A Study on Balanced Chromosomal Translocations in Couples with Recurrent Pregnancy Loss

A Retrospective Analysis of Robertsonian Translocations from a Single Center in China

Robertsonian translocations (ROBs) are the most common structural chromosomal abnormalities in the general population, with an estimated incidence rate of 1/1000 births. In this study, we retrospectively analyzed the cases of ROBs from September 2015 to August 2022 and totally identified ROB carriers from 84,569 specimens karyotyped in a single accredited laboratory in China, including 189 cases of balanced ROBs and 3 of mosaic ROBs. Microsoft Excel and descriptive statistics were used to record and analyze the collected data. The male/female ratio of ROBs is 1/1.29, with der(13;14) and der(14;21) being the main karyotypes. Among the 192 patients, 7 were lost to follow-up, 82 had given birth, and 103 were childless (such as miscarriage, fetal chromosomal abnormalities, in vitro fertilization (IVF) failure, or divorce). A total of 44 amniocenteses were performed in 42 couples; ROB cases with natural pregnancies showed that the normal karyotype and balanced ROBs of fetal accounted for 66.67% (16/24), while the results of assisted pregnancies showed 90.00% (18/20). This study represents the largest collections of ROBs in Jiangxi population and reminder that the ROB carriers can achieve the ideal outcome for pregnancy with the appropriate genetic guidance and assisted reproductive technologies (ART).

Evaluation of chromosomal abnormalities in the postnatal cohort: A single-center study on 14,242 patients

BACKGROUND AND AIM

Chromosomal analysis is a laboratory technique used to examine the chromosomes of an individual, offering insights into chromosome numbers, structures, and arrangements to diagnose and comprehend genetic diseases. This retrospective study provides a comprehensive understanding of the distribution by indications in a large cohort of 14,242 patients and the frequency of chromosomal abnormalities in different clinical populations.

METHOD

The study examined various indications for karyotype evaluation, with recurrent pregnancy loss being the most common indication, followed by intellectual disability, dysmorphic features, congenital anomalies, and developmental delay.

RESULTS

The overall chromosomal abnormality rate was found to be 5.4%, with numerical abnormalities accounting for the majority of cases (61.7%). Trisomies, particularly trisomy 21, were the most frequent numerical abnormalities. In terms of structural abnormalities, inversions and translocations were the most commonly identified. The rates of chromosomal anomalies varied in specific indications such as amenorrhea, disorders of sex development, and Turner syndrome. The study also highlighted significant differences between males and females in the presence of chromosomal abnormalities across certain indications. Males exhibited a higher incidence of chromosomal abnormalities in cases of Down syndrome and infertility, whereas females showed higher abnormalities in terms of recurrent pregnancy loss.

CONCLUSION

While this study provides valuable insights into the frequency and distribution of chromosomal abnormalities, it has limitations, including its retrospective design and reliance on data from a single medical genetics department. Nevertheless, the findings emphasize the importance of karyotype analysis in diagnosing chromosomal disorders and providing appropriate management, while also pointing to potential gender-related variations in chromosomal abnormalities that warrant further investigation.

The embryo non-invasive pre-implantation diagnosis era: how far are we?

Advancements in assisted reproduction (AR) methodologies have allowed significant improvements in live birth rates of women who otherwise would not be able to conceive. One of the tools that allowed this improvement is the possibility of embryo selection based on genetic status, performed via preimplantation genetic testing (PGT). Even though the widespread use of PGT from TE biopsy helped to decrease the interval from the beginning of the AR intervention to pregnancy, especially in older patients, in AR, there are still many concerns about the application of this invasive methodology in all cycles. Therefore, recently, researchers started to study the use of cell free DNA (cfDNA) released by the blastocyst in its culture medium to perform PGT, in a method called non-invasive PGT (niPGT). The development of a niPGT would bring the diagnostics power of conventional PGT, but with the advantage of being potentially less harmful to the embryo. Its implementation in clinical practice, however, is under heavy discussion since there are many unknowns about the technique, such as the origin of the cfDNA or if this genetic material is a true representative of the actual ploidy status of the embryo. Available data indicates that there is high correspondence between results observed in TE biopsies and the ones observed from cfDNA, but these results are still contradictory and highly debatable. In the present review, the advantages and disadvantages of niPGT are presented and discussed in relation to tradition TE biopsy-based PGT. Furthermore, there are also presented some other possible non-invasive tools that could be applied in the selection of the best embryo, such as quantification of other molecules as quality biomarkers, or the use artificial intelligence (AI) to identify the best embryos based on morphological and/or morphokitetic parameters.

