Preimplantation genetic diagnosis (PGD): the Gothenburg experience.

BACKGROUND: A program for preimplantation genetic diagnosis of pre-embryos from patients with hereditary disorders was set up in our unit at Sahlgrenska University Hospital in 1994. The majority of the patients were carriers of X-chromosome linked disorders; a few patients were translocation carriers. In this paper we describe our experiences of our first 36 cycles, 30 gender determinations and six analyses of embryos with possible translocations. METHODS: Conventional hormone replacement treatment with intracytoplasmic sperm injection to fertilize the eggs followed by blastomere biopsy and fluorescent in situ hybridization at the eight cell stage was used for sexing as well as detection of translocations. RESULTS: Out of the 30 cycles in 13 patients for gender determination, blastomere biopsies could be carried out in 25 cycles. Transfer of normal female embryos (XX) was performed in 18 cycles, resulting in five pregnancies (pregnancy rate 27.8%) and an implantation rate of 20% per transfer. Three girls have been born. Hence the take home baby rate was 16.7% per transfer and 10% per started cycle. Six cycles (three patients) for detection of translocations in embryos were performed. Diagnosis was possible in four cycles. Transfer of normal embryos was carried out in one cycle. No pregnancy was achieved. CONCLUSION: Successful PGD in its clinical application demands close collaboration between a large group of specialists. Even so, the success rate is considerably lower than after conventional IVF or ICSI procedures. Taking into account the stress caused to the parents facing late interruption of pregnancy following conventional prenatal diagnosis we are convinced that this technique is well worthwhile continuing and refining.

The outcome of intracytoplasmic sperm injection is unrelated to 'strict criteria' sperm morphology.

Sperm morphology was assessed according to the 'strict criteria' established for in-vitro fertilization treatment in the semen samples used for 354 consecutive treatment cycles for intracytoplasmic sperm injection (ICSI). The semen samples were classified according to the three predictive categories of the Tygerberg strict criteria: excellent prognosis (>14% morphologically normal spermatozoa), good prognosis (4-14%) and poor prognosis (<4%). It was found that 37 (10.5%) of the ICSI cycles belonged to the excellent prognosis category, 197 (55.6%) to the good prognosis category, and 120 (33.9%) to the poor prognosis category. The outcomes of the ICSI treatments were evaluated and compared with the sperm morphology classification in order to determine whether the strict criteria could aid in predicting the outcome of ICSI. The fertilization rates in the three categories were 61.6, 66.8, and 61.9%, the pregnancy rates per oocyte retrieval 18.9, 24.9, and 28.3%, and the implantation rates 9.9, 13.0, and 14.9% respectively. No significant differences were found in fertilization, pregnancy, or implantation rates between the three prognosis categories, i.e. the poor prognosis category had an equal chance of obtaining pregnancy compared with the good prognosis category. The results indicate that strict sperm morphology is not related to the outcome of ICSI.

Fluorescent in situ hybridization analysis of chromosomally normal gametes and abnormal arrested embryos.

OBJECTIVE: The purpose of the present study was to investigate if the arrested embryos from a couple with several previously failed IVF treatments were chromosomally normal. Probes for chromosomes X, Y and 18 were used. RESULTS: A couple had undergone 7 in vitro fertilization treatments over a 2 1/2-year period without achieving a pregnancy. In each cycle, where fertilization was obtained, the development of the embryos was arrested. Fluorescent in situ hybridization probes for chromosomes X and Y (and 18) was carried out on gametes and on embryos in 2 separate cycles. Sperm and oocytes were normally haploid X0 or Y0. The nuclei of the blastomeres were fragmented and mosaic for X or Y, or monosomic X0, despite the fact that 2 pronuclei had been assessed on day 1 following intracytoplasmic sperm injection. CONCLUSION: Chromosomally normal gametes can result in abnormal embryos manifested by arrested development and unexplained infertility.

Human chorionic gonadotrophin self-administered by the subcutaneous route to induce oocyte maturation in an in-vitro fertilization and embryo transfer programme.

