常规体外受精失败后行补救性卵胞质内单精子注射的临床总结

目的回顾分析常规IVF受精完全失败在临床中的发生情况及受精失败后应用补救性卵母细胞内单精子注射（ICSI）的临床结局。方法总结1999年5月-2009年5月,在我中心行常规IVF患者中,受精完全失败的发生情况。回顾性分析了2004年1月-2009年5月,因受精完全失败行补救性ICSI后的临床结局。结果1999年至2009年5月,我中心共行常规IVF8359个周期,其中,受精完全失败232个周期,发生率为2．78％。2004年1月至2009年5月,共184个周期受精完全失败,资料完整,对其中115个周期共838个MII期卵子行补救性ICSI,其受精率、卵裂率与优质胚胎率分别为71.0％、93．78％和51．79％;临床妊娠率为11％,获得活产儿5个。结论补救性ICSI能获得较高的受精率和卵裂率,降低周期取消率,但并没有明显增加活产儿出生数,改善妊娠结局。     

Rescue ICSI of oocytes that failed to extrude the second polar body 6 h post-insemination in conventional IVF

BACKGROUND: Attempts to 'rescue' by ICSI oocytes that remained unfertilized 24 h after conventional IVF have generally resulted in poor outcomes. The aim of the present study was to compare the outcome of rescue ICSI performed on one group of patients 6 h after initial insemination with those of another group where rescue ICSI was performed 22 h after initial insemination. METHODS: Twenty-five patient IVF cycles provided the oocytes for rescue ICSI 6 h after initial insemination, and 20 cycles provided the oocytes for rescue ICSI 22 h after initial insemination in this retrospective study. Fertilization and cleavage rates, embryo quality, implantation, and pregnancy rates after rescue ICSI were the main outcome measures. RESULTS: A fertilization rate of 70.3% was achieved with 6 h rescue ICSI compared with 48.5% with 22 h rescue ICSI (P < 0.0001). From 6 h rescue ICSI, 12 clinical pregnancies (48.0%) resulted in three sets of twins, eight singletons and one abortion. From 22 h rescue ICSI there was one (5.0%) singleton pregnancy and delivery of a healthy baby. Likewise, the implantation rate was 20.2% from 6 h rescue ICSI compared with 1.72% from 22 h rescue ICSI (P < 0.02). CONCLUSIONS: Rescue ICSI after 6 h post-insemination (46 h post-HCG) gave better fertilization, pregnancy and implantation rates compared with rescue ICSI after 22 h when oocytes have become aged.     

Outcome of conventional IVF and ICSI on sibling oocytes in mild male factor infertility

BACKGROUND: Decisions concerning the treatment choice for assisted reproduction (IVF or ICSI) are usually made after the evaluation of male fertility factors, or after taking into account the results of previous IVF attempts. There are no widely accepted criteria, so decisions for couples with male subfertility are often empirical and may lead to complete fertilization failure after IVF, or to the unnecessary use of ICSI. METHODS: A study was conducted in which half the oocytes from each of 58 couples with moderate oligo +/- astheno +/- teratozoospermia were inseminated (conventional IVF) and the other half microinjected (ICSI). The technique used for subsequent cycles depended on the results of the first cycle. RESULTS: Nineteen of the 58 IVF/ICSI attempts resulted in fertilization after ICSI only (32.8%) and 39 in fertilization after IVF and ICSI (67.2%). For patients with oocyte fertilization only after ICSI, 61.5% of the oocytes microinjected were fertilized. A mean of 2.2 embryos per patient were transferred, leading to eight clinical pregnancies (42.1%).The implantation rate was 21.4%. All subsequent cycles were carried out with ICSI. Couples with oocyte fertilization after both IVF and ICSI had slightly better semen characteristics than those with oocyte fertilization only after ICSI, but this difference was not significant. Overall, no statistically significant difference was observed between IVF and ICSI in sibling oocytes for any of the variables studied: fertilization rate, embryo morphology and rates of development, pregnancy and implantation. Although only small numbers of oocytes or embryos were available for each couple, six couples had lower fertilization rates after IVF and eight had lower embryo quality after IVF. Eight patients had lower sperm quality in the second cycle, and only seven couples underwent subsequent IVF cycles. CONCLUSIONS: This strategy enabled us to avoid 32.8% of complete fertilization failures after IVF, but not to decrease significantly the number of ICSI attempts in subsequent cycles. However, the uncertainties concerning the safety of ICSI suggest that ICSI should be used cautiously and judiciously.     