The effect of parental carrier of de novo mutated vs. inherited balanced reciprocal translocation on the chance of euploid embryos

OBJECTIVE

To evaluate whether the effect of de novo mutated balanced reciprocal translocation on the rate of euploid embryos varied from inherited balanced reciprocal translocation.

DESIGN

A retrospective cohort study compared the percentage of euploid embryo and proportion of patients with at least 1 euploid embryo between de novo mutated balanced reciprocal translocation (i.e., the group of de novo mutated carriers) and inherited balanced reciprocal translocation (i.e., the group of inherited carriers).

SETTING

An academic fertility center.

PATIENT(S)

A total of 413 couples with balanced reciprocal translocation (219 female carriers and 194 male carriers) who underwent their first cycle of preimplantation genetic testing for structural rearrangements were included.

INTERVENTION(S)

Carriers of balanced reciprocal translocation either de novo mutated or inherited.

MAIN OUTCOME MEASURE(S)

The percentage of euploid embryo and proportion of patients with at least 1 euploid embryo.

RESULT(S)

The carriers of the de novo mutated balanced reciprocal translocation had a lower percentage of euploid embryos (19.5% vs. 25.5%), and were less likely to have at least 1 euploid embryo (47.1% vs. 60.1%) compared with the carriers of the inherited balanced reciprocal translocation. In the male-carrier subgroup, the percentage of euploid embryos (16.7% vs. 26.7%) and proportion of patients with at least 1 euploid embryo (41.9% vs. 67.5%) were lower among the de novo mutated carriers than those among the inherited carriers. However, in the female-carrier subgroup, there was no statistically significant difference in the percentage of euploid embryos (22.4% vs. 24.4%) or the proportion of patients with at least 1 euploid embryo (52.3% vs. 53.7%) between the de novo mutated carriers and inherited carriers.

CONCLUSION(S)

The de novo mutated balanced reciprocal translocation was associated with a lower percentage of euploid embryos and lower chance of obtaining at least 1 euploid embryo than the inherited balanced reciprocal translocation.

The Association Between MTHFR C677T Gene Polymorphism and Repeated Pregnancy Loss in Arabic Countries: a Systematic Review and Meta-Analysis

The role of MTHFR C677T polymorphism in repeated pregnancy loss (RPL) among different populations has been studied with inconsistent results. The study objective was to determine the association between MTHFR C677T polymorphisms and RPL among Arab women. The review included all the available studies investigating the association between MTHFR C677T polymorphism and RPL from 2000 until now. The searched database included Cochrane, Trip, EMBASE, and Google Scholar. Two authors independently reviewed the searched articles for eligibility, judged their risk of bias, and extracted the characteristics of the studies. Review Manager 5.3 program was used for data analysis using odds ratio (OR) at a 95% confidence interval (CI). The study revealed a statistically significant difference between cases and controls regarding combined MTHFR C677T polymorphisms (OR = 1.50, 95% CI = 1.15-1.96), MTHFR C677T heterozygous (OR = 1.41, 95% CI = 1.08-1.83), and MTHFR C677T homozygous (OR = 4.19, 95% CI = 1.87-9.39). Considerable significant heterogeneity was recorded in the three analyses (P < 0.05). The review supported the hypothesis that MTHFR C677T mutation is considered a significant risk factor for RPL among Arab women.

First trimester recurrent pregnancy loss due to balanced chromosomal translocations in husband: A case report

Early pregnancy loss in a wanted pregnancy is stressful and frustrating to any couple. It becomes even more emotionally traumatic when it occurs repeatedly. Two or more of early pregnancy loss is known as recurrent pregnancy loss (RPL). RPL is a clinical challenge for physicians to unriddle. In this case report, we illustrate a case of a 40-year-old woman who experienced six recurrent first-trimester pregnancy losses. After the third pregnancy loss, initial maternal blood investigations were done, and the results were normal. After the fifth miscarriage, both partners’ blood was tested for the cytogenetic study, and her cytogenetic analysis revealed a normal karyotype. However, the paternal showed balanced translocation 46, XY, t(6;13) (q13;14.1) with a balanced translocation between the long arm of chromosome 6 at position 6q13 and the long arm of chromosome 13 at position 13q14.1. When the initial blood investigation is considered normal, a chromosomal study is one of important etiological investigation in couples with 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.

