction treatment efficiency. This effect appears to be mainly due to an improvement of oocyte developmental potential, but GH action on the uterus cannot be excluded.

Use of serum inhibin B levels at the start of ovarian stimulation and at oocyte pickup in the prediction of assisted reproduction treatment outcome

To assess whether serum inhibin B levels before gonadotropin administration and at oocyte pickup (OPU) are associated with pregnancy. Retrospective case-control study. University-based IVF program. Fifty-five IVF pregnancies and 55 control cycles matched by age, type of infertility, E(2) at ovulation induction, number of oocytes retrieved, and number of embryos replaced. None. Association between serum inhibin B at stimulation day 1 (SD1) and OPU and pregnancy; correlation between inhibin B with clinical and endocrine parameters; predictive accuracy of inhibin B measurements at OPU. Inhibin B on SD1 was similar between pregnant and nonpregnant subjects, whereas it was significantly higher at OPU in pregnant cycles, but did not allow differentiation between pregnancy outcomes. Inhibin B on SD1 was positively correlated with same-day E(2) in both groups and inversely with age in pregnant cycles. In both groups, inhibin B at OPU correlated positively with number of oocytes collected and with E(2) at ovulation induction. Higher inhibin B concentrations at OPU are predictive of clinical pregnancy, independently of age, peak E(2), number of oocytes retrieved and number of embryos replaced. Inhibin B on stimulation day 1 did not prove to be a useful predictor.

Prediction of outcomes of assisted reproductive technology treatment by calcium ionophore-induced acrosome reaction

Conventional semen analysis is not a good predictor of successful outcome of in vivo insemination, intrauterine insemination (IUI) or hysteroscopic intra-tubal insemination (HIT), or a predictor of complete fertilization failure (CFF) in conventional IVF (IVF). We investigated whether calcium ionophore induced acrosome reaction provides an additional indicator of pregnancy among various assisted reproduction modalities as well as an indicator of complete fertilization failure in IVF, independent of conventional semen parameters, sperm concentration and motility. prospective study Subjects included infertile couples with no female infertility factors (n=478) and women with tubal obstruction (n=32). Procedures included conventional IVF (IVF): n=148, ICSI: n=72, HIT: n=245, IUI: n=61. They all underwent a standard protocol of history-taking, physical examination and investigations including conventional semen analysis as well as a test of the sperm acrosome reaction following ionophore challenge. Every patient gave an informed consent prior to participating in this study, which was approved by the local Institutional Review Board, Faculty of Medicine. Calcium ionophore induced acrosomal reactivity was assessed in spermatozoa selected by swim-up. Spermatozoa on the slide were subjected to staining with fluorescent isothiocyanate-conjugated pisum sativum agglutinin (FITC-PSA) and with Hoescht 33258. Spermatozoa were considered viable when their heads were unstained or stained only lightly with Hoechst 33258. When the equatorial segment strongly stained with FITC-PSA, the spermatozoon was considered to have reacted. The percentage of acrosome-reacted spermatozoa to viable spermatozoa (%AR) was calculated. At least 300 spermatozoa per sample were examined to determine the %AR. We excluded abnormal or deformed spermatozoa, as well as unclassifiable fluorescence patterns. Multiple logistic regression analysis and receiver-operator characteristic (ROC) curve analysis were performed to determine the best predictive variables and cut-off values in the prediction of fertilization rate and pregnancy in each modality. χ-square analysis was used to compare the different fertilization and pregnancy rates. P<0.05 was considered significant. Cut-off value of %AR for IVF was 21% and the value was independent from the parameters of conventional semen analysis in predicting fertilization rate and pregnancy. Fertilization rate on IVF was higher for those with %AR over 21% compared to that of those with a lower percentage (63.6% vs. 35.4%; p<0.01). The pregnancy rate was also higher (43.1% vs. 18.9%; p<0.01). CFF was lower for those with %AR over 21% (24.5% vs. 4.2%,p<0.01). Fertilization rate, pregnancy rate, and CFF on ICSI did not differ for those with %AR over 21%. Pregnancy rates were higher for those with %AR over 21% than for those with a lower percentage on IUI (28.0% vs. 5.6%, p<0.05) and on HIT (23.9% vs. 6.2%, p<0.01). These data shows that %AR may be a novel parameter independent of conventional semen parameters in choosing assisted reproduction modalities. Thus, patients with acrosomal reactivity below 21% could not achieve pregnancy by IUI, HIT, or IVF with high rates. With reactivity below 21%, a low fertilization rate for initial IVF, ICSI or split fertilization is indicated.