常规IVF受精失败补救ICSI后行冻融胚胎移植的临床价值

目的探讨冻融胚胎移植在常规体外受精(IVF)失败后补救卵胞浆内单精子注射(L-ICSI)中的应用价值。方法在12个常规体外受精失败周期中应用ICSI对未受精的MⅡ期卵子进行显微授精,将获得的优质胚胎进行冷冻,再择期行冻融胚胎移植。结果对93个未受精的MⅡ卵子接受L-ICSI,受精63枚,受精率为67.7%(63/93),异常受精3枚(2枚1PN,1枚3PN),57个正常受精卵发生卵裂,卵裂率为95.0%(57/60),优质胚胎率为43.9%(25/57),10例患者冷冻胚胎25枚,其中4例采用程序化冷冻,6例采用玻璃化冷冻。9个患者行冻融胚胎移植,共移植胚胎18枚(其中解冻后胚胎碎裂死亡5枚),其中1个周期因冻融后2个胚胎碎裂放弃移植,2例获得临床妊娠,1例分娩出正常婴儿,1例正在妊娠中,临床妊娠率为22.2%。结论 ICSI可使常规体外受精失败的卵子再受精,冻融胚胎移植可以解决胚胎与子宫内膜不同步的问题,获得相对满意的临床结局,具有一定的应用价值。     

Andrology: Successful treatment of severe male factor infertility in 100 consecutive cycles using intracytoplasmic sperm injection

In this report, we present the results of our first 100 consecutivecycles of intracytoplasmic sperm injection (ICSI). Overall,fertilization occurred in 98% of cycles and embryos were transferredin 94% (2.6 embryos per cycle). About 50% of patients had embryosfrozen. The overall fertilization rate was 71%, of which 4%were abnormally fertilized (three pronuclei). A total of 30clinical pregnancies were established (32% per transfer), resultingin 18 singleton, six twin and one triplet ongoing pregnancies.The implantation rate per embryo was 15%. There were no significantdifferences in the fertilization or pregnancy rates betweenpatients Who had only occasional motile spermatozoa in the ejaculate,semen that was too poor for routine in-vitro fertilization (IVF),or who had failed routine IVF and/or subzonal sperm injection(SUZI). A group of 18 patients were treated with both ICSI androutine IVF on their first cycle because of the high likelihoodof failed fertilization due to poor sperm morphology (<20%normal). In this group, ICSI oocytes had a fertilization rateof 76% compared to only 15% for the routine IVF (control) oocytes,and six patients conceived after transfer of ICSI embryos (33%),indicating that ICSI can be used successfully on 50% of theoocytes if fertilization failure is expected. Similarly, patientswho had failed to become pregnant with SUZI achieved excellentresults after ICSI. There were no significant differences betweenICSI and routine IVF in the proportions of grade 1, 2 or 3 embryoson day 3 post-oocyte recovery. In conclusion, we have achievedresults comparable to those reported from Belgium and we havefound that ICSI is universally applicable to all forms of severemale factor infertility. ICSI produces fertilization, pregnancyand freezing rates comparable to routine IVF with normozoospermicsamples and has none of the drawbacks of other assisted fertilizationtechniques.     

IVF versus ICSI in sibling oocytes from patients with polycystic ovarian syndrome: a randomized controlled trial

BACKGROUND: This study compares the fertilization rate and embryonic development of oocytes randomly inseminated by conventional IVF or ICSI in patients with polycystic ovarian syndrome (PCOS) and normozoospermic semen during IVF cycles. METHODS: Sibling oocytes were randomized to be inseminated either by ICSI or IVF. Fertilization rate (two pronuclei/COC), day 2 embryonic morphology and rate of development were assessed. RESULTS: A total of 1089 cumulus-oocyte complexes (COC) were collected in 60 cycles (mean+/-SD, 18.2 +/- 7.2). Totals of 541 and 548 COC were inseminated by IVF and ICSI respectively, with a significantly higher fertilization rate in the ICSI group (ICSI versus IVF, 72.3 +/- 15.5 versus 44.8 +/- 25.1%). No fertilization failure occurred in the group of oocytes inseminated by ICSI, whereas the COC in nine patients (15%) inseminated by IVF had complete fertilization failure. The day 2 embryonic morphology and rate of development were not different regardless of the insemination method. CONCLUSIONS: Our results suggested that another randomized controlled study, randomizing patients instead of sibling oocytes, should be undertaken to compare the pregnancy rate per started cycle and to see whether ICSI should be performed on all, or at least on a portion of, oocytes for patients with PCOS undergoing IVF cycles.     

