Incomplete denudation of oocytes prior to ICSI enhances embryo quality and blastocyst development

BACKGROUND: Granulosa cells are essential mediators of oocyte maturation and fertilization. Because of the denudation of oocytes in preparation for ICSI, any potential positive effect of surplus cumulus cells (CCs) on further development would be unable to exert further effect. In order to evaluate the actual influence of adhering cumulus cells on further preimplantation development, this prospective study was carried out. METHODS: Sibling cumulus-oocyte complexes for 57 ICSI patients were split into a study group (incomplete denudation, n = 314) and a control group (complete denudation, n = 336). According to the cumulus cell pattern after partial denudation, mature gametes from the study group were further subdivided into type A oocytes, which showed several prominent CC clusters (n = 202), and type B (n = 75), which showed a more homogeneous pattern with CC covering the whole surface of the gamete. RESULTS: In immature oocytes, presence of adhered CCs led to a significant increase in resumption of meiosis (P < 0.01). Fertilization rate (P < 0.05) and ability to cleave (P < 0.01) was impaired in the study group, because of difficulties in ICSI of type B oocytes. By contrast, embryo morphology on days 2 (P < 0.01) and 3 (P < 0.05), as well as blastocyst formation, was better (P < 0.05) in the study group (55 blastocysts out of 88 zygotes) as compared to that in the control group (49/105). CONCLUSION: These data indicate that co-culture of oocytes with attached CCs may enhance preimplantation development.     

Monozygotic twins and transfer at the blastocyst stage after ICSI

The incidence of monozygotic twinning (MZT) is higher in pregnancies conceived after assisted reproduction than after natural conception. Alterations, produced by ovarian stimulation, in-vitro culture conditions and specifically alterations of zona pellucida are mentioned as possible causes of this phenomenon. A retrospective review was performed of the incidence of MZT in pregnancies generated in our centre during the period of January 1996 to December 1999. This variable was compared in 129 gestations that resulted from blastocyst transfer (occurring from September 1998 to August 1999) with 814 pregnancies produced by transfers of 4- to 8-cell embryos. Follicular development was induced with human menopausal gonadotrophin and urinary FSH during 1996 and 1997 and with recombinant FSH during 1998 and 1999. Blastocysts were cultured in sequential media using S1 or G1 up to 72 h and S2 or G2 to day 5. Five of the 129 pregnancies generated by blastocyst transfers were complicated by MZT gestation (3.9%). In comparison, only six of 814 pregnancies occurred from 4- to 8-cell transfers (0.7%), a difference that is statistically significant (P< 0.001 with Yates correction). The results confirm an increase of MZT in pregnancies from intracytoplasmic sperm injection as compared to the natural incidence. Moreover, the frequency of MZT was significantly higher when transfers were performed at the blastocyst stage, suggesting that extended in-vitro culture of embryos may be associated with alterations of the zona pellucida and the hatching process.     

First polar body morphology and blastocyst formation rate in ICSI patients

BACKGROUND: It may be beneficial to identify, at a very early stage of development, concepti that will result in viable blastocysts by using a non-invasive technique. METHODS: Homogeneous groups in terms of first polar body (PB) morphology were analysed with regard to fertilization, embryo quality and blastocyst formation. The strategy was to transfer a maximum of two blastocysts with an adequate inner cell mass deriving from oocytes with identical first PBs in order to obtain information about the actual implantation potential. RESULTS: A significant relationship between first PB morphology and embryo quality was found. Fragmentation after 2 days was increased in embryos derived from oocytes with fragmented first PBs (P < 0.05) in comparison with those derived from oocytes with intact PBs. No similar correlation could be demonstrated for fertilization rate. Embryos in the intact first PB group showed an increased rate of blastocyst formation as compared with the fragmented first PB group (P < 0.05). In addition, a significant difference in implantation rate (48.6 versus 22.0%; P < 0.025) and ongoing pregnancy rate (68.4 versus 34.8%; P < 0.05) was observed for the intact versus fragmented groups respectively. CONCLUSION: In conclusion, the current study provides further evidence that preselection at a very early stage may be helpful in identifying a subgroup of preimplantation embryos with a good prognosis to form blastocysts and, consequently, to implant.     

