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Biomedical subjects

G M Warnes

Publications and source records attributed to G M Warnes.

At least 37 records · Page 2Linked to original sources
PubMed1989

Adjuvant leuprolide in normal, abnormal, and poor responders to controlled ovarian hyperstimulation for in vitro fertilization/gamete intrafallopian transfer.

Fifty patients (normal responders) received either human menopausal gonadotropin (hMG) alone (control group) or leuprolide + hMG (leuprolide group). The use of leuprolide was associated with a reduction of hMG requirements (14.8 versus 17.8 ampules, P = 0.02) and the abolition of spontaneous luteinizing hormone surges (nil versus 3, P = 0.006). The rate of fertilization (87% versus 65%, P = 0.003) was higher in the leuprolide group. Pituitary and ovarian suppression was effected for 16 subjects who had previously shown a poor follicular response and a further 19 subjects who had previously responded abnormally. The poor responders required more hMG (43.9 versus 27.1 ampules, P less than 0.001), achieved a lower estradiol maximum (5.1 versus 12.1 nmol/l, P less than 0.001), and had fewer oocytes recovered (4.1 versus 11.5, P less than 0.001), than the abnormal responders.

Drug Therapy, Combination↗
PubMed1989

Increase in digyny explains polyploidy after in-vitro fertilization of frozen-thawed mouse oocytes.

Fewer frozen-thawed mouse oocytes cleaved to the 2-cell stage compared to fresh control oocytes fertilized in vitro (46% vs 79%). The reduced rate of 2-cell formation was only partly explained by a decreased rate of fertilization (63% vs 85%). However, subsequent development to expanded blastocysts was not different (75% vs 78%). An increased frequency of second polar body retention by fertilized frozen-thawed oocytes compared with controls (11.8% vs 1.3%) was shown to be largely responsible for the higher incidence of polyploidy (16.3% vs 3.7%). The frequency of polyspermic fertilization was not different in the two groups (3.9% vs 2.3%).

Animals↗
PubMed1988

The effect of transferring pronuclear embryos on pregnancy outcome after in vitro fertilization.

In a prospective clinical trial the pregnancy rate in patients matched for infertility status, degree of hyperstimulation, and number of oocytes recovered was unaffected by whether embryos were transferred while still pronuclear (day 1) or after they had undergone cleavage (day 2). The pregnancy rates per transfer were 27% and 22%, respectively, for the two transfer times. Unlike results of a previous study, no difference was detected in the outcome of pregnancies from the two groups.

Cell Division↗
PubMed1988

Comparison of zona cutting and zona drilling as techniques for assisted fertilization in the mouse.

Zona cutting and zona drilling of the mouse oocyte significantly increased the fertilization rate (3.8-90%) at low sperm concentrations (less than 200,000/ml) compared with zona-intact controls (0-45%). More oocytes were fertilized after zona drilling. Zona cutting was associated with a low loss of oocytes (less than 1%), no increase in polyspermy and normal development in vitro and in vivo after fertilization. There was a 4% oocyte loss rate after zona drilling, mostly due to extrusion of the oocyte from the zona during the procedure. Hatching of blastocysts occurred about 12 h earlier for zona-drilled than for zona-cut and zona-intact control oocytes. Zona drilling was associated with a higher, but not statistically significant, rate of polyspermy at all sperm concentrations tested. The proportion of zygotes developing to the blastocyst stage was not different between the techniques (zona cut, 77%; zona drilled, 66%; control, 71%). Similarly, no difference was found in the percentage of embryos implanting after blastocyst transfer to the uterine horns of pseudopregnant female mice (zona cut, 67%; zona drilled, 68%; control, 77%). Transmission electron microscopy demonstrated the induced defects in the zona with no damage to the oocyte or oolemma. Parthenogenetic activation was not seen after either of the micromanipulative techniques. Both techniques have promise for application to the human.

Animals↗
PubMed1986

Pregnancy-related chemotactic activity of human follicular fluid.

