H. Joris

Pregnancies after intracytoplasmic injection of single spermatozoon into an oocyte

Intracytoplasmic sperm injection (ICSI) is a promising assisted-fertilisation technique that may benefit women who have not become pregnant by in-vitro fertilisation (IVF) or subzonal insemination (SUZI) of oocytes. We have used ICSI to treat couples with infertility because of severely impaired sperm characteristics, and in whom IVF and SUZI had failed. Direct injection of a single spermatozoon into the ooplasm was done in 47 metaphase-II oocytes: 38 oocytes remained intact after injection, 31 became fertilised, and 15 embryos were replaced in utero. Four pregnancies occurred after eight treatment cycles--two singleton and one twin pregnancy, and a preclinical abortion. Two healthy boys have been delivered from the singleton pregnancies and a healthy boy and girl from the twin pregnancy.

Sperm characteristics and outcome of human assisted fertilization by subzonal insemination and intracytoplasmic sperm injection

Objective To investigate the influence of sperm characteristics on the treatment by subzonal insemination (SUZI) and intracytoplasmic sperm injection of couples with severe male infertility. Design A retrospective analysis of 300 consecutive cycles of assisted fertilization concerning 202 infertile couples was performed. One hundred fifty-three couples underwent 362 unsuccessful IVF cycles, whereas on 49 couples IVF was not performed because of poor sperm characteristics. Setting Procedures were performed in an institutional research environment. Patients, Participants Couples in which the male partner was the presumed cause of repeated failure to achieve conception by IVF or in which seminal parameters were unacceptable for IVF. Interventions Three hundred transvaginal oocyte retrievals were performed after superovulation by GnRH agonist and gonadotropins. Main Outcome Measures After SUZI and intracytoplasmic sperm injection the following parameters were evaluated: fertilization, cleavage, pregnancy, and implantation rates in relation to the sperm parameters and the proportion of acrosome-free spermatozoa after different treatments. Results Normal fertilization occurred in 18% of the oocytes treated by SUZI and in 44% after intracytoplasmic sperm injection. Only the treatment by electroporation showed a positive correlation with the fertilization rate. Fourteen pregnancies were obtained after SUZI, 8 pregnancies after intracytoplasmic sperm injection, and 8 pregnancies after a combination of the two procedures. A score calculated from the sperm parameters after selection correlated with the fertilization obtained after SUZI, whereas a score calculated from the parameters before sperm selection correlated with the pregnancy rate. Sperm morphology influenced the implantation rate of the embryos obtained with these two procedures. Conclusions Intracytoplasmic sperm injection and SUZI can successfully treat couples who fail IVF or who cannot benefit from IVF. Different treatments can be applied to semen samples to increase the number of acrosome-reacted spermatozoa. The few significant relations found between sperm characteristics and the outcome of assisted fertilization cannot predict the outcome.

Influence of individual sperm morphology on fertilization, embryo morphology, and pregnancy outcome of intracytoplasmic sperm injection

OBJECTIVE To evaluate the influence of morphology of individual spermatozoa on fertilization and pregnancy outcome. DESIGN Retrospective analysis. SETTING An IVF center in an institutional research environment. PATIENT(S) Fertilization and embryo quality according to individual sperm morphology were analyzed in 662 consecutive ICSI cycles. Pregnancy outcome was evaluated for these cycles and an additional 1005 consecutive ICSI cycles. INTERVENTION(S) ICSI was performed using sperm cells of ejaculated, epididymal, or testicular origin. Observation through an inverted microscope was used to prospectively classify injected sperm cells as normal or morphologically abnormal. MAIN OUTCOME MEASURE(S) Oocyte fertilization, embryo morphology, and pregnancy outcome of unmixed embryo transfers. RESULT(S) Injection of morphologically abnormal spermatozoa (irrespective of origin) resulted in a lower fertilization rate (60.7%) than did injection of morphologically normal spermatozoa (71.7%). Embryo cleavage quality did not differ between groups. Higher pregnancy and implantation rates were obtained in patients with normal sperm morphology (36.7% and 18.7%, respectively) than in those with abnormal sperm morphology (20.2% and 9.6%). CONCLUSION(S) Individual sperm morphology assessed at the moment of ICSI correlated well with fertilization outcome but did not affect embryo development. The implantation rate was lower when only embryos resulting from injection of an abnormal spermatozoon were available.