The effect of intracytoplasmic sperm injection and semen parameters on blastocyst development in vitro

The present study compares the development and quality of blastocysts derived from conventional oocyte insemination with those derived from intracytoplasmic sperm injection (ICSI). Oocytes were collected from patients undergoing ovarian stimulation with human menopausal gonadotrophins for IVF. Patients with normal semen were assigned to conventional oocyte insemination while those with progressive motility <20% and/or normal sperm morphology < or =4% were assigned to ICSI. Resulting embryos were cultured for up to 6 days. The mean number and percentage of embryos reaching the blastocyst stage and the mean number and percentage of blastocysts of high quality on days 5-6 were assessed for both treatment groups and compared. The influence of paternal factors (sperm concentration, motility, progressive motility, morphology) on blastocyst development and quality were assessed by regression analyses. Significantly more ICSI-derived embryos arrested at the 5- to 8-cell stage (P = 0.024) concomitant with the activation of the paternal genome than those derived from conventional oocyte insemination. Significantly fewer ICSI-derived embryos reached the blastocyst stage on days 5-6 (P<0.001) and significantly fewer ICSI-derived embryos were of high quality (P = 0.002) compared with conventional oocyte insemination. When treatment groups were combined and evaluated by regression analysis, progressive motility and sperm morphology were significantly correlated with diminished blastocyst development and quality (P < 0.05). From these data, we conclude that paternal factors and/or performing ICSI in cases of severe male factor infertility may have a detrimental effect on blastocyst development and their quality.     

Developmental competence of oocytes after ICSI in the rhesus monkey

Oocyte quantity and quality are critical to assisted reproductive technology (ART), yet few assessments beyond counting metaphase II (MII) oocytes exist. In this study, 30 +/- 2 oocytes per cycle were recovered from rhesus monkeys subjected to follicular stimulation with human gonadotrophins, of which 15 +/- 1 were MII. Oocyte quality was investigated by monitoring the developmental potential of oocytes subjected to intracytoplasmic sperm injection (ICSI). Despite uniform fertilization rates (71 +/- 4%), progression of embryos to blastocysts varied when expressed as a monthly average, from 20 to 85%, with lows from February to April and again in October, which could be attributed to developmental failure of a significant number of oocyte cohorts (14 of 55). Blastocyst rates, after elimination of failed cohorts, were uniform over time (59 +/- 4%). Neither culture conditions, the number of follicular stimulations, nor the individual sperm or oocyte donor were associated specifically with developmental failure, suggesting that intrinsic differences between stimulation cycles account for the observed variation in developmental potential. The in-vivo developmental competence of ICSI-produced embryos grown to blastocysts in vitro was also assessed. Two ongoing pregnancies and the birth of a normal female, 'Blastulina', represent landmarks in efforts to expand the use of ART in the rhesus monkey.     

A comparison of ICSI outcomes with fresh and cryopreserved epididymal spermatozoa from the same couples

The published experience with frozen-thawed epididymal spermatozoa and intracytoplasmic sperm injection (ICSI) suggests that fertilization and pregnancy success rates are comparable to those achieved with freshly retrieved spermatozoa. However, no study has exactly compared clinical outcomes between the two IVF/ICSI cycles in the same couples. To formally address this issue, we assessed ICSI outcomes in couples each of whom had had two IVF/ICSI cycles: one using fresh and the second using frozen-thawed epididymal spermatozoa obtained from a single aspiration procedure. From a pool of 101 consecutive patients undergoing IVF/ICSI with epididymal spermatozoa, 19 couples initially used fresh epididymal spermatozoa and subsequently underwent a second IVF/ICSI procedure with frozen-thawed spermatozoa from the same aspiration. Normal (2PN) oocyte fertilization rates, embryo quality and pregnancy rates were compared between the two IVF/ICSI cycles for each couple. In the fresh epididymal sperm group, 58.4% of the injected oocytes fertilized normally compared with 62.0% of the injected oocytes in the frozen-thawed epididymal sperm group, revealing no statistically significant difference. Graded embryo quality also did not differ significantly between the paired IVF/ICSI cycles. The clinical pregnancy rates were 31.6% (6/19) and 36.8% (7/19) in the first and second cycles respectively. All but one pregnancy were singletons. In summary, this study provides strong evidence to support the notion that motile, cryopreserved and thawed epididymal spermatozoa are equal to freshly retrieved spermatozoa for ICSI in couples with obstructive azoospermia.     

