Miscarriage Products Research Articles

Micro-CT and high-field MRI for studying very early post-mortem human fetal anatomy at 8weeks of gestation.

This study involved very early post-mortem (PM) examination of human fetal anatomy at 8weeks of gestation (WG) using whole-body multimodal micro-imaging: micro-CT and high-field MRI (HF-MRI). We discuss the potential place of this imaging in early first-trimester virtual autopsy. We performed micro-CT after different contrast-bath protocols including diffusible iodine-based contrast-enhanced (dice) and HF-MRI with a 9.4T machine with qualitative and quantitative evaluation and obtained histological sections. Nine fetuses were included: the crown-rump length was 10-24mm and corresponded to 7 and 9 WG according to the Robinson formula. The Carnegie stages were 17-21. Dice micro-CT and HF-MRI presented high signal to noise ratio, >5, according to the Rose criterion, and for allowed anatomical phenotyping in these specimens. Imaging did not alter the histology, allowing immunostaining and pathological examination. PM non-destructive whole-body multimodal micro-imaging: dice micro-CT and HF-MRI allows for PM human fetal anatomy study as early as 8 WG. It paves the way to virtual autopsy in the very early first trimester. Obtaining a precision phenotype, even regarding miscarriage products, allows a reverse phenotyping to select variants of interest in genome-wide analysis, offering potential genetic counseling for bereaved parents.

Whole exome sequencing in unexplained recurrent miscarriage families identified novel pathogenic genetic causes of euploid miscarriage.

Can whole exome sequencing (WES) followed by trio bioinformatics analysis identify novel pathogenic genetic causes of first trimester euploid miscarriage? We identified genetic variants in six candidate genes that indicated plausible underlying causes of first-trimester euploid miscarriage. Previous studies have identified several monogenic causes of Mendelian inheritance in euploid miscarriages. However, most of these studies are without trio analyses and lack cellular and animal models to validate the functional effect of putative pathogenic variants. Eight unexplained recurrent miscarriage (URM) couples and corresponding euploid miscarriages were included in our study for whole genome sequencing (WGS) and WES followed by trio bioinformatics analysis. Knock-in mice with Rry2 and Plxnb2 variants and immortalized human trophoblasts were utilized for functional study. Additional 113 unexplained miscarriages were included to identify the mutation prevalence of specific genes by multiplex PCR. Whole blood from URM couples and their <13 weeks gestation miscarriage products were both collected for WES, and all variants in selected genes were verified by Sanger sequencing. Different stage C57BL/6J wild-type mouse embryos were collected for immunofluorescence. Ryr2N1552S/+, Ryr2R137W/+, Plxnb2D1577E/+, and Plxnb2R465Q/+ point mutation mice were generated and backcrossed. Matrigel-coated transwell invasion assays and wound-healing assays were performed using HTR-8/SVneo cells transfected with PLXNB2 small-interfering RNA and negative control. Multiplex PCR was performed focusing on RYR2 and PLXNB2. Six novel candidate genes, including ATP2A2, NAP1L1, RYR2, NRK, PLXNB2, and SSPO, were identified. Immunofluorescence staining showed that ATP2A2, NAP1L1, RyR2, and PLXNB2 were widely expressed from the zygote to the blastocyst stage in mouse embryos. Although compound heterozygous mice with Rry2 and Plxnb2 variants did not show embryonic lethality, the number of pups per litter was significantly reduced when backcrossing Ryr2N1552S/+ ♂ with Ryr2R137W/+ ♀ or Plxnb2D1577E/+ ♂ with Plxnb2R465Q/+ ♀ (P < 0.05), which were in accordance with the sequencing results of Family 2 and Family 3, and the proportion of Ryr2N1552S/+ offspring was significantly lower when Ryr2N1552S/+ female mice were backcrossed with Ryr2R137W/+ male mice (P < 0.05). Moreover, siRNA-mediated PLXNB2 knockdown inhibited the migratory and invasive abilities of immortalized human trophoblasts. Besides, additional 10 variants of RYR2 and PLXNB2 were detected in 113 unexplained euploid miscarriages by multiplex PCR. The relatively small number of samples is a limitation of our study which may result in the identification of variants in unique candidate genes with no definitive although plausible causal effect. Larger cohorts are needed to replicate these findings and additional functional research is needed to confirm the pathogenic effects of these variants. Moreover, the sequencing coverage restricted the detection of low-level parental mosaic variants. For first-trimester euploid miscarriage, variants in unique genes may be underlying genetic etiologies and WES on trio could be an ideal model to identify potential genetic causes, which could facilitate individualized precise diagnostic and therapeutic regimens in the future. This study was supported by grants from the National Key Research and Development Program of China (2021YFC2700604), National Natural Science Foundation of China (31900492, 82101784, 82171648), Basic Science Center Program of the National Natural Science Foundation of China (31988101), Key Research and Development Program of Shandong Province (2021LCZX02), Natural Science Foundation of Shandong Province (ZR2020QH051), Natural Science Foundation of Jiangsu Province (BK20200223), Taishan Scholars Program for Young Experts of Shandong Province (tsqn201812154) and Young Scholars Program of Shandong University. The authors declare no conflicts of interest. N/A.

