Richard N. Porter

Maternal blood platelet physiology and luteal-phase endocrinology as a means of monitoring pre- and postimplantation embryo viability following in vitro fertilization

The discovery that the fertilized mouse ovum triggers an increased demand for platelets and results in thrombocytopenia during the preimplantation phase of pregnancy provides a monitor for embryo survival and viability. This paper reports a study in which the platelet count was significantly reduced throughout the human preimplantation phase of pregnancy and returned to normal following embryo implantation. The human embryo was shown to produce a platelet activating factor in vitro which caused the reduction in platelet count after embryo transfer. This factor in the embryo culture medium could be measured using a bioassay which provided a means of assessing embryo viability prior to transfer. Some women showed no reduction in platelets after transfer. These embryos failed to produce a platelet activating factor in vitro and pregnancy was not established. Other women displayed a reduction in platelets following transfer but failed to become pregnant. All of these women had elevated luteal-phase plasma E2 levels compared to pregnant patients, which may have interfered with the implantation process. Our observations provide a possible rapid and simple means for monitoring the viability of human embryos cultured in vitro and the survival of embryos in utero.

Maternal recognition of pregnancy prior to implantation: methods for monitoring embryonic viability in vitro and in vivo.

Embryo transfer is the step in the in vitro fertilization (IVF) and embryo transfer (ET) procedure that is the least successful. Well over 80% of all embryos transferred failed to result in the establishment of pregnancy.’.’ It is currently not possible to detect the presence of the embryo in utero prior to implantation. This leaves a period of more than a week in which it is not possible to monitor the fate of the transferred embryos. The absence of such a monitor has previously precluded investigation of the causes of this high embryonic loss. This period of pregnancy has eluded study because there has been little biochemical evidence for the production of embryonic signals prior to implantation. Some recent studies have shown that changes in maternal physiology occurred during the preimplantation phase of pregnancy and that these changes were solely a consequence of the presence of the embryo.’*4 We report here that an increased vascular demand for blood platelets, resulting in mild thrombocytopenia, was an initial maternal response to pregnancy in mice and humans. Monitoring the maternal platelet count in early pregnancy allowed assessment of embryonic viability in utero. This thrombocytopenia was caused by the production of a platelet activating factor(s) by the fertilized ovum. Monitoring the production of this factor by the embryo in vitro, using a bioassay, provided a means of assessing embryo quality. Monitoring early pregnancy-associated thrombocytopenia (EPAT), the production of an embryo-derived platelet-activating factor(s) (EDPAF), and the maternal luteal-phase endocrine profile was shown to be a powerful tool for (1) assessing

The Role of Hysteroscopy in Patients Having Failed IVF/GIFT Transfer Cycles

Summary: Fifty patients who had undergone 2 or more failed in vitro fertilization (IVF) embryo transfer (ET) cycles or failed GIFT cycles where fertilization had been demonstrated, underwent hysteroscopy; 28% were found to have intrauterine abnormalities which may have been responsible for the failure of the IVF‐ET or GIFT. Patients with an abnormality found at hysteroscopy had undergone a significantly higher mean number of transfer cycles. These results suggest that intrauterine abnormalities may be a cause for failure of IVF‐ET or GIFT and therefore hysteroscopy should be part of the infertility work‐up of all patients prior to undergoing IVF treatment.

Oocyte pickup by laparoscopy replaced by transvaginal aspiration in an in vitro fertilization program

The results of laparoscopic (lap) and transvaginal (TV) oocyte pickups (OPUs) performed concurrently for in vitro fertilization in 232 consecutive treatment cycles have been reviewed. The patients were compared for age, preoperative estradiol concentration, luteal-phase support, and number of follicles aspirated and were found to be similar but were not matched for cause of infertility. The lap OPU group had more oocytes recovered per follicle aspirated (P<0.001), but because of a lower fertilization rate (P<0.01), the number of embryos transferred was similar. Nevertheless, more (P<0.05) pregnancies occurred in the TV OPU group. Patients were subgrouped so that comparisons of patients with the same cause of infertility, tubal disease alone, were considered. This showed that the pregnancy rate was still higher in the TV OPU group (P<0.05). TV OPU was less painful and not associated with increased morbidity, and since the data suggest that TV OPU was at least as successful as lap OPU, it is recommended that all oocyte pickups in the future be performed transvaginally.

Microinjection pregnancy following cryopreservation

1. Silber SJ, Ord T, Balmaceda J, Asch RH, Borrero C: Pregnancy with sperm aspiration from the proximal head of the epididymis: A new treatment for congenital absence of vas deferens. Fertil Steril 1988;50:525-528 2. Silber SJ, Ord T, Balmaceda J, Patrizio P, Asch RH: Congenital absence of the vas deferens: The fertilizing capacity of human epididymal sperm. N Engl J Med 1990;323:1788-1792 3. Temple-Smith PD, Southwick GJ, Yates CA, Trounson AO, DeKretser DM: Human pregnancy by in vitro fertilization (IVF) using sperm aspirated from the epididymis. J Vitro Fert Embryo Transfer 1985;2:119-122 4. Mathieu C, Guerin JF, Cognat M, Lejeune H, Pinatel M-C, Lornage J: Motility and fertilizing capacity of epididymal human spermatozoa in normal and pathological cases. Fertil Steril 1992;57:871-876

Sperm microinjection twins: deoxyribonucleic acid fingerprinting

The twins described are clearly nonidentical. The DNA fingerprints obtained show that they are the children of the putative mother and father, indicating the success of the microinjection procedure.

Failure of implantation in human in vitro fertilization and embryo transfer patients: the effects of altered progesterone/estrogen ratios in humans and mice**Supported by grant D18215709 from the Australian Research Grants Scheme.

Daily blood samples were taken for progesterone (P) and estradiol (E2) measurements from women who showed a platelet response consistent with the presence of viable embryos after in vitro fertilization and embryo transfer procedures. A comparison of steroid levels between those women who became pregnant and those who did not revealed the following: at and after the time of transfer, women who failed to become pregnant had significantly higher E2 levels and a lower ratio of P/E2 than women who became pregnant. The P/E2 ratio was a better predictor of implantation failure than was the absolute level of either hormone. Experiments were done in mice to test the hypothesis that P could protect implantation of the embryo against the inhibitory effects of high E2. In mice, implantation was inhibited by relatively high levels of E2. This effect was overcome by concomitant administration of P. There was a significant dose-response-related interaction of P with the E2