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Thessaloníki, Greece

Ferraretti A.P.,Sismer Reproductive Medicine Unit | La Marca A.,University Hospital Policlinico of Modena | Fauser B.C.J.M.,University Utrecht | Tarlatzis B.,Unit for Human Reproduction | And 2 more authors.
Human Reproduction

The definition presented here represents the first realistic attempt by the scientific community to standardize the definition of poor ovarian response (POR) in a simple and reproducible manner. POR to ovarian stimulation usually indicates a reduction in follicular response, resulting in a reduced number of retrieved oocytes. It has been recognized that, in order to define the poor response in IVF, at least two of the following three features must be present: (i) advanced maternal age or any other risk factor for POR; (ii) a previous POR; and (iii) an abnormal ovarian reserve test (ORT). Two episodes of POR after maximal stimulation are sufficient to define a patient as poor responder in the absence of advanced maternal age or abnormal ORT. By definition, the term POR refers to the ovarian response, and therefore, one stimulated cycle is considered essential for the diagnosis of POR. However, patients of advanced age with an abnormal ORT may be classified as poor responders since both advanced age and an abnormal ORT may indicate reduced ovarian reserve and act as a surrogate of ovarian stimulation cycle outcome. In this case, the patients should be more properly defined as 'expected poor responder'. If this definition of POR is uniformly adapted as the 'minimal criteria needed to select patients for future clinical trials, more homogeneous populations will be tested for any new protocols. Finally, by reducing bias caused by spurious POR definitions, it will be possible to compare Results: and to draw reliable conclusions. © 2011 The Author. Source

Papanikolaou E.G.,Vrije Universiteit Brussel | Fatemi H.,Vrije Universiteit Brussel | Venetis C.,Unit for Human Reproduction | Donoso P.,Vrije Universiteit Brussel | And 4 more authors.
Fertility and Sterility

Objective: To compare the incidence of monozygotic twinning between cleavage-stage and blastocyst-stage embryo transfer in a large cohort of patients undergoing single embryo transfer. Design: Retrospective study. Setting: Dutch-speaking Free University of Brussels. Patient(s): This study covered the period between July 2003 and December 2005. 1,951fresh IVF/ICSI cycles in which single embryo transfer was performed were retrospectively reviewed. Only the first cycle of each patient was included. Intervention(s): Five hundred eighty seven (n = 587) cycles that resulted in clinical pregnancies were identified; 308 after single day-3 embryo transfer and 271 after single blastocyst transfer. Main Outcome Measure(s): The incidence of monozygotic twinning. Result(s): Overall, 13 cases (2.2%) of monozygotic twinning were observed, 2.6% in the cleavage-stage group (n = 8/308) and 1.8% in the blastocyst group (n = 5/271). No statistically significant differences were observed in the probability of monozygotic twinning between the Cleavage-stage and the Blastocyst group (difference: +0.8%; 95% CI, -1.97 to +3.41). All of these pregnancies resulted in the delivery of 24 healthy babies. The crude odds ratio for the incidence of monozygotic twinning after day-5 embryo transfer was calculated to be 0.71 (95% CI, 0.23-2.18). Conclusion(s): To investigate the potential association between the day of embryo transfer (day 3 or 5) and the incidence of monozygotic twinning, the clinical pregnancies analyzed should have been established after single embryo transfer. The current study represents the first methodologically appropriate study attempting to investigate the above research question. Our findings support that opting for blastocyst transfer does not increase the probability for monozygotic twins. © 2010 American Society for Reproductive Medicine. Source

Venetis C.A.,Unit for Human Reproduction | Kolibianakis E.M.,Unit for Human Reproduction | Tarlatzi T.B.,Unit for Human Reproduction | Tarlatzis B.C.,Unit for Human Reproduction
Annals of the New York Academy of Sciences

Poor ovarian response is not infrequent and represents one of the major therapeutic challenges in in vitro fertilization. Although several tests have been proposed, which aim at predicting poor response to ovarian stimulation, available data are conflicting regarding their accuracy and clinical usefulness. Even though several therapeutic approaches have been explored, a single effective strategy has not yet been established. One of the major limitations of interpreting the relevant literature is the wide variability in the definitions used for poor ovarian response. Regarding the interventions that have been proposed to improve the probability of pregnancy in poor responders, limited evidence from relevant randomized controlled trials suggests that addition of growth hormone during ovarian stimulation, as well as performing embryo transfer on day 2 instead of day 3, might be beneficial. Further randomized control trials are warranted to reliably determine which would be the best approach for treating poor ovarian response. © 2010 New York Academy of Sciences. Source

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