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Biomedical subjects

F S Stander

Publications and source records attributed to F S Stander.

At least 19 recordsLinked to original sources
PubMed2003

Factors affecting pregnancy outcome in a gamete intrafallopian transfer (GIFT) programme.

OBJECTIVE: To identify the factors that most significantly affected pregnancy rates in a gamete intrafallopian transfer (GIFT) programme. METHODS: A total of 863 GIFT cycles were analysed retrospectively. The variables found to be associated significantly with pregnancy were then used to obtain multivariate analysis using logistical regression. RESULTS: Overall and ongoing pregnancy rates were significantly better in patients < or = 38 years than in patients > 38 years (37.3% and 28.4% v. 23.7% and 11.0% respectively), and age was positively associated with success after GIFT (odds ratio (OR) 1.87, 95% confidence interval (CI): 1.22-2.85). Metaphase I (MI) oocytes were negatively associated with pregnancy (OR 1.54, 95% CI: 0.28-1.04). The highest pregnancy rates occurred when 3 metaphase II (MII) oocytes were transferred (39.8%, OR 7.51, 95% CI: 1.74-32.42). With regard to sperm morphology, overall pregnancy rates of 25.5% (< or = 4% normal forms) and 37.2% (> 4% normal forms) were obtained. Morphology of > 4% normal forms was positively associated with pregnancy (OR 1.58, 95% CI: 1.04-2.42). CONCLUSION: The results of this study suggest that the most important factors influencing pregnancy rates in a GIFT programme are the woman's age and those factors pertaining to the characteristics of the gametes. Considering the emotional and financial costs it is important to relate this information to all prospective participants in a GIFT programme.

Adult↗
PubMed1990

The in vitro fertilisation programme at Tygerberg Hospital and the University of Stellenbosch. Five years' experience, April 1983-January 1988.

The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate.

Female↗
PubMed1990

The evaluation of morphological characteristics of human spermatozoa according to stricter criteria.

The evaluation of the morphology of human spermatozoa varies widely between and sometimes even within laboratories. The purpose of this study was to determine whether the method that has been developed in our laboratory and which resulted in the use of stricter criteria for the evaluation of sperm morphology is a practical, reliable and repeatable method and to establish the within and between observer variations. The criteria used for a 'normal' spermatozoon are based on the appearance of spermatozoa found in the mucus of the upper endocervical canal. The results of the morphological evaluations of 26 samples by four observers were statistically analysed by various methods. The method of Barnett showed a high degree of relative accuracy between observers with error variances of between 2.89 and 19.67 as well as high Spearman rank correlation coefficients of between 0.8675 and 0.6537 (P less than 0.0003). The Spearman correlation coefficient for 15 duplicate evaluations by one observer was 0.9650 (P less than 0.0001) while the coefficients of variation for repeated evaluations of single samples were also within acceptable limits. Based on these results, the method described in this article allows comparable and reliable results between and within observers to be obtained. From this and other studies it can be concluded that the method also has a good prognostic value for the prediction of expected IVF fertilization, the hamster test and hemizona assay.

Cytodiagnosis↗
PubMed1989

Human pregnancy after transfer of intact frozen-thawed embryos.

Since the birth of the first baby as a result of in vitro fertilisation (IVF) in 1978, many clinics around the world have achieved pregnancies and births for their patients by using IVF and gamete intrafallopian transfer procedures. With the storage of excess embryos, multiple laparoscopies can be avoided; this has favoured the development of better cryopreservation techniques. In our clinic 8-cell human embryos are frozen in a 1.5M dimethyl sulphoxide solution as cryoprotectant using the slow freeze-thaw method. Sixteen thawed embryos were replaced in 8 patients, resulting in 1 pregnancy. Of the thawed embryos 51.6% survived the freezing process in that they had 50% or more of the original number of blastomeres and also the zona pellucida intact.

Cryopreservation↗
PubMed1989

Does the wash-up and swim-up method of semen preparation play a role in sex selection?

Because of the higher built ratio of boys to girls (1.5 : 1) by in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) at Tygerberg Hospital, the question arose as to whether the wash-up and swim-up method of semen preparation, used for our IVF procedure, plays a role in sex selection. Semen samples of 20 men were evaluated at different time intervals to determine the percentage of F-body-positive spermatozoa. It was found that the swim-up time affects the relationship between Y- and X-bearing spermatozoa, especially at time intervals of 30 and 45 min, where an optimum percentage of Y-bearing spermatozoa (p = 0.0039 and p = 0.0092, respectively) was found. Sperm obtained at these specific time intervals may influence the outcome of sex by IVF and GIFT in favor of males.

Fertilization in Vitro↗
PubMed1987

A comparative analysis of grade 1 and grade 2 water in the Tygerberg Hospital in vitro fertilisation programme.

