John L. Yovich

Reduced in‐vitro fertilization of human oocytes from patients with raised basal luteinizing hormone levels during the follicular phase

Summary. A series of 62 women were managed in the University of Western Australia/PIVET Laboratory in‐vitro fertilization programme. In 60 of them follicle growth was stimulated with clomiphene citrate’ with or without additional human menopausal gonadotrophin (hMG) and in two with hMG alone. Follicles were aspirated at laparoscopy following an hCG trigger injection and occasionally following a spontaneous luteinizing hormone (LH) surge. Oocytes were inseminated with 0·5×105−105 sperm/ml 3–6 h later. A significant reduction (P<0·001) in the fertilization rate of mature oocytes was observed in those patients whose basal serum LH values were >1 SD above the mean. Fifty‐nine women subsequently had embryo transfer and of 10 clinical pregnancies, none occurred in those with elevated LH values. Reduced fertilization may be a reflection of premature oocyte maturation or ageing. This may have clinical implications in the management of some patients with unexplained infertility.

Influence of pentoxifylline in severe male factor infertility

Two in vitro fertilization sperm preparation protocols using pentoxifylline (long and short exposure before insemination) were studied in 57 couples (61 cycles) with male factor infertility. For each cycle, oocytes were divided into two groups for insemination using either pentoxifylline-treated or control semen. Fertilization rates improved over controls in the short protocol (P less than 0.001) and fewer couples experienced fertilization failure (P = 0.02). Sixteen pregnancies ensued (30% per collection with the short protocol), and 4 were from cases with less than 1.0 X 10(6) progressively motile sperm count per milliliter, 1 being as low as 0.2 X 10(6) progressively motile count per milliliter. Seventeen healthy infants have now delivered and pregnancy wastage is not increased. Pentoxifylline is thus a useful sperm treatment for cases of male factor infertility.

The treatment of infertility associated with endometriosis by in vitro fertilization.

In vitro fertilization and embryo transfer (IVF-ET) was performed on women with tubal disease only (28 women, 40 cycles), endometriosis grade I (15 women, 24 cycles), grade II (25 women, 37 cycles), grade III (26 women, 36 cycles), or grade IV (31 women, 52 cycles). Rates of oocyte recovery and fertilization were not affected by the presence of endometriosis. Pregnancy rates per cycle were similar to that of the tubal group (18%) for women with grade I (13%) or grade II (14%) endometriosis, lower in women with grade III endometriosis (6%) and significantly reduced in women with grade IV (2%, P less than 0.05).

The long protocol of administration of gonadotropin-releasing hormone agonist is superior to the short protocol for ovarian stimulation for in vitro fertilization

Objective To investigate whether pituitary desensitization with the gonadotropin-releasing hormone agonist (GnRH-a), buserelin acetate, before the administration of human menopausal gonadotropin (hMG) for ovarian stimulation in in vitro fertilization (IVF) is superior to the simultaneous administration of both hormones at the beginning of the treatment cycle. Design Prospective randomized study. Patients Ninty-one patients having their first attempt at IVF. Interventions Patients in group 1 (long protocol) were administered subcutaneous (SC) buserelin acetate 200 μ g/d from day 1 of the menstrual cycle, and hMG was started only after pituitary desensitization had been achieved at least 14days later. Patients in group 2 (short protocol) were administered SC buserelin acetate 200 μ g/d from day 2 and the same dose of hMG used in the long protocol from day 3 of the menstrual cycle. Results The median total amount of hMG required in both groups was comparable. There were significantly more follicles ( P =0.0001), oocytes ( P =0.0008), fertilized oocytes ( P =0.0001), and cleaved embryos ( P =0.0001), and a higher fertilization rate ( P =0.0047) in patients in group 1. The pregnancy rates per initiated cycle and per embryo transfer were 19.57% and 25.71% in group 1 compared with 8.89% and 16.67% in group 2. Conclusions The long protocol is superior in terms of significantly greater follicular recruitment, oocyte recovery and fertilization rates, and significantly greater number of embryos available for transfer. In general, it is the preferred method when GnRH-a are used for ovarian stimulation in IVF.

The limitations of in vitro fertilization from males with severe oligospermia and abnormal sperm morphology

Thirty-one patients whose infertility was attributed to oligospermia were included for treatment by in vitro fertilization and embryo transfer. Three subgroups were defined: severe oligospermia (≤5 million motile sperm/ml), moderate oligospermia (6 to <12 million motile sperm/ml), and abnormal sperm morphology (>60% atypical). The fertilization rates were compared to those of a normospermic group managed concurrently. A modified overlay technique of sperm preparation is described for oligospermic samples so that the number of motile spermatozoa inseminated into each tube or culture dish containing a mature preovulatory oocyte was similar in each category, within the range 0.5 to 2×105/ml. Significantly fewer oocytes were fertilized in the severe oligospermic group (P<0.001), suggesting a reduced capacity for fertilization by spermatozoa from severely oligospermic males. The fertilization rate of oocytes was normal in the moderate oligospermic group and those with abnormal morphology, although in the latter there was a significant delay noted in reaching the pronuclear stage (P<0.001), and the embryos were at a less advanced stage of cleavage at the time of transfer (0.001

Embryo transfer technique as a cause of ectopic pregnancies in in vitro fertilization.