The spectrum of chromosomal translocations in the Arab world: ethnic-specific chromosomal translocations and their relevance to diseases

Chromosomal translocations (CTs) are the most common type of structural chromosomal abnormalities in humans. CTs have been reported in several studies in the Arab world, but the frequency and spectrum of these translocations are not well characterized. The aim of this study is to conduct a systematic review to estimate the frequency and spectrum of CTs in the 22 Arab countries. Four literature databases were searched: PubMed, Science Direct, Scopus, and Web of Science, from the time of inception until July 2021. A combination of broad search terms was used to collect all possible CTs reported in the Arab world. In addition to the literature databases, all captured CTs were searched in three chromosomal rearrangement databases (Mitelman Database, CytoD 1.0 Database, and the Atlas of Genetics and Cytogenetics in Oncology and Hematology), along with PubMed and Google Scholar, to check whether the CTs are unique to the Arabs or shared between Arabs and non-Arabs. A total of 9,053 titles and abstracts were screened, of which 168 studies met our inclusion criteria, and 378 CTs were identified in 15 Arab countries, of which 57 CTs were unique to Arab patients. Approximately 89% of the identified CTs involved autosomal chromosomes. Three CTs, t(9;22), t(13;14), and t(14;18), showed the highest frequency, which were associated with hematological malignancies, recurrent pregnancy loss, and follicular lymphoma, respectively. Complex CTs were commonly reported among Arabs, with a total of 44 CTs, of which 12 were unique to Arabs. This is the first study to focus on the spectrum of CTs in the Arab world and compressively map the ethnic-specific CTs relevant to cancer. It seems that there is a distinctive genotype of Arabs with CTs, of which some manifested with unique clinical phenotypes. Although ethnic-specific CTs are highly relevant to disease mechanism, they are understudied and need to be thoroughly addressed.

Preimplantation Genetic Testing for Couples with Balanced Chromosomal Rearrangements

BACKGROUND

Chromosomal rearrangements play an important role in infertility. Carriers of chromosomal rearrangements have a lower chance of producing normal or balanced gametes due to abnormal segregation of chromosomes at meiosis, which leads to recurrent spontaneous abortions and infertility. Preimplantation genetic testing for structural chromosome rearrangements (PGT-SR) is offered to couples who have balanced chromosomal rearrangements in order to select embryos with a balanced karyotype prior to implantation, thereby increasing the chances of pregnancy. The purpose of the current study was to assess the outcomes of PGT-SR in patients carrying various balanced chromosomal rearrangements and to assess their clinical pregnancy outcome after in vitro fertilization (IVF).

METHODS

In this study, infertile couples with balanced chromosomal abnormalities undergoing PGT-SR were retrospectively analyzed at a single fertility center from January 2016 to December 2019.

RESULTS

PGT-SR was performed on 87 embryos from 22 couples in whom one partner carried a balanced translocation or an inversion. Fifty-seven (65.5%) of these embryos had unbalanced or sporadic aneuploidies, 30 (34.5%) embryos were normal or chromosomally balanced, which were then transferred in 18 couples. A higher rate of unbalanced translocations in comparison to sporadic aneuploidies was observed in couples with reciprocal translocation. The live birth rate per embryo transfer was found to be 66.6% (12/18).

CONCLUSION

PGT-SR is a useful tool in selecting normal or balanced embryos for transfer in IVF, which could lead to a pregnancy by reducing the chance of miscarriages due to chromosome aneuploidy in couples with balanced chromosomal rearrangements.

Chromosomal abnormalities of 19,000 couples with recurrent spontaneous abortions: a multicenter study

OBJECTIVE

To investigate the demographic data and karyotypes of 19,000 couples who experienced recurrent spontaneous abortion (RSA).

DESIGN

A cross-sectional study of 19,000 couples.

SETTING

Five hospitals.

PATIENT(S)

A total of 19,000 couples experiencing RSA.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Cytogenetic analysis of blood lymphocytes.