There are conflicting reports in the literature about the effect of the water source for growth and insemination media in an in vitro fertilisation (IVF) programme. A controlled trial was carried out in which two-cell mouse embryos were cultured in Ham F10 medium containing either grade 1 water (test group) or grade 2 water (control group). Of the two-cell embryos, 92.0% (69 of 75) in the test group and 91.8% (67 of 73) in the control group cleaved to the blastocyst stage (no statistically significant difference). On the basis of this experiment grade 2 water was used in the Tygerberg Hospital human IVF programme with good results. A continuing pregnancy rate of 23% per embryo transfer over a 1-year period is reported.

Animals↗
PubMed1987

The effect of serum supplementation on the cleavage of human embryos.

The effect of serum supplementation was evaluated on 108 oocytes obtained from 29 patients. The oocytes were all mature and randomly distributed in two groups. Each ovum was paired with another ovum within the same patient. The experimental group contained no serum in the insemination and growth medium, but in the control group 10% serum was added to the insemination and growth medium. In the experimental group the cleavage rate was 66.7%, compared to 83.3% in the control group. The embryos from each patient were individually evaluated. The sign test was used for statistical analysis. A significant difference between the two groups (P = 0.01) indicated that in this study the addition of serum to the medium gives better cleavage results. The effect of serum on embryos is discussed, as well as the practical implications of this finding.

Blood Proteins↗
PubMed1986

The development of one- and two-cell mouse embryos in the absence of human serum.

One- and two-cell embryos were obtained from F1 hybrid female mice stimulated with human menopausal gonadotrophin and randomly distributed into two groups--group 1 (no serum) and group 2 (10% patient's serum). Fifty of 53 (94.3%) one-cell embryos in group 1 had cleaved to the blastocyst stage and 44 of 49 (89.79%) in group 2 after 96 hours (no significant difference--chi-square test). In the two-cell embryos in group 1, 78 of 89 (87.6%) reached the blastocyst stage after 72 hours and 80 of 86 (93.02%) in group 2 (no significant difference--chi-square test). According to microscopic evaluation cleavage to the blastocyst stage without serum supplementation is possible. The value of serum is discussed.

Animals↗
PubMed1986

Results of the in vitro fertilization programme at Tygerberg Hospital, phases II and III.

Phases II and III of the human in vitro fertilization programme at Tygerberg Hospital are presented. In phase II, 42 laparoscopies were performed and oocytes were obtained from 76% of the follicles aspirated, but with a fertilization rate of only 37%. The viable pregnancy rate per embryo transfer was 4%. Important changes took place in the programme, which led to a fertilization rate of 77% in phase III. Of the 78 patients subjected to laparoscopy, 65 (83%) reached the embryo transfer stage, resulting in a clinical pregnancy rate per embryo transfer of 23%, and with a 19% pregnancy rate per laparoscopy. The changes, methods and results of phases II and III are discussed.

Embryo Transfer↗
PubMed1986

Sperm morphologic features as a prognostic factor in in vitro fertilization.

To determine whether there is a prognostic value in the percentage normal sperm morphologic features in a human in vitro fertilization (IVF) program, the authors conducted a prospective study in women with bilateral tubal damage. Based on the percentage of morphologically normal spermatozoa, the patients were divided into four groups: group I, normal morphologic features between 0% and 14%; group II, 15% to 30%; group III, 31% to 45%; and group IV, 46% to 60%. One hundred ninety successful laparoscopic cycles were evaluated. In group I, 104 oocytes were obtained, of which 37% fertilized, but no pregnancy resulted; in group II, 81% of 324 oocytes were fertilized, with a pregnancy rate per embryo transfer (ET) of 22%; in group III, 82% of 309 oocytes were fertilized, with a 31% pregnancy rate; and in group IV, 91% of 69 oocytes were fertilized, with a pregnancy rate of 12%. Probability models indicated that there was a clear threshold in normal sperm morphologic features at 14%, with high fertilization and pregnancy rate in the groups with normal sperm morphologic features greater than 14%.

Embryo Transfer↗
PubMed1985

The effect on cleavage of two-cell mouse embryos after a delay in embryo retrieval in a human in vitro fertilization programme.

Two-cell mouse embryos are used for quality control in a human in vitro fertilization programme. A controlled experiment was designed to evaluate the effect on cleavage of two-cell mouse embryos after a delay in embryo retrieval. In the test group, two fallopian tubes were incubated in Whittingham's T6 medium for 2 1/2 hours per experiment before the embryos were removed for culture. In the control group embryos were removed from the fallopian tubes immediately after the mice were sacrificed. Five experiments were performed. Eight of 141 two-cell embryos (5,7%) reached the blastocyst stage in the test group, and in the control group 143 of 151 two-cell embryos (94,7%) reached the blastocyst stage after 72 hours. Embryos must be removed immediately after the mice are sacrificed to obtain constant results. If not, poor cleavage can lead to unnecessary confusion in the laboratory.

