Mean Total Motile Sperm Count Research Articles

Adolescent microsurgical varicocelectomy and changes in sperm parameters: A matched cohort analysis.

Varicocele, a common vascular abnormality surrounding the testis, is known to be associated with impaired semen parameters and male infertility in adults. However, its impact on the adolescent and young adult (AYA) population is less well known. The study aimed to assess the improvement in sperm parameters following varicocelectomy in the AYA population, comparing them to matched adult counterparts, and investigating potential advantages of early intervention. A retrospective analysis was conducted using a comprehensive database at the University of Miami spanning from 2012 to 2023. We included AYA (under 25 years of age) men who underwent varicocelectomy. To ensure comparability, they were matched with adult patients (over 30 years of age) based on preoperative follicle-stimulating hormone (FSH) values and varicocele grade in a 1:2 ratio. Semen parameters were evaluated before and after surgery, including sperm count, motility, morphology, and overall semen quality. We included 45 patients in the Adolescents and Young Adults (AYA) category, and matched them with 116 adults based on FSH and varicocele grade, all of whom underwent microsurgical varicocelectomy. The AYA group exhibited greater improvements post-varicocelectomy compared to the matched cohort. Furthermore, postoperative sperm concentration in the AYA men demonstrated a remarkable increase, with a 1.7-fold increase in mean concentration compared to the adult group (p<0.001). Additionally, motility also displayed significant enhancement among the AYA men, with a final mean total motile sperm count (TMSC) improvement of 2.25-fold compared to the adult cohort (p=0.002). This study highlights the potential benefits of varicocelectomy as a viable treatment option for adolescents and young adults with varicocele, particularly those with impaired semen parameters. By intervening at an earlier stage of development, patients in this age group can achieve significant improvements in semen quality, as compared to their adult counterparts. These findings underscore the importance of considering varicocelectomy as a valuable therapeutic approach for the younger demographic, potentially alleviating future fertility concerns.

(277) Predictors of Cryopreserved Sperm Quality Among Transgender Females Compared to Cisgender Males

Abstract Introduction Approximately 70% of transgender females express future interest in having children (Auer et al, 2018). However, studies have demonstrated poor semen parameters among this population who undergo sperm cryopreservation (Rodriguez-Wallberg et al, 2021). It remains poorly understood the underlying etiologies which place individuals at increased risk of suboptimal semen parameters. Objective We sought to identify clinical predictors of lower sperm quality among a cohort of transgender females and to compare this to a cohort of cisgender males. Methods We retrospectively identified 19 transgender women who underwent sperm cryopreservation at a single andrology lab within an academic institution between November 2021 and April 2023. We identified 16 age-matched cisgender male patients who also underwent sperm cryopreservation prior to oncologic treatment or vasectomy during this period. Data was abstracted from the electronic medical record. Statistical analysis was performed using SPSS version 28. Results Median age and body mass index of the transgender cohort was 25 years (range: 18-35) and 25.1 kg/m2 (range: 18.0-51.5). Median age and BMI of the cisgender cohort was 29 years (range: 17-37) and 25.2 kg/m2 (range: 18.7-38.0). Cisgender patients underwent sperm cryopreservation for oncologic treatment (81%) and pre-vasectomy planning (19%). 32% of transgender patients were initiated on gender affirming hormonal therapy (estradiol, spironolactone, or both) prior to semen analysis, with mean duration of 25 months (range: 1-108). 37% of transgender and 13% of cisgender patients were on a psychiatric medication with mean duration of 7.6 months (range: 1-19) and 7.5 months (range: 3-12) preceding sperm cryopreservation. 11% of transgender and 6% of cisgender patients endorsed tobacco use. 37% of transgender and 38% of cisgender patients endorsed alcohol use. Mean total motile sperm count (TMSC) was 61 million in the cisgender cohort and 105 million in the transgender cohort (p=0.159). 21% and 38% of the transgender and cisgender cohort had low TMSC (&amp;lt;10 million). Mean post-thaw motility recovery was similar among the two groups (56% vs 57%, p=0.894). Transgender women on hormonal therapy had lower TMSC (p=0.867) and post-thaw motility recovery (p=0.535; Table 1) compared to their hormone-naïve counterparts. Alcohol use was a significant predictor of decreased post-thaw motility recovery among cisgender patients (63% vs 46%; p=0.011; Table 2). Conclusions Cisgender men had lower TMSC, but this was likely confounded by underlying malignancy. There was a trend toward worse semen parameters among transgender women with a history of hormone use, but larger studies are needed to validate this finding. Psychiatric medications similarly did not appear to be significant predictors of sperm quality among transgender women. Further studies are needed with a larger sample size and cisgender males without malignancy to validate the effect of these modifiable lifestyle factors. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific, Endo Pharmaceuticals.

