Before the beginning: the genetic risk of a couple aiming to conceive.

Disorders of genetic etiology exist in 2%-3% of live-born infants. Identifying couples with increased susceptibility for offspring with anomalies or genetic disorders is increasingly effective as a result of molecular advances. Preimplantation genetic testing (PGT) with the use of trophectoderm biopsy, 24-chromosome testing, and molecular testing have allowed wider applicability for avoiding a clinical pregnancy termination. Cell-free DNA in maternal blood is another targeted option, although invasive prenatal genetic diagnosis provides the greatest amount of genetic information. DNA-based methods to detect subtle chromosomal abnormalities are much more sensitive than traditional karyotypes and do not require cultured cells. Aneuploidy and structural chromosomal abnormalities can be readily detected with the use of small amounts of DNA, if necessary amplified, as in PGT. Novel approaches exist for detecting perturbations in single-gene disorders. Not only has the molecular basis for many monogenic disorders been elucidated, but modest costs for DNA sequencing has made testing feasible. As the number of testable genetic disorders has increased, principles underlying screening have advanced. Genetic screening for disorders of high incidence in certain ethnic groups was initiated decades ago; however, limitations exist, and reduction in live-born incidence is not infrequently small. Expanded carrier screening is now offered in panethnic fashion, extending surveillance to couples of mixed ethnicities and involving many more genetic conditions. Targeted gene panels (e.g., adult-onset cancer genes) further increase the number of genetic disorders amenable to screening, often leading to PGT.

Prenatal genetic testing and treatment for congenital adrenal hyperplasia.

Couples at risk for autosomal recessive congenital adrenal hyperplasia often request anticipatory guidance and genetic counseling. Initially, hormones in amniotic fluid were measured to distinguish affected female fetuses from unaffected fetuses. With the molecular era, more-targeted approaches became possible. Prenatal genetic diagnosis via amniocentesis or chorionic villus sampling was used to determine the need for continuing fetal therapy (dexamethasone), allowing cessation if the fetus was unaffected. Newer methods now allow diagnosis earlier in gestation, further shortening the treatment time for unaffected female fetuses who will not develop genital ambiguity. Preimplantation genetic testing permits transfer only of an unaffected female or male fetus. Analysis of maternal cell-free DNA based on quantitative differences in the amount of allele parental DNA permits affected pregnancies to be differentiated from unaffected pregnancies.

Overview of Preimplantation Genetic Diagnosis (PGD): Historical Perspective and Future Direction.

Preimplantation genetic diagnosis (PGD) can be considered the earliest form of prenatal testing. It was first used in humans over 26 years ago. At its inception, PGD could only be performed for a limited number of genetic disorders. Technological advances in molecular biology and cytogenomics have been utilized in the field of PGD to greatly expand the spectrum of genetic disorders that can now be detected in early human embryos.

Author Correction: Enabling precision medicine in neonatology, an integrated repository for preterm birth research.

The original version of the Data Descriptor contained errors in the author list and affiliations. Rita Leite's first name was misspelled as "Rite" and affiliations 4 and 5 were incorrectly swapped. In addition, members of the March of Dimes Prematurity Research Center consortium were not listed in the agreed positions within the author list. These errors have now been corrected in the HTML and PDF versions.

Enabling precision medicine in neonatology, an integrated repository for preterm birth research.

Preterm birth, or the delivery of an infant prior to 37 weeks of gestation, is a significant cause of infant morbidity and mortality. In the last decade, the advent and continued development of molecular profiling technologies has enabled researchers to generate vast amount of 'omics' data, which together with integrative computational approaches, can help refine the current knowledge about disease mechanisms, diagnostics, and therapeutics. Here we describe the March of Dimes' Database for Preterm Birth Research (http://www.immport.org/resources/mod), a unique resource that contains a variety of 'omics' datasets related to preterm birth. The database is open publicly, and as of January 2018, links 13 molecular studies with data across tens of thousands of patients from 6 measurement modalities. The data in the repository are highly diverse and include genomic, transcriptomic, immunological, and microbiome data. Relevant datasets are augmented with additional molecular characterizations of almost 25,000 biological samples from public databases. We believe our data-sharing efforts will lead to enhanced research collaborations and coordination accelerating the overall pace of discovery in preterm birth research.

Forty years of IVF.