Is intracytoplasmic sperm injection (ICSI) a safe procedure? What do we learn from early pregnancy data about ICSI?

The aim of this study was to evaluate the safety of the intracytoplasmicsperm injection (ICSI) procedure by analysing early pregnancydata from ICSI and in-vitro fertilization (IVF) patients. Inall, 50 ICSI pregnancies were compared with 226 FVF pregnancies.Comparisons were made during the first 9 weeks after the theoreticallast menstrual period (7 weeks after oocyte retrieval) withregard to epidemiological data, plasma hormonal concentrationsand transvaginal ultrasonographical findings. Although patientswere significantly (P < 0.001) younger in ICSI (31 years)than in IVF pregnancies (33 years), their duration of infertilitywas similar. Miscarriage and multiple gestation rates were notsignificantly different in ICSI pregnancies (respectively 24and 24%) from those found after IVF (32 and 29%). The probabilityof developmental arrest of the intrauterine sac (miscarriagesand vanishing twins) was similar in both ICSI (16%) and IVF(25%) cases. The mean plasma hormonal concentrations startingfrom day 11 after oocyte retrieval were similar in both groups.Every ICSI and IVF pregnancy showed an embryo with cardiac activityat 7 weeks. Early pregnancy data did not show any abnormal findingsfor pregnancies achieved using ICSI compared to those achievedby FVF.     

Rare association of ovarian implantation site for patients with heterotopic and with primary ectopic pregnancies after ICSI and blastocyst transfer

Two cases of patients with ruptured ovarian pregnancies (P1 = ovarian heterotopic and P2 = primary ovarian ectopic) after intracytoplasmic sperm injection and blastocyst transfer are presented. Laparoscopy was performed on day 40 and day 27 after transfer in cases P1 and P2 respectively. In both cases the ectopic pregnancies were located on the left ovary and were successfully removed by laparoscopy preserving the ovaries. In case P1 the intrauterine pregnancy was not affected. A healthy boy was born after 37 weeks of pregnancy. In this way, potential fertility of the patients and the intrauterine pregnancy were maintained. These cases occurred during a series of blastocyst transfers in which 129 pregnancies were obtained. There were no cases of ovarian ectopic/heterotopic pregnancies from January 1996 to September 1999 in 814 pregnancies obtained from day 2 or day 3 embryo transfers. Because the ovarian ectopic pregnancies occurred in patients with day 5 embryo transfer who otherwise did not have any predisposing factors for ectopic pregnancy, it is advisable to conduct a large scale analysis of future data about the possible association between blastocyst-stage embryo transfer and the somewhat higher risk of unexpected complications of clinical outcome.     

