The accuracy of cell-free DNA screening for fetal segmental copy number variants: A systematic review and meta-analysis.

BACKGROUND: The performance of cell-free DNA (cfDNA) screening for microscopic copy number variants (CNVs) is unclear. OBJECTIVES: This was a systematic review and meta-analysis to investigate the sensitivity, specificity and positive predictive value (PPV) of cfDNA screening for CNVs. SEARCH STRATEGY: Articles published in EMBASE, PubMed or Web of Science before November 2022 were screened for inclusion. This protocol was registered with PROSPERO (23 March 2021, CRD42021250849) prior to initiation. SELECTION CRITERIA: Articles published in English, detailing diagnostic outcomes for at least 10 high-risk CNV results with cfDNA were considered for inclusion. DATA COLLECTION AND ANALYSIS: The PPV was calculated and pooled with random-effects models for double-arcsine transformed proportions, using cases with diagnostic confirmation. Overall sensitivity, specificity and a summary receiver-operating characteristics (ROC) curve were calculated using bivariate models. The risk of bias was assessed using QUADAS-2. MAIN RESULTS: In all, 63 articles were included in the final analysis, detailing 1 591 459 cfDNA results. The pooled PPV was 37.5% (95% confidence interval [CI] 30.6-44.8), with substantial statistical heterogeneity (I2  = 93.9%). Bivariate meta-analysis estimated sensitivity and specificity to be 77.4% (95% CI 65.7-86.0) and 99.4% (95% CI 98.0-99.8), respectively, with an area under the summary ROC curve of 0.947 (95% CI 0.776-0.984). CONCLUSIONS: Approximately one-third of women who screen high-risk for CNVs with cfDNA will have an affected fetus. This value is of importance for screening counselling.

The accuracy of prenatal cell-free DNA screening for sex chromosome abnormalities: A systematic review and meta-analysis.

OBJECTIVE: Although cell-free DNA screening for sex chromosome abnormalities is increasingly used in clinical practice, its diagnostic accuracy and clinical utility remain unclear. This systematic review and meta-analysis aimed to determine the performance of cell-free DNA in the detection of sex chromosome abnormalities. DATA SOURCES: Medline and PubMed, Embase, and Web of Science were searched from inception to January 2022 for articles relating to cell-free DNA screening for sex chromosome abnormalities. STUDY ELIGIBILITY CRITERIA: Original articles, randomized control trials, conference abstracts, cohort and case-control studies, and case series with more than 10 cases with diagnostic confirmation were considered for inclusion. METHODS: Quality assessment of each included publication was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. The positive predictive value was calculated as the proportion of true positive cases among those who tested positive and underwent diagnostic testing. Sensitivity and specificity were pooled, and a summary receiver operating characteristic curve was produced using bivariate models that included studies that had diagnostic confirmation for high- and low-risk women. RESULTS: The search identified 7553 results. Of these, 380 proceeded to the full-text screening, of which 94 articles were included in the meta-analysis with a total of 1,531,240 women tested. All studies reported a confirmatory genetic test. The pooled positive predictive value was 49.4% (95% confidence interval, 45.8-53.1). The pooled positive predictive value was 32.0% (95% confidence interval, 27.0%-37.3%) for monosomy X, 67.6% (95% confidence interval, 62.5%-72.5%) for XXY, 57.5% (95% confidence interval, 51.7%-63.1%) for XXX, and 70.9% (95% confidence interval, 63.9%-77.1%) for XYY. The pooled sensitivity and specificity of cell-free DNA for sex chromosome abnormalities were 94.1% (95% confidence interval, 90.8%-96.3%) and 99.5% (95% confidence interval, 99.0%-99.7%), respectively, with an area under the summary receiver operating characteristic curve of 0.934 (95% confidence interval, 0.907-0.989). CONCLUSION: Although the sensitivity and specificity of cell-free DNA for sex chromosome abnormalities are high, the positive predictive value was approximately 50%. The positive predictive value was higher for sex chromosome abnormalities with a supernumerary Y chromosome and lower for monosomy X. Clinicians should inform couples about these findings when offering cell-free DNA for sex chromosome abnormalities.