This monograph, written by the pioneers of IVF and reproductive medicine, celebrates the history, achievements, and medical advancements made over the last 40 years in this rapidly growing field.

The International Glossary on Infertility and Fertility Care, 2017.

STUDY QUESTION: Can a consensus and evidence-driven set of terms and definitions be generated to be used globally in order to ensure consistency when reporting on infertility issues and fertility care interventions, as well as to harmonize communication among the medical and scientific communities, policy-makers, and lay public including individuals and couples experiencing fertility problems? SUMMARY ANSWER: A set of 283 consensus-based and evidence-driven terminologies used in infertility and fertility care has been generated through an inclusive consensus-based process with multiple stakeholders. WHAT IS KNOWN ALREADY: In 2006 the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) published a first glossary of 53 terms and definitions. In 2009 ICMART together with WHO published a revised version expanded to 87 terms, which defined infertility as a disease of the reproductive system, and increased standardization of fertility treatment terminology. Since 2009, limitations were identified in several areas and enhancements were suggested for the glossary, especially concerning male factor, demography, epidemiology and public health issues. STUDY DESIGN, SIZE, DURATION: Twenty-five professionals, from all parts of the world and representing their expertise in a variety of sub-specialties, were organized into five working groups: clinical definitions; outcome measurements; embryology laboratory; clinical and laboratory andrology; and epidemiology and public health. Assessment for revisions, as well as expansion on topics not covered by the previous glossary, were undertaken. A larger group of independent experts and representatives from collaborating organizations further discussed and assisted in refining all terms and definitions. PARTICIPANTS/MATERIALS, SETTING, METHODS: Members of the working groups and glossary co-ordinators interacted through electronic mail and face-to-face in international/regional conferences. Two formal meetings were held in Geneva, Switzerland, with a final consensus meeting including independent experts as well as observers and representatives of international/regional scientific and patient organizations. MAIN RESULTS AND THE ROLE OF CHANCE: A consensus-based and evidence-driven set of 283 terminologies used in infertility and fertility care was generated to harmonize communication among health professionals and scientists as well as the lay public, patients and policy makers. Definitions such as 'fertility care' and 'fertility awareness' together with terminologies used in embryology and andrology have been introduced in the glossary for the first time. Furthermore, the definition of 'infertility' has been expanded in order to cover a wider spectrum of conditions affecting the capacity of individuals and couples to reproduce. The definition of infertility remains as a disease characterized by the failure to establish a clinical pregnancy; however, it also acknowledges that the failure to become pregnant does not always result from a disease, and therefore introduces the concept of an impairment of function which can lead to a disability. Additionally, subfertility is now redundant, being replaced by the term infertility so as to standardize the definition and avoid confusion. LIMITATIONS, REASONS FOR CAUTION: All stakeholders agreed to the vast majority of terminologies included in this glossary. In cases where disagreements were not resolved, the final decision was reached after a vote, defined before the meeting as consensus if passed with 75%. Over the following months, an external expert group, which included representatives from non-governmental organizations, reviewed and provided final feedback on the glossary. WIDER IMPLICATIONS OF THE FINDINGS: Some terminologies have different definitions, depending on the area of medicine, for example demographic or clinical as well as geographic differences. These differences were taken into account and this glossary represents a multinational effort to harmonize terminologies that should be used worldwide. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: N/A.

The International Glossary on Infertility and Fertility Care, 2017.

