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PubMed1986

Effect of continuous intrauterine administration of prostaglandin F2 alpha and indomethacin on fertilization of rabbits.

The effect of continuous intrauterine administration of prostaglandin F2 alpha (PGF2 alpha) or indomethacin or indomethacin together with PGF2 alpha and PGE2 or vehicle on fertilization of rabbits was studied. These substances and vehicle were delivered into the cornua of the uterus via an Alzet minipump for 11 days. The animals were inseminated vaginally. Compared with controls (104 eggs of which 88.5% were fertilized) a reduction of the fertilization rate was observed with indomethacin (74 eggs of which 70% were fertilized). Exogenously added PGF2 alpha did not change the fertilization rate. The administration of indomethacin together with PGE2 raised the fertilization rate to 86% (63 eggs of which 54 were fertilized). The application of PGF2 alpha together with indomethacin showed a fertilization rate of 85% (59 eggs of which 50 were fertilized). The indomethacin application was associated with a reduction of prostaglandin production in several tissues from the female genital tract, showing that indomethacin is taken up by the endometrium of the rabbit. The ovary, oviduct, cervix and vagina were mainly affected by this treatment. The route of transport of this drug is not known, however. The reduction of the total number of eggs together with the decrease of the fertilization rate after indomethacin administration point towards multiregional sites of interference of prostaglandins in reproductive functions. PGF2 alpha seems to be the more important factor since PGE2 may be converted to PGF2 alpha in reproductive tissues.

Animals↗

PubMed1991

Spontaneous and induced demographic change.

When some scholars from abroad analyze the role of family planning policies in developing countries in changes in the fertility rate, they differentiate 2 categories of change: one is "developmental change in the fertility rate" and the other is "induced change in the fertility rate". Professor Tian Xinyuan, of American nationality, quotes this concept in his analysis of changes in China's fertility rate, and believes that changes in China's fertility rate belong to fairly successful "induced change in fertility behavior". The author agrees with this differentiation, and feels that there is a need to incorporate this kind of differentiation in all analysis of the characteristics and mechanism of demographic change in China. Due to the inclusion of a set of intervening social variables, in fact demographic change in all countries has already evolved the 2 fundamental types of demographic change, spontaneous and induced. However, until now, the authors have not seen a systematic discussion of the differences and the relationship between these 2 types of demographic change. This paper attempts to make some theoretical investigations into the above, and firmly believes that this has definite significance for enriching theories of demographic change and guiding China's family planning practices.

Asia↗

PubMed1998

Outcome of in vitro fertilization and intracytoplasmic injection of epididymal and testicular sperm extracted from patients with obstructive and nonobstructive azoospermia.

OBJECTIVE: To evaluate IVF outcome after epididymal and testicular sperm retrieval in patients with obstructive or nonobstructive azoospermia. DESIGN: Retrospective clinical analysis. SETTING: Public university-affiliated IVF unit. PATIENT(S): One hundred twenty-three azoospermic patients (178 cycles). INTERVENTION(S): Sixty-three patients (103 cycles) with obstructive azoospermia (group 1) underwent either epididymal or testicular sperm retrieval, and 60 patients (75 cycles) with nonobstructive azoospermia (group 2) underwent testicular sperm retrieval combined with IVF treatment. Mature oocytes were fertilized using intracytoplasmic sperm injection. After sperm preparation, supernumerary spermatozoa were cryopreserved. MAIN OUTCOME MEASURE(S): Oocyte fertilization rate and clinical pregnancy rate (PR). RESULT(S): The oocyte fertilization rate was 48.4% (534/1,104) in group 1 and 41.5% (312/751) in group 2 (not significant [NS] difference). A total of 100 cycles (97.1%) and 62 cycles (82.7%) in the obstructive and nonobstructive groups, respectively, had embryos for replacement (NS difference). The clinical PRs per ET cycle were 24% (24/100) and 17.7% (11/62) in the two groups, respectively. Oocyte fertilization rates, when fresh (46.4%) or frozen-thawed (41.8%) spermatozoa were used, were not significantly different in the two groups. The PR when fresh sperm were used was 23.6% (30/127), versus 14.3% (5/35) when frozen sperm were used (NS difference). The PR for women aged < or = 35 years was similar to that for women >35 years of age (20.7% or 29/140 and 18.2% or 4/25, respectively). CONCLUSION(S): Epididymal and testicular sperm obtained in azoospermic patients can fertilize oocytes successfully and may lead to high fertilization rates and PRs. Freezing of these spermatozoa does not reduce the outcome of treatment significantly.