Comparative sperm recovery rate after density gradient centrifugation with two media for in vitro fertilization.

To compare the efficacy of two density gradient centrifugation media for retrieving spermatozoa from semen samples by evaluating the total motile sperm count (TMSC) and the percentage recovery. Twenty-two men with different sperm counts participated in the study. The samples were divided into two equal aliquots and processed using the commercial ISolate Sperm Separation Medium (Irvine Scientific, United States) and the GV Gradiente (IngáMed, Brazil). After separation, samples were counted and evaluated for motile sperm recovery. The mean TMSC in the fresh sample was 19.65±21.08 million/mL. After the ISolate separation the TMSC was 6.71±7.29 million/mL, and for the GV Gradiente it was 6.27±6.82 million/mL. The percentage of motile spermatozoa recovered was 36.47%±21.61 for ISolate and 35.22%±21.24 for the GV Gradiente (p>0.05). The samples from 6 oligospermic patients (27%) were evaluated separately and the TMSC for ISolate was 4.83±2.92 million/mL, and for the GV Gradiente, it was 4.16±3.12 million/mL (p=0.54). When evaluating only normospermic patient samples, the TMSC for ISolate was 9.05±7.29 million/mL, and for the GV Gradiente, it was 8.47±6.79 million/mL (p=0.83). There was no statistical difference in retrieving motile sperm using the GV Gradiente and the ISolate Separation Medium.

Experience of our clinic in intrauterine insemination cycles made with microfluidic sperm sorting chips

Objective: Determination of the clinical pregnancy rate in intrauterine insemination (IUI) cycles performed with microfluidic sperm sorting chips.&#x0D; Material and Methods: In Giresun University Obstetrics and Pediatrics Hospital Infertility Clinic, 133 patients who underwent IUI after ovarian stimulation with gonadotropins in unexplained infertility, mild to moderate male factor, ovulatory dysfunction, mild endometriosis were retrospectively analyzed between January 2016-January 2020. Microfluidic sperm sorting chip was used for sperm preparation.&#x0D; Results: The number of cycles was found to be 133. Mean female age was; 29.9±4.7 years, mean total motile sperm count was; 72.9±63.7 million, mean antral follicle count was; 18.1±10.1, the mean total gonadotropin dose used was 897.6±366 IU. Considering the causes of infertility; 54.1% unexplained, 8.3% mild male factor, 31.6% polycystic ovary syndrome (PCOS) and 6% endometriosis. The clinical pregnancy rate was found to be 19.5% (26/133).&#x0D; Conclusion: Microfluidic sperm sorting chips provide an increase in clinical pregnancy rates compared to conventional methods in IUI cycles and allow for a practical and rapid sperm preparation.&#x0D; Key Words: IUI, microfluidic sperm sorting chip, clinical pregnancy rate.

Do antioxidants improve serum sex hormones and total motile sperm count in idiopathic infertile men?

