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Biomedical subjects

M Shelef

Publications and source records attributed to M Shelef.

At least 19 recordsLinked to original sources
PubMed2003

Pregnancy rate fluctuations during routine work in an assisted reproduction technology unit.

BACKGROUND: Fluctuations in spontaneous pregnancy rates have been observed in the general population. The purpose of this study was to evaluate whether pregnancy rates fluctuate over time in a homogeneous assisted reproduction treatment unit. METHODS: The study sample consisted of 3522 consecutive assisted reproduction cycles conducted from January 1996 to December 1999. Only fresh cycles in women <41 years old were included. All pertinent clinical data were prospectively collected on a computerized database and analysed at the end of the study. RESULTS: Throughout the 4 years of the study, monthly pregnancy rates fluctuated between 10.5 and 34.1% (mean 21.4%) per cycle, and between 13.6 and 41% (mean 27.26%) per transfer. These fluctuations did not follow any specific seasonal pattern. CONCLUSION: During routine work in an assisted reproduction treatment unit, there are random fluctuations in the pregnancy rate. This factor should be considered in studies performed in a specific time-period.

Female↗
PubMed2000

The rationale for requesting a second consecutive sperm ejaculate for assisted reproductive technology.

We assessed the value of requesting a second semen sample provided within 1 hour of the first in cases of unacceptable ejaculate quality (compared to previous occasions) or very poor semen characteristics. The study population consisted of 109 males with severe oligo-terato-astenospermic (OTA) syndrome in an assisted reproduction program. Semen volume, sperm count and sperm motility were recorded in the first and second samples with a Makler Counting Chamber before sperm processing, and total motile sperm in the ejaculate was calculated. Differences in sperm parameters between the consecutive samples were determined by paired-sample t test. In 36 cases (33%) the second sample was found to be superior in quality to the first and was therefore used for the fertilization process. Of the 12/109 cases in which the first ejaculate demonstrated no motile sperm, five (41%) had detectable motile sperm in the second (total 0.1 x 10(6), 0.2 x 10(6), 0.3 x 10(6), 8.4 x 10(6) and 20.8 x 10(6)). We conclude that a request for second ejaculate immediately after the first in males with poor semen quality or no detectable motile sperm can yield a better sample in a significant percentage of cases. Using this method, clinicians can avoid the utilization of elaborate sperm processing techniques and the need for unnecessary micromanipulative fertilization.

Ejaculation↗
PubMed1999

Fibrin glue improves pregnancy rates in women of advanced reproductive age and in patients in whom in vitro fertilization attempts repeatedly fail.

OBJECTIVE: To evaluate the possible contribution of fibrin sealant to the ET stage of IVF. DESIGN: Case-control study. SETTING: An assisted reproductive technology unit that performed 2,535 treatment cycles from 1996-1997. PATIENT(S): All consecutively seen patients who underwent ET from January 1996 to September 1997. INTERVENTION(S): All women who underwent ET with the aid of fibrin sealant during the study period were compared with those who underwent standard ET (controls). Thereafter, a case-control study was conducted on the first consecutively seen 174 women who underwent ET with fibrin sealant and a control group that was matched for age and number of previous unsuccessful cycles. MAIN OUTCOME MEASURE(S): Patient age, number of previous unsuccessful IVF attempts, number of embryos transferred, and pregnancy rates. RESULT(S): During the study period, ET was performed with fibrin sealant in 265 women and by the standard procedure in 1,402 women. Women in the fibrin sealant group were significantly older. The pregnancy rate was not significantly different between the groups in the whole-cohort study (20.4% versus 23.1%), but it was significantly higher in the fibrin sealant group in the case-control study (25.3% versus 14.9%). This also was true when the older women (>35 years) and the women with > or =4 previous failed IVF attempts were analyzed separately (23.2% versus 9.8% and 26.1% versus 13.4%, respectively). CONCLUSION(S): The use of fibrin sealant in ET appears to be beneficial in women of advanced reproductive age and in patients in whom IVF attempts repeatedly fail.

Adult↗
PubMed1997

Morphology and clinical outcomes of embryos after in vitro fertilization are superior to those after intracytoplasmic sperm injection.

