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Biomedical subjects

V Vlaisavljevic

Publications and source records attributed to V Vlaisavljevic.

8 recordsLinked to original sources
PubMed2001

Value of the serum estradiol level on the day of human chorionic gonadotropin injection and on the day after in predicting the outcome in natural in vitro fertilization/intracytoplasmic sperm injection cycles.

OBJECTIVE: To predict the risk of premature ovulation and possibility of pregnancy in natural IVF/ICSI cycles on the basis of the estradiol (E2) level on the day of hCG injection and on the day after. DESIGN: A prospective study. SETTING: Hospital research program. PATIENT(S): One hundred sixty-four women undergoing 305 IVF/ICSI natural cycles. INTERVENTION(S): Serum E2 levels were measured approximately 12 h before (day 0) and 12-17 h after hCG administration (day 1). MAIN OUTCOME MEASURE(S): E2 levels on day 0 and day 1, the ratio of the day 1 to day 0 levels, and cycle outcome. RESULT(S): In cycles with premature ovulation and in conception cycles, the average E2 level on day 0 was statistically significantly higher than in other cycles, whereas the E2 ratio was statistically significantly lower. Multiple logistic regression was used to determine the connection of the E2 level on day 0 (B0 = -0.742, B = 2.147, P =.01) and the E2 ratio (B0 = -0.742, B = -3.135, P<.001) with premature ovulation. Only the E2 ratio (B0 = 0.659, B = -2.209, P =.0068) was significantly connected with conception. CONCLUSION(S): In predicting the outcome of natural IVF/ICSI cycles, the importance lies not in the E2 level on the day of hCG administration or on the day after, but rather in the E2 ratio.

Adult↗
PubMed2001

Subendometrial contractility is not predictive for in vitro fertilization (IVF) outcome.

OBJECTIVES: The aim of the study was to investigate whether endometrial thickness, endometrial pattern, endometrial movement and serum estradiol and progesterone affect the outcome of in vitro fertilization. METHODS: Prospectively collected data of endometrial thickness, endometrial pattern and subendometrial activity were analyzed in 122 consecutive in vitro fertilization cycles. All measurements were made on the day of hCG administration (day -2), day of embryo transfer (day +2), day +6 and day +12. RESULTS: It would appear that pregnant women tend to have a thicker endometrium on day +12 than non-pregnant women. There appears to be no appreciable difference between pregnant and non-pregnant women in endometrial movement and thickness, nor in serum estradiol and progesterone on day +2 and day +6. In combining three echographic variables (thickness, pattern and movement) and hormone level (estradiol and progesterone), only progesterone on day +12 could be used to predict the outcome. CONCLUSIONS: Subendometrial contractility plays no important role in implantation on the day of embryo transfer or 4 days later.

Adult↗
PubMed2000

Configuration of maternal and paternal chromatin and pertaining microtubules in human oocytes failing to fertilize after intracytoplasmic sperm injection.

The microtubules and chromosomes of 180 human oocytes failing to fertilize after intracytoplasmic sperm injection were observed in order to establish how sperm chromatin and sperm astral microtubule configuration is related to the phases of oocyte cell cycle, and to find the defects in those structures causing fertilization arrest. As many as 125 (69%) oocytes were arrested at metaphase II. In one-fourth of them, damages of the second meiotic spindle were noted. In their cytoplasm intact sperm were found in 38 (30%) cases, a swollen sperm head in 36 (29%) and prematurely condensed sperm chromosomes (G1-PCC)-a result of active mitosis promoting factor (MPF)-in 51 (41%) cases. G1-PCC were mostly (73%) surrounded by the bipolar paternal spindle instead of astral microtubules. A male pronucleus was never presented in metaphase II oocytes. In 19 (11%) oocytes, arrested at anaphase II, no intact sperm were found. As many as 9 (47%) oocytes contained sperm in G1-PCC form, which proves that anaphase II oocytes mostly retain active MPF, despite oocyte activation. As many as 78% of 36 monopronucleate oocytes contained sperm, with delay in the process of sperm nucleus decondensation. Sperm in G1-PCC form and a bipolar paternal spindle were never found in monopronucleate oocytes. From this we conclude that sperm that does not activate the oocyte may continue decondensing the chromatin, but the oocyte prevents male pronucleus formation before the female one, mostly by causing PCC in the sperm and by duplicating the sperm centrosome. Mol. Reprod. Dev. 55:197-204, 2000.