CRYOPRESERVATION OF SUPERNUMERARY MULTICELLULAR HUMAN EMBRYOS OBTAINED AFTER INTRACYTOPLASMIC SPERM INJECTION

OBJECTIVE To investigate the pregnancy rate of frozen-thawed human supernumerary multicellular embryos that were cryopreserved after intracytoplasmic sperm injection or IVF. DESIGN A clinical study. SETTING Consenting patients in an academic research environment. PATIENTS Couples with severe male infertility, indicated by failed or sporadic fertilization after IVF or subzonal insemination or by < 500,000 progressively motile spermatozoa in the entire ejaculate, and couples for IVF during the same period. INTERVENTIONS After microinjection or IVF, the three best-quality embryos were transferred, and 1,171 embryos from intracytoplasmic sperm injection compared with 2,495 embryos from IVF were frozen with dimethyl sulphoxide. Of these, 413 and 969 embryos were thawed, respectively. MAIN OUTCOME MEASURE The survival rate, the total and clinical pregnancy rates, the delivery rate, and the preclinical abortion rate were calculated. RESULTS Fifty-three percent of the thawed intracytoplasmic sperm injection embryos survived. Twenty-two pregnancies have been established in 101 transfers, corresponding to a total pregnancy rate of 21.8% per transfer. The clinical pregnancy rate was 12.9% per transfer and the delivery rate was 5.9% per transfer. Of the IVF embryos, 51% survived and 37 pregnancies have been established in 253 transfers. The total and clinical pregnancy rates and the delivery rate were 14.6%, 10.7%, and 7.1%, respectively. The preclinical abortion rate was 40.9% for cryopreserved intracytoplasmic sperm injection embryos and 27.0% for IVF embryos. CONCLUSIONS The high incidence of preclinical abortions after transfer of human embryos cryopreserved after intracytoplasmic sperm injection requires extension of the series.

Quality of frozen-thawed testicular sperm and its preclinical use for intracytoplasmic sperm injection into in vitro-matured germinal-vesicle stage oocytes.

OBJECTIVE To study the effects of cryopreservation on the quality of human testicular spermatozoa and the efficiency of intracytoplasmic sperm injection (ICSI) with frozen-thawed testicular sperm into metaphase II oocytes in vitro-matured from the germinal-vesicle stage oocyte. DESIGN Preclinical freezing study on supernumarary testicular spermatozoa after ICSI. SETTING Tertiary IVF center coupled with an institutional research environment. PATIENT(S) Twenty-nine patients undergoing excisional testicular biopsy for ICSI. INTERVENTION(S) Isolated testicular spermatozoa were cryopreserved and thawed; frozen-thawed motile testicular spermatozoa were microinjected. MAIN OUTCOME MEASURE(S) Prefreezing and post-thawing motility and viability, survival rate, fertilization rate, cleavage rate, and embryo quality after ICSI. RESULT(S) Mean percentage motility decreased from 21% before freezing to 6% after thawing. Vitality was impaired to a similar extent, decreasing from 68% to 22% (32% recovery rate). Injection of frozen-thawed testicular spermatozoa into in vitro-matured oocytes resulted in a fertilization rate of 50.9%. Cleavage rate was severely impaired. Half of the fertilized oocytes became arrested in the one-cell stage. CONCLUSION(S) Despite the low quality of the fresh testicular spermatozoa, a high percentage of prepared testicular sperm fractions showed survival and motility after the freezing and thawing process. Injection of frozen-thawed testicular sperm into matured oocytes resulted in fertilization rates comparable with these with fresh testicular sperm, but cleavage rates were severely impaired, which might be due to source of oocytes used for ICSI.

Clinical application of preimplantation diagnosis for myotonic dystrophy

Myotonic dystrophy (DM) or Steinerts disease is a progressive autosomal dominant disease characterized by increasing muscle weakness, myotonia, cataracts, and endocrine abnormalities such as diabetes and testicular atrophy. The gene for DM was cloned in 1992 and the mutation was shown to be an expanded trinucleotide (CTG) repeat. A polymerase chain reaction (PCR)‐based assay was described soon after that would allow (prenatal) diagnosis of the disease. Based on these PCR assays, we have developed a method for carrying out single‐cell PCR for DM. In preimplantation diagnosis, embryos obtained in vitro are checked for the presence or absence of a disease, after which only embryos shown to be free of the disease under consideration are returned to the mother. A single‐cell assay was developed for preimplantation diagnosis in couples where one of the parents is afflicted with DM. Twenty intracytoplasmic sperm injection (ICSI) cycles were carried out in eight patients and between one and four embryos were replaced in 17 out of 20 cycles. Two of the patients became pregnant and have had prenatal diagnosis which has confirmed that they are unaffected.