Against an overall risk of around 2% ectopic pregnancies in in vitro fertilization programs around the world, we report an incidence more than three times greater (5 tubal ectopic pregnancies in 80 clinical in vitro fertilization pregnancies). Of two techniques used for embryo transfers, one produced a significantly higher risk for ectopic pregnancy (P less than 0.05). Four of the ectopic pregnancies occurred in a small group of 24 patients in whom the embryo transfer technique attempted to deliver the embryos at the uterine fundus (mean distance of catheter insertion 62.9 +/- 7.9 mm from the external cervical os). Only one ectopic pregnancy occurred in 56 patients whose embryos were transferred to a standard, generally midcavity position. It is concluded that the delivery catheter need be inserted only 55 mm as a routine and less in patients with a shortened cervix or with the hypoplastic uterus usually encountered in women with primary ovarian failure who have ovum or embryo donation. In such cases an ultrasonic measurement of length may indicate that a shorter transfer distance is required.

Pregnancies following pronuclear stage tubal transfer

Pronuclear stage tubal transfer (PROST) is a technique that involves in vitro fertilization (IVF) of oocytes, followed by the transfer of pronuclear oocytes into the fallopian tubes. It has been developed for its prognostic value of confirming fertilization in couples with oligospermia or asthenospermia and enabling fertilization in cases with antispermatozoal antibodies (ASAB). PROST has provided useful diagnostic information in the management of couples who have failed to conceive in other treatment programs and has particular advantages over IVF for those receiving fresh donated oocytes for ovarian failure. Fourteen pregnancies resulted from 52 transfers, providing a pregnancy rate of 27% per transfer. The pregnancy rates were higher than a matched IVF series in the male factor and female ASAB groups and reached statistical significance for the ovum donation group. It is anticipated that both pregnancy rates and fetal wastage will be improved over conventional IVF and embryo transfer for the described infertility groups.

The relative chance of pregnancy following tubal or uterine transfer procedures

In a 7-month study period, a total of 113 pregnancies were generated in 380 women (30%) undergoing transfers in one of four assisted conception procedures: gamete intrafallopian transfer (GIFT), pronuclear stage tubal transfer (PROST), tubal embryo stage transfer (TEST), and in vitro fertilization and embryo transfer (IVF-ET). It was shown that both the pregnancy rate per transfer procedure and the number of pregnancy sacs arising per embryo transferred were significantly higher among the groups having tubal transfer (P less than 0.001). There were no significant differences in the pregnancy or implantation rates among the three groups having tubal transfer procedures when the GIFT results were adjusted for a 72% fertilization rate noted in the combined IVF-ET and PROST groups. Early pregnancy wastage showed a similar pattern among the four groups and, overall, 67% of pregnancies advanced beyond 20 weeks.

Preliminary results using pentoxifylline in a pronuclear stage tubal transfer (PROST) program for severe male factor infertility

In vitro trials with washed spermatozoa incubated in medium containing 1 mg/ml of the methyl xanthine phosphodiesterase inhibitor PF showed improved counts of total motile and total progressively motile spermatozoa in cases of oligospermia/asthenospermia. Application of this agent in a PROST program for a series of nine couples presenting for treatment with histories of failed fertilization in vitro resulted in five pregnancies (four singleton, one triplet) and the subsequent delivery of normal infants. The results warrant further evaluation of this sperm treatment for cases of severe male factor infertility.

Embryo culture: can we perform better than nature?

Culture of preimplantation-stage embryos has always been a key element of laboratory embryology and has contributed substantially to the success of many assisted reproduction procedures. During the past decade, its importance has increased as extended in-vitro embryo culture and single blastocyst transfer have become indispensable parts of the approach to decreasing the chance of multiple pregnancy while preserving the overall efficiency of the treatment. However, in spite of the scientific and commercial challenge stimulating research worldwide to optimize embryo culture conditions, a consensus is missing even in the basic principles, including composition and exchange of media, the required physical and biological environment and even the temperature of incubation. This review attempts to summarize the controversies, demonstrate the fragility of some widely accepted dogmas and generate an open-minded debate towards rapid and efficient optimization. New approaches expanding the traditional frames of mammalian embryo culture are also discussed. Although some researchers suppose that the efficiency of the presently applied in-vitro culture systems have already approached the biological limits, authors are confident that substantial improvement may be achieved that may expand considerably the possibilities of future assisted reproduction in humans.