This study was initiated to evaluate oocyte maturation and the outcome of in-vitro fertilization (IVF) cycles following the s.c. administration of human chorionic gonadotrophin (HCG) by the patient herself or her partner. A group of 104 women who entered our IVF embryo transfer programme were prospectively randomized to have 5000 IU or 10,000 IU HCG s.c. or i.m. The HCG was administered for induction of the final oocyte maturation in cycles with pituitary down-regulation with a gonadotrophin-releasing hormone agonist according to a long protocol and where ovarian stimulation had been achieved with pure follicle stimulating hormone. The mean concentration of HCG in serum 12 and 36 h after the HCG injection was significantly higher in the women receiving 5000 IU i.m. compared to the s.c. route. However, in women receiving 10,000 IU HCG there were no significant differences in the mean concentrations 12 and 36 h after the injection, irrespective of the route of administration. Furthermore, there were no significant differences in the relative numbers of retrieved mature oocytes between the groups. When comparing the clinical outcome in the different groups, no significant differences were found between those receiving 5000 IU or 10,000 IU HCG, i.m. or s.c. Our data indicate that HCG can be given s.c. without reducing the chance of retrieving a mature oocyte and that the clinical outcome with regard to pregnancies is not negatively affected.

Factors of importance for the establishment of a successful program of intracytoplasmic sperm injection treatment for male infertility.

OBJECTIVE: To establish an intracytoplasmic sperm injection treatment program for couples with male infertility and to determine those factors important for success. DESIGN: A retrospective analysis of 171 consecutive cycles of intracytoplasmic sperm injection concerning 145 infertile couples. SETTING: Infertility clinic in a private hospital associated with a university hospital. PATIENTS: Couples with infertility in the male partner whose sperm parameters were unacceptable for conventional IVF or in whom fertilization by conventional IVF failed repeatedly. INTERVENTIONS: One hundred seventy-one transvaginal oocyte retrievals were completed after superovulation with GnRH agonist and gonadotropins. MAIN OUTCOME MEASURES: The parameters evaluated included fertilization, cleavage, implantation, pregnancy, and spontaneous abortion in relation to patient indications and improved procedures. RESULTS: After intracytoplasmic sperm injection, normal fertilization occurred in 45% of the oocytes (n = 1,499). Of 171 treatment cycles, 93% of the couples had fertilization and 86% had ET. Thirty-six pregnancies were achieved. During the period studied, the mean fertilization rate increased from 21.3% during the first 17 weeks to 67.8% during the last 13 weeks, and the pregnancy rate (PR) per started cycle increased from 12.8% to 31.3%. CONCLUSIONS: Technical factors critical for achieving high rates of fertilization and pregnancy were the use of standardized intracytoplasmic sperm injection pipettes, the immobilization of sperm before injection, and the aspiration of a minimal amount of ooplasm before reinjection with the sperm. Intracytoplasmic sperm injection appears to be superior to other micromanipulation methods for alleviating male infertility.

Microfertilization techniques--the Swedish experience.

Intracytoplasmic sperm injection (ICSI) has been studied in this animal research programme since 1990. In 1993, the technique was first applied clinically and up to the present time (September 1994), a total of 456 couples have been studied in 538 cycles. The principal indication for the use of ICSI has been severe male sub-fertility as judged by a semen analysis. In addition, men with high titres of antisperm antibodies, blockage of the vas deferens and neurological disorders such as spinal cord lesions have been included in the programme. Men with genetic disorders such as cystic fibrosis and acrosome-deficient spermatozoa have also been treated successfully. The overall fertilization rate using ICSI was 59%, which is similar to the conventional in vitro fertilization (IVF) programme in Göteborg, however, the pregnancy rate per embryo transfer (29%) and the ongoing pregnancy rate per transfer (22%) were slightly lower. The total number of pregnancies was 144 with 111 of the pregnancies either ongoing or already delivered. To date, 36 healthy children have been born following 29 deliveries and no major malformations have been diagnosed. Being the first programme in Scandinavia to perform ICSI, this unit has experienced long waiting lists which indicates that severe male sub-fertility will be one of the major groups for treatment with assisted reproductive technologies in the future.

Subzonal insemination (SUZI) or in vitro fertilization (IVF) in microdroplets for the treatment of male-factor infertility.