Laser-assisted zona pellucida thinning prior to routine ICSI

BACKGROUND: In MII oocytes showing difficult oolemma breakage, ICSI can cause an increase in the degeneration rate. This may be overcome by laser-assisted ICSI using a 5-10 micro m opening in the zona pellucida for injection. However, such a small opening might impair the hatching process, especially if assisted hatching is applied in addition. In order to prevent this, the present study used routine injection through an area of zona pellucida in which laser zona thinning had been applied, providing for both a reduced mechanical stress to the oocyte and assisted hatching. METHODS: This prospective study involved 100 cycles with 1016 MII oocytes. Conventional ICSI (control group) was compared with a modified laser-assisted ICSI (study group) in sibling oocytes. In the latter group oocytes were injected through an extended area of zona thinning. RESULTS: Degeneration rate was significantly lower in the study group (P < 0.004). There were no differences in fertilization, or formation and quality of blastocysts. In the study group embryo quality on day 2 was significantly better (P = 0.004) and herniation of day 5 blastocysts was increased (P = 0.005). Rates of implantation and pregnancy were not affected. However, on day 3 laser-assisted ICSI proved beneficial (P = 0.038) in terms of clinical pregnancy rate. CONCLUSIONS: The new method combines a less invasive ICSI technique with assisted hatching. Our preliminary data indicate that in addition to an improved oocyte survival, this new approach increases the hatching rate in vitro, which may explain the increase in pregnancy rate, at least in day 3 transfers.     

Fertilization and early embryology: Normal development and metabolic activity of preimplantation embryos in vitro from patients with polycystic ovaries

Polycystic ovary syndrome (PCOS) is closely associated withhigh miscarriage rates and, following in-vitro fertilization(IVF), with decreased fertilization rates, suggesting that oocytesand embryos are of poor quality. In this prospective study,we examined the development, metabolic activity and blastocystcell number of embryos following IVF from 51 patients with eitheranovulatory PCOS, ovulatory PCOS or tubal disease. The numberof oocytes retrieved and the fertilization rates were similarfor patients with PCOS and tubal disease. Following embryo transfer,46% of the patients with PCOS and 36% of patients with tubaldisease became pregnant. A similar proportion of surplus embryosfrom patients with PCOS and tubal disease developed to the blastocyststage (38% and 43% respectively). Patients with anovulatoryPCOS had embryos with less fragmentation which cleaved faster,cavitated earlier and had more cells at the blastocyst stagethan embryos from patients with tubal disease. While the profileof glucose uptake and lactate production was similar for allgroups throughout preimplantation development, patients withtubal disease who underwent ovulation induction using the ‘titrated’regimen optimized for PCOS patients resulted in embryos withreduced pyruvate uptake, in addition to low blastocyst cellnumbers. This study demonstrates that with an optimized ovulationinduction regimen, embryos from PCOS patients are of good qualityand developmental potential.     

Transfer at the blastocyst stage of embryos derived from testicular round spermatid injection

BACKGROUND: Intracytoplasmic injection of testicular round spermatids has been suggested as a salvage treatment in couples when testicular sperm extraction does not yield any mature sperm. However, the success of the procedure is debatable, and controversy surrounds issues such as the presence and (if present) identification of spermatids in testicular tissue. Progression rate to the blastocyst stage of spermatid-derived embryos appears to be low. METHODS: In this study, we investigated the feasibility and outcome of blastocyst stage embryo transfer after round spermatid injection (ROSI). ROSI was undertaken in 58 couples who did not yield mature or elongated sperm to testicular sperm extraction. RESULTS: The incidence of blastocyst formation from two pronuclear oocytes was 7.6%. A total of 16 blastocysts were transferred in 12 patients (20.7%). None of the patients conceived. CONCLUSIONS: The results of this study indicate that the blastocyst stage is reached by only very few ROSI-derived embryos and these embryos do not implant.     

Triploid pregnancy after ICSI of frozen testicular spermatozoa into cryopreserved human oocytes: case report

Although freezing oocytes is ethically more acceptable than cryopreservation of embryos, variable oocyte survival, fertilization rate and possible risk of increased ploidy after cryopreservation have precluded the widespread clinical application of oocyte cryopreservation in assisted reproduction techniques. We report a triploid pregnancy from intracytoplasmic sperm injection of recombinant FSH-stimulated frozen/thawed testicular spermatozoa into cryopreserved oocytes in a hormone replacement cycle. To our knowledge, this is the first report of a pregnancy where both gametes have been frozen. It illustrates the need for further research when applying new techniques in assisted reproduction.     