OBJECTIVE: To compare embryos obtained after IVF and intracytoplasmic sperm injection (ICSI) regarding morphology and the likelihood of achieving clinical pregnancy. DESIGN: Case-control study. SETTING: An IVF unit controlling 1,310 cycles in 1996. PATIENT(S): Women having a total of 477 IVF and 475 ICSI consecutive cycles. INTERVENTION(S): Ovarian stimulation, IVF-ET, or ICSI-ET for all couples. MAIN OUTCOME MEASURE(S): Number of grade-A embryos transferred, preclinical pregnancy losses, and clinical pregnancy rates in IVF and ICSI cycles. RESULT(S): In comparison with the ICSI group, the IVF group showed significantly more grade-A embryos available for transfer (mean, 2 +/- 1.6 versus 1.8 +/- 1.5), significantly fewer preclinical pregnancy losses (1.6% versus 4%), and significantly higher clinical pregnancy rates (25% versus 19.1%). CONCLUSION(S): Embryos obtained after IVF are superior to those obtained after ICSI in relation to embryo morphology and the likelihood of achieving clinical pregnancy.

Adult↗
PubMed1997

Interleukin-2 production by human pre-implantation embryos.

The study was conducted to determine whether pre-implantation embryos secrete interleukin-2. Conditioned media of 27 embryos derived from women during in vitro fertilization (IVF) cycles were analyzed for interleukin-2 concentration. The results showed that conditioned embryo medium from the two pronuclei stage to 24 hours later contains interleukin-2. Endometrial large granular lymphocytes, which are probably involved in placentation, replicate in response to interleukin-2. It may therefore be speculated that interleukin-2 secreted by human embryos may modulate the function and replication of large granular lymphocytes.

Blastocyst↗
PubMed1994

Unanticipated benefits of automotive emission control: reduction in fatalities by motor vehicle exhaust gas.

In 1970, before the implementation of strict controls on emissions in motor vehicle exhaust gas (MVEG), the annual USA incidence of fatal accidents by carbon monoxide in the MVEG was approximately 800 and that of suicides approximately 2000 (somewhat less than 10% of total suicides). In 1987, there were approximately 400 fatal accidents and approximately 2700 suicides by MVEG. Accounting for the growth in population and vehicle registration, the yearly lives saved in accidents by MVEG were approximately 1200 in 1987 and avoided suicides approximately 1400. The decrease in accidents continues unabated while the decrease in expected suicides by MVEG reached a plateau in 1981-1983. The reasons for this disparity are discussed. Juxtaposition of these results with the projected cancer risk avoidance of less than 500 annually in 2005 (as compared with 1986) plainly shows that, in terms of mortality, the unanticipated benefits of emission control far overshadow the intended benefits. With the spread of MVEG control these benefits will accrue worldwide.

Accidents↗
PubMed1991

GnRH agonist increases pregnancy potential of retrieved oocytes given adequate preincubation before insemination: a comparative study.

Preincubation of oocytes aspirated from follicles in IVF-ET programs is a controversial approach. While some investigators recommend this technique others doubt its necessity. We have studied the embryo quality in 100 women, undergoing IVF-ET, in whom ovulation was induced by the combination of GnRH agonists (GnRHa) and menotropins and compared to a control group in whom ovulation was induced with menotropins alone. No statistically significant difference was noted with regard to the fertilization and cleavage rates as well as to the preincubation period. Significantly higher pregnancy rates (P less than 0.001) were encountered in the first group in comparison with the control group.

Female↗
PubMed1991

The impact of the refractory period to gonadotropin therapy in IVF-ET cycles post longacting gonadotropin-releasing hormone (GNRH) analogue.

Sixty-nine women were treated with a long-acting gonadotropin-releasing hormone analogue (GnRHa), D-Trp-6-LH-RH (DTRP6) 3.2 mg (Decapeptyl, Ferring, Kiel, F.R.G.) prior to induction of ovulation for in vitro fertilization (IVF) with human menopausal gonadotropin (hMG; Pergonal; Serono Laboratories, Inc., Randolph MA). Three types of response were noted: Group I (18 patients) responded between days 1-3 of the treatment; Group II (30 patients) responded between days 4-6 of the therapy, and Group III (21 patients) responded after 7 days of treatment. Although a higher number of oocytes were encountered in Group I than in the latter two groups fertilization and clinical pregnancy rates were lower than in Group II (P less than 0.05), respectively, but higher than in Group III (P less than 0.07 and P less than 0.01), respectively. The best results were achieved by Group II patients, while Group III seemed to represent low responders as the number of embryos and pregnancy rate were significantly lower than in the other two groups. It seems that the level of ovarian suppression achieved by GnRH analogue results in a period of refraction of the ovary, and its duration has most probably an effect upon the results of the IVF cycles.

