Cytogenetic signatures of recurrent pregnancy losses

Patterns of Cytogenomic Findings from a Case Series of Recurrent Pregnancy Loss Provide Insight into the Extent of Genetic Defects Causing Miscarriages

Background  A retrospective study was performed to evaluate the patterns of cytogenomic findings detected from a case series of products of conception (POC) in recurrent pregnancy loss (RPL) over a 16-year period from 2007 to 2023. Results  This case series of RPL was divided into a single analysis (SA) group of 266 women and a consecutive analysis (CA) group of 225 women with two to three miscarriages analyzed. Of the 269 POC from the SA group and the 469 POC from the CA group, a spectrum of cytogenomic abnormalities of simple aneuploidies, compound aneuploidies, polyploidies, and structural rearrangements/pathogenic copy number variants (pCNVs) were detected in 109 (41%) and 160 cases (34%), five (2%) and 11 cases (2%), 35 (13%) and 36 cases (8%), and 10 (4%) and 19 cases (4%), respectively. Patterns with recurrent normal karyotypes, alternating normal and abnormal karyotypes, and recurrent abnormal karyotypes were detected in 74 (33%), 71 (32%), and 80 (35%) of consecutive miscarriages, respectively. Repeat aneuploidies of monosomy X and trisomy 16, triploidy, and tetraploidy were detected in nine women. Conclusions  A comparable spectrum of cytogenomic abnormalities was noted in the SA and CA groups of RPL. A skewed likelihood of 2/3 for recurrent normal and abnormal karyotypes and 1/3 for alternating normal and abnormal karyotypes in consecutive miscarriages was observed. Routine cytogenetic analysis should be performed for consecutive miscarriages. Further genomic sequencing to search for detrimental and embryonic lethal variants causing miscarriages and pathogenic variants inducing aneuploidies and polyploidies should be considered for RPL with recurrent normal and abnormal karyotypes.

The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is both mental and physical health problem affecting about 1-5% of women of childbearing age. The etiology of RPL is complex, involving chromosomal abnormalities, autoimmune diseases, metabolic disorders, and endometrial dysfunction. The causes of abortion are still unknown in more than 50% of these cases. With the development of science and technology, an increasing number of scholars focus on this field and find that genetic factors may play an essential role in unexplained RPL, such as embolism-related genes, immune factor-related genes, and chromosomal numeric, and structural variation. This review summarizes the genetic factors associated with RPL, including genetic mutations and genetic polymorphisms, chromosomal variants, and chromosomal polymorphisms. Many related genetic factors have been found to be demographically and geographically relevant, some of which can be used for risk prediction or screening for the etiology of RPL. However, it is difficult to predict and prevent RPL due to uncertain pathogenesis and highly variable clinical presentation. Therefore, the genetic factors of RPL still need plentiful research to obtain a more accurate understanding of its pathogenesis and to provide more detection means for the screening and prevention of RPL.

Association of male factors with recurrent pregnancy loss

The role of male factors in recurrent pregnancy loss (RPL) is receiving increased attention since sperm quantity and quality, male genetic mutations, as well as epigenetic modifications, have all been associated with RPL. A growing number of studies have been published on the relationship between male factors and RPL; however, these reports are limited due to small sample sizes, inconsistent inclusion criteria, and detection methods. Herein, we investigate the effects of several male factors on RPL from a genetic and non-genetic perspective to aid clinicians in determining the etiology and optimal treatment strategy for patients with RPL.

Maternal and Perinatal Risk Factors for Infantile Hemangioma: A Matched Case-Control Study with a Large Sample Size

Introduction

Infantile hemangioma (IH) is the most common benign tumor in infancy, but information about its pathogenesis is limited. The aim of this study was to determine maternal and perinatal risk factors for IH.

Methods

A total of 1033 IH patients were enrolled in the study between 2017 and 2020. IH patients were matched with controls by sex. Trained investigators collected detailed information from the participants. Logistic regression models were used for multivariate analysis.

Results

The statistical analysis demonstrated that miscarriage history (odds ratio [OR] = 4.275; 95% confidence interval [CI] [3.195, 5.720]), anemia in pregnancy (OR = 4.228; 95% CI [3.083, 5.799]), preterm premature rupture of membranes (PPROM) (OR = 3.182; 95% CI [1.359, 7.454]), placenta previa (OR = 2.440; 95% CI [1.787, 3.333]), threatened miscarriage (OR = 2.290; 95% CI [1.726, 3.039]), premature rupture of membranes (PROM) (OR = 1.785; P < 0.05), progesterone use (OR = 1.614; P < 0.001) and abnormal amniotic fluid volume (OR = 1.499; P < 0.05) were independent risk factors for IH. Gestational diabetes mellitus (GDM) (OR = 0.607; 95% CI [0.464, 0.794]), multiple gestations (OR = 0.407; 95% CI [0.232, 0.713]), hypothyroidism (OR = 0.407; 95% CI [0.227, 0.730]) and uterine fibroids (OR = 0.393; 95% CI [0.250, 0.618]) may reduce the risk of IH.

