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Biomedical subjects

K Coetzee

Publications and source records attributed to K Coetzee.

At least 19 recordsLinked to original sources
PubMed2006

Endometrial polyps smaller than 1.5 cm do not affect ICSI outcome.

This study aimed to determine whether the presence of endometrial polyps discovered during ovarian stimulation affects the outcomes of intracytoplasmic sperm injection (ICSI) cycles. This retrospective descriptive study was conducted in a private assisted reproductive technology unit. Medical records of ICSI cycles performed between January 2003 and December 2004 were reviewed. Patients were divided into three groups: patients with endometrial polyps discovered during ovarian stimulation (group 1, n=15), patients who underwent hysteroscopic polyp resection prior to their ICSI cycle (group 2, n=40) and patients without polyps (group 3, n=956). Main outcome measures were clinical pregnancy rates and implantation rates. Age of the patients, age of the husbands, body mass index, total amount of gonadotrophins used, length of stimulation, peak oestradiol concentrations, peak endometrial thickness and number of embryos replaced were not significantly different between the groups, nor were the pregnancy and implantation rates. Only one patient (12.5%) from the first group experienced miscarriage within 12 weeks of pregnancy. In conclusion, endometrial polyps discovered during ovarian stimulation do not negatively affect pregnancy and implantation outcomes in ICSI cycles.

Endometrium↗
PubMed2004

Comparative analysis of pregnancy rates after the transfer of early dividing embryos versus slower dividing embryos.

BACKGROUND: We compared retrospectively the pregnancy outcome in two subgroups of ICSI patients, using early division (26 h post injection) to the 2-cell stage as a criterion for embryo quality and viability (ability to produce a pregnancy). METHODS AND RESULTS: In the early dividing embryo (EDE) group, at least one of the transferred embryos was early dividing. In the late dividing embryo (LDE) group, no early dividing embryo was transferred. Additionally, tubal and uterine transfer in the two groups was also evaluated. Clinical pregnancy rates in the EDE group were significantly increased when compared with that in the LDE group (41.3 versus 20.0%). This was also true for ongoing pregnancy rates (33.3 versus 16.3%). The tubal transfer route showed increased (but not significant) ongoing pregnancy rates when compared with uterine transfer in both EDE (38.5 versus 25.0%) and LDE (22.7 versus 8.3%) groups respectively. In uterine transfer cycles, however, clinical pregnancy rates for EDE were significantly increased compared to LDE (37.5 and 11.1% respectively). The baby rate (number of live babies/embryos transferred) was also significantly increased in the EDE group and the tubal transfer group. Statistical analysis of pregnancy outcome, adjusted for the total number of embryos transferred (expressed as percentage risk difference - %RD), resulted significantly in favour of EDE compared to LDE (RD = 18%, P = 0.02). When adjusted for the combined factors: total number of embryos transferred, EDE and LDE, the pregnancy outcome result was significantly in favour of tubal transfer compared to uterine transfer (RD = 15%, P = 0.05). Pregnancy results of the LDE group only were significantly better in the tube compared to the uterus (RD = 19%, P = 0.04) but not significantly so for the EDE group (RD = 10%, P = 0.4). CONCLUSION: Early division is associated with embryo quality and a very easy and successful embryo transfer selection method. Our results also suggest that when EDE are available, both tubal and uterine embryo transfer can be considered. When only LDE are available, however, tubal transfer should be the preferred transfer route.

Adult↗
PubMed2002

Intracytoplasmic sperm injection with testicular spermatozoa in men with azoospermia.

PURPOSE: The aim of the study was to gain an insight into the optimal management of the infertile couple with the husband suffering from azoospermia. METHODS: One hundred and forty-two intracytoplasmic sperm injection (ICSI) cycles performed with testicular extracted spermatozoa were retrospectively analysed. The following factors were investigated for their possible influence on fertilization, cleavage, damage, pregnancy, and ongoing pregnancy rates: the use of fresh, cryopreserved, and preincubated (24 h) spermatozoa and the etiology of the husbands' azoospermia (obstructive and nonobstructive). All microinjections were performed with apparently normal spermatozoa--a head with a tail of normal length. In 116 cycles at least two embryos were available for transfer. RESULTS: The overall fertilization, clinical pregnancy, and ongoing pregnancy rates obtained for the 116 cycles were 65.0, 30.2, and 22.4% respectively. Similar outcomes were obtained for cycles using fresh testicular and cryopreserved testicular spermatozoa. Similarly, no significant differences were obtained between the cycles using spermatozoa from obstructive or nonobstructive azoospermic patients. An increase in motility after a 24-h preincubation was observed, and although this group was relatively small (n = 17), a significant improvement in fertilization (73.7%) and pregnancy (53.9%) rate was obtained when the testicular sample was preincubated for 24 h. This improvement prevailed in the obstructive azoospermic group, but was less pronounced in nonobstructive patients. CONCLUSIONS: This study shows that the outcome of fresh and frozen-thawed testicular spermatozoa in ICSI is comparable, obstructive and nonobstructive etiologies perform the same, and that preincubation of testicular spermatozoa results in increased fertilization and pregnancy rates. All testicular biopsies are therefore performed the day before oocyte retrieval, superfluous spermatozoa cryopreserved, and the remaining testicular homogenate preincubated for the 24 h prior to oocyte retrieval. With this regime, most azoospermic patients are treated successfully, irrespective of the use of fresh or frozen-thawed spermatozoa from obstructive or nonobstructive cases.