Adult↗

PubMed2003

Agricultural management practices to sustain crop yields and improve soil and environmental qualities.

In the past several decades, agricultural management practices consisting of intensive tillage and high rate of fertilization to improve crop yields have resulted in the degradation of soil and environmental qualities by increasing erosion and nutrient leaching in the groundwater and releasing greenhouses gases, such as carbon dioxide (CO2) and nitrous oxide (N2O), that cause global warming in the atmosphere by oxidation of soil organic matter. Consequently, management practices that sustain crop yields and improve soil and environmental qualities are needed. This paper reviews the findings of the effects of tillage practices, cover crops, and nitrogen (N) fertilization rates on crop yields, soil organic carbon (C) and N concentrations, and nitrate (NO3)-N leaching from the soil. Studies indicate that conservation tillage, such as no-till or reduced till, can increase soil organic C and N concentrations at 0- to 20-cm depth by as much as 7-17% in 8 years compared with conventional tillage without significantly altering crop yields. Similarly, cover cropping and 80-180 kg N ha(-1) year(-1) fertilization can increase soil organic C and N concentrations by as much as 4-12% compared with no cover cropping or N fertilization by increasing plant biomass and amount of C and N inputs to the soil. Reduced till, cover cropping, and decreased rate of N fertilization can reduce soil N leaching compared with conventional till, no cover cropping, and full rate of N fertilization. Management practices consisting of combinations of conservation tillage, mixture of legume and nonlegume cover crops, and reduced rate of N fertilization have the potentials for sustaining crop yields, increasing soil C and N storage, and reducing soil N leaching, thereby helping to improve soil and water qualities. Economical and social analyses of such practices are needed to find whether they are cost effective and acceptable to the farmers.

Agriculture↗

PubMed1995

Randomized trial of partial zona dissection for male infertility.

OBJECTIVES: To compare IVF rates using partial zona dissection versus zona intact insemination in couples with male infertility. To analyze pregnancy rates relative to sperm characteristics, fertilization rates, and treatment. DESIGN: Randomized prospective comparison of fertilization in sibling oocytes. Transfer of the three best quality embryos from one or both treatments. SETTING: Department of Gynaecology and Reproductive Medicine, University Hospital, London, Ontario, Canada. PARTICIPANTS: Thirty-two couples undergoing IVF with a principal diagnosis of male infertility. INTERVENTION: Treatment with partial zona dissection. MAIN OUTCOME MEASURES: Fertilization and pregnancy. RESULTS: Fertilization rates were 26% and 9% after partial zona dissection and IVF, respectively. Polyspermy was < 1% in each treatment. There were five singleton pregnancies in 29 completed cycles, three in cycles with fertilization only by partial zona dissection and two in cycles with both partial zona dissection and IVF fertilization. There were no pregnancies after fertilization by IVF only. Stepwise logistic regression analysis indicated that pregnancy was related to partial zona dissection, initial sperm concentration, and total acrosin activity. CONCLUSION: Partial zona dissection was associated with minimal polyspermic fertilization and higher normal fertilization rates than sibling oocytes treated by modified IVF. Pregnancy occurred only after transfer of embryos from partial zona dissection or combined partial zona dissection and IVF.

Adult↗

PubMed1988

Fertility and legal abortion in England and Wales: performance indicators for family planning services.

The relation between fertility rates and legal abortion rates was investigated in a sample of health authorities in England and Wales to see how these varied. Total period fertility rates and total period legal abortion rates were derived from the average number of live births or legal abortions that would be experienced per woman if women experienced the age specific rates of the year in question throughout their childbearing years. The sample of 30 health authorities was selected by taking the districts with the highest and lowest fertility rates in each English region and in Wales in 1986. Total period fertility rates varied from 1.37 in Riverside to 2.42 in Tower Hamlets, while abortion rates varied from 0.25 in East Yorkshire to 0.99 in Riverside. When the two rates were added to provide a potential fertility rate it became clear that some districts with similar potential fertility rates had very different underlying component rates. Such comparisons can be used for service monitoring, indicating the need for better abortion and family planning services in districts with high fertility rates and for better family planning services in those with high abortion rates.

Abortion, Legal↗

PubMed1999

Trends in teenage pregnancy in England and Wales: how can we explain them?

