ABSTRACT
PURPOSE: To determine embryo and cycle-specific parameters associated with twin live birth in day 3 cryopreserved double embryo transfer (DET) cycles, and to propose a new prediction model for external validation. METHODS: All cycles with autologous or donor cryopreserved DET of day 3 embryos from 2002 to 2011 at a single academic institution with a singleton or twin live birth were included (n = 207). Patient characteristics, post-thaw embryo morphology and freeze-thaw parameters were compared between patients with a single and twin live birth. RESULTS: Demographic characteristics were similar, except that patients delivering twins were younger at age of cryopreserved embryo transfer (CET), fewer were parous and more were anovulatory. Duration of embryo storage, time in culture post-thaw, endometrial thickness and use of assisted hatching were comparable. Six predictors of twin delivery were identified: patient age <35 year at CET, intact survival of the lead embryo, resumption of mitosis, 7-8 viable cells in the non-lead embryo, transfer of a lead embryo with ≥7 cells and a sum of ≥14 viable cells in the two transferred embryos. Regression modeling predicted a step-wise increase in the probability of twins with addition of each predictor; with all six present, the risk of twins was predicted to be 53 % and with none present, the risk decreased to 6 %. CONCLUSIONS: The six identified variables associated with twin live birth following day 3 cryopreserved DET have been applied to derive a prediction model for estimating the risk of twin delivery. External validation of the model is required prior to clinical application.
Subject(s)
Cryopreservation , Live Birth , Pregnancy, Twin , Single Embryo Transfer , Age Factors , Aged , Embryo Transfer/methods , Female , Fertilization in Vitro , Humans , Pregnancy , Pregnancy Rate , Pregnancy, Multiple , TwinsABSTRACT
PURPOSE: The cryopreservation of immature oocytes permits oocyte banking for patients at risk of losing their fertility. However, the optimum protocol for such fertility preservation remains uncertain. METHODS: The present study investigated the survival, maturation, cytoskeletal and chromosome organization of sibling immature oocytes leftover from controlled ovarian stimulation cycles, that were either slow-frozen (with choline-substitution) or vitrified. A comparison group included oocytes that were never cryopreserved. RESULTS: Among the three groups, comparable rates were observed for both survival (67-70%) and polar body extrusion (59-79%). Significantly more oocytes underwent spontaneous activation after IVM following slow-freezing compared with either vitrification or no cryopreservation. Likewise, the incidence of spindle abnormalities was greatest in the slow-frozen group, with no differences in spindle morphometrics or chromosome organization. CONCLUSIONS: While the overall incidence of mature oocytes with normal bipolar spindles from warmed immature oocytes was low, the yield using Cryoleaf vitrification was slightly superior to choline-based slow-freezing.
Subject(s)
Choline , Cryopreservation/methods , Oocytes/cytology , Actin Cytoskeleton/physiology , Chromosomes, Human/physiology , Humans , Microtubules/physiology , Oocytes/physiology , VitrificationABSTRACT
To evaluate the effect of luteal estrogen supplementation on pregnancy rates in normal responder IVF patients treated with recombinant FSH and fixed multidose GnRH antagonist, patients were randomized into two groups to receive vaginal 600 mg/d micronized progesterone for luteal phase supplementation with or without transdermal estrogen supplementation (100 microg/d). Because pregnancy rates and ongoing pregnancy rates were similar with and without estrogen supplementation (50.0% vs. 55.2% and 36.6% vs. 34.4%, respectively), we concluded that luteal estrogen supplementation in fixed multidose GnRH antagonist cycles did not change the pregnancy rates significantly.