New insights regarding origin of monosomy occurrence in early developing embryos as demonstrated in preimplantation genetic testing

IntroductionAnalyses of miscarriage products indicate that the majority of aneuploidies in early developing embryos derive from errors occurring during maternal meiosis and the paternal contribution is less than 10%. Our aim was to assess the aneuploidy (mainly monosmies) frequencies at the earliest stages of embryo development, 3 days following fertilization during In vitro fertilization (IVF) treatments and to elucidate their parental origin. Later, we compared monosomies rates of day 3 to those of day 5 as demonstrated from Preimplantation Genetic Testing for Structural chromosomal Rearrangement (PGT-SR) results.MethodsFor a retrospective study, we collected data of 210 Preimplantation Genetic Testing for Monogenic Disorder (PGT-M) cycles performed between years 2008 and 2019.This study includes 2083 embryos, of 113 couples. It also included 432 embryos from 90 PGT-SR cycles of other 45 patients, carriers of balanced translocations. Defining the parental origin of aneuploidy in cleavage stage embryos was based on haplotypes analysis of at least six informative markers flanking the analyzed gene. For comprehensive chromosomal screening (CCS), chromosomal microarray (CMA) and next generation sequencing (NGS) was used.ResultsWe inspected haplotype data of 40 genomic regions, flanking analyzed genes located on 9 different chromosomes.151 (7.2%) embryos presented numerical alterations in the tested chromosomes. We found similar paternal and maternal contribution to monosomy at cleavage stage. We demonstrated paternal origin in 51.5% of the monosomy, and maternal origin in 48.5% of the monosomies cases.ConclusionIn our study, we found equal parental contribution to monosomies in cleavage-stage embryos. Comparison to CCS analyses of PGT-SR patients revealed a lower rate of monosomy per chromosome in embryos at day 5 of development. This is in contrast to the maternal dominancy described in studies of early miscarriage. Mitotic errors and paternal involvement in chemical pregnancies and IVF failure should be re-evaluated. Our results show monosomies are relatively common and may play a role in early development of ART embryos.

O-235 ERICA (Embryo Ranking Intelligent Classification Assistant) AI predicts miscarriage in poorly ranked embryos from one static, non-invasive embryo image assessment