PURPOSE: The results of subzonal insemination (SUZI) and in vitro fertilization with microdroplet insemination used in couples with male-factor infertility are presented. RESULTS: The total fertilization rate was 17.4% for SUZI (n = 89) and 49.3% for microdroplet IVF (n = 100). The fertilization rate for standard IVF (n = 510), not including any male-factor infertility and performed during the same period, was 73.2%. The "take-home baby rate" per started cycle and per embryo transfer (ET), respectively, was 10 and 17.6% for SUZI and 20 and 24.7% for microdrop IVF. For standard IVF these figures were 27 and 31.7%. CONCLUSION: It was concluded that microdroplet IVF can be used with good results in cases of moderate male-factor infertility. The normal (2PN) fertilization rate with the SUZI technique was only 15.1%. However, despite the low fertilization rate, SUZI should be considered when dealing with severe male-factor infertility.

The concentration of lidocaine in follicular fluid when used for paracervical block in a human IVF-ET programme.

Lidocaine is a well-documented local anaesthetic often used for paracervical block (PCB) in pregnant women. For this reason, the substance was used early on for PCB in connection with transvaginal follicle aspiration. However, the concentration reached in follicular fluid after PCB or local infiltration of the vaginal wall has not been previously determined. Furthermore, if lidocaine reaches the follicle, it seems important to determine if the concentration reached influences fertilization and early cleavage of the embryo and the pregnancy rate. The study included 46 women who had PCB with lidocaine (50 mg) and 46 women who had no PCB in connection with follicle aspiration. The mean concentration in follicular fluid was 0.36 +/- 1.1 micrograms/ml. There was no significant difference in lidocaine concentration between follicles containing oocytes that were fertilized and those that were not. Furthermore, the fertilization and cleavage rates did not differ significantly in women with and without PCB with lidocaine. The pregnancy rate did not differ between the two groups. It thus seems that the concentration of lidocaine found in the follicular fluid after PCB with 50 mg lidocaine does not negatively affect fertilization of the human oocyte or early cleavage of the human embryo.

Chromatin bodies in multidrug resistant hybrid cells have centromeres and originate from homogeneously staining regions.

Antikinetochore antibodies from patients with the CREST syndrome of scleroderma were used as probes to study homogeneously staining regions (HSRs) in multidrug resistant (MDR) mouse tumor cells, and chromatin bodies (CBs) in MDR mouse-hamster hybrid cells. In one mouse tumor line the C-band positive HSR showed antigenic properties and displayed many weekly fluorescent spots, i.e. it contained kinetochore proteins. The immunofluorescence pattern of the HSR could also be observed in interphase nuclei. The C-band positive CBs of the hybrid cells had active centromeres, as shown by double kinetochore spots. These results support our hypothesis that CBs originate from C-band positive HSRs.

The semistability of centric chromatin bodies during long-term passage of multidrug resistant mouse-Chinese hamster cell hybrids.

In a cell fusion experiment with multidrug resistant (MDR) mouse SEWA tumor cells and sensitive Chinese Hamster CHO cells, the resistant hybrid cells were completely without recognizable mouse chromosomes. Instead, numerous chromatin bodies (CB) were found that contained copies of a high molecular weight P-glycoprotein gene (PGY1) associated with the MDR condition. The present paper reports on the CB under long-term selective and nonselective growth. The CB were of a stability intermediate between that of double minutes (DM) and homogeneously staining regions (HSR). The stability of the CB was different in the two hybrid lines studied.

Novel cytogenetic expression of gene amplification in actinomycin D-resistant somatic cell hybrids: transfer of resistance by centric chromatin bodies.

SEWATC13 mouse cells, resistant to 0.1 microgram/ml of actinomycin D (AMD), were fused to AMD-sensitive cells of the Chinese hamster ovary cell line (CHO). Twenty-two hybrid clones were isolated and put into serial culture in the selective medium. Unexpectedly, identifiable mouse chromosomes were found only in one of the hybrids. All the others had only hamster chromosomes and, in addition, numerous chromatin bodies (CBs), mostly small and irregularly shaped, but also larger, more chromosome-like ones. The CBs were distinctly C-band positive and a mouse satellite probe hybridized strongly to them. The AMD resistance of the murine parental cells had previously been attributed to gene amplification in two large homogeneously staining regions (HSR-AMD1 and 2). They were not observed in the hybrid cells but had supposedly reappeared in the guise of the CBs. It was established by Southern DNA blot analysis that amplified DNA sequences, localized to the HSR-AMD1 and 2 of the SEWA parent were present in multiple copies in the hybrids. It was also established by in situ hybridization that they were located in the CBs. Unlike double minutes (DMs) the CBs were all centric.