Harold Bourne

Factors affecting low birthweight after assisted reproduction technology: difference between transfer of fresh and cryopreserved embryos suggests an adverse effect of oocyte collection

BACKGROUND Data show that differences exist in the birthweight of singletons after frozen embryo transfer (FET) compared with fresh transfer or gamete intra-Fallopian transfer (GIFT). Factors associated with low birthweight (LBW) after assisted reproduction technology (ART) were studied. METHODS Birthweight, distribution of birthweight, z-score, LBW (<2500 g), gestation and percentage preterm (<37 weeks) for singleton births >19 weeks gestation, conceived by ART or non-ART treatments (ovulation induction and artificial insemination) between 1978 and 2005 were analysed for one large Australian clinic. RESULTS For first births, the mean birthweight was significantly (P < 0.005) lower, and LBW and preterm birth more frequent for GIFT (mean = 3133 g, SD = 549, n = 109, LBW = 10.9% and preterm = 10.0%), IVF (3166, 676, 1615, 11.7, 12.5) and ICSI (3206, 697, 1472, 11.5, 11.9) than for FET (3352, 615, 2383, 6.5, 9.2) and non-ART conceptions (3341, 634, 940, 7.1, 8.6). Regression modelling showed ART treatment before 1993 and fresh embryo transfer were negatively related to birthweight after including other covariates: gestation, male sex, parity, birth defects, Caesarean section, perinatal death and socio-economic status. CONCLUSIONS Birthweights were lower and LBW rates higher after GIFT or fresh embryo transfer than after FET. Results for FET were similar to those for non-ART conceptions. This suggests IVF and ICSI laboratory procedures affecting the embryos are not causal but other factors operating in the woman, perhaps associated with oocyte collection itself, which affect endometrial receptivity, implantation or early pregnancy, may be responsible for LBW with ART.

High fertilization rate with intracytoplasmic sperm injection in mosaic Klinefelter's syndrome

With the introduction of intracytoplasmic sperm injection (ICSI) as a practical successful treatment for male infertility, we are able to offer the procedure to a group of patients who probably could never father a child of their own. From a patient with mosaic Klinefelters syndrome, sufficient motile sperm for intracytoplasmic sperm injection were obtained from a fresh ejaculate estimated to contain < 100 motile sperm. In the first IVF-ICSI attempt, out of seven oocytes that were collected from the wife, four were mature and were injected by ICSI. Fertilization occurred in all four oocytes but only one cleaved and was transferred to the uterus. Pregnancy test was negative 16 days after ET. In the second treatment cycle four out of eight oocytes were selected for ICSI. All four fertilized, three cleaved at the right time, and two were transferred into the wifes uterus. One embryo was frozen. Pregnancy test 16 days after ET was negative. The high fertilization rate achieved in this case indicates the potential of ICSI to treat extreme male infertility. Its use offers hope to those patients with conditions previously considered to be untreatable.

Pregnancies after intracytoplasmic injection of sperm collected by fine needle biopsy of the testis

OBJECTIVE To investigate the use of intracytoplasmic sperm injection with sperm collected by fine needle biopsy of the testis as a treatment for male genital tract obstruction. DESIGN Sperm isolated from a fine needle biopsy of the testis were used to inseminate oocytes by intracytoplasmic sperm injection. SETTING A hospital-based tertiary referral infertility service. PATIENTS Case studies of two couples in whom the male partner had a genital tract obstruction. MAIN OUTCOME MEASURES Fertilization and pregnancy. RESULTS In the first case, 9 oocytes fertilized normally out of 13 injected. After the transfer of fresh (one cycle) and frozen (four cycles) embryos, a single intrauterine fetal heart pregnancy was achieved. In the second case, five oocytes fertilized normally from nine oocytes injected; two embryos were transferred fresh and three were frozen. A single fetal heart intrauterine gestation was obtained after the initial transfer of two fresh embryos. CONCLUSIONS A high normal fertilization rate and pregnancies are possible with intracytoplasmic sperm injection using sperm collected directly from the testis. Sperm retrieval by fine needle biopsy offers a viable alternative to microsurgical aspiration and is also suitable for treating patients with intratesticular blockage.

