Using blastocyst re-expansion rate for deciding when to warm a new blastocyst for single vitrified-warmed blastocyst transfer.

Research Question: Can predictive post-warm parameters that support the decision to transfer a warmed blastocyst or to warm another blastocyst be identified in women with multiple frozen-vitrified blastocysts?

Design: Retrospective single-centre observational cohort analysis. A total of 1092 single vitrified-warmed blastocyst transfers (SVBT) with known Gardner score, maternal age and live birth were used to develop live birth prediction models based on logistic regression, including post-warm re-expansion parameters. Time-lapse incubation was used for pre-vitrification and post-warm embryo culture.

Pre-Vitrification and Post-Warming Variables of Vitrified-Warmed Blastocysts That Are Predictable for Implantation.

Human IVF embryos that are not used for fresh transfer are cryopreserved by vitrification for later embryo transfers. This study evaluates pre-vitrification and post-warming embryo characteristics that are suitable to predict the chance of clinical pregnancy in single vitrified blastocyst transfer (SVBT) cycles. In a multicenter observational trial (IMBOS trial), embryos were cultured in a time-lapse system before and after vitrification.

Comparing performance between clinics of an embryo evaluation algorithm based on time-lapse images and machine learning.

Purpose: This article aims to assess how differences in maternal age distributions between IVF clinics affect the performance of an artificial intelligence model for embryo viability prediction and proposes a method to account for such differences.

Methods: Using retrospectively collected data from 4805 fresh and frozen single blastocyst transfers of embryos incubated for 5 to 6 days, the discriminative performance was assessed based on fetal heartbeat outcomes. The data was collected from 4 clinics, and the discrimination was measured in terms of the area under ROC curves (AUC) for each clinic.

Monochorionic twins after single blastocyst transfer: retrospective cohort and blinded time lapse annotation analysis.

Research Question: Is it possible to identify monochorionic twin pregnancies before blastocyst transfer based on maternal or embryo characteristics registered by time lapse?

Design: A retrospective cohort study including women who received fertility treatment (n = 6501) between 2010 and 2019 at two fertility clinics in central Denmark. The treatment resulted in 2239 pregnancies after single embryo transfer (SET) and, of those, 43 (1.92%) were monochorionic twins.

Selection of High-Quality Spermatozoa May Be Promoted by Activated Vitamin D in the Woman.

Context: The vitamin D receptor (VDR) and enzymes involved in activation (CYP2R1, CYP27B1) and inactivation (CYP24A1) of vitamin D are expressed in ovary, testes, and spermatozoa.

Objective: Determine responsiveness to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] in spermatozoa from normal and infertile men, and identify the site of exposure and how 1,25(OH)2D3 influences sperm function.

Design: Spermatozoa expressing VDR, CYP2R1, CYP27B1, and CYP24A1 were analyzed in normal and infertile men.