Teenage pregnancy is associated with adverse social and physical outcomes for both mother and child. We drew on various sources--birth and abortion statistics from the Office for National Statistics, data from the National Survey of Sexual Attitudes and Lifestyles, and routinely collected data from family planning clinics--to identify trends in England and Wales and their possible determinants. The rate of teenage sexual activity has increased steadily and consistently over the past four decades, whilst the rate of teenage fertility has shown greater variation. When the teenage fertility rate is calculated against the denominator of sexually active women, rather than the total sample of teenage women, the underlying trend in teenage fertility over the past four decades has been downwards, though not consistently so. Fluctuations in the teenage fertility rate seem to track intervention-related factors such as access to, and use of, contraceptive services and the general climate surrounding the sexual health of young people.

Abortion, Induced↗

PubMed1991

The extent and timing of prenatal loss in gilts.

The potential litter size of gilts that is based on the ovulation rate is much higher than the actual litter size, which depends on the fertilization rate and subsequent prenatal mortality. Prenatal mortality is divided into embryonic mortality (before Day 30) and fetal mortality (after Day 30). Prenatal loss includes both fertilization failure and prenatal mortality. Crossbred gilts (n = 149) were bred at the first observed estrus after being exposed to the boar at 200 days of age. Time of the first insemination after estrus detection was determined by measurement of vaginal conductivity using a Walsmeta meter. A second insemination was administered either 8 or 16 hours later. Artificial insemination with fresh semen (0 to 3 days old) was used throughout the experiment. Gilts were slaughtered on Day 3 (n = 26), Day 10 (n = 42), Day 30 of gestation (n = 45) or they were allowed to farrow (n = 36). Gilts slaughtered on Day 3 were used to estimate the fertilization rate. Gilts slaughtered on Day 10 and Day 30 were used to calculate embryonic mortality, while fetal mortality was calculated from the gilts that farrowed. The mean (+/-SEM) number of corpora lutea (CL) was 13.15+/-0.46, 13.36+/-0.37 and 12.97+/-0.39 for gilts slaughtered at Days 3, 10 and 30, respectively (P>0.05), and the mean (+/-SEM) number of normal embryos recovered was 11.12+/-0.69, 9.46+/-0.55 and 9.33+/-0.58, respectively. Litter size at parturition was 9.10+/-0.54. There was a significant difference between the number of normal embryos on Day 3 and Day 30 (P=0.05) and also between the number of normal embryos at Day 3 and the number of piglets at term. Ninety percent of the ova were recovered at Day 3. The fertilization rate was calculated either 1) assuming that unrecovered ova had a similar fertilization rate as the recovered ova (FRER=94.5+/-2.0%) or 2) assuming that unrecovered ova were unfertilized (FROR=84.5+/-2.5%). It was concluded that FRER was a more accurate estimation of the fertilization rate. Based on this fertilization rate, embryonic mortality between Day 3 and Day 10 was 20.8+/-8.3%, with an additional 12.5+/-7.1% loss between Day 10 and Day 30, when all gilts were included (P = 0.308). Thus the total prenatal loss, including fertilization failure, up to Day 10 was 26.3% and to Day 30 it was 38.8%. Fetal mortality was 2.2%, giving a total prenatal mortality (excluding fertilization failure) of 35.5% and a prenatal loss of 41%. Most of the prenatal loss was due to embryonic mortality. In those gilts that remained pregnant most of the embryonic loss occurred before Day 10 (19.0+/-6.3%; P=0.003). There was no further loss between Day 10 and 30 of pregnancy. There was a significant difference between the loss from Day 3 to Day 10 compared with the loss from Day 10 to Day 30 (P=0.05); therefore, most of the embryonic loss in pregnant gilts occurred before Day 10. Since fetal mortality was 3.2+/-6.3%, most of the prenatal loss was due to embryonic mortality.

Journal Article↗

PubMedDate not supplied

The effect of varying inseminating sperm concentration in male factor and non-male factor infertility during in vitro fertilization.

