Luteinizing hormone profiles during ovarian stimulation in assisted reproductive treatment.

Introduction: Few data is available on the natural course of luteinizing hormone (LH) during ovarian stimulation, but it has been suggested that 'oversuppressed' LH could decrease fertility outcomes. Our aim with this study is to evaluate the changes in LH depending on the used stimulation protocol to better define LH oversuppressioin.

Methods: Patients undergoing oocyte retrieval in a tertiary fertility center between 01-01-2015 and 30-09-2020 after stimulation with a short-agonist (SA) or antagonist (A) protocol were included.

Cumulative pregnancy rates of two strategies: Day 3 fresh embryo transfer followed by Day 3 or Day 5/6 vitrification and embryo transfer: a randomized controlled trial.

Study Question: Are cumulative pregnancy rates better if supernumerary embryos are vitrified on Day 5/6 instead of Day 3?

Summary Answer: The results do not show a significant difference in cumulative pregnancy rates between the Day 3 and Day 5/6 vitrification groups.

What Is Known Already: Pregnancy and live birth rates following IVF or ICSI treatment are higher after extended embryo culture and blastocyst transfer (Day 5/6) compared to cleavage-stage (Day 3) transfer. Cumulative pregnancy rates from one oocyte retrieval (OR) cycle show no significant difference after fresh and frozen embryo transfers, but only one study has used vitrification for the cryopreservation of supernumerary embryos while four studies have used a slow freezing protocol.

The Impact of Chronic Endometritis on Infertility: Prevalence, Reproductive Outcomes, and the Role of Hysteroscopy as a Screening Tool.

Objectives: The objective of this study was to examine the prevalence of chronic endometritis (CE) in infertile women, its impact on reproductive outcomes, and the accuracy of hysteroscopy as a screening tool for CE.

Design: This was a prospective observational study.

Participants: Participants involved in this study were 514 asymptomatic patients with infertility.

Preclinical workup using long-read amplicon sequencing provides families with de novo pathogenic variants access to universal preimplantation genetic testing.

Study Question: Can long-read amplicon sequencing be beneficial for preclinical preimplantation genetic testing (PGT) workup in couples with a de novo pathogenic variant in one of the prospective parents?

Summary Answer: Long-read amplicon sequencing represents a simple, rapid and cost-effective preclinical PGT workup strategy that provides couples with de novo pathogenic variants access to universal genome-wide haplotyping-based PGT programs.

What Is Known Already: Universal PGT combines genome-wide haplotyping and copy number profiling to select embryos devoid of both familial pathogenic variants and aneuploidies. However, it cannot be directly applied in couples with a de novo pathogenic variant in one of the partners due to the absence of affected family members required for phasing the disease-associated haplotype.

Parental genomes segregate into distinct blastomeres during multipolar zygotic divisions leading to mixoploid and chimeric blastocysts.

Background: During normal zygotic division, two haploid parental genomes replicate, unite and segregate into two biparental diploid blastomeres.

Results: Contrary to this fundamental biological tenet, we demonstrate here that parental genomes can segregate to distinct blastomeres during the zygotic division resulting in haploid or uniparental diploid and polyploid cells, a phenomenon coined heterogoneic division. By mapping the genomic landscape of 82 blastomeres from 25 bovine zygotes, we show that multipolar zygotic division is a tell-tale of whole-genome segregation errors.