Influence of group culture and culture volume on the formation of human blastocysts: a prospective randomized study.

The optimal culture conditions for embryos to reach the blastocyst stage are under investigation. One factor is the putative influence of autocrine or paracrine factors produced by the embryo itself. Studies in mice blastocysts showed a beneficial influence of micro-cultures and communal growth on pregnancy and implantation rates, attributed to these growth or survival factors. In humans, studies have only involved embryos up to day 2 or 3 without consistent results. Therefore a prospective, randomized study was designed to assess whether group culture or incubation volume would influence day 3 human embryos to develop into blastocysts. Embryos were initially cultured in groups until day 3, after which patients were randomly allocated to four groups. Group 1: group culture in a small volume; group 2: single culture in a small volume; group 3: single culture in a large volume; group 4: group culture in a large volume. No significant differences in blastocyst formation could be found between the four groups (35, 45, 36 and 36% respectively). Therefore any of the four modes can be used, whichever is most convenient. The only factor which made a statistically significant contribution was the number of embryos on day 3. An increase in the number of embryos by one embryo decreased the odds of obtaining a blastocyst by 6%. The overall pregnancy rate per transfer was 40%, and the implantation rate was 28%. Single culture in a small volume allows a direct and individual assessment of embryo morphology, and as such it seems preferable.     

The impact of the source of spermatozoa used for ICSI on pronuclear morphology.

BACKGROUND: The aim of this prospective study was to find out whether the source of spermatozoa used for intracytoplasmic sperm injection (ICSI) has an impact on the morphological features of pronucleate zygotes, which make up the basis of a pronuclear scoring system for the selection of the most viable embryos for transfer. METHODS AND RESULTS: The study group consisted of 194 two pronucleate (2PN) ICSI zygotes, of which 144 originated from ejaculated (ES) and 50 from testicular spermatozoa (TS). At 18 h postinjection, 2PN zygotes were assessed for pronuclear alignment, polarity in nucleoli and cytoplasmic appearance; all of which were found to exhibit similar patterns of distribution between the ES and TS groups (P = not significant). At 25 h, the presence of first cleavage was similar for both groups; 11% of zygotes in the ES and 10% of those in the TS group underwent early cleavage (P = not significant). At 48 h, a quality score was obtained for cleaving embryos by multiplying the number of blastomeres with the grade of the embryo. Pronuclear scoring in both groups of spermatozoa correlated with embryo quality score at 48 h postinjection. There was a trend for a higher incidence of early cleavage and a lower incidence of pronuclear arrest with better pronuclear scoring embryos for both types of spermatozoa. CONCLUSION: The morphological features of pronucleate zygotes at 18 h after microinjection with ES and TS are similar to each other.     

Cognitive development of 12 month old Greek infants conceived after ICSI and the effects of the method on their parents

BACKGROUND: ICSI is widely used as a method of assisted reproduction in Greece. Research shows that children conceived after the application of ICSI develop normally. However, Bowen et al. (1998) reported that children conceived after ICSI had lower scores in the Mental Development Index (MDI) of the Bayley Scales of Infant Development compared with infants conceived naturally or by standard IVF treatment. This finding raised concerns about the effects of ICSI on infants' cognitive development. The aim of the present study was twofold. First to compare the cognitive development of Greek infants conceived after ICSI treatment to a control group of infants conceived after IVF treatment and to a further control group conceived naturally (NC). Second, to investigate the psychological effects of ICSI compared to IVF on Greek parents. METHODS: The Bayley Scales of Infant Development were employed to assess cognitive development of infants. A 37 item semi-structured interview was devised to obtain demographic information and to assess and compare the psychological effects of ICSI and IVF on parents. RESULTS: The mental development of infants in all three groups was within the normal range (ICSI 101.4, IVF 95.7, NC 98.9). The differences between the three groups were not statistically significant. The duration of pregnancy and the birthweight differed in the three groups. Furthermore, mothers in the IVF and the ICSI groups experienced anxiety during pregnancy. IVF mothers differed in the mode of delivery and a smaller number of these mothers breastfed their infants. CONCLUSIONS: This study has shown that Greek infants, born after the application of ICSI, have mental and motor scores within the normal range. With regard to the psychological effects, it appears that mothers in the ICSI and IVF groups experience greater anxiety during their pregnancies than those in the NC group.     