Abstract Study question Does ERICA’s prognosis ranking based on ploidy, predict early miscarriage following positive biochemical pregnancy test? Summary answer The lower ERICA grades embryos, the higher the likelihood of early miscarriage, irrespective of age group. What is known already The vast majority of early miscarriages are due to aneuploidy, but preimplantation genetic testing for aneuploidy (PGTA) is potentially invasive, expensive, time-consuming and usually necessitates cryopreservation. Current methods for embryo selection based on morphology and morphokinetics are poorly correlated with ploidy. ERICA is a deep-learning non-invasive tool for embryo ranking, trained to identify ploidy, and has previously been shown to be similar or better than experienced embryologists in assessing implantation potential. AI-based tools capable of embryo ranking and assessment could help save laboratory time and costs, avoiding risk to embryos from invasive techniques. Study design, size, duration Retrospective analysis of 599 blastocysts transferred over 12 months in which ERICA was used to assist embryologists during the embryo selection process. ERICA’s prognosis based on ploidy potential is presented as groups labelled as “optimal”, “good”, “fair”, or “poor”. Embryo transfers (ET) reaching biochemical pregnancy (beta-hCG ≥ 20iu) were considered for the study. Early pregnancy loss (EPL) was defined as a biochemical pregnancy failing to develop a gestational sac and/or failure to show heartbeat (FHR). Participants/materials, setting, methods ETs resulting in biochemical pregnancies at two IVF clinics were followed-up to FHR till 8 weeks gestation. EPLs were divided into groups according to the presence or absence of a pregnancy sac. ERICA’s suggested prognosis during the embryo selection process was tested against pregnancy outcomes. Further analysis of pregnancy outcomes and their relation to ERICA’s labels was also performed based on age groups. Z-test for two proportions was used to assess statistical significance. Main results and the role of chance 506 ETs were performed for 599 embryos (mean 1.2 embryos), from which 285 resulted in positive pregnancy tests (56.3%). Thirty-one (10.9%) EPLs happened before the identification of a gestational sac (GS). Ten pregnancies failed to develop FHR after initial GS identification (3.9%), for an overall EPL of 14.4%. The average age in this group was 35.4 years. When evaluated using ERICA’s labels “optimal”, “good”, “fair, and “poor”, chances of miscarriage before GS were 8.9% (8/89); 14.1% (11/78); 18.5% (5/27); and 18.7% (9/48) respectively, where denominator represents total number within a label (i.e. EPL/n). When including all EPLs, chances of miscarriage according to the same labels were 11.2%; 17.9%; 22.2%; and 22.9% respectively. ERICA’s performance to anticipate the risk of EPL showed statistical significance when the optimal label was compared against all other labels (Z -1.786, p &amp;lt; 0.05), and against the poor prognosis label (Z=-1.653, p &amp;lt; 0.05). After stratifying the dataset according to age groups, increasing miscarriage rates were maintained as ERICA’s prognosis for an embryo worsened, regardless of age groups. The most notable performance was for ≤35-year-olds, where embryos ranked as optimal had an EPL rate of 14.3% in contrast to lowest ranked embryos having a 33.3% EPL rate. Limitations, reasons for caution The retrospective nature of this study along with its sample-size might limit the reach of our conclusions, in particular for older patients. The results we present must still be confirmed prospectively, and on a larger dataset. Wider implications of the findings Most EPLs are attributed to genetic factors, hence ERICA’s training for embryo ranking was based on ploidy. We conclude that ERICA’s AI is able to identify embryos at a higher risk of EPL non-invasively. Cytogenetic studies from products of miscarriage would help to confirm the hypothesis. Trial registration number Not applicable

Identifying the causes of recurrent pregnancy loss in consanguineous couples using whole exome sequencing on the products of miscarriage with no chromosomal abnormalities

Recurrent miscarriages occur in about 5% of couples trying to conceive. In the past decade, the products of miscarriage have been studied using array comparative genomic hybridization (a-CGH). Within the last decade, an association has been proposed between miscarriages and single or multigenic changes, introducing the possibility of detecting other underlying genetic factors by whole exome sequencing (WES). We performed a-CGH on the products of miscarriage from 1625 Iranian women in consanguineous or non-consanguineous marriages. WES was carried out on DNA extracted from the products of miscarriage from 20 Iranian women in consanguineous marriages and with earlier normal genetic testing. Using a-CGH, a statistically significant difference was detected between the frequency of imbalances in related vs. unrelated couples (P < 0.001). WES positively identified relevant alterations in 11 genes in 65% of cases. In 45% of cases, we were able to classify these variants as pathogenic or likely pathogenic, according to the American College of Medical Genetics and Genomics guidelines, while in the remainder, the variants were classified as of unknown significance. To the best of our knowledge, our study is the first to employ WES on the products of miscarriage in consanguineous families with recurrent miscarriages regardless of the presence of fetal abnormalities. We propose that WES can be helpful in making a diagnosis of lethal disorders in consanguineous couples after prior genetic testing.