Comparison between intracytoplasmic sperm injection and in-vitro fertilization (IVF) with high insemination concentration after total fertilization failure in a previous IVF attempt.

The aim of this prospective study was to evaluate whether couples with total fertilization failure in a previous in-vitro fertilization (IVF) attempt should be offered an additional IVF treatment with elevated insemination concentration or should be treated with intracytoplasmic sperm injection (ICSI). In 23 cycles 228 sibling metaphase II (MII) oocytes were randomly divided: 143 and 85 oocytes were utilized for ICSI and IVF respectively. Of the 143 injected (ICSI) oocytes, 90 (62.9%) were normally fertilized (two pronuclei), whereas 21 (14.7%) oocytes were damaged by the ICSI procedure. Of the fertilized oocytes 72 (80%) developed into transferable embryos. No fertilization at all was observed in the 85 sibling MII oocytes which were inseminated (P < 0.001). In all 23 cycles at least one embryo, obtained by ICSI, could be replaced. Eight pregnancies were achieved of which six resulted in the delivery of nine healthy children. In conclusion, for couples with no or almost no fertilization of oocytes in previous IVF attempts, ICSI appeared to be far superior to an additional IVF attempt with further elevated insemination concentrations.     

Controlled comparison of conventional in-vitro fertilization and intracytoplasmic sperm injection in patients with asthenozoospermia.

A controlled comparison between conventional in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) has been carried out for patients with 相似文献   

部分卵胞浆内单精子显微注射112例分析

目的分析本中心行部分卵胞浆内单精子显微注射的病例,探讨half-ICSI的指征的可行性。方法选择2004年1月至2008年12月在本中心行half-ICSI的112个周期,按适应症分三组,A组为男方中度少弱畸精子症,B组为前次IVF受精失败或低下(30%),C组为不明原因不孕,以同期常规IVF治疗的1377个周期为对照,分别比较三组中发生受精失败或低下发生率(受精率30%)情况的比例,以及half-ICSI的效果。结果 half-ICSI的112个周期共获卵1633个,行IVF766个卵,受精率为54.7%,其中完全不受精27个周期,受精低下(30%)11个周期,行ICSI部分867个卵,MII765个,受精645个,受精率84.3%,移植周期临床妊娠率为39.4%(其中IVF完全不受精者临床妊娠率为32.0%)。112个周期有38个周期发生受精失败或低下,发生率为33.9%(38/112),其中A组发生率31.8%,B组50.0%,C组30.8%。对照组发生受精失败或低下率为7.0%(96/1377),结果有显著性差异(P0.05)。结论对存在高危因素的病人在同一治疗周期中行half-ICSI可明显减少因不受精无胚胎移植的情况出现,从而提高妊娠率,又因有IVF胚胎移植,可减少ICSI子代遗传和先天缺陷的风险。     

Dizygotic twin pregnancy after intracytoplasmic sperm injection of 1 day old unfertilized oocytes

We report on a case where late intracytoplasmic sperm injection (ICSI) on unfertilized oocytes after standard in-vitro fertilization (IVF) cycles resulted in a dizygotic twin pregnancy. Fifteen oocytes were harvested from a patient with a history of salpingotomy. After a single cycle of IVF, only one oocyte showed two pronuclei. Subsequently ICSI was performed on six unfertilized metaphase II oocytes, and three of these oocytes showed two pronuclei. Three fertilized embryos were transferred (two derived from ICSI and one from IVF). A normal twin pregnancy resulted, and after delivery of two healthy boys the twins were confirmed to be dizygotic by DNA analysis of several loci. We conclude that at least one of the embryos was derived from the reinsemination by 'second day ICSI'.      