Intracytoplasmic sperm injection for treating infertility associated with sperm autoimmunity

Objective: To determine whether intracytoplasmic sperm injection (ICSI) can be used to achieve normal fertilization, embryo cleavage, and pregnancies in cases of sperm autoimmunity. Design: A retrospective analysis of ICSI results in sperm antibody-positive and randomly selected antibody-negative groups. Setting: University- and hospital-based reproductive research laboratory and tertiary referral IVF program. Patient(s): Thirty-nine couples selected on the basis of a strongly positive result for sperm antibodies of immunoglobulin (Ig) G and/or IgA immunoglobulin class in the male partner and a control group of 140 antibody-negative couples. Intervention(s): Human menopausal gonadotropin, hCG and Lucrin (Abbott Australasia, Kurnell, NSW, Australia) were given by injection. Oocyte collection was by transvaginal ovarian puncture. Blood was collected for β-hCG measurement. Main Outcome Measure(s): Normal fertilization, embryo cleavage, establishment of clinical pregnancy, and delivery. Result(s): There were no significant differences in fertilization rates (62% versus 58%) or clinical pregnancy rates (19% versus 12%) between sperm antibody-positive and sperm antibody-negative patient groups. Conclusion: Intracytoplasmic sperm injection is an effective treatment for patients with severe sperm autoimmunity.

The developmental potential of cryopreserved human embryos.

Using rigorously matched non-frozen controls we have shown that cryopreservation does not alter the implantation potential of early cleavage stage (day 2) human embryos if no blastomere loss occurs. Thawed intact 4-cell embryos have a significantly higher implantation (fetal heart) rate (16.9%) than similar 2-cell embryos (7.2%). This difference is not due to blastomere number per se since increasing the cell number in frozen embryos by allowing an extended period in culture prior to freezing does not alter their intrinsic developmental potential. Blastomere loss, which occurred in almost half of all thawed embryos, is directly related to a reduction in developmental potential. We estimate that approximately 30% of the expected fresh embryo implantations are lost as a consequence of cryopreservation. Both preimplantation and peri-implantation losses may contribute to this outcome.

Normal fertilization and embryo development by intracytoplasmic sperm injection of round-headed acrosomeless sperm

OBJECTIVE To investigate the ability of round-headed acrosomeless sperm to bind to the human zona pellucida (ZP) and oolemma and to fertilize human oocytes by intracytoplasmic sperm injection. DESIGN Oocytes that had failed to fertilize in IVF were used for sperm-ZP and spermoolemma binding tests. Sperm from a fertile donor was used as a control for oocyte variability. Intracytoplasmic sperm injection was used for assisted fertilization. SETTING University- and hospital-based reproductive research laboratory and tertiary referral IVF program. PATIENTS Case study of a couple in which the man has 100% round-headed acrosomeless sperm in the ejaculate. MAIN OUTCOME MEASURE Fertilization and embryo development and the ability of sperm to bind to the ZP and oolemma. RESULTS No ZP or oolemma binding was achieved, but normal fertilization and embryo development was obtained after intracytoplasmic injection of round-headed acrosomeless sperm. However, no pregnancy was achieved after the transfer of two cleaving embryos. CONCLUSIONS Normal fertilization and embryo development from round-headed acrosomeless sperm is possible with intracytoplasmic sperm injection. However, it remains to be reported whether pregnancy can result from fertilization with this type of sperm defect.

Embryonic factors affecting outcome from single cryopreserved embryo transfer.