Reactive oxygen species reduce the male sex hormone levels and disrupt the hormonal balance that regulates male reproductive functions. They disrupt spermatozoa and other testicular cells. This study aimed at evaluating the effect of antioxidant treatment on serum gonadal hormones and sperm parameters in men with idiopathic infertility. A total of 100 idiopathic infertile men aged 23-46 years were included in the study. Control group and antioxidant treatment group consisted of 50 men each. Patients in the treatment group received oral antioxidant supplement once a day. The antioxidant supplement content included L-carnitine, L-arginine, vitamin E, vitamin C, coenzyme Q, glutathione, beta-carotene, magnesium, vitamin B12, zinc, vitamin A, vitamin B6, vitamin D3, folic acid, and selenium. Reproductive hormones and sperm parameters were compared between the groups at 6 months after starting the antioxidant therapy. No significant differences were observed in the patient age (p=0.861), partner age (p=0.081), total motile sperm count (TMSC) (p=0.324), and follicle-stimulating hormone (FSH) (p=0.557), luteinizing hormone (LH) (p=0.235), and total testosterone levels (p=0.851) at baseline between the treatment and control groups. Although the mean TMSC did not increase significantly, the mean FSH (p=0.008), LH (p=0.008), and total testosterone (p=0.006) levels significantly increased from baseline to post-treatment in the treatment group. However, no significant differences from baseline to post-treatment were observed in TMSC (p=0.486), FSH (p=0.712), LH (p=0.696), and total testosterone levels (p=0.546) in the control group. The research draws attention to the alternate treatment approaches in infertile men. Antioxidant treatment can increase the serum sex hormone levels.

Outcome of varicocelectomy on different degrees of total motile sperm count: A systematic review and meta-analysis

ABSTRACTIt is crucial to identify the subfertile men with varicocele who will benefit the most from varicocelectomy, and the factors which help in predicting the response to varicocelectomy. We aimed to evaluate the impact of varicocelectomy on total motile sperm count (TMSC) and spontaneous pregnancy (SP) rates. A comprehensive literature search was performed using Medline/PubMed and Google Scholar up to December 26, 2018, with no restriction on language and year of publication. Published articles reporting different degrees of TMSC before and after varicocelectomy in infertile men with varicocele (palpable and/or clinical) were extracted. In addition, SP rates as a function of TMSC after varicocelectomy were reviewed. Potential biases were analyzed to rule out skewing factors. Mean TMSC was graded as: <2 million – profound, 2–5 million – severe, 5–10 million – moderate, and >10 million – mild. Data were analyzed using Stata11. Among the total 96 articles identified through electronic and manual searches of references, nine articles fulfilling the inclusion criteria were included. All degrees of TMSC resulted in a significant postoperative improvement, with only small differences, among the profound [10.20 million (95% confidence interval [CI]: 9.11–11.30, p < 0.0001)], severe [15.77 million (95% CI: 10.65–20.89, p < 0.0001)], and moderate groups [19.18 million (95% CI: 10.40–27.96, p < 0.0001)]. However, the mild group demonstrated a highly significant improvement [49.68 million (95% CI: 38.74–60.62, p < 0.0001)]. After varicocelectomy, the SP rate was highest in the TMSC >20 million group (55.4%), followed by TMSC 5–20 million group (45.4%), and TMSC <5 million group (26.3%). In comparison, the TMSC <1.5 million group demonstrated the lowest SP rate (16.0%). Moderate evidence suggests that varicocelectomy results in a significantly improved TMSC. The improvement in TMSC and SP rates is higher in patients who present a mild or moderate decreased TMSC.Abbreviations: TMSC: total motile sperm count; SP: spontaneous pregnancy; ART: assisted reproductive technology; IVF: in-vitro fertilization; IUI: intrauterine insemination; WMD: weighted mean difference; CI: confidence interval

The impact of age on fertility rate in patients who underwent microsurgical varicocelectomy.