Birth of a healthy infant after in vitro oocyte maturation and ICSI in a woman with diminished ovarian response: case report

In vitro maturation of oocytes (IVM) has been developed as a treatment option for subjects with good prognosis in assisted reproduction. We present successful IVM treatment in connection with a woman from whom low numbers of embryos were obtained after repeated failed conventional IVF cycles. A 35 year old woman, after 5 years infertility and two intrauterine insemination and three conventional IVF cycles, underwent first an IVM cycle with low dose FSH stimulation, and after failure, another natural IVM cycle. Three oocytes were obtained. After 36 h of IVM the oocytes had reached metaphase II stage, and fertilization using ICSI resulted in one 4-cell stage embryo, which was transferred 2 days later. The result was an uneventful pregnancy and birth of a healthy female infant weighing 4150 g. IVM may be an option for women from whom only low numbers of oocytes are obtained after gonadotrophin stimulation.     

不同受精方式对胚胎冻融结局影响的比较

目的比较常规体外受精(IVF)和卵胞浆内单精子注射(ICSI)对胚胎冻融结局的影响。方法选取2008年1月至2008年12月在我中心进行胚胎冻融移植的142周期(IVF104周期,ICSI38周期),比较两组患者的临床结局。结果142周期共复苏胚胎375枚,IVF组275枚,ICSI组100枚,两组的复苏胚胎存活率相比无差异(89.09%和87.00%);IVF组妊娠率、种植率分别为38.46%、21.22%,ICSI组分别为34.21%、24.14%,两组相比也无统计学差异(P0.05)。结论本研究结果提示ICSI对冻融胚胎的存活率和发育潜能没有显著影响。     

Obstetric outcome of pregnancies after the transfer of cryopreserved and fresh embryos obtained by conventional in-vitro fertilization and intracytoplasmic sperm injection.

This study reports the obstetric outcome of pregnancies obtained after the transfer of cryopreserved or fresh embryos where the initial procedure was standard in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Pregnancies obtained after frozen IVF (n = 245) or frozen ICSI (n = 177) were compared with a control group of pregnancies after fresh embryo transfer in standard IVF (n = 245) and ICSI (n = 177) cycles were selected as controls. The controls were matched according to maternal age, parity and date of embryo transfer. In the standard IVF group, the biochemical pregnancy rates in the cryopreserved and fresh groups were 18.8 and 9.8% respectively (P < 0.01). In the ICSI group, the biochemical pregnancy rates in the cryopreserved and fresh groups were 16.4 and 6.8% respectively (P < 0.01). The miscarriage rates were comparable between the cryopreserved and fresh groups. However, in the frozen ICSI group the miscarriage rate (26.0%) was significantly higher than in the frozen conventional IVF group (13.1%) (P = 0.001). The frequencies of preterm deliveries, infants with very low birthweight and intrauterine deaths were similar in the groups. The low birthweight rates in the frozen IVF (16.1%) and ICSI (12.1%) groups were significantly lower than those in the fresh IVF (32.2%) and ICSI (32.7%) groups (P < 0.001). The major malformation rates in the frozen IVF (2.4%) and ICSI (2.9%) groups were not different from the major malformation rates in the fresh IVF (4.5%) and ICSI (2.4%) groups. In conclusion, the cryopreservation process had no negative impact on the outcome of pregnancies over 20 weeks of gestation. Long-term follow-up studies are needed in order to prove the safety of the freezing-thawing process.     

Comparison of fertilization, cleavage and pregnancy rates of oocytes from large and small follicles