OBJECTIVE: To assess the effect of varying inseminating sperm concentrations on fertilization rates and polyspermy in human in vitro fertilization (IVF). SUBJECTS AND METHODS: Eighty-six couples who completed 107 consecutive IVF cycles were assigned to one of three groups according to the results of their semen analysis (SA), sperm penetration assay (SPA), and titers of antisperm antibodies (ASA). Group 1 (non-male factor) had normal results for SA, SPA and ASA; group 2 had one abnormal result; and group 3 had two or more abnormal results. Inseminating concentrations of 50,000, 250,000, or 500,000 progressively motile sperm/oocyte were prospectively assigned to groups 1, 2 and 3, respectively. MAIN OUTCOME MEASURES: Incidence of polyspermy and fertilization rates. RESULTS: A total of 992 oocytes were available for analysis. The fertilization rate of 61% for non-male factor patient (group 1) was significantly higher than for male-factor patients [group 2 (48%) and group 3 (43%; P < .01)]. The incidence of polyspermy was 3.3%, 5.5%, and 0% for groups 1, 2 and 3, respectively, and did not differ significantly between the non-male factor and male factor groups (P = .16). Polyspermic fertilization was increased in both mature (4.1%) and postmature (5.7%) as compared to immature oocytes (1.4%; P < .05). CONCLUSION: In male factor infertile couples, increasing the inseminating concentration to 250,000 or 500,000 motile sperm/oocyte does not result in an increase in the incidence of polyspermy but does not improve fertilization rates.

Adult↗

PubMed1991

Fertility decline in Taiwan: a study using parity progression ratios.

Taiwan's decline in fertility is studied by using period parity progression ratios. Levels of marriage and motherhood are found to have been high and essentially constant though the late 1980s, suggesting that the decline has been due almost entirely to declines in second and higher order-births. Families with three or more children play an important role in maintaining the current level of fertility. The level of fertility would be even lower without these families. They contributed more than one-half child per woman to the total fertility rate during most of the 1980s. Total fertility rates computed from the period parity progression ratios indicate a substantially higher level of fertility than the conventional total fertility rate; they remained above or at replacement level through 1988. A formal demographic analysis suggests that the conventional total fertility rate has been depressed by shifts in age at childbearing.

Adult↗

PubMed1998

Male subfertility induced by acute scrotal heating affects embryo quality in normal female mice.

The aim of this experiment was to design a suitable mouse model for male subfertility in which to study the effect of decreased sperm quality on embryo quality in vivo and in vitro. To achieve male subfertility, testes of adult male mice were immersed in water at either 42 degrees C (heated) or 33 degrees C (controls) during 20 min. Twenty-eight days after treatment, all heat stressed males showed a significant decrease in relative testis weight [384.7 mg in controls (286.7-460.6) versus 323 mg in stress heated groups (117.9-405.6); P < 0.001], sperm concentration [3.75 x 10(6)/ml (2.75-7.25) versus 1.00 x 10(6)/ml (0-4.00); P < 0.001] and progressive sperm motility [57.5% (48.0-79.0) versus 42.5% (14.0-66.0); P < 0.001]. Moreover, after mating to heat exposed males, not only the number of pregnant females (20/22 versus 18/30) but also the weight of their embryos [275.4 mg (78.7-339.4) versus 261.8 mg (68.1-339.0); P < 0.001] was significantly lower at 14.5 days post coitum when compared to controls. Neither the number of resorption sites nor the number of viable embryos per pregnant female was significantly different between groups. Also, the in-vitro fertilization rate of oocytes, fertilized by spermatozoa collected from heat stressed males, was significantly lower (44.9%; P < 0.0001) when compared to controls (65.1%; P < 0.0001). In conclusion, the results of this study suggest that male subfertility induced by acute scrotal heating may result in impaired sperm quality, reduced embryo weight in vivo and decreased fertilization rate in vitro.

Animals↗

PubMed2000

Defective sperm-zona pellucida interaction: a major cause of failure of fertilization in clinical in-vitro fertilization.

Sperm-zona pellucida binding and penetration were assessed on the oocytes that failed to fertilize from couples with >/=3 oocytes treated by standard in-vitro fertilization (IVF). There were four groups: fertilization rate 0% (n = 369), 1-25% (n = 194), 26-50% (n = 81) and 51-95% (n = 100). Of the couples with zero fertilization rate 70% had </=5 spermatozoa bound per zona pellucida and 42% had no spermatozoa penetrating the zona pellucida of any oocyte. In contrast, in the 51-95% fertilization rate group, only 17% had </= 5 spermatozoa bound per zona pellucida and 6% had no spermatozoa penetrating the zona pellucida. There was a significantly higher frequency of poor sperm morphology (</= 5% normal) in couples with zero fertilization rate (36%) than in the fertilization rate group 51-95% (7%). Incubation of oocytes from 68 couples with zero fertilization rate and low sperm-zonae pellucidae binding with fertile donor spermatozoa resulted in normal sperm-zona pellucida binding and most zonae pellucidae being penetrated. In conclusion, defective sperm-zona pellucida interaction was the major cause for low fertilization rates in standard IVF. This was usually because of defects of the spermatozoa rather than defects of the oocytes. Sperm defects likely to cause failure of fertilization should be diagnosed before commencing IVF and the patients directed to intracytoplasmic sperm injection.

