Does EmbryoGlue transfer medium affect embryo transfer success rate?

OBJECTIVE: Verification of the effect of EmbryoGlue (EG) transfer medium enriched with hyaluronan on the embryo transfer success rate. DESIGN: A prospective study. SETTING: Fertimed, Fertility Treatment Centre, Olomouc. METHODS: 484 patients undergoing IVF + ET were engaged who were divided according to the medium used during transfer: Sage or Vitrolife culture medium (n = 135) and EG transfer medium (n = 349). The influence of other factors was also evaluated: age, number of received oocytes, percentage of fertilised oocytes, endometrium height on the day of transfer, number of preserved embryos, number of transferred embryos and the length of cultivation (48, 72, 96, 120 h). These factors were considered quantitative variables while the method of hormone stimulation, the type of culture medium and the application of EG were considered qualitative (categorical) variables. RESULTS: With the use of EG the chances of conception increased by approximately 9%. The negative effect of higher age on implantation proportion and the positive effect of cultivation prolongation were proven. The effect of EG on miscarriages was not proven. The probability of miscarriage diminished with higher oocyte fertilisation. The culture medium used (Sage or Vitrolife) before the application of EG does not affect the gravidity result. CONCLUSION: Using the transfer medium of EmbryoGlue before embryo transfer affects the pregnancy rate (PR) in a positive manner. The influence on pregnancy loss with the application of EG was not proven.

HCG level after embryo transfer as a prognostic indicator of pregnancy finished with delivery.

OBJECTIVE: To examine patients after embryo transfer for predictive influence of the human chorionic gonadotropin (hCG) level on the probability of finishing pregnancy with delivery. DESIGN: Retrospective study. SETTING: Fertimed, Fertility Treatment Centre, Olomouc. METHODS: 490 patients pregnant after IVF + ET treat-ment placed in the study. The influence of other factors: age (patients 20-50), number of transferred embryos (one, two and more) and the length of cultivation on the probability of finishing pregnancy with delivery or loss and the possibility to predict multiple pregnancy was also related to the known hCG value. The transferred embryos were divided into two groups - early (cultivation 48 and 72 hrs) and prolonged cultivation (PC 96 and 120 hrs). The answer here, therefore, is a multinomial variable with four levels. For that reason the data was analysed through a multinomial logistic model vs. multinomial distribution of a mistake and generalised logistic link function. RESULTS: The hCG level grows exponentially in the course of the 9th to 17th day after an embryo transfer (ET). The probability of one child delivery after the transfer of one embryo overdue after prolonged cultivation (96 or 120 hrs) grows with the average and above-average hCG values on the day of the draw. The hCG value was 678 (564-815) IU/l1 on the 14th day after ET in pregnancy ended in delivery, 321 (216-477) IU/l on average in abortion, 82 (51-132) IU/l in biochemical pregnancy and 1070 (737-1554) IU/l in multiple pregnancy. The probability of multiple pregnancy increased with hCG values greatly above the average and on the other hand, below-average values indicated abortion or biochemical pregnancy. The patients age was not proven to be of significant influence, the hCG level slightly decreased with higher age. On the contrary, an increasing frequency of abortions depending on the increasing age of the mother was once again confirmed. CONCLUSION: The measured hCG values are considerably different depending on the pregnancy result, which is why this value is considered a quality predictive factor of the pregnancy result.

Is there a declining trend in ovarian function among infertility clinic patients?