Cryopreservation↗
PubMed2001

Comparison of normal sperm morphology outcomes from two different computer-assisted semen analysis systems.

By eliminating the human evaluation variable, it was possible to carry out an investigation into the 'true' association between normal sperm morphology outcomes assessed according to the World Health Organization guidelines and strict criteria. Two computer-assisted semen analysis systems were used, IVOS and Mika, to evaluate Diff-Quik and Papanicolaou stained slides. As expected, the mean normal sperm morphology outcomes for the World Health Organization classification evaluations were markedly higher for both the Diff-Quik (mean difference = 40.13%) and the Papanicolaou (mean difference = 32.55%) stained slides. The association between the outcomes were low for the Diff-Quik stained slides (r = 0.379) and poor for the Papanicolaou stained slides (r = 0.110). While the association achieved with the computer-assisted semen analysis systems using Diff-Quik stained slides was comparable to the association between the manual evaluations (r = 0.386), the manual evaluation of Papanicolaou stained slides produced a relatively good association (r = 0.690). Although the numbers were small, the results show the probability of poor class correlations. Approximately 40% of outcomes were incorrectly classed at a 14% (strict criteria) and 50% (World Health Organization guidelines) cut-off point for both staining methods. This study confirms the fundamental differences between the two classification systems. The results also indicate that, of the two stains used, Diff-Quik should be the preferred staining method for computer-assisted sperm morphology evaluations.

Autoanalysis↗
PubMed2001

Stepwise regression analysis to study male and female factors impacting on pregnancy rate in an intrauterine insemination programme.

The aim of this study was to evaluate the impact of male and female factors on the pregnancy rate in an intrauterine insemination (IUI) programme. Data on 522 cycles were retrospectively studied. All patients 39 years or younger were included in the study where data were available on male and female diagnosis, as well as on ovulation induction methodology. Regression analysis was possible on 495 cycles to study different factors affecting the pregnancy rate per treatment cycle. Logistic regression identified variables which were related to outcome and were subsequently incorporated into a statistical model. The number of follicles was found to have a linear association with the risk ratio (chance) of pregnancy. The age of the woman was also found to have a linear (negative) association with pregnancy. The percentage motility and percentage normal morphology (by strict criteria) of spermatozoa in the fresh ejaculate were the male factors that significantly and independently predicted the outcome. Percentage motility > or = 50 was associated with a risk ratio of pregnancy of 2.95 compared to percentage motility < 50. Percentage normal sperm morphology > 14% was associated with a risk ratio of pregnancy of 1.8 compared to percentage normal morphology < or = 14%. Female patients with idiopathic infertility were divided into three groups according to normal sperm morphology. The pregnancy rate per cycle was 2.63% (1/38) for the P (poor) pattern group (0-4% normal forms), 11.4% (17/149) for the G (good) pattern group (5-14%), and 24% (18/75) for the N (normal) pattern group (> 14% normal forms). A female diagnosis of endometriosis or tubal factor impacted negatively on the probability of pregnancy (risk ratio of 0.17), compared with other female diagnoses. Male and female factors contribute to pregnancy outcome, but the clinician can influence prognosis by increasing the number of follicles, especially in severe male factor cases.

Adult↗
PubMed2001

Ultrastructural evaluation of recurrent and in-vitro maturation resistant metaphase I arrested oocytes.

An infertile couple whose female partner showed recurrent retrieval of immature metaphase I (MI) oocytes that were resistant to in-vitro maturation, was studied. Four spermiograms revealed teratozoospermia. Consistent non-fertilization and negative pregnancy outcomes were obtained after intrauterine insemination, gamete intra-Fallopian transfer and IVF. Two intracytoplasmic sperm injection (ICSI) cycles were finally performed. All oocytes (n = 17) in both cycles were arrested at MI and failed to mature after 48 h culture. ICSI also resulted in total non-fertilization. In the last cycle, two oocytes were analysed by transmission electron microscopy and showed almost identical results. All organelles showed normal characteristics of an MI oocyte. The main abnormality found was related to the MI spindle, with absence of microtubules and dispersion of the female chromosomes. Minor abnormalities were observed (immature fibrous appearance of the zona pellucida; the presence of small vesicle aggregates which formed a foam-like body). The injected sperm nucleus was arrested in the middle of the chromatin decondensation process, with no visible nuclear envelope reformation. Normal disruption of sperm acrosomal and flagellar components were observed. Only a partial cortical reaction was observed. This represents the first documented case of developmental arrest due to complete absence of spindle formation in association with an otherwise mature ooplasm.