Female↗

PubMed2000

[Clinical experience with assisted reproductive technology along the development of micro fertilization].

In 1993 we had the first success of micro fertilization in our clinic. The method by partial opening of oocyte zona pellucida initially used achieved a fertilization rate per egg of only 26.7%. Although transfer of sperm under the zona raised the fertilization rate to 39.2%, the new method involved problems such as polyspermy, which represented approximately 30% of the total fertilization rate. In addition, use of this method was limited to patients meeting several conditions. In 1994, we had a successful case of pregnancy after intracytoplasmic sperm injection (ICSI). The ICSI method resulted in a fertilization rate of about 70%, and has solved the problem of polyspermy. Fertilization of eggs has become possible using immotile sperm, and the technique of microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE) has been established. Clinical data have confirmed that a fertilization rate by frozen sperms is not lower than that by fresh sperms. Sperm can be stored frozen after MESA or TESE and therefore are surely available when needed, allowing to avoid spoiling retrieved eggs. No difference in fertilization rate was found between conditions needing micro fertilization or sperm recovery methods. No difference in pregnancy rate was shown between treatment cycles. Recent reports show improved pregnancy rates using techniques such as transferring a frozen embryo after endometrical adjustment. Further development in assisted reproductive technology is anticipated.

Female↗

PubMed1997

The relationship between sperm morphology and rates of fertilization, pregnancy and spontaneous abortion in an in-vitro fertilization/intracytoplasmic sperm injection programme.

The morphological normality of a spermatozoon is considered to be an important factor in relation to its ability to fertilize an oocyte. We examined the influence of morphology (strict criteria) on the rates of fertilization, pregnancy and spontaneous abortion obtained following conventional in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in our clinical programme. We found our fertilization cut-off values for conventional IVF to be slightly different from those of the Kruger group (10 and 5%, compared to 14 and 5%). We also found the pregnancy rate per transfer to be as good or better in the groups with < 5% normal forms: 36% of these men had a fertilization rate > 50% using conventional IVF, showing that fertilization capacity is not necessarily impaired even in this 'poor prognosis' group. With the exception of the ICSI group with 5-9% normal forms, the rate of spontaneous abortion in this study was similar to or lower than in our IVF/ICSI programme overall. When the 5-9% normal spermatozoa group was divided into those with teratozoospermia as the only factor and those with additional sperm factors, the increased abortion rate was found in the group with multiple sperm factors (67% spontaneous abortions).

Abortion, Spontaneous↗

PubMed2006

Cryopreservation of unfertilized human oocytes.

Previous investigations revealed that choline-based freezing media developed in our laboratory were superior to conventional sodium-based media for storing mouse oocytes. This paper examines the ability of the choline-based medium CJ2 and a modified form of this medium, CJ3, to cryopreserve unfertilized human oocytes. Oocytes that were consented for research and matured overnight, as well as freshly collected, donor, mature metaphase II (MII) oocytes, were cryopreserved using choline-based media and an optimized slow-cooling protocol. The results showed higher survival and fertilization rates when CJ3 supplemented with 0.2 mmol/l sucrose was used as compared with CJ2 supplemented with either 0.1 mmol/l or 0.2 mmol/l sucrose. Freshly collected oocytes were more difficult to cryopreserve than those matured in vitro. Modification of the base medium proved to be one of the key factors in obtaining survival rates over 90%. Fertilization rates, embryo development, and genetic analysis of embryos resulting from control and frozen-thawed oocytes are provided. There appears to be a high correlation between chromosomal anomalies and abnormal morphology in embryos from thawed oocytes.

Choline↗

PubMed1998

Low pregnancy rate is achieved in patients treated with intracytoplasmic sperm injection due to previous low or failed fertilization in in-vitro fertilization.