BACKGROUND: There is a growing body of evidence that testicular function has decreased rapidly over the last 50 years. However, much less is known about corresponding trends in ovarian function. Herein, we examine the temporal changes in ovarian function in a large sample of infertile patients from the Czech Republic over a period of 14 years. METHODS: In a retrospective study, we analysed a large body of data from women, 20-40 years of age, undergoing IVF/ICSI treatment between 1995 and 2008. We defined ovarian function using five variables: basal FSH level, estradiol (E2) level on the day of HCG administration, dose of gonadotrophins used for ovarian stimulation, number of retrieved oocytes and dose of gonadotrophins per oocyte. Controlling simultaneously for temporal changes in patient age and stimulation protocol, we applied generalized additive models to describe the temporal trends. RESULTS: During the study period the mean age of the study population increased by 2.7 years. Whereas the basal FSH and gonadotrophin dose did not change over time, the E2 level and oocyte retrieval declined, and the dose of FSH per oocyte increased during the study period. CONCLUSIONS: The results are indicative of a small, but detectable decrease in ovarian function over a period of 14 years, which is not causally related to the ageing population.

[The age of women treated for infertility increases]. / Vek zen podstupujících lécbu neplodnosti roste.

OBJECTIVE: The age of women at first child in the Czech Republic increases. We investigated whether this trend translates into the group of patients treated for infertility by IVF. SETTING: Fertimed, infertility centre, Olomouc. METHODS: We summoned data from 4689 women treated for infertility in our centre. We investigated the age of the patient, FSH levels, E2 levels, number of FSH units needed for ovarian stimulation, number of oocytes and embryos. We analysed the results by the method of regression analysis. RESULTS: We found that the mean age increased from 28.7 to 32 years in a period of 10 years. We also demonstrated that the increasing age was accompanied by a decrease in ovarian function. CONCLUSION: Women older than 32 years should be informed about the decreased ability to conceive. The treatment of women for infertility can be complicated by the growing age of patients in coming decades.

A new geographical gradient in vole population dynamics.

A new geographical gradient in the dynamics of small rodents is demonstrated by analysing 29 time series of density indices of the common vole (Microtus arvalis) from Poland, the Czech Republic and the Slovak Republic. This gradient extends from more stable northerly populations in coastal Poland to more variable and cyclic populations in the southernmost parts of the Slovak Republic, and is hence a reversal of the Fennoscandian gradient. All studied variables (such as mean density, cycle amplitude, density variability and the coefficients in a second-order autoregressive model) exhibit consistent latitudinal variation. Possible underlying factors are discussed. In particular, we suggest that seasonality may be a key element in explaining the observed new gradient.

Density-dependent life histories in female bank voles from fluctuating populations.

Using long-term data sets from two lowland floodplain forest bank vole populations in central Europe, we tested two predictions that with increasing densities: (i) proportions of nonparous females in winter populations would increase; and (ii) age of both nonparous and parous females would increase. These two predictions follow from the assumption that changes in age structure are driven by density-dependent shifts in age at first reproduction. Both populations were sampled by snap trapping between 1956 and 1976. For each year, we examined samples of animals collected between November and April for proportions of females with and without breeding experience and analysed their variation in age relative to the population density. The presence or absence of placental scars was used to discriminate between the parous and nonparous animals. Age was determined by measuring the length of the first mandibular molar (M1 ) roots. Both populations exhibited multi-annual fluctuations in numbers closely resembling those in northern Fennoscandia. The proportion of nonparous females in our total sample was 0.73, suggesting that it is uncommon for parous female bank voles to breed in two successive years and that their life histories are largely designed for breeding in one season only as a major reproductive strategy. Using a logistic-binomial regression model, we found that the probability of females being nonparous or parous at capture varied significantly with time, space and population density. The final model producing the best fit to data predicted that the proportion of nonparous females would be slightly larger over winter and substantially larger after high-density breeding seasons, which is consistent with the tested prediction. With increasing densities during the breeding seasons, both the nonparous and parous females became older at the onset of winter. Again, the field evidence was consistent with the predicted pattern. The age of parous females in the autumn at high densities was older, mainly because of an increased proportion of females entering their second winter. We propose a new intrinsic mechanism by which a delayed density dependence in age-specific fitness components can arise in microtines. This mechanism, based on an increased bimodality in age at first reproduction towards northern latitudes, has a potential to explain the south-north gradient in cyclicity observed in microtine populations in Fennoscandia.