Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Mara Koifman is active.

Publication


Featured researches published by Mara Koifman.


Fertility and Sterility | 1997

A simplified coculture system with luteinized granulosa cells improves embryo quality and implantation rates: a controlled study.

Martha Dirnfeld; Shlomit Goldman; Yael Gonen; Mara Koifman; Ilan Calderon; Haim Abramovici

OBJECTIVE To investigate the use of a simplified short-term coculture system with luteinized granulosa cells (GCs) in patients with failed IVF-ET. DESIGN Controlled clinical study. SETTING IVF unit, Department of Obstetrics and Gynecology, Carmel Medical Center. PATIENT(S) Patients with poor embryo quality in their previous IVF-ET cycles. INTERVENTION(S) Embryos from 40 patients, in which > 50% of the embryos were classified as poor quality in their previous IVF attempts, were grown on autologue GC culture system for a short period (24-48 hours) before being replaced in the uterine cavity. MAIN OUTCOME MEASURE(S) Embryo quality. RESULT(S) Significant decrease in poor quality embryos and increase in the proportion of good quality embryos were observed using a coculture system with autologue human GCs. Pregnancy rates in this groups of patients reached our standard IVF results during the same period. CONCLUSION(S) This study describes a simplified short-term coculture system with human autologue GCs. Poor quality embryos may be rescued to cleave regularly.


Fertility and Sterility | 2003

Decreased expression of tissue inhibitor of matrix metalloproteinases in follicular fluid from women with polycystic ovaries compared with normally ovulating patients undergoing in vitro fertilization

Shirly Lahav-Baratz; Zaki Kraiem; Hanna Shiloh; Mara Koifman; David Ishai; Martha Dirnfeld

OBJECTIVE To compare activity of matrix metalloproteinases (MMP) and expression of their tissue-specific inhibitor (TIMP) in the follicular fluid of normally ovulating women and women with the polycystic ovary syndrome (PCOS). DESIGN Prospective study. SETTING IVF unit and endocrine research unit. PATIENT(S) Fourteen patients undergoing IVF treatment (seven with normal ovulation and seven with PCOS). MAIN OUTCOME MEASURE(S) Activity of MMP-2 and MMP-9 and expression of MMP-1, TIMP-1, and TIMP-2 was measured in follicular fluid of the leading follicles by using gel zymography and immunoblot analysis. RESULT(S) The activity of MMP-2 and MMP-9 and expression of MMP-1 was similar in follicular fluid of normally ovulating patients and patients with PCOS. Significantly lower expression of TIMP-1 was found in follicular fluid of patients with PCOS women compared with normally ovulating patients. CONCLUSION(S) Because MMPs and TIMPs play a role in the physical and chemical structure of the follicular compartment, the decreased expression of TIMP in patients with PCOS may be part of a compensatory process to overcome the physical properties of the thick ovarian capsule.


Journal of Assisted Reproduction and Genetics | 1991

The use of long-acting gonadotropin-releasing hormone agonist (GnRH-a;decapeptyl) and gonadotropins versus short-acting GnRH-a (buserelin) and gonadotropins before and during ovarian stimulation for in vitro fertilization (IVF)

Yael Gonen; Martha Dirnfeld; Shlomit Goldman; Mara Koifman; Haim Abramovici

The efficiency of two ovarian stimulation protocols using different gonadotropin-releasing hormone agonists (GnRH-a) for in vitro fertilization (IVF) was examined and compared with human menopausal gonadotropin (hMG)-only stimulation. Fifty-four patients who had 57 aspiration cycles were treated with protocol 1, which consisted of long-acting GnRH-a D-Trp6 (Decapeptyl Depot) and hMG. Protocol 2 entailed intranasal administration of short-acting GnRH-a (Buserelin) and human menopausal gonadotropin (hMG) in 66 women, who underwent 70 aspiration cycles. Fifty-five patients who had 59 ovum pickups (OPU) treated with hMG only served as a control. No differences were observed in cycle parameters and hormonal concentrations among the three groups. The total clinical pregnancy rates per OPU for patients receiving protocols 1 and 2 were 12.3 and 27.1%, respectively (P<0.05). The pregnancy loss was significantly lower in protocol 2 than in protocol 1 (26.3 versus 71.4%;P<0.05). Our data show superiority of short-acting GnRH-a over the long-acting agents in achievement of pregnancy and its outcome, though neither was significantly different from the hMG-only protocol.


Journal of Assisted Reproduction and Genetics | 1991

A randomized prospective study on the effect of short and long Buserelin treatment in women with repeated unsuccessful in vitro fertilization (IVF) cycles due to inadequate ovarian response

Martha Dirnfeld; Yael Gonen; Arie Lissak; Shlomit Goldman; Mara Koifman; Yoram Sorokin; Haim Abramovici

Fifty four women with repeated unsuccessful in vitro fertilization (IVF) cycles due to inadequate ovarian response to stimulation with human menopausal gonadotropins (hMG) participated in this study. They were randomized to receive either gonadotropin releasing hormone agonist (GNRHa), Buserelin, prior to and during induction of ovulation by hMG (Group I—long protocol), or GnRHa starting on the first day of the cycle together with induction of ovulation by hMG (Group II—short protocol). Mean follicular phase serum luteinizing hormone (LH) and progesterone (P) levels were significantly lower in Group I than in Group II (P<0.01). Cancellation rate was significantly lower in Group I than in Group II (P<0.01). The long GNRHa protocol resulted in statistically significant lower cancellation rates, more oocytes per pickup (OPU), more embryos trans-ferred per patient, and a higher pregnancy rate. Significantly more hMG ampoules and more treatments days were required in the long GNRHa protocol. Our data demonstrate that the use of GNRHa prior to and during ovarian stimulation with hMG offers a very good alternative for patients with repetitive unsuccessful IVF cycles due to inadequate response.