Seroprevalence of neosporosis in stray adult dogs in Chalkidiki, Northern Greece

Despite the importance of N. caninum in veterinary medicine, knowledge on the prevalence of this parasitosis in dogs is limited in some countries. The aim of this study was to assess the prevalence of canine neosporosis in dogs in Chalkidiki, Northern Greece. This prospective study was conducted between January 2018 and December 2019 in stray dogs aged ≥6 months old. Blood samples were collected by venipuncture before the female and male dogs underwent the spay and castration procedures, respectively. The indirect enzyme-linked immunosorbent assay (ELISA) was used to screen dogs for the presence of IgG antibodies against N. caninum . Of 511 dogs included in this study, 39 (7.63%) were positive for IgG antibodies against N. caninum . Of all the dogs, 221 were males and 290 females, with positive results for IgG antibodies found in 16 (7.24%) males and 23 (7.93%) females. Because of their free ranging, stray adult dogs, in addition to ingestion of sporulated oocysts from the environment, they can have direct access to ingest tissue cysts originating from miscarriage products of cattle abortions or consumption of row meat of other intermediate hosts. Preventive measures should be developed and implemented to break the domestic cycle between dogs and bovine. We want to highlight the importance of regional reporting of neosporosis prevalence and control measures by veterinarians and veterinary authorities to farmers and public, in order to avoid this disease’s spread.

Copy number variations in miscarriage products and their relationship with consanguinity and recurrent miscarriage in individuals with normal karyotypes

Copy number variations in miscarriage products and their relationship with consanguinity and recurrent miscarriage in individuals with normal karyotypes

Pregnancy outcomes of Q fever: prospective follow-up study on Reunion island

BackgroundQ fever has been associated with perinatal complications. We conducted a prospective follow-up study to assess both the incidence of adverse pregnancy outcomes (APOs) associated with Coxiella burnetii infection and the contribution of Q fever to APOs.MethodsBetween May 1 and October 31, 2013, within the regional perinatal health care centre of Saint Pierre, Reunion island, we investigated unexplained miscarriages, stillbirths, preterm births or small-for-gestational age children. Seropositivity for C. burnetii antibodies was defined using indirect immunofluorescence for a phase 2 IgG titre ≥1:64. Acute Q fever was defined for a high phase 2 IgG titre ≥1:256 (compatible with recent or active infection) or the detection of C. burnetii genome in miscarriage products and placentas. Incidence rate ratios (IRR) for Q fever related APOs (taken as a composite outcome or individually) were assessed using Poisson regression models for dichotomous outcomes controlling major confounders.ResultsOver a 6-month period, 179 pregnant women suspected or diagnosed with an APO were investigated for Q fever, of whom 118 met the definition for an APO. Of these, 19 were seropositive and 10 presented a profile indicative of an acute infection. For three women with an acute Q fever, the chronology between the onset of infection, the APO (2 miscarriages, 1 preterm birth) and the seroconversion suggested causality in the pathogenesis. The cumulative incidence of Q fever related APOs was estimated between 2.2‰ and 5.2‰, whether causality was required or not. Both C. burnetii exposure and acute Q fever were independently associated with APOs (IRR 1.55, 95% CI 1.31–1.84; IRR 1.47, 95% CI 1.15–1.89, respectively).ConclusionsIn the endemic context of Reunion island, acute Q fever may lead to APOs. To limit the burden of Q fever on reproduction, pregnant women should be kept away from farms and avoid direct contact with ruminants.

Application of chromosomal microarray analysis in products of miscarriage

BackgroundChromosomal abnormality is one of the major cause of spontaneous abortion. Most available guidelines suggest genetic testing after three miscarriages, which has been proved to be difficult to adhere to and somewhat of low cost-effectiveness. As chromosomal microarray analysis has been recommended to be applied on miscarriage products, we managed a retrospective study on our experience investigate the potential impact of this technique on previous guidelines and our present management on miscarried couples and products.ResultsOf the 405 products of conceptions, the overall detection rate of pathogenetic results was 55.3% (224/405), including 7.1% (16/224) copy number changes which could be missed by conventional karyotyping analysis. Of the 222 natural conception samples, abnormal genetic results were found in 126 cases (56.8%). The detection rate in the assistant reproductive treatment group was 53.6% (98/183). No significant difference was found between these two groups (p = 0.645, OR = 1.110 with 95% CI: 0.713–1.726). The detection rate was 53.2% (75/141) in 141 product-of-conceptions (POCs) of mothers with adverse pregnancy histories. Of the 264 POC samples of mothers without abnormal pregnancy histories, 56.4% (149/264) were genetically abnormal. The detection rate and maternal age between these two groups were all compatible.ConclusionsChromosomal microarray testing should be referred to couples at their first miscarriage regardless of the way how they get pregnant.

