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Biomedical subjects

I Craft

Publications and source records attributed to I Craft.

At least 37 records · Page 2Linked to original sources
PubMed1990

Development of assisted conception.

Advances in assisted human conception in the last twenty years were founded on the detailed knowledge of the mammalian reproductive cycle gained in the earlier years of this century. Several lines of study coincided in the 1960's, including the use of ovarian stimulants to regulate follicle growth, oocyte maturation and ovulation, fertilization and embryonic growth in vitro, and the introduction of safer and better methods of laparoscopy. A combination of these techniques with embryo replacements in the uterus permitted the introduction of IVF for the alleviation of infertility. In turn, these methods were extended to other forms of assisted conception, including GIFT, which gave a wider choice of methods for the treatment of specific causes of infertility. Advances during the last decade include rapid progress in the use of ultrasound, the introduction of the LHRH agonists in new forms of stimulation, embryo cryopreservation, and micromanipulative techniques on oocytes and embryos for the alleviation of male infertility and the diagnosis of genetic disease in preimplantation embryos.

Female↗
PubMed1990

Factors affecting the outcome of assisted conception.

In order to assess the major biological and clinical factors which influence the outcome of both IVF and GIFT, the results of a large GIFT series performed in this unit have been analysed over a time interval when two different policies have been in force as to the number of oocytes that should be transferred. The reason for using GIFT data, as opposed to IVF, is simply because it is more difficult to adversely affect the outcome of GIFT treatment, as opposed to IVF, and hence this allows more critical appraisal and interpretation of results. The GIFT series to be described was conducted between March 1986 and October 1987, when a flexible policy on the number of oocytes for transfer was in operation. Since then a fixed policy has been in force at the request of the Hospital's Ethics Committee and the Voluntary Licensing Authority (now the Interim Licensing Authority), whereby three, or exceptionally four, oocytes are transferred irrespective of individual patient's circumstances because of concern about the relative risk and sequelae of multiple pregnancy and selective reduction of pregnancy. I still believe, however, that some infertile couples have a lower chance of pregnancy with assisted, or natural conception and also a lower risk of multiple pregnancy and that it is therefore important to assess the biological and clinical factors influencing fecundity in order to formulate appropriate treatment policies.

Adult↗
PubMed1990

Gamete intra-fallopian transfer in non-endometriotic pelvic adhesions.

This report presents our experience with gamete intra-Fallopian transfer (GIFT) in cases with non-endometriotic pelvic adhesions. Two-hundred-and-eight GIFT attempts, where pelvic adhesions were identified laparoscopically in patients with no previous history of endometriosis, were subdivided into two groups: (i) post-surgical (n = 134) and (ii) non-surgical (n = 74). The extent of the adhesions was further classified according to the American Fertility Society (AFS) classification system. The overall clinical pregnancy rate was 39.4% (82 out of 208 attempts). There was no significant difference in the clinical pregnancy rate per attempt between the surgical (38.8%) and the non-surgical (40.5%) groups. A gradual, but not significant decline in the pregnancy rate was noticed from adhesion Stages I to III, but Stage IV had a significantly lower pregnancy rate (22.7%) than Stage I (47.4%). The intra-uterine pregnancy rate was observed to be higher, but not significantly, in the non-surgical (37.8%) than in the surgical (29.1%) cases. The overall ectopic pregnancy rate was 7.2% per attempt and 18.3% per clinical pregnancy. In the post-surgical group, the ectopic pregnancy rate per pregnancy was 3.5 times that in the non-surgical (23.2% versus 6.5%, respectively), and it was significantly higher in Stage IV (40%; two out of five pregnancies) than in Stage I adhesions (11.1%; three out of 27 pregnancies). In cases with a history of tubal surgery, the ectopic pregnancy rate was 33.3% (10 out of 30 pregnancies). Our results indicate that GIFT can offer a successful treatment option for selected cases with non-endometriotic pelvic adhesions.

Adult↗
PubMed1989

Alternatives to IVF: the outcome of 1071 first GIFT procedures.

Gamete intra-Fallopian transfer (GIFT) is the most important treatment method for infertile couples that has been developed since in-vitro fertilization and embryo transfer (IVF/ET) became available. Analysis of the data of 1071 first GIFT procedures is presented and the predominant factors affecting success are discussed. An overall pregnancy rate of 33.6% was achieved in this group of patients who were unselected in relation to age, number of oocytes transferred, quality of sperm and response to ovulation induction. The success of GIFT is dependent upon the number and quality of oocytes transferred and upon the quality of the sperm. Pregnancy occurred in 21.4% of patients receiving up to four oocytes compared with 40.3% in whom five or more were transferred. Multiple pregnancy rates however were 17.3% in the first group and 32.3% in the second group. Age is a major factor influencing the chances of success with patients less than 30 years of age achieving a 40.2% pregnancy rate reducing to 19.2% in the over 40 group. Conversely the spontaneous abortion rate increased from 23.4% in the under 30 group to 48.6% in those over 40 years of age. No pregnancies were achieved when sperm motility was less than 20% in the original specimen, whereas pregnancy rates of up to 20% resulted when sperm density was below 10 million. The overall results of this study show comparable success rates for different causes of infertility and that there is a definite association between the outcome of treatment and the number and quality of gametes transferred. A philosophy of flexibility in the treatment of infertile couples is advocated.

Abortion, Spontaneous↗
PubMed1988

Analysis of 1071 gift procedures--the case for a flexible approach to treatment.

An analysis of the outcome of first gamete intrafallopian transfers for 1071 women indicates that for those aged 40 years or more all the oocytes had to be transferred to obtain a 19.2% pregnancy rate. In this age-group pregnancy rate and multiple pregnancy rate were significantly lower than those for younger women. Success rate, but not multiple pregnancy rate, was significantly higher in the group of women from whom 11 or more oocytes were recovered and transferred after ovulation induction than when only 1-4 oocytes were recovered and transferred. The findings suggest that the number of oocytes transferred should depend on clinical circumstances.

Abortion, Spontaneous↗
PubMed1988

Follicular fluid histamine concentrations in infertile women with pelvic adhesions.

Dense pelvic adhesions can arise as a result of pelvic infection, endometriosis, peritonitis, or pelvic surgery. The burnt-out disease is associated with evidence of a chronic inflammatory response. One of the chemical mediators of inflammation is histamine; and human and animal studies have indicated a role for histamine in the ovulatory process. In women with dense pelvic adhesions we have found significantly elevated concentrations of histamine in the follicular fluid when compared with the follicular fluid obtained from women without adhesions. This may lead to premature ovulation during a normal cycle, resulting in the release of an immature oocyte. It is possible that this may contribute to the lower fertility in women who have pelvic endometriosis but patent fallopian tubes, and in those patients where tubal patency has been restored following tubal surgery.

Female↗