RESULT(S)

A total of 844 couples (4.44%) showed chromosomal aberrations in either partner. Females were more likely to have chromosomal aberrations. The mean age of females and males with chromosomal aberrations was younger than that of females and males without chromosomal aberrations. Interestingly, sex and age distribution varied significantly depending on the subtypes of chromosomal aberrations. We detected 324 balanced translocations, including 223 novel ones. They were distributed across all chromosomes; the frequency of balanced translocations decreased according to the numerical order of autosomes (strong negative correlation; r = -0.84). Individuals with balanced translocations were younger than other groups. All 58 inversions, including 25 novel ones, were detected in autosomes; the negative correlation also existed. Thirteen Robertsonian translocations, 5 deletions, and 3 duplications were detected. Six types of Turner variants, triple X mosaicism, and mosaic Down syndrome were detected in females; Klinefelter variants and mosaic XYY syndrome were detected in males. Marker chromosomes at various mosaic levels and 7 different complex chromosomal rearrangements were also observed.

CONCLUSION(S)

Patients who experienced RSA induced by chromosomal aberrations experienced miscarriages at a younger age. Significant correlations existed between the patients' age or sex and the subtypes of chromosomal aberrations. This study detected several chromosomal abnormalities associated with RSA, including various novel aberrations.

Cross-sectional study of chromosomal aberrations and immunologic factors in Iraqi couples with recurrent pregnancy loss

BACKGROUND

Parental chromosomal aberrations are important causes of recurrent pregnancy loss (RPL). Some immunological factors such as antiphospholipid antibodies and interleukin-6 (IL-6) also contribute to this complication. The aim of this study was to determine the frequency of chromosomal abnormalities and to evaluate some of the immunological factors in couples with RPL from different cities in Iraq.

METHODS

This study was conducted on 25 couples (50 individuals) who had more than two first trimester abortions in the past and 25 healthy females as controls. Karyotyping was performed on peripheral blood of all participants. Anticardiolipin (IgG and IgM), antiphosopholipid (IgG and IgM), lupus anticoagulant, and IL-6 were assayed. Data were analyzed using appropriate statistical tests.

RESULTS

Chromosomal abnormalities were found in 28.0% (n = 7/25) of RPL couples. Of these five (10.0%) were female and two (4.0%) were male. The types of structural abnormalities were as follows: 45, XX, t(21; 21); 45, XX, rob (14, 15); 46, XX, add (21) (p13); 46 XY, add (21)(p13); 46, XX, 21ps+; 46, XY, per inv (9) (p11q12) and 45, XX, t(13q, 13q). No chromosomal abnormalities were found in the control group. Also, no significant differences were found in the immunological parameters of the couples with RPL and the control group.

CONCLUSION

In this study, karyotyping revealed a high number of chromosomal abnormalities associated with the RPL in Iraqi couples. Since identification of genetic causes of miscarriage is important for genetic counseling and educating couples about the risk of future pregnancies, it is recommended that conventional karyotyping be investigated in patients with RPL.

A Case-Control Study on Chromosomal Anomalies in Parents Experiencing Repeated Spontaneous Abortions From Northern India

Objectives

Many women lose their fetuses through miscarriage due to a variety of causes. The incidence of three or more consecutive pregnancy losses is often classified as repeated spontaneous abortion (RSA) and is considered the most frustrating and complex area in reproductive medicine. Parental chromosomal abnormalities, underlying medical condition, heritable or acquired thrombophilias, immunologic abnormalities, infections, and environmental factors are reported to be possible etiologies responsible for RSA. Gametes with unbalanced chromosomes, which are formed when abnormalities exist in parent chromosomes, are one such cause and are responsible for about 50-60% of first-trimester pregnancy loss. This paper aims to identify whether there is an association between chromosomal anomalies in parents and RSA.

Method

A case-control study was performed on a total sample size of 600 individuals, including 150 couples with a history of RSA and 150 fertile couples as control. The participants were cytogenetically analyzed using G-banding. Associations between variables were tested using Chi-square and Fisher’s exact test (a p-value<0.05 was considered significant). Informed consent from participants and institutional ethical clearance was obtained before the research began.

Results

Chromosomal anomalies were detected in 21 individuals (7%) with a history of RSA. Female preponderance was observed with a female to male ratio of 2.5:1. Structural chromosomal aberrations (SCAs) were detected in 17 patients, with nine (53%) cases showing balanced reciprocal translocation (involving chromosomes 1,3,6,8,12,13,15,16,18,22 and X) and three (17.65%) cases of Robertsonian translocation (exclusively in males). Mosaicism was observed in four (19.05%) cases. A statistically significant positive association (p-value <0.05) was observed between the presence of parental chromosomal anomalies and RSA.