Cell Cycle↗
PubMed1997

Attaining dominance in vivo: distinguishing dominant from challenger follicles in humans.

This study provides the first report of local suppression of follicle growth in vivo by the dominant follicle in humans. Analyses were focused on antral follicles > or =6 mm in diameter, classified as dominant (ovulatory) and challenger (large, non-ovulatory) follicles. We examined antral follicle characteristics, interactions and location in the ovary in the follicular phase of natural, ovulatory cycles in humans. Individual antral follicles (> or =2 mm) were identified and monitored using a system, developed by the authors, incorporating mapping and computer modelling from ultrasound imaging of the ovary. Results showed that antral follicle development was not restricted to a particular location in the ovary. The apparent randomization of location may provide a developmental advantage for follicles. The population of challenger follicles peaked at mid follicular phase, suggesting a period when the ovarian environment was supportive of larger antral follicle development. As ovulation date approached, however, challenger follicles did not attain the visible characteristics of dominance: mid-level echogenicity, large size, smooth antral wall, round shape. Furthermore, dominant follicles subsequently appeared to reduce the number of neighbouring challenger follicles. The results strongly suggest that a paracrine secretion of the dominant follicle was the source of this localized effect. This process may provide increased nutrient level and space at a critical growth stage for dominant follicles.

Female↗
PubMed1995

Prediction of ovarian cycle outcome by follicular characteristics, stage 1.

Both dominant and subdominant follicles have been identified and individually monitored over the follicular phases of 54 natural cycles in 36 women. Population dynamics of all antral follicles, visible by ultrasonography, in the ovary over the entire cycle have also been characterized for the first time. This has been accomplished by developing a new system of mapping and monitoring follicles, including a three-dimensional computer imaging model and correlation program. The different dominant follicle types were characterized by their ultrasonographic properties. Ovulatory follicles were rounded in shape and mid-range echogenic, with a smooth antral edge by late follicular phase. Luteinized unruptured follicles were round, had low echogenicity and a very smooth antral edge. Atretic follicles were irregular in shape and antral edge and had mid-range echogenicity. A further important finding was that follicle success appears to be related to timing of growth and to the subdominant follicle population present in the ovary. An analysis of follicle population dynamics in ovulatory cycles showed a drastic decrease in number at the end of the luteal phase, followed by a sharp increase at the beginning of the follicular phase. This study has demonstrated that characteristics of individual follicles and population dynamics of both dominant and subdominant follicles are strongly associated with cycle outcome. These findings will contribute towards a predictive model of dominant follicle status and cycle outcome. A new hypothesis of follicle competition has also been proposed.

Adult↗
PubMed1992

In vitro fertilization program based on programmed cycles monitored by ultrasound only.

OBJECTIVE: Programmed oocyte retrieval was performed in order to make the in vitro fertilization (IVF) program cheaper and work of the IVF team easier. METHOD: In a group of 77 patients included in the IVF program, the menstrual cycle was modified with estrogen-progesterone contraceptive pills. For this reason, it was possible to start the stimulation protocol in all patients on the same day. The stimulation protocol was a combination of clomiphene (100 mg) for 5 days and HMG (150 IU) every other day. Cycles were monitored by ultrasound only. RESULT: The implantation rate per embryo transfer was 22.4%. The number of embryos per embryo transfer was low (2.6 +/- 1.4) and eliminated the need for cryopreservation. Fertilization rate (82%) and embryo transfer rate (87%) were high. The take home baby rate was 14.3%. CONCLUSION: Seventy percent of all punctures were performed in 3 days in the middle of the week. In our conditions, programmed oocyte retrieval is associated with significant economic benefits.

Clinical Protocols↗