Fetal HLA-G alleles and their effect on miscarriage.

Immunosuppression at the feto-maternal interface is crucial for a successful pregnancy outcome. Human leukocyte antigen-G (HLA-G) seems to be a major contributor to fetal tolerance. The HLA-G expression is seen in cytotrophoblasts and in maternal blood. Fetal HLA-G acts on decidual antigen-presenting cells (APCs), natural killers (NKs) and T cells. Recent findings revealed that defects in placentation and their consequences are associated with maternal HLA-G variants and their expression levels. The objective of this article is to investigate the relationship between fetal HLA-G alleles and miscarriage, which has not been investigated to date. The present study includes 204 recurrent miscarriage (RM) cases who were admitted to our clinic between 2012 and 2016. Twenty-eight miscarriage products without maternal cell contamination and any known pathology were analyzed by HLA-G typing. In addition, 3' untranslated region (UTR) 14-base pair (bp) insertion/deletion polymorphism was also investigated by Sanger sequencing. For our population, the most frequent HLA-G type was G*01:01, both in the study group (30.3%) and in the control group (47%). The study revealed that the G*01:04 allele was significantly associated with miscarriage (p = 0.007). The 3' UTR 14bp deletion was more frequent in the miscarriage group, but there was no significant correlation. HLA-G alleles seem to be related with miscarriage and should be considered in RM cases.

QF-PCR and MLPA: a reliable molecular system to detect chromosomal alterations in miscarriages

The aim of this study was to assess the efficacy of the quantitative fluorescent-polymerase chain reaction (QF-PCR) and multiplex ligation-dependent probe amplification (MLPA) combined system to detect chromosome alterations in miscarriage products, as an alternative to conventional cytogenetic testing. This study was conducted between 2011 and 2015 on 264 samples, analyzed using the combined system: QF-PCR/MLPA. This approach first analyzed miscarriage products for chromosomes 13, 18, 21, X and Y, using QF-PCR analysis; in case of ovular fragments, an analysis of maternal DNA was carried out in order to establish the origin of material. Whenever fetal origin was determined, MLPA analysis on the subtelomeric regions was car- ried out. On 264 miscarriages analyzed, 229 were of fetal origin and produced the following results: 53.7% normal and 46.3% pathological. Of the latter, 74.4% were autosomal aneuploidies, 10.4% triploidies, 8.5% sex chromosomal aneuploidies, 3.7% structural alterations, and 2.7% multiple aneuploidies. Results from QF-PCR were obtained from all samples, whereas unambiguous MLPA re- sults were obtained in about 90% of all cases. This approach results being highly effective for examining all chromosome aneuploidies, triploidies, as well as structural unbalanced alterations in the subtelomeric regions.

Efficient and cost-effective genetic analysis of products of conception and fetal tissues using a QF-PCR/array CGH strategy; five years of data

BackgroundTraditional testing of miscarriage products involved culture of tissue followed by G-banded chromosome analysis; this approach has a high failure rate, is labour intensive and has a resolution of around 10 Mb. G-banded chromosome analysis has been replaced by molecular techniques in some laboratories; we previously introduced a QF-PCR/MLPA testing strategy in 2007. To improve diagnostic yield and efficiency we have now updated our testing strategy to a more comprehensive QF-PCR assay followed by array CGH. Here we describe the results from the last 5 years of service.MethodsFetal tissue samples and products of conception were tested using QF-PCR which will detect aneuploidy for chromosomes 13, 14, 15, 16, 18, 21, 22, X and Y. Samples that were normal were then tested by aCGH and all imbalance >1Mb and fully penetrant clinically significant imbalance <1Mb was reported.ResultsQF-PCR analysis identified aneuploidy/triploidy in 25.6% of samples. aCGH analysis detected imbalance in a further 9.6% of samples; this included 1.8% with submicroscopic imbalance and 0.5% of uncertain clinical significance. This approach has a failure rate of 1.4%, compared to 30% for G-banded chromosome analysis.ConclusionsThis efficient QF-PCR/aCGH strategy has a lower failure rate and higher diagnostic yield than karyotype or MLPA strategies; both findings are welcome developments for couples with recurrent miscarriage.

