Conventional ovarian stimulation vs. delayed single dose corifollitropin alfa ovarian stimulation in oocyte donors: a prospective randomized study. Tail trial.

The present study compares two protocols for ovarian controlled stimulation in terms of number of cumulus-oocyte complexes and metaphase II oocytes. We employed a single injection of 150mcg of corifollitropin alfa after a 7-day oral contraceptive pill-free interval for TAIL group and a conventional administration of corifollitropin alfa after a 5-day OCP-free interval with additional rFSH from 8th of ovarian controlled stimulation. Prospective, randomized, comparative, non-inferiority, opened and controlled trial carried out in 180 oocyte donors 31 were excluded, 81 were randomized to the control group and 68 to the TAIL group. No differences were found in the number of follicles larger than 14 and 17 mm at triggering day. However, a lower number of cumulus-oocyte complexes and metaphase II oocytes were obtained in TAIL group compared to the control group, expressed as median (interquartile range): 10.5 (5.5-19) vs. 14 [11-21] and 9 (4-13) vs. 12 (9-17) respectively. Additionally, the incidence of failed retrieval or metaphase II oocytes = 0 was higher in TAIL group 7(10.3%) vs. 1(1.2%) p = 0.024. The use of a single injection of corifollitropin alfa after a 7-day oral contraceptive pill-free interval in oocyte donors resulted in a lower number of cumulus-oocyte complexes and metaphase II oocytes. No additional rFSH was administered in this group. Clinical Trial Registration: https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-001343-44/results.

Impact of endometrial compaction on reproductive outcomes after cryotransfer of euploid embryos in a modified natural cycle: protocol for a prospective cohort study.

Introduction: Embryo implantation is a complex and poorly understood process. Most studies to date have focused on the analysis of the endometrium at the end of the estrogenic phase, while the available data on its importance after secretory transformation are limited and inconsistent. Current evidence does not allow for a conclusive interpretation of the changes observed in the pre-implantation endometrium, whether in the natural or replacement cycle, and their relevance in the development of a pregnancy or the implications for clinical practice. Methods: Multicenter prospective observational cohort study. Based on our sample size calculation, the study group will consist of 206 women (exposed or "compaction" group: 103 women with a decrease of ≥ 5% in endometrial thickness between the estrogenic phase and the day of embryo transfer; non-exposed "non-compaction" group: 103 women with similar or greater endometrial thickness between these time points). The main objective of this study is to compare the ongoing pregnancy rates in natural cycles for euploid embryo transfer in patients who present endometrial compaction at the time of transfer versus those who with a stable or greater endometrial thickness with respect to the estrogenic phase. The estimated duration of the study is 30 months. Inclusion criteria are: 18 to 50 years of age, with primary or secondary infertility, subjected to endometrial preparation in a modified natural cycle for transfer of a genetically euploid blastocyst, from their own oocyte or oocyte donation, with a normal uterine cavity. Exclusion criteria are: uterine or endometrial disease (e.g., multiple myomatosis, severe adenomyosis, Asherman syndrome, refractory endometrium), conditions that prevent correct ultrasound assessment (tilted uterus), or a history of recurrent implantation failure or repeated miscarriages. Discussion: The findings from this study will provide valuable insights into the potential influence of the "endometrial compaction" phenomenon on reproductive outcomes during natural cycle endometrial preparation. By examining this aspect, we aim to contribute to a better understanding of the factors that may impact successful outcomes in fertility treatments.

Clinical outcomes in elective vitrification of embryos / Resultados clínicos en el programa de vitrificación electiva de embriones

Objective: To compare the clinical outcomes of an elective vitrification program with those of a fresh embryo transfer program including vitrification of the remaining embryos. Material and methods: Retrospective study of 99 cycles from the elective vitrification program (Group A) and 150 cycles from the nonelective vitrification program (Group B) carried out from January 2014 to December 2015 in Instituto Bernabeu, Alicante, Spain. In both groups, the embryos were from the patient’s own oocytes. The variables evaluated in group A were clinical indication, endometrial preparation protocols for frozen embryo transfer, percentage of embryo survival after thawing, and day of embryo vitrification. The main clinical indication (54.5% of cases) in Group A was to avoid ovarian hyperstimulation syndrome. Outcomes: The percentage of embryo implantation (35.2% vs. 27%), the percentage of positive pregnancies with beta-hCG (58.5% vs. 42.9%), and the percentage of clinical pregnancy (41.5% vs. 32.5%) were superior in Group A when we transferred embryos of types A and/or B according to the ASEBIR classification, although no statistically significant differences were found (p = 0.230, p = 0.082, and p = 0.360, respectively). Conclusions: A "freeze-all" strategy is the procedure of choice for avoiding ovarian hyperstimulation syndrome or possible embryo-endometrium asynchrony at the time of the transfer. It also provides clinical results that are at least comparable to those obtained with fresh embryo transfer