Ovarian stimulation for in-vitro fertilization (IVF) causes development of several cohorts of follicles. At the time of oocyte collection, oocytes are thus retrieved from a wide range of follicles of different sizes and developmental stages. A relationship between size of follicles and pregnancy rates has earlier been demonstrated. The aim of the present study was to compare fertilization, cleavage and pregnancy rates between oocytes retrieved from large and small follicles in conventional IVF and intracytoplasmic sperm injection (ICSI). A total of 200 conventional IVF patients and 175 ICSI patients underwent oocyte retrieval where oocytes from both large and small follicles were collected. A follicle with a volume of > or = 2 ml, corresponding to a follicular diameter > or = 16 mm as determined by ultrasound, was regarded as a large follicle. Only one cycle from each patient was included. Fertilization and cleavage rates were calculated per patient for oocytes from large and small follicles. The mean fertilization and cleavage rates for conventional IVF and ICSI cycles were calculated. Comparison of pregnancy rates was performed for patients receiving embryos derived from oocytes of only large or only small follicles. For conventional IVF patients, fertilization rates were 71.4 and 58.1% (P < 0.01, Wilcoxon paired test) for oocytes of large and small follicles respectively. The corresponding cleavage rates were 95.4 and 93.9% respectively. The pregnancy rate for the two groups was 47% (60/127) and 15% (2/13) (P < 0.05, chi2 test). For ICSI patients the fertilization rate was 72.0 and 71.1% for oocytes of large and small follicles respectively. The corresponding cleavage rate was 93.0 and 91.1%. The pregnancy rate in the two groups was 41% (46/113) and 42% (5/12). The results show that oocytes from smaller follicles also yield fertilization and pregnancies, although in conventional IVF to a lesser extent than oocytes from larger follicles. For IVF cycles, a higher proportion of immature oocytes (which are normally not included in the ICSI procedure) in the group of oocytes from small follicles is most probably the explanation for the lower fertilization rate. The decrease in pregnancy rate with oocytes from small follicles in the IVF cycles was not observed in the ICSI cycles. The possibility of evaluating the degree of oocyte maturation prior to fertilization may be an advantage of the ICSI technique. This suggests that the disadvantages of oocytes from small follicles might be overcome by means of ICSI.      

High fertilization and implantation rates after intracytoplasmic sperm injection

Previously reported better fertilization rate after intra-cytoplasmicsingle sperm injection (ICSI) than after subzonal inseminationof several spermatozoa was confirmed in a controlled comparisonof the two procedures in 11 patients. Intracytoplasmic sperminjection was carried out in 150 consecutive treatment cyclesof 150 infertile couples, who had failed to have fertilizedoocytes after standard in-vitro fertilization (IVF) proceduresor who were not accepted for IVF because not enough motile spermatozoawere present in the ejaculate. A single spermatozoon was injectedinto the ooplasm of 1409 metaphase II oocytes. Only 117 oocytes(8.3%) were damaged by the procedure and 830 oocytes (64.2%of the successfully injected oocytes) had two distinct pronucleithe morning after the injection procedure. The fertilizationrate was not influenced by semen characteristics. After 24 hof further in-vitro culture, 71.2% of these oocytes developedinto embryos, which were transferred or cryopreserved. Only15 patients did not have embryos replaced. Three-quarters ofthe transfers were triple-embryo transfers. High pregnancy rateswere noticed since 67 pregnancies were achieved, of which 53were clinical, i.e. a total and clinical pregnancy rate of 44.7%and 35.3% per started cycle and 49.6% and 39.2% per embryo transfer.A total of 237 supernumerary embryos were cryopreserved in 71treatment cycles.     

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.     

反复体外受精方法失败者卵胞浆内单精子注射预后分析

目的　探讨反复常规体外受精 -胚胎移植 (IVF -ET)方法失败伴受精不良者行卵胞浆内单精子注射 (ICSI)预后。方法　收集 1999年 10月到 2 0 0 2年 8月在我院生殖中心接受常规IVF技术治疗至少 1个周期以上失败伴受精率低于5 0 %的 2 3例 (31个周期 )女性不育患者为研究对象 ,在以后的治疗周期采用ICSI治疗方法。同时选择 2 0 0 1年 10月到 2 0 0 2年 8月因男性因素不育而行ICSI的 30例 (32个周期 )患者为对照组 ,对比两组的临床结果。采用常规超排卵治疗长方案治疗 ,成熟的卵母细胞行单精子显微注射。结果　两组平均获卵数和受精率、四、六细胞卵裂率无显著差异。但八细胞卵裂率、种植率、临床妊娠率 ,IVF失败组分别为 :2 6 .6 %、7.5 %、2 1.4 % ,男性因素不孕组分别为 :35 .8%、18%、4 7.2 %。两组有显著性差异。同时比较失败组自身前后两种不同受精方法的实验室情况。IVF的受精率 ,四、六细胞卵裂率无显著差异。但八细胞卵裂率、种植率、临床妊娠率 ,IVF失败组分别为 :2 6 6 %、7 5 %、2 1 4 % ,男性因素不孕组分别为 :35 8%、18%、4 7 2 %。两组有显著性差异。同时比较失败组自身前后两种不同受精方法的实验情况。IVF的受精率 ,四、六、八细胞卵裂率分别为 4 8.1%、35 .4 %、2 9.9%、2 6 .8%。ICSI     