Intracytoplasmic sperm injection into zona-free human oocytes results in normal fertilization and blastocyst development

Zona-free human oocytes are frequently encountered in in-vitro fertilization (IVF) laboratories. The oocytes escape out of the zona pellucida, following zona fracture, which can occur during oocyte retrieval or manipulation, but occasionally may be the result of increased zona fragility. Some of the zona-free oocytes are mature and morphologically healthy; nevertheless, all are typically discarded. In this report, we demonstrate that zona-free oocytes can be fertilized normally using intracytoplasmic sperm injection (ICSI) and can subsequently develop without zona to the blastocyst stage in vitro. We therefore suggest that those mature and morphologically normal zona-free oocytes may be rescued, fertilized with ICSI and then cultured to the blastocyst stage for subsequent transfer or cryopreservation.     

Efficient treatment of infertility due to sperm DNA damage by ICSI with testicular spermatozoa

BACKGROUND: Sperm DNA damage (fragmentation) is a recently discovered cause of male infertility for which no efficient treatment has yet been found. Previous findings have suggested that clinically relevant sperm DNA damage may occur at the post-testicular level. This study was undertaken to assess the clinical usefulness of ICSI with testicular spermatozoa in this indication. METHODS: The percentage of spermatozoa with fragmented DNA, assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling assay, and ICSI outcomes were compared in two sequential attempts performed, respectively, with ejaculated and testicular spermatozoa in 18 men with increased sperm DNA fragmentation. RESULTS: The incidence of DNA fragmentation was markedly lower in testicular spermatozoa as compared with ejaculated spermatozoa. No differences in fertilization and cleavage rates and in embryo morphological grade were found between the ICSI attempts performed with ejaculated and with testicular spermatozoa. However, eight ongoing clinical pregnancies (four singleton and four twin) were achieved by ICSI with testicular spermatozoa (44.4% pregnancy rate; 20.7% implantation rate), whereas ICSI with ejaculated spermatozoa led to only one pregnancy which was spontaneously aborted. CONCLUSIONS: These data show that ICSI with testicular spermatozoa provides the first efficient assisted reproduction treatment option for men with high levels of sperm DNA damage.     

Cryopreservation of human oocytes and fertilization by two techniques: in-vitro fertilization and intracytoplasmic sperm injection

Human oocyte cryopreservation results in poor survival and subsequentfertilization rates. It has been suggested that freeze-thaw-inducedchanges in the zona pellucida may impair sperm penetration orattachment. The aim of this study was to compare fertilizationand cleavage rates in cryopreserved oocytes inseminated by conventionalin-vitro fertilization (IVF) or intracytoplasmic sperm injection(ICSI). A total of 220 oocytes, obtained from volunteers whohad undergone ovarian stimulation, were cryopreserved usinga slow freeze-rapid thaw protocol with 1.5 M propanediol asthe cryoprotectant. Surviving oocytes (n= 74, 34.4%) were randomlyallocated for fertilization by conventional IVF (group 1) orICSI (group 2) using cryopreserved spermatozoa from a singledonor of proven fertility. Fertilization was achieved in five(13.5%) of the oocytes in group 1 and 17 (45.9%) in group 2(P < 0.005), with only one oocyte in group 1 exhibiting normalfertilization as opposed to 16 (43.2%) in group 2 (P < 0.001).Similarly, one oocyte fertilized by IVF cleaved, while all fertilizedwith ICSI cleaved (P < 0.001). We conclude that althoughthe survival of oocytes is poor following cryopreservation,fertilization and cleavage rates can be enhanced significantlyusing ICSI. These data also suggest that the method of cryopreservationused in this study affected the zona pellucida, such that normalsperm attachment or penetration was impaired.     