Impacts of a subinguinal microsurgical varicocelectomy on the sperm parameters and fertility rates were investigated in three different ages according to their age at the time of the varicocelectomy: Group 1 was ≤20years old, Group 2 was 21-30years old, and Group 3 was ≥31years old. The patients were also classified both preoperatively and post-operatively according to the total motile sperm count (TMSC) into the following categories: invitro fertilisation, intrauterine insemination and naturally fertile. The proportion of patients who upgraded to a higher TMSC category level was calculated, and natural fertility rates were recorded. The mean infertility duration was statistically longer in Group 3, compared to Group 1 and 2. The mean TMSCs and normal sperm morphology rates increased in all groups. The mean post-operative natural fertility rates were similar. The highest rate of TMSC upgrade was observed in Grade 3 varicocele patients under 20years of age, compared to other grades of varicocele in patients older than 20years. A microsurgical subinguinal varicocele repair, which is an effective treatment modality reduces the need for any type of ART, has an important impact on the TMSC increase in patients, particularly in the younger population.

Pregnancy Success via Intrauterine Insemination and Effect of Sperm Morphology: Systematic Review &amp; Meta-Analysis [10E

INTRODUCTION: Couples in which the man has abnormal sperm morphology are often counseled that natural conception and intrauterine insemination are ineffective and that in vitro fertilization is the only option. Our objective is to determine the effect of sperm morphology on pregnancy success using intrauterine insemination (IUI). METHODS: We systematically searched for studies published prior to January 2017 that 1) reported ultrasound-verified clinical pregnancies per IUI cycle; 2) assessed sperm morphology using the Kruger Strict Criteria; and 3) reported morphology at the &gt;4% and ≤4% and/or ≥1% and &lt;1% thresholds. For all studies, mean female age was between 25 and 40 years and mean total motile sperm count (TMC) was greater than 10 million. Estimates were pooled using random effects meta-analysis. RESULTS: Data were extracted from 20 observational studies involving 41,018 cycles of IUI. Comparing men with &gt;4% and ≤4%, the rate of ultrasound-verified pregnancy per cycle of IUI was not statistically or clinically different (14.2% vs. 12.1%, p=0.06) and the risk difference was 3.0% (95% CI 1.4–4.6%), indicating three additional pregnancies per 100 IUI cycles. Comparing men with ≥1% and &lt;1%, there were no statistical or clinical differences in the rate of ultrasound-verified pregnancy per cycle of IUI (14.0% vs. 13.9%, p=0.97) or in the risk difference (1.6%, 95% CI -4.5–7.6%). CONCLUSION: There appears to be no clinical difference in IUI pregnancy success among those with normal and abnormal sperm morphology, when accounting for total motile sperm count and female age. Abnormal sperm morphology alone should not exclude couples from attempting IUI.

Fate of Recurrent or Persistent Varicocele in the Era of Assisted Reproduction Technology: Microsurgical Subinguinal Redo Varicocelectomy Versus Observation

To compare sperm parameters, serum hormone levels, and pregnancy and miscarriage rates between the infertile men with recurrent or persistent varicocele who underwent microsurgical subinguinal redo varicocelectomy or had observation only. The study included 217 primary infertile men with recurrent or persistent varicocele. The patients were divided into 2 groups: 120 men underwent microsurgical subinguinal redo varicocelectomy, and 97 had observation only. Differences in total motile sperm count and serum hormone levels, and pregnancy and miscarriage rates were compared between the 2 groups. The mean total motile sperm count increased from 20.93 ± 2.87 to 45.54 ± 6.28 million in the microsurgical redo varicocelectomy group, and decreased from 16.62 ± 2.75 to 15.6 ± 2.81 million in the control group, revealing significant difference between the 2 groups (P = .000). Increase in total testosterone level was significantly higher in the microsurgical redo varicocelectomy group (+1.36 ± 0.32 ng/mL) than in the control group (-0.23 ± 0.1 ng/mL) (P = .000). Of the couples, 63 achieved pregnancy in the microsurgical redo varicocelectomy group (52.5%), and 38 had pregnancy in the control group (39.2%) (P <.05). Spontaneous pregnancy rate was significantly higher in the microsurgical redo varicocelectomy group (39.7%) than in the control group (15.8%) (P <.01). Use of assisted reproductive technology to achieve pregnancy was significantly lower in the microsurgical redo varicocelectomy group (60.3%) than in the control group (84.2%) (P <.01). Microsurgical subinguinal redo varicocele repair improves postoperative sperm parameters, serum total testosterone level, and spontaneous pregnancy rates compared with the controls. It also decreases need for use and level of assisted reproductive technology.