Conclusion

These results support an association between RSA and parental chromosomal abnormalities. Currently, clinicians treating cases of RSA face challenging clinical conditions. Identifying a cytogenetic cause for RSA may be of great help to clinicians who manage affected couples.

Advancing research on recurrent pregnancy loss: Overcoming obstacles and opportunities for translation

Recurrent pregnancy loss (RPL) is one of the most complex and challenging scenarios in reproductive medicine. New theories about the mechanisms behind RPL have recently emerged, highlighting the multifactorial nature of this serious pregnancy complication.  Unfortunately, these preclinical observations are rarely validated in the human scenario, where treatment remains ineffective and empirical. New technologies such as organoids, organ-on-a-chip, and 3D printing can be used to characterize the molecular cross talk between the uterine environment with its unique inflammatory cells and the developing embryo. Understanding the mechanisms behind RPL and identifying mediators and effectors and validating these targets for prevention and therapy in humans will have a profound impact on women's health.

Risk Factors Associated with Recurrent Pregnancy Loss and Outcome of Pre-Implantation Genetic Screening of Affected Couples

Background:

Recurrent pregnancy loss (RPL) is a multifactorial disorder which affects up to 5% of couples around the world. Several factors are considered to be involved in RPL; but, the etiology remains unexplained in 35-60% of cases. The aim of this study was to assess the frequency of risk factors associated with RPL in a group of our clinic clients, and their pre-implantation genetic screening (PGS) outcome.

Materials and Methods:

We designed a retrospective descriptive study among, 602 Iranian couples referred to the Royan Reproductive Clinic (Tehran-Iran) from 2006 to 2018. Their karyotyping test and PGS outcomes were analyzed. PGS had been applied by array comparative genomic hybridization (array-CGH) on embryos from these patients. Also, karyotyping test had been performed using standard cytogenetic techniques.

Results:

G-banding analysis revealed a frequency of 15.61% chromosomal abnormalities in RPL couples. Also, the reciprocal translocations were more frequent (33/1204 cases) compared to the other structural abnormalities. Pregnancy rate per embryo transferred were 50% with array-CGH approach.

Conclusion:

Our findings could confirm a positive correlation between chromosomal abnormalities and RPL rate. Applying PGS for the RPL couples, leads to improvement of pregnancy success rate.

Recurrent spontaneous abortion related to balanced translocation of chromosomes: two case reports

Background

Recurrent spontaneous abortion (RSA) is often idiopathic, but structural chromosomal abnormality is an important nosogenesis. Balanced translocations or inversions can lead to unbalanced gametes depending on the specific recombination and segregation patterns during meiosis. An unbalanced karyotype in the conceptus of a couple when one partner has a structural chromosomal abnormality may result in failure to implant, miscarriage, or ongoing pregnancy of a fetus with an unbalanced karyotype.

Case presentation

We report two rare Han cases of RSA associated with balanced translocation of chromosomes. In case 1, a women who had had four spontaneous abortions, the karyotype was 46, XX, t (4;7) (q31;q22). In case 2, a women who had two spontaneous abortions and one stillborn fetus, the karyotype was 46, XX, t (3;15) (q12;p11.2), inv (5) (P13q13). The abnormal karyotype was not found in other chromosomes.

Conclusions

It is very important that couples with more than two miscarriages be provided with chromosomal analysis. Referring couples for karyotyping will rule out or confirm possible hereditary etiology and the source of chromosomal abnormalities in recurrent miscarriages.

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.

Recurrent pregnancy loss

Recurrent pregnancy loss is a distressing pregnancy disorder experienced by ~2.5% of women trying to conceive. Recurrent pregnancy loss is defined as the failure of two or more clinically recognized pregnancies before 20-24 weeks of gestation and includes embryonic and fetal losses. The diagnosis of an early pregnancy loss is relatively straightforward, although progress in predicting and preventing recurrent pregnancy loss has been hampered by a lack of standardized definitions, the uncertainties surrounding the pathogenesis and the highly variable clinical presentation. The prognosis for couples with recurrent pregnancy loss is generally good, although the likelihood of a successful pregnancy depends on maternal age and the number of previous losses. Recurrent pregnancy loss can be caused by chromosomal errors, anatomical uterine defects, autoimmune disorders and endometrial dysfunction. Available treatments target the putative risk factors of pregnancy loss, although the effectiveness of many medical interventions is controversial. Regardless of the underlying aetiology, couples require accurate information on their chances of having a baby and appropriate support should be offered to reduce the psychological burden associated with multiple miscarriages. Future research must investigate the pathogenesis of recurrent pregnancy loss and evaluate novel diagnostic tests and treatments in adequately powered clinical trials.