Outcome of ICSI in HIV-1-infected women

BACKGROUND: Since 2001, French law has permitted the use of assisted reproductive technology in human immunodeficiency virus (HIV)-1 infected women under strict conditions. This report describes a preliminary series of seropositive women who underwent assisted reproduction treatment at our facility. To minimize contamination of culture media, equipment, and therefore of male gametes and embryos, we chose to perform ICSI in all cases. The outcome of ICSI was compared with the outcome in an age-matched group of non-HIV-1-infected women. Since several previous reports have indicated that HIV infection may be associated with a decrease in spontaneous fertility, our goal was also to assess the fertility status of the HIV-1-infected women entering our ICSI programme. METHODS: The French law governing the use of assisted reproduction protocols in HIV-1-infected women was strictly applied. The inclusion criteria were absence of ongoing disease, CD4((+)) count >200 cells/mm(3), and stable HIV-1 RNA level. Since mean age at the time of ICSI was higher in HIV-1-infected women than in the overall group of non-HIV-infected women, we compared outcome data in HIV-1-infected women (group I) to a group of non-HIV-1-infected women matched with regard to age and follicle retrieval period (group II) as well as to the overall group of women who underwent ICSI at our institution (group III). RESULTS: A total of 66 ovarian stimulations was performed in 29 HIV-1-infected-infected women. The percentage of cancelled cycles was higher in infected women than in matched controls (15.2 versus 4.9%, P < 0.05). The duration of ovarian stimulation (13.3 versus 11.7 days, P < 0.05) and amount of recombinant FSH injected (2898 versus 2429 IU, P < 0.001) were also higher in infected women. The number of retrieved oocytes, mature oocytes, and embryos obtained as well as embryo quality was similar in all groups. The fertilization rate was higher in infected women than in matched controls (67 versus 60%, P < 0.01). The pregnancy rate was not significantly different between groups I and II (16.1 versus 19.6%) in spite of the fact that the number of embryos transferred was purposefully restricted in the HIV-1-infected group to minimize multiple pregnancy (2.0 versus 2.4, not significant). CONCLUSION: The results of this preliminary series of ICSI cycles in HIV-1-infected women indicate that optimal ovarian stimulation is slightly more difficult to achieve than in matched seronegative women. However, when criteria for oocyte retrieval were fulfilled, ICSI results were similar to those of age-matched controls.     

Comparison of Ca2+ and CaMKII responses in IVF and ICSI in the mouse

Novel methods of egg activation in human assisted reproductive technologies and animal somatic cell nuclear transfer are likely to alter the signalling process that occurs during normal fertilization. Intracytoplasmic sperm injection (ICSI) bypasses the normal processes of the acrosome reaction, sperm-egg fusion, and processing of the sperm plasma membrane, as well as alters some parameters of intracellular calcium ([Ca(2+)](i)) dynamics (reported previously by Kurokawa and Fissore (2003)). Herein, we extend these studies to determine if ICSI alters the activity of the Ca(2+)-dependent protein, Ca(2+)/calmodulin-dependent kinase II (CaMKII), which is responsible for the completion of meiosis in vertebrate eggs. After ICSI or in vitro fertilization (IVF), individual mouse eggs were monitored for their relative changes in both [Ca(2+)](i) and CaMKII activity during the first [Ca(2+)](i) rise and a subsequent rise associated with second polar body extrusion. The duration of the first [Ca(2+)](i) rise was greater in ICSI than in IVF, but the amplitude of the rise was transiently higher for IVF than ICSI. However, a similar mean CaMKII activity was observed in both procedures. During polar body extrusion, the amplitude and duration of the Ca(2+) rises were increased by a small amount in ICSI compared with IVF, whereas the CaMKII activities were similar. Thus, compared with IVF, ICSI is not associated with decreased or delayed CaMKII activity in response to these Ca(2+) signals in the mouse.