We measured chemotactic activity in 238 follicular fluids (FF) aspirated from 45 women who had undergone ovarian stimulation with a combination of clomiphene citrate and human menopausal gonadotropin for oocyte retrieval, in vitro fertilization, and embryo transfer. Fifteen of the treatment cycles resulted in pregnancy. The mean chemotactic activity, measured as the distance in microns granulocytic leukocytes migrated through a 3.0-micron membrane, was significantly higher in FF from conceptual cycles, compared with nonconceptual cycles. Serum chemotactic activity was significantly lower in conceptual cycles, compared with nonconceptual cycles. A chemotactic gradient appears to exist between the peripheral circulation and the ovarian follicle. The gradient favors the follicle in conceptual cycles, as indicated by the chemotactic quotient (the ratio of chemotactic activity of FF to serum). In conceptual cycles the chemotactic quotient was 1.7 +/- 0.17, compared with 0.7 +/- 0.03 for nonconceptual cycles. The presence of leukocyte chemotactic factor in FF appears to discriminate prospectively with a 90% degree of confidence between conceptual and nonconceptual in vitro fertilization and embryo transfer cycles.

Androstenedione↗
PubMed1986

Timing of ovulation by determination of the urinary luteinizing hormone surge with an enzyme-linked monoclonal antibody dipstick (OvuStick).

An enzyme-linked double monoclonal antibody dipstick for measuring luteinizing hormone in urine was tested for timing ovulation in thrice daily urine samples collected for several days around mid-cycle in 24 women undergoing artificial insemination. The assay produced information comparable to single daily serum LH measurements. The dipsticks could be used by untrained people to test their own urine as an aid to the detection of ovulation for the timing of artificial insemination or of sexual intercourse to promote or avoid conception.

Antibodies, Monoclonal↗
PubMed1985

Improved pregnancy rate in human in vitro fertilization with the use of a medium based on the composition of human tubal fluid.

Significantly more mouse zygotes developed to blastocysts in culture in a medium formulated on the composition of human tubal fluid (HTF) than in modified Tyrode's medium (T6). In a randomized 2 X 2 factorial trial of human in vitro fertilization that compared the two media and culture under oil versus culture in loosely capped tubes, significantly more clinical pregnancies (30% of 60 transfers) were obtained with HTF medium than with T6 medium (11% of 53 transfers). Decreasing the K+ content of HTF medium to that present in T6 medium significantly decreased the number of mouse zygotes that developed in culture. Modifying Ca++ levels had no effect. It is therefore likely that the higher K+ content in HTF medium is primarily responsible for the superiority of HTF medium over T6 medium, but other differences in the composition of the two media could contribute to the results observed.

Animals↗
PubMed1985

The effect of porcine relaxin vaginally applied at human embryo transfer in an in vitro fertilization programme.

It has been suggested that the polypeptide hormone relaxin is an early pregnancy factor which facilitates implantation and pregnancy maintenance. To test this hypothesis a double blind randomized placebo controlled trial was conducted where 2 mg purified porcine relaxin or distilled water was given in a vaginal gel on the day of embryo transfer and again 3 days later in a human in vitro fertilization (IVF) programme. There were 96 patients in the randomized trial and 73 patients who were treated concurrently in the same IVF programme acted as a further control group. Of the 51 patients who received relaxin, 10 pregnancies were confirmed and 8 continued successfully. In the 45 patients treated with placebo 10 pregnancies were also confirmed and 6 continued successfully. Amongst the 73 patients concurrently treated outside the trial 14 achieved a pregnancy and 10 continued to term. Thus, porcine relaxin given in these circumstances in a human IVF programme did not appear to improve or interfere with the pregnancy rate. Possible factors that affected the implantation rates in this trial are discussed.

Animals↗
PubMed1985

Culture factors affecting the success rate of in vitro fertilization and embryo transfer.

The development of one-cell mouse zygotes to the blastocyst stage in vitro has been used as a quality control for the media and handling procedures employed for human in vitro fertilization and embryo transfer (IVF/ET). One-cell mouse zygotes were placed in culture in medium containing bovine serum albumin. Aliquots of the same batch of medium containing female patients' homologous serum were used for the fertilization and culture of human oocytes. The following procedures were associated with high rates of mouse embryo development and human pregnancies following IVF/ET: adequate gassing and equilibration of the medium, double-rinsing of pipets and catheters used to handle embryos, use of a HEPES-buffered medium for manipulating embryos in the absence of an atmosphere containing 5% CO2, control of excessive temperature in the vicinity of the embryos, and ET using medium containing 50% patient's serum. The institution of these procedures gave more consistent pregnancy rates. However, there was no obvious association between fertilization and cleavage of human oocytes and the quality of the medium ascertained by the mouse embryo development test. In a continuing trial, we are comparing two culture media (modified Tyrode's and a medium formulated on the composition of human fallopian tube fluid [HTF]) and two culture techniques (culture in medium under oil in petri dishes and in loosely capped tubes). Significantly more mouse zygotes developed in HTF medium compared to Tyrode's medium. In a randomized 2 X 2 factorial trial with human IVF/ET, the highest pregnancy rate occurred when fertilization and culture were carried out in HTF medium under oil, but numbers are not yet sufficient to show any statistical difference between treatments.

