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Biomedical subjects

R G Edwards

Publications and source records attributed to R G Edwards.

At least 145 records · Page 8Linked to original sources
PubMed1987

Pregnancies after IVF when high tonic LH is reduced by long-term treatment with GnRH agonists.

Some patients show high output of urinary LH when superovulated with clomiphene citrate and HMG. Recent evidence has shown that this is detrimental to successful IVF. By the use of an GnRH analogue we have managed to ameliorate this condition and successfully establish pregnancy in these women. Further, the association between failure of IVF-ER and elevated levels of LH may explain the aetiology of some 'idiopathically' infertile couples.

Adult↗
PubMed1987

Short term use of an LHRH agonist to treat poor responders entering an in-vitro fertilization programme.

Seven patients who had previously responded poorly to stimulation with clomiphene citrate (CC) and human menopausal gonadotrophin (HMG) and also exhibited high tonic urinary LH output (greater than 0.25 IU/h) were given an LHRH agonist (500 micrograms/daily) on days 1 to 3 of the menstrual cycle followed by exogenous gonadotrophin stimulation. During the latter stages of follicular development plasma and urinary LH output were significantly lower (P less than 0.01) than in the previous CC/HMG stimulated cycle. All seven patients had oocytes recovered, and embryos replaced. Three out of these seven became pregnant. To conclude, the efficacy of short term LHRH agonist treatment is equivalent to present longer term modes of administration in reducing gonadotrophin secretion and inhibiting the LH surge. The more widespread adoption of this abbreviated protocol could improve the prognosis for patients undergoing IVF in centres where facilities for intensive endocrine monitoring are not available.

Buserelin↗
PubMed1987

In vitro fertilization: past and future.

The current clinical status of in vitro fertilization is reviewed including ovarian stimulation, fertilization, implantation after replacement and luteal phase support. The evolution of singleton or multiple pregnancies after IVF is discussed; pregnancy loss can occur after ectopic pregnancy or abortion. Several new scientific advances are described: the cryopreservation of embryos, the studies on the metabolism of embryos by non-invasive methods and the use of fetal tissues to restore abnormal conditions in adults. The current ethical issues of IVF are discussed: freezing of embryos, oocyte and embryo donation, surrogate motherhood as well as the rights of an early embryo and the ethics of embryo research.

Embryo Transfer↗
PubMed1986

Factors affecting survival and implantation of cryopreserved human embryos.

Five- to ten-cell embryos and expanded blastocysts from 68 patients were thawed in an attempt to establish pregnancy. Three fresh embryos had been replaced unsuccessfully in these patients. Forty-five patients had intact freeze-thawed embryos replaced and 12 became clinically pregnant. Ten of these pregnancies have now advanced beyond week 24. The preliminary results presented here demonstrate that significantly more expanded blastocysts survive cryopreservation than cleaving embryos. Faster-growing embryos did not survive better than slowly growing embryos, but the incidence of implantation was higher with faster-developing embryos. Significantly more blastocysts with a "normal" morphology survived cryostorage than those scored as "irregular" (77 versus 7%). A similar trend was observed when normal and irregular cleaving embryos were frozen, but the difference was not significant. The severity of contraction of blastocysts upon the addition of cryoprotectant increased the incidence of survival. The proportion of patients whose embryos had holes in the zona pellucida following cryopreservation was significantly higher when embryos were frozen at the cleaving stage (39%) rather than the expanded blastocyst stage (16%). Almost all embryos with damaged zonae degenerated. The proportion of cleaving embryos that survived cryostorage was inversely correlated with the number of follicles aspirated.

Blastocyst↗
PubMed1986

Observations on 767 clinical pregnancies and 500 births after human in-vitro fertilization.

Details of 767 clinical pregnancies and 500 births from Bourn Hall are reported. All treated patients included some over 40 years old, many with ovarian or uterine defects, male infertility, etc. Patients were treated during their natural cycle or stimulated with clomiphene or clomiphene and human menopausal gonadotrophin. Follicular maturation was induced by an endogenous luteinizing hormone surge or human chorionic gonadotrophin. A maximum of three embryos were replaced, except in a few patients receiving four. Twenty-eight percent of pregnancies aborted, occurring more frequently in patients who were over 40, with a complicated obstetric history, and given clomiphene alone. Approximately 18% of fetuses 'vanished' in multi-pregnancies. Seventy-one sets of binovular twins and nine sets of triplets have been born, and seven twins and three triplets are ongoing. Seventeen and a half per cent of patients aged 39 and less with one or more replaced embryos delivered one or more children, rising to almost 25% with three replaced embryos. A mean of 1.3 children were born per delivery when three embryos were replaced. Most deliveries were by Caesarean section. There were two cases of placenta praevia, one stillbirth, four major and eight minor anomalies. All the triplets, and some twins and singletons had low birth weights and were born prematurely. The sex ratio was 247 males to 253 females.