Effect of Sperm Morphology on Pregnancy Success via Intrauterine Insemination: A Systematic Review and Meta-Analysis

Men with abnormal sperm morphology are often counseled that natural conception and intrauterine insemination are ineffective, and invitro fertilization is the only option. Our objective was to determine the effect of sperm morphology on the pregnancy success of intrauterine insemination. We systematically searched for studies published prior to January 2017 that 1) reported ultrasound verified clinical pregnancies per intrauterine insemination cycle, 2) assessed sperm morphology using the Kruger strict criteria and 3) described morphology at the greater than 4% and 4% or less and/or the 1% or greater and less than 1% thresholds. In all studies mean female age was between 25 and 40 years and mean total motile sperm count was greater than 10 million. Estimates were pooled using random effects meta-analysis. Data were extracted from 20 observational studies involving a total of 41,018 cycles. When comparing men at the greater than 4% and 4% or less thresholds, the rate of ultrasound verified pregnancy per intrauterine insemination cycle was not statistically or clinically different (14.2% vs 12.1%, p = 0.06) and the risk difference was 3.0% (95% CI 1.4-4.6), indicating 3.0 additional pregnancies per 100 intrauterine insemination cycles. When comparing men at the 1% or greater and the less than 1% thresholds, there were no statistical or clinical differences in the rate of ultrasound verified pregnancy per cycle of intrauterine insemination (14.0% vs 13.9%, p = 0.97) or in the risk difference (1.6%, 95% CI -4.5-7.6). There appears to be no clinical difference in intrauterine insemination pregnancy success among men with normal and abnormal sperm morphology when accounting for total motile sperm count and female age. Abnormal sperm morphology alone should not exclude couples from attempting intrauterine insemination.

Microsurgical Varicocelectomy for Isolated Asthenospermia

Varicocele represents the most common cause of male infertility, and most reports indicate that varicocelectomy has a beneficial effect on male fertility and pregnancy outcome. We evaluated the clinical outcomes of infertile couples with varicocele and isolated asthenospermia who chose to undergo varicocelectomy as well as those who chose not to undergo the procedure. We performed a retrospective review of 118 consecutive infertile couples in whom the man presented with clinical varicocele and isolated asthenospermia (less than 50% motile sperm). All couples were presented with possible treatment options (observation, varicocelectomy, assisted reproductive technologies). The clinical characteristics and outcomes of 2 subgroups of men--those who elected to undergo surgery (varicocelectomy, 69) and those who did not (49)--were examined and compared. Mean male and female patient age, duration of infertility and baseline total motile sperm count were not significantly different in the control and surgery groups. The mean total motile sperm count increased significantly after varicocelectomy (29.6 million preoperatively vs 39.0 million postoperatively, p <0.05). The spontaneous pregnancy rate was significantly higher in the surgery group compared to the control group (65% vs 32%, respectively, p <0.01). The combined spontaneous and intrauterine insemination pregnancy rate was also significantly higher in the surgery group compared to the control group (74% vs 36%, respectively, p <0.01). Use of in vitro fertilization/intracytoplasmic sperm injection was significantly higher in the control group compared to the surgery group (32% vs 11%, respectively, p <0.05). Our data support the practice of varicocelectomy for the treatment of clinical varicocele and isolated asthenospermia.