Animals↗
PubMed1984

Improved conception rate after intrauterine insemination of washed spermatozoa from men with poor quality semen.

The efficacy of high intrauterine insemination of a washed motile fraction of spermatozoa from men with poor quality semen on the day after the luteinising hormone (LH) surge was compared with that of natural intercourse based on symptothermal methods and a single act of intercourse timed on the day after the LH surge in the same 35 couples in a controlled and randomised trial of the three types of cycle. Each couple had been trying to conceive for at least 3 years, the woman being potentially fertile and the only detectable defect related to poor semen quality. After 39 intrauterine insemination cycles, 8 women conceived (all in their first insemination cycle); this procedure was significantly more successful than LH-timed intercourse (0/38; p less than 0.05) and natural intercourse timed by symptothermal methods (1/34; p = 0.022). The technique of intrauterine AIH, with a 'Tomcat' catheter, was simple, painless, and uncomplicated.

Clinical Trials as Topic↗
PubMed1984

In vitro fertilization and embryo transfer program, Department of Obstetrics and Gynecology, University of Adelaide at the Queen Elizabeth Hospital, Woodville, South Australia.

A review is presented summarizing the in vitro fertilization experience at the University of Adelaide, Australia. Initial attempts utilizing the normal cycle were unsuccessful in obtaining a pregnancy. Since 1982 the overall ongoing pregnancy rate has been 21% per embryo transfer, 16% per laparoscopy, and 12% per treatment cycle. A detailed description of presently utilized methodology is presented.

Adult↗
PubMed1984

Culture factors in relation to the success of human in vitro fertilization and embryo transfer.

The development of 1-cell mouse zygotes to the blastocyst stage in vitro has been used as a quality control for the media employed for human in vitro fertilization and embryo transfer (IVF-ET). The following procedures were associated with high rates of mouse embryo development and human pregnancies following IVF-ET: adequate gassing and equilibration of the medium, double rinsing of pipettes and catheters used to handle embryos, use of a HEPES-buffered medium for manipulating embryos in the absence of an atmosphere containing 5% CO2, control of excessive temperature in the vicinity of the embryos, and ET using medium containing 50% patient's serum. The institution of these procedures gave more consistent pregnancy rates. However, there was no obvious association between fertilization and cleavage of human oocytes and the quality of the medium ascertained by the mouse embryo development test.

Animals↗
PubMed1984

Endocrinology of ovarian stimulation for in vitro fertilization.

Understanding of the endocrinology of in vitro fertilization has advanced rapidly in the past 5 years. Despite a multitude of ovarian stimulation regimens a particular regimen has not demonstrated a marked superiority. In principle the achievement of high FSH levels during the early follicular phase to recruit a maximum number of follicles with a tolerable degree of asynchrony for final maturation is confined to a limited time span or 'FSH window' of about 3 to 4 days before negative E2 feedback induces below-threshold FSH levels, thereby condemning all subsequent follicles in that cycle to atresia. It appears that one can widen and/or amplify the 'FSH window' too far from gross hyperstimulation resulting in the recruitment of many follicles with an intolerable degree of asynchrony. This may lead to a defective endocrine environment for the oocytes contained within these follicles or an abnormal luteal environment and an increased frequency of fertilization, cleavage and implantation failure. Whichever regimen is used, the stimulation should ideally be sufficient to promote the development of at least 3 follicles beyond 18mm diameter at the time of OPU. This can be expected to result in at least 2 embryos to be available for transfer. Monitoring of follicular response by a combination of E2 and ultrasonic parameters is recommended so that the administration of HCG is given close to the anticipated endogenous rise of LH. This can be achieved by detecting a reduction in the rate of E2 rise (to plateau).(ABSTRACT TRUNCATED AT 250 WORDS)

Chorionic Gonadotropin↗
PubMed1983

Incidence of multiple pregnancy after in-vitro fertilisation and embryo transfer.