Journal of Assisted Reproduction and Genetics | 1993

A modest increase in serum progesterone levels on the day of human chorionic gonadotropin (hCG administration may influence pregnancy rate and pregnancy loss in in vitro fertilization-embryo transfer (IVF-ET) patients

Martha Dirnfeld; Shlomit Goldman; Yael Gonen; Mara Koifman; Arie Lissak; Haim Abramovici

PurposeOur purpose was to study the effect of a modest increase in preovulatory serum progesterone (P4) levels in hyperstimulated patients and its association with pregnancy rate and pregnancy loss following in vitro fertilization (IVF) and embryo transfer (ET).PatientsOnly patients with mechanical factor and three transferred embryos were included in the present study. They were divided into two groups according to two critical breakpoints for P4 serum levels on the day of hCG administration: serum P4 below 0.6 ng/ml in 28 cycles (group I) and >0.6 ng/ml in 80 cycles (group II).SettingThe setting was the IVF program at Carmel Medical Center, Haifa, Israel.ResultsThe pregnancy rate per embryo transfer was 53% (15/28) in group I and 10% (8/80) in group II (P < 0.025). Of 15 pregnancies achieved in group I, 14 were ongoing pregnancies, compared to 4 of 8 ongoing pregnancies in group II (P <0.03).ConclusionsOur findings suggest that a very modest increase in serum P4 levels on the day of hCG administration is associated with lower pregnancy and ongoing pregnancy rates in IVF-ET.


Fertility and Sterility | 1993

Different morphology and proliferative ability of cumulus and granulosa cells originating from cystic follicles aspirated from stimulated in vitro fertilization patients

Shlomit Goldman; Martha Dirnfeld; Yael Gonen; Mara Koifman; Arie Lissak; Haim Abramovici

OBJECTIVE To investigate the morphology and proliferative ability of cumulus and granulosa cells (GCs) originating from cystic follicles and normal-sized follicles after ovarian stimulation. DESIGN Granulosa cells, cumulus cells, and follicular fluid (FF) were aspirated from cystic follicles and normal-sized follicles from the same ovary. Morphology and proliferative ability of cumulus and GCs were assessed by Giemsa stain and thymidine incorporation, respectively. Cell proliferation was assessed in medium or FF originating from cystic follicles or normal-sized follicles. RESULTS An oocyte was found in 40% of the cystic follicles versus 68% in the normal-sized follicles. Changes in dispersion and adhesion properties were observed in cystic versus normal aspirated corona cumuli complex. Proliferative ability was consistently lower in GCs originating from cystic follicles versus normal-sized follicles. Proliferation of GCs originating from normal-sized follicles or cystic follicles was inhibited or increased when grown in FF from cystic follicles or FF from normal-sized follicles, respectively. Differences in embryo quality were significantly in favor of oocytes originating from normal-sized follicles. Although the fertilization rate of those oocytes appeared to be higher, the difference was not of statistical significance. CONCLUSIONS Inhibition of GC proliferation in FF from cystic follicles can be reversed by incubating cells in FF from normal-sized follicles. We conclude that factors in the FF may affect cell proliferation.


Reproductive Biomedicine Online | 2016

p27 and its ubiquitin ligase Skp2 expression in endometrium of IVF patients with repeated hormonal stimulation

Shirly Lahav-Baratz; Mara Koifman; Edmond Sabo; Ron Auslender; M. Dirnfeld

This preliminary study examined a possible effect of long duration repeated hormonal stimulation on the endometrium using a molecular tool. The expression of the hormone stimulated, cell cycle regulators, p27 and its ligase S-phase kinase-interacting protein2 (Skp2), were assessed in 46 endometrial samples of patients who underwent repeated IVF cycles (3-21). Skp2 protein is usually undetectable in normal tissue and can be demonstrated only in rapidly dividing cells. Samples from non-stimulated, normal cycling women served as control group A. Samples of endometrial carcinoma served as control group B. In secretory endometrium, the expression of p27 was found to be lower and Skp2 higher in the study group compared with control group A. Moreover, in 25% of patients of the study group, Skp2 expression was significantly higher (P < 0.05) compared with control group A, reaching concentrations demonstrated in endometrial carcinoma. The findings of this study suggest that repeated hormone stimulation cycles may disrupt endometrial physiology, potentially towards abnormal proliferation. These changes in protein expression are described for the first time in IVF patients and should be further investigated.


Human Reproduction | 2004

The impact of cigarette smoking on zona pellucida thickness of oocytes and embryos prior to transfer into the uterine cavity

Hanna Shiloh; S.Lahav Baratz; Mara Koifman; David Ishai; D. Bidder; Z. Weiner‐Meganzi; Martha Dirnfeld


Human Reproduction | 1991

Does the choice of catheter for embryo transfer influence the success rate of in-vitro fertilization?

Yael Gonen; Martha Dirnfeld; Shlomit Goldman; Mara Koifman; Haim Abramovici


Human Reproduction | 1999

Shortened exposure of oocytes to spermatozoa improves in-vitro fertilization outcome: a prospective, randomized, controlled study.

M. Dirnfeld; David Bider; Mara Koifman; Ilan Calderon; Haim Abramovici

Collaboration


Dive into the Mara Koifman's collaboration.

Top Co-Authors

Avatar

Martha Dirnfeld

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Haim Abramovici

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hanna Shiloh

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

M. Dirnfeld

Rappaport Faculty of Medicine

View shared research outputs
Top Co-Authors

Avatar

Shirly Lahav-Baratz

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

David Ishai

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Zaki Kraiem

Technion – Israel Institute of Technology

View shared research outputs
Researchain Logo
Decentralizing Knowledge