Adult↗
PubMed1991

Age and pregnancy rates in in vitro fertilization.

The influence of women's age on the results of in vitro fertilization (IVF) was analyzed in 1801 women undergoing the procedure. Advancing age was found to be related to significant reduced success rates from an average of 30.1% per transfer below the age of 36 years to 15.9% per transfer at 37 years or more (P less than 0.001). The decrease was related to a reduction in oocyte production (five at 25 years or less, four below the age of 40 years, three at 40 years or more, and two in the 43 to 47-year group) and probably due to reduced implantation. It is concluded that a woman's age must be considered an important prognostic factor when IVF is suggested.

Adult↗
PubMed1991

The prognostic value and significance of preclinical abortions in in vitro fertilization-embryo transfer programs.

UNLABELLED: Preclinical abortions occur in natural conceptions as well as in in vitro fertilization-embryo transfer (IVF-ET) cycles. Nevertheless, although known, this entity is ill defined. OBJECTIVE: The purpose of this study was to propose a classification of these pregnancies on the basis of pathophysiological evidence and to evaluate their future clinical impact. DESIGN: Of 970 IVF-ET cycles, 114 cycles (11.7%) terminated in preclinical abortions. Abortions were divided according to peak beta human chorionic gonadotropin (beta-hCG) values into chemical abortions (52%) occurring 2 weeks after ET with beta-hCG values not higher than 21 mIU/mL and peri-implantation abortions (47%) terminating spontaneously 4 weeks after ET; the latter had higher beta-hCG values for a longer period of time but without any sonographic evidence of gestational sac. No woman in the two groups needed curettage. RESULTS: After a chemical abortion, the pregnancy outcome had better ongoing pregnancy rates (24.7%) in comparison with the 17% achieved in the total IVF-ET cycles. CONCLUSIONS: It is concluded that these two groups most probably have different pathophysiological backgrounds and concomitantly different future clinical impacts.

Abortion, Spontaneous↗
PubMed1991

Combination of long and short term GnRH analogue protocols: a new therapeutic approach to persistent high progesterone levels in IVF cycles.

Thirty-four patients who had had persistently high progesterone (P) levels during menotrophin therapy in previous in-vitro fertilization (IVF) cycles, despite pretreatment with a long acting gonadotrophin-releasing hormone analogue (GnRHa), were randomly divided into two groups according to the mode of ovulation induction used. In 16 women (group 1), induction of ovulation was performed with decapeptyl (DTRP6)/pure follicle-stimulating hormone (PFSH)/human menopausal gonadotrophin (HMG)/human chorionic gonadotrophin (HCG). In 18 patients (group II), the protocol was identical to the former group, except for the addition of a short-acting GnRHa (buserelin) that was started when P levels were persistently high. The combination of long and short acting GnRH analogues (group II) resulted in an improved follicular phase with significantly lower P levels on the day of HCG administration (P less than 0.001). Furthermore, a significantly higher number of oocytes was retrieved, fertilized and cleaved (P less than 0.005; P less than 0.001; P less than 0.005, respectively) and, as a consequence, significantly higher pregnancy rates were achieved (22.2 versus 12.5%; P less than 0.005). These results indicate that a combination of long- and short-acting GnRH agonists may be of value in cases of persistent high P levels during menotrophin therapy in IVF cycles. Further larger studies must be performed before the true efficacy of this mode of treatment can be determined.

Adult↗
PubMed1990

The impact of embryo quality on pregnancy outcome in elderly women undergoing in vitro fertilization-embryo transfer (IVF-ET).

Most IVF-ET units limit the procedure to women below age 38. Nevertheless, demands for infertility treatment, including IVF therapy, are more frequent nowadays. We compared 46 cycles for ovulation induction for IVF in 46 women aged 40 or more (Group I) to 51 induced cycles for this procedure in younger women of mean age 30.2 years (Group II). Cancellation rates due to early luteinization or ovulation were significantly higher in group I than in group II (28.2 and 17.6%, respectively) (P less than 0.001). Also, significantly higher abortion rates were observed in older women (62.5%), in comparison to the younger control group, (25%), (P less than 0.001). It is suggested that the high abortion rate considered to be due to genetic factors in older women, may possibly also be due to the aging uterine environment. Furthermore, while embryos with fragmentations may often produce clinical pregnancies in the young, the aging uterus in the elderly woman does not encourage the development of clinical pregnancies in such embryos. Consequently the higher abortion rate in the elderly woman.