7 multiple pregnancies occurred in a series of 20 pregnancies after oocyte recovery for in-vitro fertilisation and embryo transfer. After ovarian stimulation with clomiphene alone or with human menopausal gonadotropin, 102 laparoscopies were carried out in 62 women and the ongoing pregnancy rate beyond the first trimester was 17/102 laparoscopies (17%), including 5 sets of twins. 1 triplet and 1 twin pregnancy showed evidence of regression of two sacs and one sac, and both are progressing as singleton pregnancies at 16 and 34 weeks, respectively. 3 abortions occurred at 7, 8, and 9 weeks--a spontaneous abortion rate of 15%. The pregnancy and multiple pregnancy rates after stimulation with clomiphene alone or with human menopausal gonadotropin were comparable, but oocyte pickup based on a knowledge of the duration of the endogenous rise in luteinising hormone, rather than 36 h after administration of human chorionic gonadotropin, increased the pregnancy rate. As the quality and number of embryos transferred to the uterus increased, the risk of multiple pregnancy also rose. Consideration should therefore be given to restricting the number of embryos transferred to limit multiple pregnancies to twins.

Adult↗
PubMed1983

Endocrine responses of goats after induction of superovulation with PMSG and FSH.

Goats in Group A were pretreated for 9 days with a synthetic progestagen, administered via intravaginal sponge, and 1000 i.u. PMSG s.c. on Day 12 of the oestrous cycle. Goats in Group B had the same PMSG treatment, but not the progestagen pretreatment. Group C goats received a s.c. twice daily injection of a porcine FSH preparation (8 mg on Day 12, 4 mg Day 13, 2 mg Day 14 and 1 mg Day 15). Oestrus was synchronized in all animals by 50 micrograms cloprostenol, 2 days after the start of gonadotrophin treatment. The vaginal progestagen sponges were removed from Group A at the same time. Mean ovulation rate was slightly higher in FSH-treated than in the PMSG-treated animals, whereas the incidence of large follicles that failed to ovulate was significantly elevated in PMSG-treated animals in Group B. More goats in Groups A and B than in Group C exhibited premature luteal failure. Progestagen pretreatment appeared to suppress both follicular and luteal activity, as indicated by numbers of large non-ovulating follicles and by the magnitude and duration of elevated plasma oestradiol levels following PMSG stimulation, and by decreased plasma progesterone levels before and after PMSG treatment. Oestrogenic response to FSH was considerably less than that to PMSG, as indicated both by a considerably shorter duration of elevation of circulating oestradiol levels during the peri-ovulatory period, and by lower maximal oestradiol levels. Differences in the ovarian responses to PMSG and FSH may be attributed primarily to differences in the biological half-life of each preparation.

Animals↗
PubMed1983

Superovulation treatments and embryo transfer in Angora goats.

A high incidence of early luteal regression after PMSG superovulation was associated with low recovery of embryos from reproductive tracts of Angora goats flushed later than Day 5 after onset of oestrus. Embryos were successfully recovered (mean 7.9/female) by flushing on Days 2-5. Mean ovulation rate after an FSH regimen (16.1 +/- 0.8) was significantly higher than that after a single injection of PMSG (10.8 +/- 1.2). Fertilization rate and survival of embryos following transfer to naturally synchronized recipient feral goats did not differ between the two gonadotrophin regimens: the mean number of kids born to 47 donors treated with FSH (7.5 +/- 0.6) was significantly greater than that to 28 donors treated with PMSG (4.8 +/- 0.6). Irrespective of hormonal treatment, the numbers of embryos recovered and of kids born were correlated with ovulation rate (r = 0.82, P less than 0.001 for both). Embryo survival was influenced by ovulation rate in recipients, with 52%, 63% and 75% of transferred embryos being carried to term by recipients with 1,2 and 3 CL, respectively (P less than 0.01). More embryos survived (65%) when 2 embryos were transferred to each recipient than when 1 (51%) or 3 (48%) were transferred. In recipients receiving 2 embryos, survival was significantly improved by transfer of both embryos to the same oviduct (70%) than when one was transferred to each oviduct (62%). The percentage survival of embryos was optimal when oestrus of recipients was synchronized within +/- 1 day of oestrus in donors.

Animals↗