Abortion, Spontaneous↗
PubMed1986

Uptake of pyruvate by early human embryos determined by a non-invasive technique.

Normal levels of pyruvate in freshly collected follicular fluid were found to be 0.45 mM, a value approximately 4 X that of serum. The utilization of pyruvate by human oocytes and early embryos has been measured, non-invasively, using two similar but separate analytical methods. The mature oocyte has a high level of pyruvate uptake (36 pmol/embryo/h). After fertilization this value falls, and then slowly increases to reach a peak just prior to the morula stage of 27 pmol/embryo/h before decreasing. Degenerating oocytes and embryos demonstrated much lower pyruvate uptake rates. The possible usefulness of this method for assessing embryo viability is discussed.

Blastocyst↗
PubMed1986

Measurement of specific IgG antibody levels in serum of patients on regimes comprising high total dose beta-lactam therapy.

Sera from 125 patients receiving mean total doses of beta-lactam therapy of 215 g over a mean of 14 days were assayed by radioimmunoassay. Titres of anti-penicilloyl antibodies, expressed in arbitrary units of specific IgG per microliter of serum (u/microliter), ranged from undetectable (less than 3 u/microliter) to 1,650 u/microliter. There was a higher prevalence of elevated IgG levels in patients who developed haemolytic anaemia or neutropenia compared with patients with no adverse reactions but only in those patients who developed haemolytic anaemia were the antibody titres significantly higher. A subsidiary finding was that a correlation was established between mean total dose and prevalence of positive IgG titres, on a patient group basis (r = 0.87).

Anemia, Hemolytic↗
PubMed1985

The influence of hapten density on the assay of penicilloylated proteins in fluids.

The use of inhibition radioimmunoassays for the measurement of penicilloylated proteins in biological fluids is compromised by the dominant influence of hapten density. Precise quantitation, and therefore assessment of antigenicity and immunogenicity, cannot be achieved in the absence of knowledge of the number and distribution of haptenic groups on the protein carrier. These assays may not, therefore, be appropriate for the measurement of potential allergenic residues in food products.

Allergens↗
PubMed1985

Current status of human conception in vitro.

The scientific and medical advances culminating in the introduction of in vitro fertilization of human oocytes into clinical practice are reviewed. Current methods that use clomiphene, human menopausal gonadotrophin, and both as follicular stimulants, and the endogenous LH surge or an injection of human chorionic gonadotrophin to induce ovulation are described. The effects of multifolliculation, the diurnal rhythm of the LH surge, and the collection of oocytes from the ovary are related to current clinical practice. The success of in vitro fertilization for infertile men and women is considered in relation to the nature of embryonic growth in vitro. Investigations into blastulation, hatching from the zona pellucida and the use of DNA probes for typing embryos are described. The implantation of embryos is the major remaining problem, and physiological and statistical analyses of implantation are given, comparing results from different clinics. The possibility of embryo 'helping' and factors leading to multipregnancy are considered, and details are given of the incidence of abortion and the birth of children. The use of immature oocytes, the frozen-storage of embryos and methods of raising the chance of implantation are described briefly.

Abortion, Spontaneous↗
PubMed1985

Implantation, abortion, and birth after in vitro fertilization using the natural menstrual cycle or follicular stimulation with clomiphene citrate and human menopausal gonadotropin.

The incidence of pregnancy and abortion was analyzed in 1679 patients having embryos replaced after oocyte recovery and in vitro fertilization in order to alleviate their infertility. In these patients, 364 pregnancies were achieved and 108 abortions occurred. Patients were treated either on their natural cycle, having a spontaneous luteinizing hormone (LH) surge to induce ovulation, or after ovarian stimulation using clomiphene citrate alone or in combination with human menopausal gonadotropin (hMG). The data were assessed in relation to the numbers of embryos replaced, the follicular stimulation and ovulation induction regime used, the dose of gonadotropins and the dose of antiestrogens, and the age of the patient. The most successful treatment for the number of live births per laparoscopy was the use of clomiphene citrate in combination with human menopausal gonadotropin followed by human chorionic gonadotropin (hCG) to induce follicular maturation and ovulation. This treatment produced a significantly higher (P less than 0.001) number of patients with multiple embryos (86.5%). There was no significant effect on pregnancy or abortion with a low (less than 400-mg) or high (greater than or equal to 400-mg) dose of clomiphene. The total dose of gonadotropins used did not influence the incidence of pregnancy or abortion. The use of hCG with hMG induced a significant (P less than 0.01) positive effect on the incidence of pregnancy. The incidence of pregnancy showed a progressive decline with increasing age but there was a highly significant (P less than 0.01) increase in the incidence of abortion with increasing age. With increasing numbers of embryos replaced, up to three, the incidence of deliveries increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