Objetivo: Comprobar los resultados clínicos del programa de vitrificación electiva de embriones frente al de transferencia en fresco y congelación de los embriones restantes. Material y métodos: Se han estudiado de forma retrospectiva 99 ciclos de vitrificación electiva (Grupo A) y 150 ciclos de vitrificación no electiva (Grupo B) realizados entre enero de 2014 y diciembre de 2015 en el Instituto Bernabeu de Alicante. En ambos grupos los embriones obtenidos provenían de ovocito propio. En el grupo A se valoraron las indicaciones clínicas, los protocolos de preparación endometrial para la criotransferencia (CT), el porcentaje de supervivencia embrionaria a la descongelación y el día de vitrificación embrionaria. La indicación clínica mayoritaria (54.5% de los casos) en el grupo A fue evitar el Síndrome de Hiperestimulación Ovárica (SHO). Resultados: El porcentaje de implantación embrionaria (35,2% vs. 27%), el de embarazo positivo con beta (58.5% vs. 42,9%) y el de embarazo clínico (41,5% vs. 32,5%) fue superior en el grupo A cuando se transfirieron embriones de categoría A y/o B según los criterios de la Asociación Española para el Estudio de la Biología de la Reproducción (ASEBIR), aunque no se alcanzaron diferencias estadísticamente significativas (p = 0,230, p = 0,082 y p = 0,360, respectivamente). Conclusiones: La vitrificación electiva de embriones nos ha permitido por un lado evitar complicaciones como el SHO y por otro, obtener resultados clínicos cuanto menos comparables a los ofrecidos con transferencia embrionaria en fresco

Estudio de la vascularización placentaria mediante Power Doppler tridimensional en la semana 20 en gestaciones espontáneas y tras técnicas de reproducción asistida / Study of placental vascularization using 3D Power Doppler on week 20 of spontaneous pregnancies and after assisted reproductive techniques

OBJETIVO: Comprobar si hay diferente vascularización placentaria en gestaciones espontáneas comparadas con las conseguidas tras técnicas de reproducción asistida (TRA). MÉTODOS: Se realizó un estudio observacional de casos y controles retrospectivo, de embarazos únicos en semana 20, mediante ecografía transvaginal con Tridimensión y power Doppler. Los volúmenes adquiridos fueron analizados utilizando el programa de imagen VOCAL (Virtual Organ Computer Aided Analysis), para evaluar el Índice de Vascularización (IV), el Índice de Flujo (IF) y el Índice de Vascularización de Flujo (IVF). RESULTADOS: De 130 gestantes incluidas en el estudio, 55 de ellas se habían sometido a tratamientos de esterilidad y 75 eran gestaciones espontáneas. En un análisis comparativo, la vascularización placentaria en el grupo de TRA mostró diferencias estadísticamente significativas, siendo menores, tanto para el IF (p = 0,033) como para el IVF (p = 0,038), acercándose a la significación estadística el IV (p = 0,076). CONCLUSIONES: El estudio de la vascularización placentaria, podría ser de utilidad para comprender algunas diferencias entre gestaciones espontáneas y tras TRA que explicarían algunos resultados perinatales adversos en este tipo de gestaciones

AIM: Check for different placental vascularization in spontaneous pregnancies compared with those obtained after assisted reproduction techniques (ART). METHODS: An observational retrospective study of cases and controls, on singleton pregnancies at week 20, performed by tridimensional transvaginal sonographer and Power Doppler. The volumes acquired were analyzed using the program image VOCAL (Virtual Organ Computer Aided Analysis), to assess the vascularization index (VI), the flow index (FI) and vascularization index Flow (VIF). Outcome: Of 130 pregnant women included in the study, 55 of them had undergone a fertility treatment and 75 were spontaneous pregnancies. In a comparative analysis, placental vascularization in the ART group showed statistically significant differences, being lower for both the FI (p = 0.033) and for VIF (p = 0.038), approaching the VI statistical significance (p = 0.076). CONCLUSIONS: The study of placental vascularization could be useful to understand some differences between spontaneous and after ART pregnancies, to explain some adverse perinatal outcomes in those pregnancies

Anomalías congénitas tras técnicas de reproducción asistida y su correlación con la calidad embrionaria / Congenital anomalies after assisted reproduction techniques and their correlation with embryonic quality

OBJETIVO: Conocer la posible relación entre la calidad de los embriones transferidos en ciclos de Fecundación In Vitro (FIV) y Microinyección Intracitoplásmica de Espermatozoides (ICSI) con la presencia de anomalías fetales. MATERIAL Y MÉTODOS: Análisis retrospectivo incluyendo casos de anomalías congénitas (n=76), comparándolos con un grupo control (n=240) de nacimientos tras técnicas de reproducción asistida (TRA). Según los tipos de embriones obtenidos, se dividieron los casos en transferencia de calidad alta, media y baja. RESULTADOS: La aparición de defectos es similar con embriones de calidad alta (22,5 %) y media (21,8 %) pero se incrementa cuando se emplean los de baja calidad (40,0 %). Es similar en cuanto a la técnica empleada (FIV o ICSI), gestación única o múltiple, cultivo corto o largo. Sí hay influencia según la edad materna. CONCLUSIÓN: La transferencia de embriones de baja calidad, se asocia a la aparición de un mayor número de defectos congénitos

OBJECTIVE: To find out the possible correlation between the quality of embryos transferred in In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) cycles and fetal anomalies. MATERIALS AND METHODS: Retrospective study including cases of congenital anomalies (n=76), compared to the control group (n=240) in births after assisted reproductive techniques (ART). Depending on the type of embryos obtained, the cases were divided into cases of high, medium and low quality transfer. RESULTS: The appearance of defects is similar between high (22.5 %) and medium (21.8 %) quality embryos, but increase when low quality embryos are used (40.0 %). This is similar in both techniques (IVF or ICSI), single or multiple pregnancies, long and short cultures. Maternal age does have an influence. CONCLUSION: Transferring low quality embryos is related to the appearance of a higher number of congenital defects