Aneuploidy in oocytes from women of advanced maternal age: analysis of the causal meiotic errors and impact on embryo development.

Study Question: In oocytes of advanced maternal age (AMA) women, what are the mechanisms leading to aneuploidy and what is the association of aneuploidy with embryo development?

Summary Answer: Known chromosome segregation errors such as precocious separation of sister chromatids explained 90.4% of abnormal chromosome copy numbers in polar bodies (PBs), underlying impaired embryo development.

What Is Known Already: Meiotic chromosomal aneuploidies in oocytes correlate with AMA (>35 years) and can affect over half of oocytes in this age group.

EuMAR: a roadmap towards a prospective, cycle-by-cycle registry of medically assisted reproduction in Europe.

More than 20 years ago, the survey of activities in medically assisted reproduction (MAR) was initiated in Europe and resulted in cross-sectional annual reports, as issued by the European IVF Monitoring (EIM) consortium of ESHRE. Over time, these reports mirror the continuous development of the technologies and contribute to increased transparency and surveillance of reproductive care. Meanwhile, progressive changes of existing treatment modalities and the introduction of new technologies resulted in the need of a cumulative approach in the assessment of treatment outcomes, which warrants a prospective cycle-by-cycle data registry on MAR activities, including fertility preservation.

Improving access to ART in low-income settings through knowledge transfer: a case study from Zimbabwe.

It may be assumed that infertility is not a problem in resource-poor areas where fertility rates are high. However, evidence overwhelmingly shows that childlessness is highly stigmatized in these settings and that women who are unable to bear children suffer significant social and psychological consequences. The World Health Organization has recommended that infertility be considered a global health problem and stated the need for ART to be adapted to low-resource settings.

Intra-individual purifying selection on mitochondrial DNA variants during human oogenesis.

Study Question: Does selection for mtDNA mutations occur in human oocytes?

Summary Answer: We provide statistical evidence in favor of the existence of purifying selection for mtDNA mutations in human oocytes acting between the expulsion of the first and second polar bodies (PBs).

What Is Known Already: Several lines of evidence in Metazoa, including humans, indicate that variation within the germline of mitochondrial genomes is under purifying selection. The presence of this internal selection filter in the germline has important consequences for the evolutionary trajectory of mtDNA.

A Bayesian network model for predicting pregnancy after in vitro fertilization.

We present a Bayesian network model for predicting the outcome of in vitro fertilization (IVF). The problem is characterized by a particular missingness process; we propose a simple but effective averaging approach which improves parameter estimates compared to the traditional MAP estimation. We present results with generated data and the analysis of a real data set.