The main indications for intracytoplasmic sperm injection (ICSI) are severe male factor and fertilization failure or a low fertilization rate in previous in-vitro fertilization (IVF) treatments. The fertilization and pregnancy rates after ICSI, however, are seldom reported separately for these two different indications. The aim of this study was to compare the treatment outcome and pregnancy rate after ICSI between 65 patients with previous failed fertilization or a low fertilization rate without male factor, and 219 patients with a primary male factor. From the 2726 oocytes collected, 2087 (77%) were micro-injected and 1355 (65%) achieved normal fertilization. The oocyte fertilization rate was similar in the group with previous failed fertilization or a low fertilization rate and the group with a male factor (65 and 65% respectively), as was the cleavage rate of normally fertilized oocytes (92 and 94% respectively). Despite the similar fertilization and cleavage rates and the similar number and morphological quality of embryos transferred in both groups, the pregnancy rate was significantly lower (P < 0.05) in the group with previous failed fertilization or a low fertilization rate than in the group with a male factor (19.6 versus 33.5% respectively; 95% confidence intervals for the difference, 2-26%). The implantation rate was also lower (P = 0.01) in patients with previous failed fertilization or a low fertilization rate (9.6%) than in the group with a male factor (19.5%). We conclude that patients with previous failed fertilization or a low fertilization rate in standard IVF without male factor have a significantly smaller chance of becoming pregnant after subsequent ICSI than patients with a primary male factor. This poor outcome probably reflects intrinsic oocyte defects not bypassed by ICSI.

Adult↗

PubMedDate not supplied

[Mexico: reproductive behavior and social margination, 1970-1990. Elements of geographic diagnosis in reproductive health].

The lack of a definite knowledge on regional reproductive behavior characteristics hinders the evaluation of the goals stated in the General Population Law (Ley General de Población) and counteracts any efforts towards equating population growth with regional development. The present work aims at overcoming this problem. Indirect specific fertility rates and global fertility rates (GFR) were obtained by state, using census and vital statistics data for the states of Mexico during the 1970-1990 period. Reproductive behavior was related to social deprivation indexes used by PRONASOL and CONAPO for those years. A high statistically significant correlation (p < 0.01) between state social deprivation levels and the downward trends of GFR for the same decades was found. Findings evidence a general downward trend of GFR during the period of study. However, this trend was not uniform across the country. Further studies are needed to determine whether these differences are due to the various social deprivation levels rather than to the effectiveness and extension of family planning programs. Mapping these results could be useful as diagnostic elements of the reproductive behavior of the population and also generates information necessary to support social organized responses in reproductive health.

Adult↗

PubMed2005

Low temperature storage of rhesus monkey spermatozoa and fertility evaluation by intracytoplasmic injection.

The objective was to develop a sperm freezing procedure suitable for use in the propagation of valuable founder animals by assisted reproductive technologies. Here, we report a comparison of processing methods by measuring the motility of fresh and frozen-thawed rhesus monkey spermatozoa and fertility via intracytoplasmic spermatozoa injection (ICSI) of sibling oocytes. Washed spermatozoa were frozen in straws or in pellets using different cryoprotective media and processed post-thaw with or without a density gradient centrifugation step. Among the four study series, motility post-thaw was improved with density gradient centrifugation (17-24% versus 75%, P<0.01) achieving levels similar to fresh spermatozoa. Spermatozoa injected oocytes (total n=377) were co-cultured on BRL cells and observed for fertilization and development. With spermatozoa frozen in straws in liquid nitrogen vapors, the fertilization rate after ICSI was lower than with fresh spermatozoa (40-44% versus 77-86%, P<0.05), even with the Percoll-enriched fraction that exhibited robust motility. In contrast, somewhat slower freezing of spermatozoa in pellets on dry ice supported fertilization rates (73%) that were similar to the fresh counterpart. Developmental rates of fertilized eggs were similar in all experiments. A total of 106 embryo transfers has resulted in the first primate born after ICSI with F/T ejaculated spermatozoa plus 22 other infants to date. Additionally, a 3-4 h incubation after thawing improved the fertilization rate with spermatozoa from a male with poor post-thaw recovery of sperm motility. In conclusion, an acceptable fertilization rate after ICSI with motile, frozen-thawed primate spermatozoa was observed comparable to that obtained with fresh spermatozoa allowing small quantities of competent spermatozoa to be used with ICSI to facilitate propagation of desirable primate genotypes.

Animals↗