Intrauterine Insemination With Double Ejaculate Compared With Single Ejaculate in Male Factor Infertility: A Pilot Study

The aim of this study was to compare the efficiency of using a double ejaculate with the efficiency of using a single ejaculate for intrauterine insemination in male subfertility. Eligibility for the study was a total motile sperm count between 1 x 10(6) and 5 x 10(6) on postwash sperm analysis. Thirty-nine couples were randomized to the study group, while another 50 couples were randomized to serve as the control group. Males in the study group were asked to produce a second semen sample within 2 hours of the first sample on the day of insemination. In the study group, the mean total motile sperm count in the first sample was 3.83 x 10(6) (SD +/- 0.85 x 10(6); range 1.1-4.9) and 3.99 x 10(6) (SD +/- 0.72 x 10(6); range 0.9-4.4) in the control group. The mean total motile sperm count in the second sample was 3.52 x 10(6) (SD +/- 1.46 x 10(6); range 0.9-3.7) in the study group. The mean total motile sperm count in the final inseminate was 7.35 x 10(6) (SD +/- 1.90 x 10(6); range 2.9-10.6) in the study group. The difference in total motile sperm counts between the study and the control group was statistically significant (P < .001). There were 6 pregnancies in the study group, providing a pregnancy rate of 15.3%, whereas there were 5 pregnancies in the control group, representing a pregnancy rate of 10% (P = .44). We concluded that although it does not increase the pregnancy rate significantly, obtaining a second semen sample when the motile sperm yield of the first semen sample is 1 million to 5 million significantly increases the total motile sperm count in the final inseminate.

Effect of adult microsurgical varicocelectomy on testicular volume

Objectives. To re-examine the potential influence of varicocelectomy on testicular volume using scrotal ultrasonography, because it has been reported that total testicular volume (assessed by physical examination) increases after adult varicocele ligation. Methods. A retrospective review of the testicular volume and semen parameters of 61 men who underwent microsurgical varicocelectomy between 1996 and 1998 was performed. Ultrasound-derived testicular volumes and total motile sperm counts were compared before varicocelectomy and at a mean of 7.2 months postoperatively. Results. Bilateral varicocelectomy was performed in 22 men; 39 men underwent a left-sided procedure only. Overall, no significant change was found in the mean total testicular volume after varicocelectomy compared with preoperatively (24.0 versus 23.9 mL, respectively; P = 0.74). Similarly, the testicular volumes did not change significantly after left or bilateral varicocelectomy ( P >0.05). Overall, the mean total motile sperm count increased significantly after varicocelectomy (17.9 to 25.4, P = 0.05). Conclusions. This was the first study to examine the effect of adult varicocelectomy on testicular volume using ultrasound-derived measurements of volume. Unlike previous findings, our data suggest that although adult varicocelectomy improves semen quality in most infertile men, it does not result in a significant increase in testicular volume.