Chromosomal microarray analysis of miscarriage products in recurrent pregnancy loss

Our objective was to determine the incidence of chromosomal aberrations detected by a newly introduced chromosomal microarray (CMA) technology based test, in aborted fetal and placental tissue from women with unexplained recurrent pregnancy loss (RPL).

First-trimester spontaneous pregnancy loss - molecular analysis using multiplex ligation-dependent probe amplification.

Spontaneous miscarriages are the most frequent complications of pregnancy and, in at least half of cases, are caused by chromosomal abnormalities, mainly aneuploidies. We present the preliminary results of the implementation of multiplex ligation-dependent probe amplification (MLPA) in the detection of chromosomal aberrations in the tissue derived from first-trimester miscarriage and evaluate the limitations and requirements of the method. We studied 181 MLPA analyses with subtelomeric and subcentromeric probe kits for all chromosomes (SALSA P070 and SALSA P181) performed on the first-trimester spontaneous miscarriage products in our Department of Genetics between September 2012 and December 2014. Conclusive MLPA results were obtained in 97.2% of samples. Chromosomal aberrations were detected in 40.3% of samples: 61.8% samples of good quality and 12.6% samples of poor quality (p < 0.001). The normal female karyotype was detected in 14.7% of good quality samples and 84.8% of poor quality samples (p < 0.001). MLPA is a useful tool for the detection of chromosomal aberrations in first-trimester miscarriage products. However, the tissue has to be well prepared before testing and the results 46,XX should be interpreted with caution.

Prenatal BoBsTM in the cytogenetic analysis of products of spontaneous miscarriage

Fifty percent of spontaneous miscarriages (SMs) are attributed to chromosomal abnormalities. Cytogenetic analysis is an important tool for patient counselling and assessment of the risk of recurrence in future pregnancies. Conventional karyotyping has been the gold standard for chromosomal investigation of products of conception (POC), but it has limitations due to sample maceration, culture failure and maternal cell contamination. Molecular cytogenetic approaches have therefore been developed and found valuable in the cytogenetic investigation of these samples. The Prenatal BoBsTM and KaryoLite BoBsTM, based on the newly developed BACs-on-BeadsTM technology, have been described as reliable tests for rapid detection of aneuploidies in prenatal and POC samples, respectively. To describe our clinical experience of routine screening of POC samples with Prenatal BoBsTM, the test used by our laboratory in France. Seventeen samples collected at the University Hospital of Sidi Bel Abbès (Western Algeria) and a further 60 from the University Hospital of Clermont-Ferrand (France) were analysed (19 chorionic villi from products of curettage, 12 placentas, 9 amniotic cells and 37 biopsy specimens). All were screened for the frequent aneuploidies (chromosomes 13, 18, 21, X and Y) in addition to nine microdeletion/microduplication syndrome regions by Prenatal BoBsTM. Standard karyotyping was performed on 51 samples, but failed in 38 cases. Prenatal BoBsTM identified one trisomy 21 and one deletion of 17p13.3. Furthermore, it provided a conclusive result in cases of culture failure (n=38) and in samples with macerated tissue (n=19). The overall failure rate was 11.4%. Prenatal BoBsTM is a promising technology that represents a fast, sensitive and robust alternative to routine screening for chromosomal abnormality in products of SM. Furthermore, it overcomes the limitations of conventional karyotyping and current molecular cytogenetic techniques.

Erratum to: Molecular analysis of miscarriage products using multiplex ligation-dependent probe amplification (MLPA): alternative to conventional karyotype analysis

Erratum to: Molecular analysis of miscarriage products using multiplex ligation-dependent probe amplification (MLPA): alternative to conventional karyotype analysis

Additional information from chromosomal microarray analysis (CMA) over conventional karyotyping when diagnosing chromosomal abnormalities in miscarriage: a systematic review and meta‐analysis