STUDY QUESTION: Can a consensus and evidence-driven set of terms and definitions be generated to be used globally in order to ensure consistency when reporting on infertility issues and fertility care interventions, as well as to harmonize communication among the medical and scientific communities, policy-makers, and lay public including individuals and couples experiencing fertility problems? SUMMARY ANSWER: A set of 283 consensus-based and evidence-driven terminologies used in infertility and fertility care has been generated through an inclusive consensus-based process with multiple stakeholders. WHAT IS KNOWN ALREADY: In 2006 the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) published a first glossary of 53 terms and definitions. In 2009 ICMART together with WHO published a revised version expanded to 87 terms, which defined infertility as a disease of the reproductive system, and increased standardization of fertility treatment terminology. Since 2009, limitations were identified in several areas and enhancements were suggested for the glossary, especially concerning male factor, demography, epidemiology and public health issues. STUDY DESIGN, SIZE, DURATION: Twenty-five professionals, from all parts of the world and representing their expertise in a variety of sub-specialties, were organized into five working groups: clinical definitions; outcome measurements; embryology laboratory; clinical and laboratory andrology; and epidemiology and public health. Assessment for revisions, as well as expansion on topics not covered by the previous glossary, were undertaken. A larger group of independent experts and representatives from collaborating organizations further discussed and assisted in refining all terms and definitions. PARTICIPANTS/MATERIALS, SETTING, METHODS: Members of the working groups and glossary co-ordinators interacted through electronic mail and face-to-face in international/regional conferences. Two formal meetings were held in Geneva, Switzerland, with a final consensus meeting including independent experts as well as observers and representatives of international/regional scientific and patient organizations. MAIN RESULTS AND THE ROLE OF CHANCE: A consensus-based and evidence-driven set of 283 terminologies used in infertility and fertility care was generated to harmonize communication among health professionals and scientists as well as the lay public, patients and policy makers. Definitions such as 'fertility care' and 'fertility awareness' together with terminologies used in embryology and andrology have been introduced in the glossary for the first time. Furthermore, the definition of 'infertility' has been expanded in order to cover a wider spectrum of conditions affecting the capacity of individuals and couples to reproduce. The definition of infertility remains as a disease characterized by the failure to establish a clinical pregnancy; however, it also acknowledges that the failure to become pregnant does not always result from a disease, and therefore introduces the concept of an impairment of function which can lead to a disability. Additionally, subfertility is now redundant, being replaced by the term infertility so as to standardize the definition and avoid confusion. LIMITATIONS, REASONS FOR CAUTION: All stakeholders agreed to the vast majority of terminologies included in this glossary. In cases where disagreements were not resolved, the final decision was reached after a vote, defined before the meeting as consensus if passed with 75%. Over the following months, an external expert group, which included representatives from non-governmental organizations, reviewed and provided final feedback on the glossary. WIDER IMPLICATIONS OF THE FINDINGS: Some terminologies have different definitions, depending on the area of medicine, for example demographic or clinical as well as geographic differences. These differences were taken into account and this glossary represents a multinational effort to harmonize terminologies that should be used worldwide. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: N/A.

Preimplantation diagnosis and other modern methods for prenatal diagnosis.

Prenatal treatment of congenital adrenal hyperplasia (CAH) has long involved prenatal treatment with dexamethasone, administered to the pregnant woman to prevent genital masculinization of an affected female fetus. Although it is unnecessary to treat unaffected or affected males because their genital development would not be disturbed, there has only been incremental progress in determining fetal gender sufficiently each to avoid treating males and unaffected females. Invasive procedures were initially necessary, with first-trimester amniocentesis at 15-20 weeks and then chorionic villus sampling (CVS) at 10-12 weeks gestation. Two approaches now allow personalized treatment of affected female fetuses prior to female genital differentiation. Only preimplantation genetic diagnosis (PGD) is available prior to clinical pregnancy. Recent technological advances have further allowed both single gene diagnosis (e.g., CAH) and aneuploidy detection concomitantly, resulting in far better pregnancy rates than heretofore possible in assisted reproduction technology.

Cross-Country Individual Participant Analysis of 4.1 Million Singleton Births in 5 Countries with Very High Human Development Index Confirms Known Associations but Provides No Biologic Explanation for 2/3 of All Preterm Births.

BACKGROUND: Preterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice. METHODS: We analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors. FINDINGS: Previous preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6-6.0 and 2.8-5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25-50% and 11-16% of excess population attributable risk, respectively (p<0.001). The importance of nulliparity and male sex on population attributable risk was driven by high prevalence despite low odds ratios for individual women. More than 65% of the total aggregated risk of preterm birth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying mechanisms of preterm birth and, hence, therapeutic intervention. Surprisingly, variation in prevalence of known risk factors accounted for less than 35% of the difference in preterm birth rates between countries. Known risk factors had an area under the curve of less than 0.7 in ROC analysis of preterm birth prediction within countries. These data suggest that other influences, as yet unidentified, are involved in preterm birth. Further research into biological mechanisms is warranted. CONCLUSIONS: We have quantified the causes of variation in preterm birth rates among countries with very high human development index. The paucity of explicit and currently identified factors amenable to intervention illustrates the limited impact of changes possible through current clinical practice and policy interventions. Our research highlights the urgent need for research into underlying biological causes of preterm birth, which alone are likely to lead to innovative and efficacious interventions.