Conclusions

Maternal and perinatal factors are closely associated with IH occurrence. Our study provides reliable clues to guide further exploration of the pathogenesis of IH.

Trial Registration

ClinicalTrials.gov, NCT03331744.

Plain Language Summary

Infantile hemangioma is the most common benign tumor in children, which seriously affects appearance and function and even threatens life. The pathogenesis is not clear, a detailed case-control study of the maternal and perinatal periods with a large sample size will facilitate the development of individualized and precise treatment, early and timely interventions for high-risk children and improvement of prognosis. Our study found that miscarriage history, anemia in pregnancy, preterm premature rupture of membranes (PPROM), placenta previa, threatened miscarriage, premature rupture of membranes (PROM), progesterone use and abnormal amniotic fluid volume were independent risk factors for IH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00756-4.

Economic impact of using maternal plasma cell-free DNA testing to guide further workup in recurrent pregnancy loss

Objective

We have previously demonstrated that maternal‐plasma cell‐free DNA (cfDNA)‐testing can detect chromosomal anomalies in recurrent pregnancy loss (RPL) with 81.8% sensitivity and 90.3% specificity. Here we assess whether this is cost effective in guiding further workup in RPLs.

Method

A decision‐analytic model was developed to compare the cost of various RPL management pathways: (1) current American Society for Reproductive Medicine (ASRM) RPL workup; (2) microarray or karyotyping analysis of products of conception (POCs) and RPL workup only for euploid cases; and (3) cfDNA testing and RPL workup only for euploid cases. Sample accessibility, failure rates, and sensitivity were specified for each test. Costs of sample collection, genetic tests, and RPL workup were considered. Analysis outcomes included detection rate of chromosomal anomaly and cost per patient tested.

Results

In comparison to existing cytogenetic testing on POCs, cfDNA testing pathway allowed for better sample accessibility with a lower cost per patient. In addition, using cfDNA to guide further workup significantly increases the number of causative fetal chromosome anomalies detected, reducing the number of patients undergoing unnecessary workup resulting in an overall cost savings.

Conclusion

Our study showed that inclusion of cfDNA testing is a cost‐effective approach to guide RPL workup.

What is already known about this topic?

Chromosomal anomalies account for 50%–70% of early pregnancy loss (EPL) and even in recurrent pregnancy loss (RPL) random aneuploidy is the single most common etiology, accounting for >50% of cases.

In a previous study we have shown that maternal‐plasma genome‐wide cell‐free DNA (cfDNA)‐based testing can reliably detect chromosomal anomalies in random EPL and RPL with a sensitivity of 81.8% and a specificity of 90.3%.

We therefore suggested cfDNA‐based testing serve to guide further management in cases of RPL: if cfDNA in the second and subsequent RPL demonstrates aneuploidy, no further action is taken; if an unbalanced rearrangement is found, parental karyotyping is recommended; if no abnormality is detected, the recommended RPL workup is performed.

What does this study add?

In this study we demonstrate that using cfDNA to guide further workup in RPL is a cost‐effective approach.

We share our algorithm to facilitate local cost‐effectiveness analysis based on prevailing billing schemes, either based on national health systems or private payor systems.

Reproductive outcomes in individuals with chromosomal reciprocal translocations

PURPOSE

Patients with reciprocal balanced translocations (RBT) have a risk for recurrent pregnancy losses (RPL), affected child, and infertility. Currently, genetic counseling is based on karyotypes found among the products of conception (POC), although factors influencing the success of assisted reproductive technologies (ART) in RBT couples are not established.

METHODS

Cytogenetic results from 261 POC and offspring of the parents (113 women and 90 men) with RBT were evaluated. Chromosome segregation modes and number of euploid embryos were assessed in couples undergoing in vitro fertilization.

RESULTS

Patients with translocations involving an acrocentric chromosome have a higher risk of unbalanced gametes caused by a 3:1 segregation. Female RBT patients have a statistically higher risk of aneuploidy due to an interchromosomal effect. The rate of euploid embryos is low due to meiosis I malsegregation of RBT, meiosis II nondisjunction, additional whole chromosome or segmental aneusomies. RBT patients with RPL have a higher rate of miscarriage of euploid fetuses with RBT.

CONCLUSION

Chromosome-specific factors, female gender, age, and history of RPL are the risk elements influencing pregnancy and in vitro fertilization success in RBT patients. Chromosomal microarray analysis of POC is necessary to provide an accurate and timely diagnosis for patients with adverse reproductive outcomes.