A comparison of four different techniques of assisted hatching

BACKGROUND: Assisted hatching (AH) has been proposed as a means to increase the implantation rate in patients with poor prognosis for pregnancy. The procedure appears to be effective when used selectively. Several different methods for AH have been introduced over the years but comparative studies are lacking. The aim of the current study was to compare retrospectively the efficacy of AH performed with four different methods in patients undergoing IVF or ICSI. METHODS: AH was performed prior to day 3 embryo transfer in 794 IVF/ICSI cycles. Indications for AH were females aged >35 years and/or elevated follicular phase FSH levels, previous failed IVF/ICSI cycles, poor embryo quality, and thick zona pellucida (>15 microm). Assignment to one of the four methods of AH was according to the availability of the particular method during the study period. The study was not randomized. RESULTS: Partial zona dissection was used in 239, acid Tyrode in 191, diode laser in 219 and pronase thinning of the zona pellucida in 145. Mean female age, mean number of previous failed IVF/ICSI cycles, number of oocytes retrieved, fertilization and cleavage rates, good quality embryos and zona thickness on day 3 did not differ between groups. Mean number of embryos transferred, implantation rate, clinical pregnancy rate, and abortion rates were likewise similar. CONCLUSIONS: Selective AH using four different methods yields similar implantation and pregnancy rates.     

Should ICSI be the treatment of choice for all cases of in-vitro conception?

The objective of this study was to examine different clinical scenarios of in-vitro conception, viz. fertilization with conventional IVF, IVF with high insemination concentration (HIC) and intracytoplasmic sperm injection (ICSI), and assess on a sibling oocyte comparison the hypothesis that ICSI should be performed in all cases requiring in-vitro conception. ICSI with husband's spermatozoa had a higher incidence of fertilization as compared with IVF or IVF with HIC with donor spermatozoa (if previous failure of fertilization had occurred) for unexplained infertility. Similarly, ICSI with husband's spermatozoa had as high an incidence of fertilization as IVF with donor spermatozoa for patients with severe oligozoospermia, asthenozoospermia and/or teratozoospermia, even when the spermatozoa were not selected for their morphology. Two studies were performed to assess ICSI in potential oocyte-related failure of IVF, viz. when fertilization occurred in >50% of oocytes for one group of patients, and in <50% of oocytes in a second group. In both of these studies a significant proportion of the oocytes that failed to fertilize with conventional IVF eventually fertilized after ICSI. The overall conclusion was that ICSI as a first option offers a higher incidence of fertilization, maximizes the number of embryos and minimizes the risk of complete failure of fertilization for all cases requiring in-vitro conception. However, among other concerns, current knowledge of ICSI as an outcome procedure does not provide the confidence to use this process in all cases of IVF for the time being.     

Experience with zona drilling and zona cutting to improve fertilization rates of human oocytes in vitro

Zona drilling (ZD) and zona cutting (ZC) were used in an IVF programme to assist fertilization in semen defect patients. Twenty-seven patients consented to ZD where acidified Tyrode's was used to create a hole in the zona pellucida. In 19 patients, ZD increased the fertilization rate to 29% compared with 8% (P less than 0.001) in their routine IVF cycles, and in eight patients precluded from routine IVF, a fertilization rate of 14% was achieved. Twenty-two patients consented to ZC where a slit in the zona is made mechanically. In 12 patients ZC increased the fertilization rate to 31% compared with 14% (P less than 0.01) from previous routine IVF cycles, and in 10 patients precluded from routine IVF, a fertilization rate of 34% was achieved. In 13 cycles, 68 uncut control oocytes were inseminated. In five cycles both control and ZC oocytes were fertilized (n.s.d.). In eight cycles no control oocytes were fertilized compared with 27% of ZC oocytes. The polyspermy rate was 4.6%. Twenty-four per cent of ZD and 12% of ZC (P less than 0.01) oocytes and embryos were degenerate after 42 h. Both ZD and ZC can increase the fertilization rate of sub-optimal semen, however, in our hands neither technique produced a pregnancy.