REPEAT VASECTOMY REVERSAL AFTER INITIAL FAILURE: OVERALL RESULTS AND PREDICTORS FOR SUCCESS

Purpose We review the treatment outcomes for microsurgical reconstruction following failed vasectomy reversal and identify predictors for success. Materials and Methods We performed a retrospective review of our experience with microsurgical reconstruction in 41 men who underwent 1 or more prior unsuccessful vasectomy reversal procedures. Of these patients 20 underwent bilateral (16) or unilateral (4) vasoepididymostomy, 11 underwent bilateral (7) or unilateral (4) vasovasostomy and 10 underwent unilateral vasoepididymostomy with contralateral vasovasostomy. Postoperative followup consisted of serial semen analyses and telephone interviews. Results Patency and pregnancy followup data were available in 33 and 31 patients, respectively. Five couples had ongoing uncorrected female factor infertility problems and were not included in pregnancy rate calculations. Mean obstructive interval was 10.6 years. Overall patency and pregnancy rates were 79 and 31%, respectively. Mean total motile sperm count for patients demonstrating patency at followup was 38.0 million. History of conception with the current partner was predictive of future conception with 4 of 5 nonremarried couples (80%) initiating a pregnancy versus 3 of 18 remarried couples (17%) (p = 0.006). Other factors, including smoking history and obstructive interval, did not correlate with postoperative success. Reconstruction with vasovasostomy on at least 1 side trended toward improved patency (p = 0.17) and pregnancy rates (p = 0.15), although they did not assume statistical significance. Conclusions Microsurgical reconstruction following failed vasectomy reversal is associated with high patency and moderate pregnancy rates at short-term followup. In our series previous conception with the current partner was predictive of future conception after reconstruction. Urologists performing repeat vasectomy reversal must be familiar with microsurgical techniques, since almost three-quarters of patients will require at least unilateral vasoepididymostomy.

The effect of human menopausal gonadotrophin and highly purified, urine-derived follicle stimulating hormone on the outcome of in-vitro fertilization in down-regulated normogonadotrophic women

It has been suggested that the luteinizing hormone (LH) activity of human menopausal gonadotrophin (HMG) preparations used for ovarian stimulation in in-vitro fertilization (IVF) may have adverse effects on reproductive outcome. In the present prospective, randomized trial of 218 infertile couples this notion was investigated. A total of 114 women were treated with Pergonal (HMG group) and 104 with Fertinorm HP (HP-FSH group). The two groups were comparable with regard to duration of infertility, cause of infertility, age and number of previous IVF attempts and all had normal basal gonadotrophin concentrations before treatment was started. A standard hormonal treatment consisting of pituitary down-regulation with gonadotrophin-releasing hormone analogue (GnRHa) for 14 days starting on cycle day 21, followed by either HMG or highly purified follicle stimulating hormone (HP-FSH), three ampoules (225 IU) per day for 7 days, was used in all cases. The daily hormone dose was thereafter individualized according to the ovarian response. A maximum of two pre-embryos were transferred after 3 days of culture. Luteal support with progesterone (300 mg per day intravaginally) was used in all cases. Serum concentrations of oestradiol, FSH and LH were measured on days 1 and 8 of stimulation and on the day of oocyte retrieval. The mean number of days of stimulation, mean number of ampoules of HMG or HP-FSH used, mean total motile sperm count on the day of oocyte retrieval and mean numbers of oocytes retrieved (13.4 versus 13.7) or pre-embryos transferred (1.8 versus 1.8) were similar for both groups. Significantly (P < 0.05) more cycles in the HP-FSH group (17 = 16%) were cancelled due to complete failure of fertilization than in the HMG group (7 = 6%). The mean fertilization rate was significantly (P < 0.05) higher in the HMG group (56%) than in the HP-FSH group (50%), and significantly more transferable pre-embryos were obtained in the HMG than in the HP-FSH group (mean: 4.0 versus 3.2; P < 0.01). Serum hormone concentrations were similar to the two groups on stimulation day 1, but differed significantly with regard to FSH, LH and oestradiol on stimulation day 8. The clinical outcome was similar in the two groups, with an ongoing pregnancy rate (> 12 weeks of gestation) per started cycle of 33% in the HMG group and 29% in the HP-FSH group. The clinical abortion rates were similar (10 and 14%), and the implantation rate was 30% in each group. In conclusion, no detrimental effect of the LH activity of HMG on the clinical outcome of IVF in GnRHa down-regulated normogonadotrophic women was found. To the contrary, some beneficial effects of HMG on fertilization rates and pre-embryo development as compared with HP-FSH were demonstrated. These effects, as well as the differences in serum hormone concentrations during ovarian stimulation, may be caused by differences in LH content and/or in the composition of FSH isoforms of the HMG and HP-FSH preparations.