Approximately 50% of spontaneous miscarriages are associated with chromosome abnormalities. Identification of these karyotypic abnormalities helps to estimate recurrence risks in future pregnancies. Chromosomal microarray analysis (CMA) is transforming clinical cytogenetic practice with its ability to examine the human genome at increasingly high resolution. The aim of this study was to determine whether CMA testing on the products of conception following miscarriage provides better diagnostic information compared with conventional karyotyping. MEDLINE (from 1996 to December 2012), EMBASE (from 1974 to December 2012), and CINAHL (from 1996 to December 2012) databases were searched electronically. Studies were selected if CMA was used on products of conception following miscarriage, alongside conventional karyotyping. Nine papers were included in the systematic review and meta-analysis. All statistical analyses were performed using stata 11.0 (Stata Corp., College Station, TX, USA). There was agreement between CMA and karyotyping in 86.0% of cases (95% CI 77.0-96.0%). CMA detected 13% (95% CI 8.0-21.0) additional chromosome abnormalities over conventional full karyotyping. In addition, traditional, full karyotyping detected 3% (95% CI 1.0-10.0%) additional abnormalities over CMA. The incidence of a variant of unknown significance (VOUS) being detected was 2% (95% CI 1.0-10.0%). Compared with karyotyping, there appears to be an increased detection rate of chromosomal abnormalities when CMA is used to analyse the products of conception; however, some of these abnormalities are VOUS, and this information should be provided when counselling women following miscarriage and when taking consent for the analysis of miscarriage products by CMA.

High rate of microdeletions in miscarriage products of conception (POC) samples suggests role for preimplantation genetic diagnosis (PGD)

High rate of microdeletions in miscarriage products of conception (POC) samples suggests role for preimplantation genetic diagnosis (PGD)

Karyotyping couples experiencing recurrent miscarriage really is worth the cost

Sir, We thank Knibbs et al.1 for their response to our paper2 and believe that they are right to be concerned that an estimated cost of between £817,280 and £1,021,600 per unbalanced pregnancy might lead to a reduction in the karyotyping service for couples with recurrent miscarriage; one of the intentions of our brief audit2 was to raise exactly this possibility. This is not because we do not appreciate the real distress caused by recurrent miscarriages but, rather, because it was difficult to justify continuing to offer this test in the UK ‘free at the point of delivery’ at the same time as Commissioners were unable to fund major new developments in genetic testing with far higher detection rates and recurrence risks. We also appreciate that the identification of a balanced translocation is useful for the 2% of people tested who are carriers. However, we do question how continuing to offer a test for obstetric referrals that will give a normal result in 98% of tests, and a typical imbalance recurrence risk of between 10 and 25%, can be supported at the same time as Commissioners are unable to fund the testing of paediatric referrals of children with congenital abnormalities using array comparative genomic hybridisation with a detection rate of over 17%3 and a recurrence risk that is frequently as high as 50%. It should also be noted that alternative more cost-effective technologies are now available to test miscarriage products directly,4 thus ascertaining whether the pregnancy loss was the result of a chromosome imbalance and hence of a parental translocation. We acknowledged that ‘we have relied on laboratory records which may not include couples who choose not to avail themselves of prenatal diagnosis after a balanced translocation has been identified, couples who decide not to get pregnant or aborted early, or couples who had a stillbirth without prenatal diagnosis’ but question the claim by Knibbs et al. that this is a ‘potentially large proportion’. Knibbs et al. are also wrong to claim that we believed our large sample size negated what they term the ‘skew’ resulting from the exclusion of such alternative pregnancy outcomes in translocation carriers; our claim was only that testing 20 432 parents who had had miscarriages from four different regions made it unlikely that we had failed to ascertain many chromosomally unbalanced pregnancies as a result of couples moving out of the areas concerned and being lost to follow up. The wider implication of our audit is to question whether each new test (or assay) should always be offered free at the point of delivery or charged for. This is contrary to the spirit of the National Health Service in the UK but we believe that it is time to surrender the notion that everything can be provided free for ever and to embark on the hard task of deciding which tests and services are of such importance that they must be provided free at the point of delivery and, if necessary, which tests and services should be charged for in future. We hoped that our brief paper might stimulate others to produce a more detailed cost–benefit analysis, prompt professional bodies to review their best practice guidelines and contribute to the debate about how best to allocate dwindling resources at a time of technological advance, the demographic time bomb in the West and the spiralling costs of healthcare services.

Detection of enlarged yolk sac on early ultrasound is associated with adverse pregnancy outcomes

Pregnancies with mean yolk sac diameter>or=5 mm on early ultrasound require monitoring and counseling about a threefold increased risk for first-trimester loss independent of maternal risk factors such as age, body mass index, polycystic ovary syndrome, smoking, and diabetes. In addition, our study shows for the first time that enlarged yolk sac diameter may be associated with an increased risk of preterm delivery.