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Biomedical subjects

E Snyman

Publications and source records attributed to E Snyman.

7 recordsLinked to original sources

The hormonal and morphological events of stimulated cycles in an in vitro fertilisation programme.

A better understanding of the physiological processes involved in the stimulated cycle for successful harvesting of mature eggs in an in vitro fertilisation programme is a prerequisite for obtaining good pregnancy results. The hormonal levels of oestradiol, luteinising hormone (LH) and follicle-stimulating hormone correlated with ultrasonographic studies of follicular growth, were followed during an in vitro fertilisation cycle giving an overall pregnancy rate of 32% per transfer procedure. The combined use of clomiphene citrate (Clomid; Mer-National) and human post-menopausal gonadotrophin (Pergonal; Script Intal) produces an average of 5.96 follicles per patient. Human chorionic gonadotrophin (HCG) was given prior to the oestrogen peak and no spontaneous LH peak occurred before the day of the HCG injection. Timing of this injection needs to be synchronised with definite hormonal and ultrasonography values.

Adult↗

Phase II of a successful university-based in vitro fertilisation programme. Changes incorporated.

the ultimate goal of any clinical programme treating infertility by means of in vitro fertilisation and embryo replacement is to maximise the number of patients who become pregnant in a treatment cycle. A 12% pregnancy rate was previously reported from this unit. Following the instigation of changes and further modifications, an overall success rate of 27% per patient was obtained in phase II. The reasons for this improved success are hard to pinpoint, but experience and changes in methodology probably play a role. These changes are described and the results discussed.

Adult↗

Primate in vitro fertilization research: preliminary results on the folliculogenic effects of three different ovulatory induction agents on the chacma baboon, Papio ursinus.

1. A study was conducted on the chacma baboon, Papio ursinus with three ovulation induction agents in an effort to define a preferential stimulatory protocol with regards to the number and quality of oocytes obtained. 2. Three folliculogenic agents applied in four stimulatory protocol regimens comprised clomiphene citrate in a high (100 mg/day) and low (50 mg/day) dosage, a combination of clomiphene citrate and pregnant mare serum, and human menopausal gonadotropin. 3. A total of 159 oocytes were aspirated by laparotomy from 10 baboon females in 20 induced cycles with an average of 8.0 +/- 5.4 oocytes per aspiration. 4. The highest mean number of oocytes (11.3 +/- 6.7) were obtained with the clomiphene/pregnant mare serum gonadotropin combination. 5. The best fertilization rate was obtained with clomiphene 50 mg. 6. The highest incidence of oocytic cleavage and embryo transfer were achieved with human menopausal gonadotropin (14.8%).

Animals↗

Supplementation of Ham's F10 culture medium with three different sera in the culturing of baboon oocytes.

1. Ten female baboons (Papio ursinus) were stimulated for a total of 20 cycles with 3 ovulation induction agents. 2. Oocytes obtained were randomly allocated to Ham's F10 culture medium supplemented with human fetal cord serum, primate serum or commercial fetal bovine serum respectively. 3. Fertilization occurred (38.1-45.5%) in all 3 supplements, but cleavage and embryo development was more successful in culture medium supplemented with fetal bovine serum. 4. Eight embryos were cultured and 6 (75%) of these were cultured in fetal bovine serum supplemented medium.

Animals↗

Endotoxin-polluted medium in a human in vitro fertilization program.

Optimal quality control measures to obtain the highest possible success rate for an in vitro fertilization and embryo transfer program is important in any program. Poor results obtained during a cycle where no pregnancies were achieved necessitated an investigation into possible causes. A suspected contamination of the multidistilled water utilized in medium preparation was confirmed. During a successful cycle with no endotoxins present, a pregnancy rate of 27.2% was achieved. This is higher than the 6.3% pregnancy rate achieved in another cycle where endotoxins were isolated in the media. This article illustrates cell morphologic and ultrastructural changes which could be ascribed to the presence of these endotoxins.

Culture Media↗

In vitro fertilization and embryo transfer in Pretoria.

Details of the in vitro fertilization and embryo transfer programme at the Department of Obstetrics and Gynaecology of the H. F. Verwoerd Hospital and the University of Pretoria are presented. From 1 March 1982 to 30 November 1983, 67 cycles in 47 patients were induced using clomiphene citrate and human chorionic gonadotrophin (hCG) (46 patients) and human postmenopausal gonadotrophin/hCG (1 patient). In 5 patients ovum recovery was unsuccessful owing to severe adhesions. In the remaining 42 patients 59 oocyte recoveries out of a total of 62 attempts were successful, a 95% recovery rate. One hundred and seventy-nine ova were recovered (2,9 per laparoscopy), of which 143 (80%) were viable. Forty-six per cent of fertilized ova cleaved actively. Forty-one transfers of 66 embryos (average 1,6 embryos per transfer) resulted in 5 pregnancies (12% pregnancy rate per transfer). Three preclinical pregnancies aborted spontaneously. Two pregnancies are ongoing at 30 and 32 weeks' gestation. Thus, the programme has so far led to 2 third-trimester pregnancies. Consolidation and refinement of techniques should lead to a steady increase in success at this centre.

Culture Media↗