Expectant management and live birth outcomes for male balanced-translocation carriers: Two case reports and a literature review

RATIONALE

Couples with male balanced-translocation carriers may experience recurrent pregnancy loss (RPL). Although the expectant management of RPL has developed over many years, genetic counseling for RPL couples with male balanced-translocation carriers remains challenging. Here, we describe the expectant management of 2 male carriers of balanced translocations.

PATIENT CONCERNS

A 32-year-old and a 28-year-old man presented at the clinic with diagnoses of infertility following spontaneous abortions by their wives.

DIAGNOSIS

Both patients had normal semen diagnosed by routine semen analysis and underwent cytogenetic diagnoses.

INTERVENTIONS

Following genetic counseling and informed consent, both couples voluntarily chose expectant management with natural conception.

OUTCOMES

One couple experienced 2 natural pregnancies, the first of which ended in spontaneous abortion and the second produced a phenotypically normal infant. The other couple's first pregnancy resulted in a fetus with a balanced translocation confirmed by amniocentesis and cytogenetic analysis.

LESSONS

Expectant management with natural conception may be an alternative to genetic counseling in male balanced-translocation carriers with RPL, especially those who are reluctant to undergo preimplantation diagnosis.

Study of Spectrum of Chromosomal Rearrangements in Recurrent Pregnancy Loss

Introduction

Recurrent pregnancy losses (RPLs) are seen in up to 15-20% of all clinically recognized pregnancies, 1-2% of women in general population. Repeated losses are seen in 5-10% of women. The prevalence of chromosomal rearrangements is 6.65% in couples with repeated pregnancy losses. Two to 4% of RPL are associated with parental balanced reciprocal and Robertsonian translocations.

Materials and Methods

The study was conducted at a tertiary care hospital in New Delhi, and in total, 204 couples with RPL enrolled in the study.

Results

In total, 4490 couples presented to the obstetric clinic, of which 204 (4.5%) couples had repeated pregnancy losses. Cytogenetic analysis was done in 198 couples. Out of total 198 patients, 14 patients (7.1%) had cytogenetic alterations. Most common aberrations observed were structural rearrangements, of which reciprocal translocations were more common. In our study cohort, all the couples had maternal age of ≤ 35 years and all the alterations were seen either in mother or in both parents.

Discussion

Our study highlights that cytogenetic alterations not only are common in first trimester miscarriages, but are an important event in miscarriages presenting at later period of gestation and in young mothers as well.

The type and prevalence of chromosomal abnormalities in couples with recurrent first trimester abortions: A Turkish retrospective study

OBJECTIVE

Chromosomal abnormalities are more common in the first trimester abortions. We aimed to investigate the types and prevalence of chromosomal abnormalities in couples with recurrent first trimester miscarriages in Sivas, Turkey.

MATERIALS AND MEDHODS

Three hundred couples (600 individuals) who had a story of recurrent abortion were included in the study. Chromosome analysis was performed after the preparation of lymphocyte culture with the standard method. Karyotype analyses were supported by FISH and aCGH studies.

RESULTS

Total 26 chromosome abnormalities (8.7%) were found in the couples (19 females and 7 males). Fifteen cases (57.7%) were structural anomalies and eleven cases (42.3%) were numerical chromosomal aberrations. We detected 5 balanced translocations (33.3%), 4 Robertsonian translocations (26.7%), 3 inversions (20%), 2 duplications (13.3%) and one deletion (6.7%) among the structural anomalies. Mosaic monosomy X in five cases (45.4%), the combination of mosaic monosomy-trisomy X in three cases (27.3%), the combination of mosaic monosomy-trisomy and tetrasomy X in two cases (18.2%) and mosaic pentasomy X in only one individual (9.1%) were encountered as numerical chromosome aberrations. 19 cases had heterochromatic changes or other chromosomal variations (satellite increments and inv9).

CONCLUSION

Chromosome analysis in couples with recurrent miscarriage is necessary for possible preimplantation genetic diagnosis. As well as numerical and structural chromosome abnormalities, some chromosomal variations (heterochromatin and satellite increments etc.) may also contribute to recurrent miscarriages. Numerical chromosomal abnormalities are often associated with sex chromosomes and usually seen in females.