Multiple pregnancy minimization by single embryo transfer is becoming more prevalent, but is less common in the case of cryopreserved embryos. This study defines embryonic characteristics in single cryopreserved embryo transfers associated with success rates equivalent to those achieved when transferring two cryopreserved embryos. In a retrospective analysis of 6916 cryopreserved day-2 embryo transfer procedures, transfer of two cryopreserved embryos resulted in higher clinical pregnancy rates when compared with transfer of a single thawed embryo but was also associated with elevated multiple pregnancy rates (26.7% in women under 36). Optimal outcome (implantation rate of 30.9%) from single cryopreserved embryo transfer (SCET) in women under 36 was associated with cryopreservation at the 4-cell stage, loss of fewer than two blastomeres and subsequent cleavage of at least two surviving blastomeres. In comparison, transfer of two cryopreserved embryos in women under 36 resulted in pregnancy and implantation rates of 25.5 and 16.1% respectively. Interestingly, in cryopreserved 4-cell stage embryos, loss of a single blastomere did not reduce implantation potential and cleavage of only a single post-thaw blastomere was not indicative of increased implantation potential. Establishment of these critical thresholds provides a rational basis for SCET.

Cross-over trial of superovulation protocols from two major in vitro fertilization centers

A study was undertaken as a controlled comparison of two different superovulation induction protocols currently in use in major Australian in vitro fertilization (IVF) clinics. Thirty patients each from the Monash University and the Royal Womens Hospital (RWH) IVF programs were stimulated for ovulation induction by the other program. Once timing for oocyte retrieval was scheduled, all care reverted to the program from which the patient first came. Results given as pregnancies per patient commencing stimulation were: RWH patients on Monash protocol, 27%; RWH control patients, 15%; Monash patients on RWH protocol, 7%; Monash control patients, 13%. In the year preceding the trial pregnancy rates were 16.9% at Monash and 10.6% at RWH. Stimulation protocols were also compared with respect to each of administration, cost, and patient stress. The results of this cross-over trial demonstrated major differences between the two ovulation induction protocols studied, although it was not possible to conclude that differences in pregnancy rate were due to stimulation alone.

Comparison of outcomes of conventional intracytoplasmic sperm injection and intracytoplasmic sperm injection using sperm bound to the zona pellucida of immature oocytes.

This study was to compare the outcomes of conventional (scientist-selected sperm) intracytoplasmic sperm injection (ICSI) and a modified ICSI using zona pellucida (ZP)-bound sperm. Although with 39 couples in each group there was no statistical significance in fertilization, embryo development, implantation, and fetal heart clinical pregnancy rates, the higher implantation and clinical pregnancy rates with ZP-bound sperm encourages further evaluation with larger numbers of subjects using sibling oocytes to determine if the ZP-bound sperm are biologically and functionally superior.

High fertilization and pregnancy rates after intracytoplasmic sperm injection in patients with disordered zona pellucida-induced acrosome reaction.

OBJECTIVE To determine whether intracytoplasmic sperm injection (ICSI) is effective treatment for patients with disordered zona pellucida (ZP)-induced acrosome reaction (AR) who have failure of standard IVF-ET. DESIGN Tests of sperm-ZP binding and penetration and the ZP-induced AR were used to diagnose patients with disordered ZP-induced AR who then were treated with ICSI. SETTING Academic reproductive medicine research laboratory associated with a tertiary referral infertility clinic. MAIN OUTCOME MEASURE(S) Clinical features and results of previous IVF-ET, semen analysis and sperm-ZP interaction tests, and ICSI were analyzed. RESULT(S) The majority of patients had consistently normal sperm characteristics and all patients had normal sperm-ZP binding but failure of sperm-ZP penetration. The AR of sperm bound to the ZP was significantly lower in the patients (mean 6%, range 0% to 16%) than in the fertile men (mean 61%, range 27% to 96%). Intracytoplasmic sperm injection was performed on 34 patients and the normal fertilization rate averaged 73% per injected oocyte. Five ongoing and eight term pregnancies including two with twins were achieved after an average of two ET procedures per patient were performed. Two couples have second ongoing pregnancies from transfer of frozen embryos after successful first pregnancies. Overall, the implantation rate was 10.5% per embryo and the pregnancy rate 19% per ET and 38% per patient. CONCLUSION(S) Disordered ZP-induced AR is a cause of severe infertility and persistent failure of IVF-ET. Intracytoplasmic sperm injection is effective treatment for this condition. Patients with idiopathic infertility should be tested for this condition before commencing IVF-ET treatment.