Animals↗
PubMed1985

The effect of fluorescent light on the cleavage of two-cell mouse embryos.

Two-cell mouse embryos were subjected to fluorescent light, 2900 lux, for 30 minutes, and the cleavage compared with that in a control group. There was no statistically significant difference in the results. In both groups 90% of two-cell embryos reached the expected level of cleavage. The possible effect of fluorescent light on the oocyte is discussed.

Animals↗
PubMed1985

Osmolarity studies with different containers and volumes in a human in vitro fertilization programme.

In performing in vitro fertilization, a stable osmolarity in the medium surrounding the egg or embryo is of the utmost importance if a good fertilization and pregnancy rate is to be achieved. This study evaluated osmolarity changes in different volumes of fluid in the Falcon 3001 and 3037 Petri dishes and the Falcon 2058 tissue culture tube over a 24-hour period. It was found that the osmolarity was more stable in the Falcon 3037 Petri dish and in the tissue culture tube. The 3037 Petri dish was chosen for culturing human embryos.

Culture Media↗
PubMed1985

Results of phase I of the in vitro fertilization and embryo transfer programme at Tygerberg Hospital.

Phase I (3 June - 31 October 1983) of the in vitro fertilization (IVF) programme at Tygerberg Hospital is outlined in this article. This programme led to the birth of the first IVF baby in South Africa after fertilization and embryo transfer (ET) took place at this institution. The baby was born on 29 April 1984; a second baby was born on 20 June 1984. During phase I 24 laparoscopies were performed; 32 oocytes were obtained from 56 follicles, of which 62,5% were fertilized. Eleven ETs were performed, which led to 3 pregnancies. An ongoing pregnancy rate of 18% per ET and a pregnancy rate of 12,5% per laparoscopy were achieved.

Adult↗
PubMed1985

The effect of surgical glove powder on cleavage of two-cell mouse embryos in an in vitro fertilization programme.

The effect of surgical glove powder on the development of early mouse embryos was studied. Embryos from F1 hybrid mice (C57 B1/6 X CBA) were suspended in Whittingham's T6 growth medium with 10% human serum, using Petri dishes (Falcon 3001). Contamination was brought about by a sterile, powdered, surgical glove touching the surface of the growth medium for less than a second in group I, and in group II the same procedure was followed but the glove was rinsed beforehand with sterile, four times distilled water and air-dried. In the control group (group III) no contamination with surgical glove powder occurred. In group I only 9 of 137 embryos (7%) reached the blastocyst stage, in contrast with 110 of 196 (56%) in group II and 258 of 287 (90%) in group III. The differences in results between groups I and III, groups I and II, and groups II and III were found to be statistically significant (P less than 0,001) by the chi-square test. It is concluded that surgical gloves are a potent inhibitor of early embryonic growth. In an in vitro fertilization programme including follicle aspiration and embryo transfer, contamination of embryos with these gloves should be avoided at all costs.

Animals↗
PubMed1984

[A comparative study of two-cell embryos of CBA and F1 mice in a human in vitro fertilization program].

The two-cell mouse embryo can develop in a chemically defined medium to the blastocyst stage but conditions must be strictly controlled. Fresh T6 (Whittingham's) medium is being used weekly for this purpose in our laboratory and subjected to a 5% CO2-in-air system 24 hours prior to use. Experiments were designed to determine whether two-cell embryos obtained from an F1 (CBA X C57/B1/6) X F1 cross were superior to the easily obtainable CBA X ICR cross. The aim was to get a 90% blastocyst result for use as a quality control. Eight experiments were performed over a 6-week period. The CBA two-cell embryos were compared with the F1 group under identical conditions. A total of 177 two-cell embryos were obtained from the CBA group and 214 two-cell embryos from the F1 group. In the CBA group 51 developed to the blastocyst stage (28.8%) compared with 187 in the F1 group (87.4%) (P less than 0.0001). In conclusion, it is advisable to obtain F1 mice to use weekly in the laboratory as a quality control measure. The CBA group yields poor cultures, and this leads to unnecessary laboratory confusion.

Animals↗
PubMed1980

[A comparative study of the white cell pipette method and the Makler counting chamber method of counting spermatozoa].

A new method for counting spermatozoa was introduced by Makler. This method was compared with the white blood cell pipette method and the results revealed high precision and accuracy (difference of means = 5,9%). Makler's method, which is very simple to perform, has the advantage that rapid and reliable sperm counts can be done. Therefore, the Makler counting chamber can be used with confidence in the performance of semen analysis by any doctor or in any laboratory.

Humans↗