Abortion, Spontaneous↗
PubMed1989

The impact of high progesterone levels in the follicular phase of in vitro fertilization (IVF) cycles: a comparative study.

Estrogen (E2) and plasma progesterone (P4) levels are valuable parameters for follicular development in in vitro fertilization (IVF) cycles. Furthermore, the progesterone concentration prior to, during, and following human chorionic gonadotropin (hCG) administration is an important marker for the detection of early luteinization and premature ovulation. The pattern of hormonal profile in relation to the number of oocytes retrieved, fertilized, and cleaved and the fate of the pregnancies achieved were compared in three groups of patients treated by the same protocol. Group I included 22 women who conceived with high progesterone levels on day hCG + 1 (P4, greater than 2.5 ng/ml). Group II included 43 women who conceived with low P4 values (P4, less than 2.5 ng/ml), while group III included 46 patients in whom no pregnancies occurred. A significant decrease in fertilization, cleavage, and pregnancy rates was observed in patients with high progesterone levels on day hCG + 1, compared to those with normal levels. Nevertheless, it is suggested that cycles with high P4 levels in the preovulatory phase should not be canceled, as a fair chance for pregnancy still exists.

Chorionic Gonadotropin↗
PubMed1989

The impact of spermatic vein ligation on the male factor in in vitro fertilization-embryo transfer and its relation to testosterone levels before and after operation.

Criteria for improved semen quality after varicocele operations are not clear, as they do not express sperm fertilization capacity, its most important qualification. Twenty-two couples, 12 with mechanical female infertility (group I) and 10 with normal female fertility (group II), in whom the husband had subfertile semen in the presence of varicocele, and who had failed preoperative in vitro fertilization-embryo transfer (IVF-ET) attempts, were readmitted for the IVF-ET procedure following the repair of varicocele. In group I, a 20% pregnancy rate was achieved after the operation, while no pregnancies occurred before surgery. In group II, four pregnancies (40%) were achieved after operation. Plasma testosterone (T) levels demonstrated a significant increase in 50% of the patients in both groups after surgery, resulting in a concurrent improved fertilization, cleavage, and pregnancy rates.

Embryo Transfer↗
PubMed1988

Comparison of a fixed and dynamic protocol for embryo replacement in an IVF/ET programme.

Implantation after embryo transfer is considered a major obstacle in terms of pregnancy rates after in-vitro fertilization. A flexible approach to the date of replacement, based on the fact that the most suitable embryonic structure for proper implantation is the four- to eight-cell embryo, has been studied. One-hundred-and-twenty patients with various aetiologies of infertility were stimulated with HMG or combined HMG and FSH, then treated by three different methods of embryo replacement. In group I embryos were replaced in mothers 48 h after ovum retrieval; in group II replacements were carried out 72 h after retrieval; and in group III replacements were related to embryonic cleavage development. Mean levels of oestradiol when HCG was given averaged 1301 +/- 121 pg/ml, 1016 +/- 96 pg/ml and 1182 +/- 101 pg/ml in the three groups, respectively. There was no significant difference in the average number of embryos transferred among the various groups. The pregnancy rates per transfer were 21.8, 24.2 and 38.7%, respectively (P less than 0.001). Although more investigation is required, a dynamic approach to embryo replacement might significantly improve pregnancy rates, because of improved interactions between the embryos and the uterus.

Chorionic Gonadotropin↗
PubMed1988

Transvaginal oocyte retrieval controlled by vaginal probe for in vitro fertilization: a comparative study.

Of 142 patients who initiated in vitro fertilization cycles, 52 underwent oocyte collection by laparoscopy, 58 by the ultrasonically guided transvesical route, both under general or local anesthesia and 36 by the ultrasonically transvaginal route under local anesthesia. When the three methods were compared the results did not differ significantly. An average of 6.4, 6.2, and 5.7 oocytes, respectively, were retrieved. Cleavage rates were 82.6, 79.4, and 81.6%, respectively, while 20.2, 22.6, and 21.1% clinical pregnancies per cycle were obtained. Complications with this procedure such as exacerbation of previous pelvic inflammatory disease, urinary tract infections, transient hematuria, and mild hemoperitoneum were rare. In general, patients greatly preferred the transvaginal method. In addition to providing greater comfort for the patient, this method requires no general anesthesia and is less expensive than other methods. Our initial experience demonstrates that in vitro fertilization can be performed successfully through this simplified alternative to oocyte retrieval.

Adult↗