Acrosome↗
PubMed1999

Assessment of interlaboratory and intralaboratory sperm morphology readings with the use of a Hamilton Thorne Research integrated visual optical system semen analyzer.

OBJECTIVE: To evaluate the level of variance produced in a multicenter study with the use of a computer-assisted sperm morphology analyzer. DESIGN: A multicenter, prospective, blinded study. SETTING: Assisted reproduction research laboratories. PATIENT(S): Semen samples produced for assisted reproductive procedures. INTERVENTION(S): Hamilton Thorne Research (Beverly, MA) integrated visual optical system semen analyzers were used at five different centers to evaluate the same set of 30 slides that were prepared and numerically coded at Tygerberg Hospital in Tygerberg, South Africa. MAIN OUTCOME MEASURE(S): The percentage of normal sperm. RESULT(S): Interlaboratory coefficients of variation (CVs) ranged between 16.31% and 23.09%. One of the participating laboratories produced an approximately 14% (-6.5-7.7) limits of agreement analysis, with a CV of 11.36%, for its duplicate readings. The use of a 10% normal sperm morphology cutoff point to determine discordance levels produced rates ranging between 10% and 23.3% for the interlaboratory and intralaboratory readings. This level of discordance equates with < or = 7 of the corresponding readings from two laboratories falling into a different normal sperm morphology group (< or = 10% or >10%). CONCLUSION(S): The magnitudes of variation produced by the readings performed in our study reached the same level as for the manual evaluation of sperm morphology. A < 10% CV can be obtained if the correct quality control measures are implemented.

Adult↗
PubMed1999

Clinical value of using an automated sperm morphology analyzer (IVOS).

OBJECTIVE: To determine the clinical value of automated normal sperm morphology outcomes. DESIGN: Prospective clinical study. SETTING: Clinical and research assisted reproduction laboratory. PATIENT(S): Two hundred seven GIFT cycles. INTERVENTION(S): The wife was induced to superovulate, laparoscopically aspirated, and the gametes were transferred laparoscopically. The husband's sperm morphology was evaluated with use of a sperm morphology analyzer using the strict criteria classification system. MAIN OUTCOME MEASURE(S): Normal sperm morphology, IVF, and pregnancy outcomes. RESULT(S): The logistic regression model showed that normal sperm morphology was significantly associated with fertilization in vitro, as dependent (age) and independent variables. Analyzing the fertilization rates across the 5% normal sperm morphology cutoff point, a fertilization rate of 39.39% (< or = 5%) compared with 62.92% (>5%) was obtained. The logistic regression model showed that normal sperm morphology was also a significant predictor of pregnancy when allowing for the number of oocytes transferred and female age. Analyzing the pregnancy rates across the 5% normal sperm morphology cutoff point, pregnancy rates of 15.15% (< or = 5%) and 37.36% (>5%) were obtained. CONCLUSION(S): Normal sperm morphology as evaluated by the automated semen analyzer (IVOS) was shown to adhere to the same fertility cutoff point (5%), as determined by the manual evaluation of sperm morphology. Automated normal sperm morphology outcomes also were found to be significant predictors of IVF and pregnancy in a GIFT program.

Adult↗
PubMed1999

Repeatability and variance analysis on multiple computer-assisted (IVOS) sperm morphology readings.

The repeatability of the Hamilton Thorne Research IVOS (version 10) semen analyser (dimension specific software, version 3) in the evaluation of sperm morphology according to strict criteria was investigated in this study. The repeat measures investigated were cell-cell (300 cells, 3 x each), intraslide (20 slides, 3 x each) and interslide (30 samples, 3 slides each), and their normal sperm morphology outcomes were recorded. Semen samples with varying normal sperm morphology percentages were obtained and sperm morphology slides prepared. The slides were stained with Diff-Quik stain. Agreements between evaluations were determined using the kappa statistic and average coefficients of variation. The predictive probability for an abnormal cell given a prior abnormal cell outcome was 91%, and 89% for a similar prediction of a normal cell. The predictive probabilities for an abnormal or a normal cell given two prior abnormal or two prior normal cell outcomes were 95% and 94%, respectively. No significant bias was obtained between the repeat probabilities for normal and abnormal sperm cells. The average coefficients of variation for the intraslide trial were 9.73% and 8.30% when 100 and 200 sperm cells were evaluated, respectively. The average coefficient of variation for the interslide trial was 15.39%. The technical importance of good sample and slide preparation technique has once again been highlighted by this study. A uniform (spatial homogeneity), high concentration (5-10 cells per computer screen) smear must be made and the cells stained with optimal intensity (maximum contrast). In a trial in which 2000 cells were evaluated, 19 objects (0.95%) were identified as spermatozoa, but were debris. The automated semen analysing system (IVOS) used in this study was shown to maintain a level of repeatability, precision and accuracy acceptable for the application of the system in a routine semen analysis situation.