Preimplantation diagnosis for fragile X syndrome based on the detection of the non-expanded paternal and maternal CGG

Fragile X syndrome is the most common monogenic cause of mental retardation in boys. It is always characterized clinically by moderate mental retardation and often by a long face with large everted ears and macro‐orchidism. The causal mutation is an expansion of a CGG triplet repeat in a 5′ exon of the FMR‐1 gene in Xq27.3. We report here for the first time a method for preimplantation genetic diagnosis (PGD) for fragile X syndrome based on the amplification of the CGG triplet in the normal allele. Our candidate–patient population, as well as two clinical preimplantation genetic diagnosis (PGD) cycles which led to a pregnancy with an unaffected fetus, are presented in this paper. Copyright

Embryo freezing after intracytoplasmic sperm injection.

This study reports on the safety and efficiency of the cryopreservation of human embryos obtained after intracytoplasmic sperm injection. For this, we evaluated the morphological survival, the capacity of the surviving embryo to develop further in vitro and in vivo. After freezing-thawing embryos obtained after ICSI, 40% of the embryos do not survive the cryopreservation procedure. After selective transfer of further cleaving frozen-thawed embryos, pregnancy loss was 31% (subclinical pregnancy rate of 13% and miscarriage rate of 18%). As a result the livebirth rate per transferred embryos and per thawed embryo was 7 and 3% respectively. Obstetric outcome as well as further follow-up of the children born indicate that cryopreservation of ICSI embryos is a safe procedure, long term follow-up of the children born however is still warranted.

Review: Preimplantation diagnosis of inherited disease

SummaryPreimplantation diagnosis of inherited diseases has become possible with the techniques ofin vitro fertilization, blastomere biopsy of the 6- to 10-cell embryo and DNA analysis of the single blastomeres. Disease-free embryos are selected for transfer to the uterus, thereby avoiding the need for termination of a fetus diagnosed as affected in prenatal diagnosis in the first or early-second trimester of pregnancy. The genetic indications for preimplantation diagnosis are theoretically the same as for prenatal diagnosis, but the defects must be detectable by the polymerase chain reaction. For X-linked recessive diseases, fluorescencein situ hybridization can be used as an alternative for the selection of female embryos. So far almost 40 healthy children have been born worldwide after preimplantation diagnosis for genetic disease. The possibilities and limitations of preimplantation diagnosis, especially in prevention of inherited disease, are discussed in this review.

Two pregnancies after preimplantation genetic diagnosis for osteogenesis imperfecta type I and type IV

Abstract. Osteogenesis imperfecta (OI) is an autosomal dominant genetic disorder characterized by the presence of brittle bones and decreased bone mass (osteopenia), as a result of mutations in the genes that encode the chains of type I collagen, the major protein of bone. The clinical features of the disease range from death in the perinatal period to normal life span with minimal increase in fractures. The present report describes two polymerase chain reaction (PCR)-based assays allowing preimplantation genetic diagnosis (PGD) on the one hand for OI type I, the mildest form, and on the other hand for OI type IV, which is intermediate in severity between OI type I and OI type III. In the couple referred for PGD for OI type I, the female partner carried a 1-bp deletion in exon 43 of the COL1A1 gene, resulting in a premature stop codon in exon 46. The synthesis of too little type I procollagen results from such a non-functional or COL1A1 null allele. In the other couple, referred for PGD for OI type IV, the male partner carried a G to A substitution in exon 19 of the COL1A2 gene, which results in an abnormal gene product due to an αGly247 (GGT) to Ser (AGT) substitution (G247S). Both mutations result in the loss of a specific restriction enzyme recognition site and can therefore be detected by PCR amplification followed by restriction fragment analysis. PCR amplification of genomic DNA of the parents-to-be with one of the two primers fluorescently labelled, followed by automated laser fluorescence (ALF) gel electrophoresis of the amplified and restricted fragments, allowed a distinction between the healthy and affected genotypes. PCR on single Epstein-Barr-virus (EBV)-transformed lymphoblasts resulted in acceptable amplification efficiencies (87% and 85% for OI type I and OI type IV respectively) and the allele drop-out (ADO) rate was assessed at 11.5% and 11.1% for OI type I and OI type IV respectively. With research blastomeres, 100% amplification rates were obtained and no contamination was observed in the blank controls, which validated the tests for clinical application. Embryos obtained after intracytoplasmic sperm injection (ICSI) were evaluated for the presence of the normal genotype of the non-affected parent. For OI type I, two frozen-thawed ICSI-PGD cycles and two fresh ICSI-PGD cycles were carried out for the same couple. The transfer of two unaffected embryos in the last cycle resulted in a twin pregnancy. A twin pregnancy was also achieved in one clinical ICSI-PGD cycle for OI type IV.