Analysis of Variance↗
PubMed1999

Intra- and inter-laboratory variability in the assessment of sperm morphology by strict criteria: impact of semen preparation, staining techniques and manual versus computerized analysis.

We designed prospective studies to compare manual and computerized analysis of sperm morphology by strict criteria using different semen processing and staining techniques. A total of 54 semen samples were studied; slides were prepared from each subject from liquefied semen and after washing, and stained with Diff-Quik or Papanicolaou. An intra-laboratory, blind assessment was performed manually (two observers) and using a computerized analyser (two readings). This demonstrated a very good correlation between manual analysis of liquefied and washed samples with both staining techniques [intraclass coefficient (ICC) = 0.93 and 0.83]. Greater agreement was observed between computerized readings (washed samples) of Diff-Quik (ICC = 0.93) than of Papanicolaou-stained slides (ICC = 0.66). An excellent intra-laboratory correlation was observed for within-computer readings (ICC = 0.93). There was moderate agreement between inter-laboratory computer readings (two centres, ICC = 0.72). Although there was lower inter-laboratory agreement for manual and manual versus computer readings, overall results of all manual and computer analyses showed good agreement (ICC = 0.73). Diff-Quik staining is reliable for both manual (liquefied) and computer (washed) analysis of strict sperm morphology. Intra- and inter-computer analyses using this method reached satisfactory levels of agreement. There is still high inter-laboratory variability for the manual method.

Adult↗
PubMed1996

Fertilization and pregnancy using metaphase I oocytes in an intracytoplasmic sperm injection program.

PURPOSE: In this study we investigated whether metaphase I oocytes collected in an intracytoplasmic sperm injection program could successfully be matured and fertilized by injecting aged (> 20-hr) spermatozoa. MATERIALS AND METHODS: Metaphase I oocytes aspirated were preincubated for 20 hr to allow the oocytes to reach meiotic maturity. Only metaphase II oocytes were injected. The original sperm sample processed on the day of aspiration was used in the microinjection process. RESULTS: One hundred eighty-three oocytes were collected, of which 42 (23%) were metaphase I oocytes. These were incubated for 20 hr and microinjected with the original sperm sample. Thirty-one (74%) of the metaphase I oocytes reached meiotic maturity (extruded polar body): 67.7% showed two pronuclei 18 hr after injection and 61.3% embryo development 40 hr postinjection. No difference in fertilization and embryo development rate was found in metaphase II oocytes injected 6 hr postaspiration versus 20 hr postaspiration. An ongoing pregnancy was also achieved using only embryos obtained from matured metaphase I oocytes. CONCLUSIONS: Metaphase I oocytes can be successfully matured in vitro and injected using aged (> 20-hr) sperm samples. Matured metaphase I oocytes, if successfully injected, produce embryos able to induce pregnancy.

Embryo Transfer↗
PubMed1994

Induced acrosome reactions as fertility predictor.

PURPOSE: This study was conducted to determine the fertility predictive value of acrosome reaction rates and indices (induced minus control) of human spermatozoa. By comparison these outcomes with in vitro fertilization success. The effect of oocyte-cumulus complex exposure on the induction of the acrosome reaction was also analyzed. Patients attending our assisted reproduction unit for infertility treatment were included in the study. Acrosome reactions were determined on ethanol-permeabilized smears using FITC-conjugated Pisum sativum agglutinin. The acrosome reaction inducing agent used was calcium ionophore A23187 (10 microM/ml). RESULTS: Poor correlations were found between all the acrosome reaction rates and indices and in vitro fertilization. The presence of oocyte-cumulus complexes had no effect on the spontaneous acrosome reactions, but had a significant effect on the inducibility of the acrosome reaction. Exposure to oocyte-cumulus complexes resulted in the mean percentage sperm induced to be 7.8% (SE = 3.1%) higher compared to the control samples. CONCLUSIONS: Acrosome reaction rates and indices were therefore found to have no significant value in the prediction of male fertility and/or in vitro fertilization success. This study did, however, show that exposure to oocyte-cumulus complexes significantly increases the inducible sperm population.

Acrosome↗
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↗