The predictive value of prenatal cell-free DNA testing for rare autosomal trisomies: a systematic review and meta-analysis.

OBJECTIVE: The diagnostic accuracy of cell-free fetal DNA in screening for rare autosomal trisomies is uncertain. We conducted a systematic review and meta-analysis aiming to determine the predictive value of cell-free DNA in screening for rare autosomal trisomies. DATA SOURCES: PubMed, Embase, and Web of Science were searched from inception to January 2022. STUDY ELIGIBILITY CRITERIA: All studies that reported on the diagnostic accuracy of cell-free DNA in the detection of rare autosomal trisomies were included. Case series were included if they contained at least 10 cases with diagnostic test results or postnatal genetic testing. METHODS: Study appraisal was completed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Statistical analysis was performed using random-effects meta-analysis of double-arcsine transformed proportions of confirmed results in the fetus out of the positive tests to obtain a pooled estimate of the positive predictive value. RESULTS: The search identified 7553 studies, of which 1852 were duplicates. After screening 5701 titles and abstracts, 380 studies proceeded to the full-text screen; 206 articles were retrieved for data extraction, of which another 175 articles were excluded. A total of 31 studies, with a total of 1703 women were included for analysis. The pooled positive predictive value of cell-free DNA for the diagnosis of rare autosomal trisomies was 11.46% (95% confidence interval, 7.80-15.65). Statistical heterogeneity was high (I2=82%). Sensitivity analysis restricted to 5 studies at low risk of bias demonstrated a pooled positive predictive value of 9.13% (95% confidence interval, 2.49-18.76). There were insufficient data to provide accurate ascertainment of sensitivity and specificity because most studies only offered confirmatory tests to women with high-risk results. CONCLUSION: The positive predictive value of cell-free DNA in diagnosing rare autosomal trisomies is approximately 11%. Clinicians should provide this information when offering cell-free DNA for screening of conditions outside of common autosomal trisomies.

Women's experience of induction of labor using PGE2 as an inpatient versus balloon catheter as an outpatient.

OBJECTIVE: Induction of labor (IOL) typically involves cervical priming in an inpatient setting. Outpatient cervical priming may be a safe and cost-effective alternative. However, little is known about women's preference and the impact of outpatient cervical priming on their healthcare experience. The objective was to compare women's healthcare experiences following IOL using a balloon catheter and going home, versus prostaglandin (PG) and remaining an inpatient. STUDY DESIGN: A randomized controlled trial was undertaken across eight Australian maternity hospitals. Between September 2015 and October 2018, 695 women with uncomplicated term singleton pregnancies were randomized. Of these, 215 and 233 women in the balloon-outpatient and PG-inpatient groups, respectively, received the allocated intervention. The PG group received Dinoprostone gel or controlled-release tape. The balloon group had a double-balloon catheter inserted and went home. Experiential and quality-of-life outcomes were measured via written questionnaire after birth. The primary outcome was a composite neonatal measure. Women's healthcare experience, health-state (EQ-5D-3 L) and pain scores are reported here. RESULTS: Questionnaire data were available for 366 (81.7 %) women enrolled who received their treatment allocation. More women in the balloon-outpatient group reported they would choose IOL next pregnancy (49.2 % vs 38.4 %; p = 0.037) and desire the same method (72.4 % vs 61.1 %; p = 0.022). The balloon-outpatient group experienced higher pain scores at the start of IOL (median (IQR) 3(2-5) vs 2(1-4); p = 0.002) but lower scores at time of rupture of membranes (3(1-5) vs 4(2-6); p = 0.007). The EQ-5D-3 L health-utility index did not differ significantly between the groups (0.77 vs 0.78; p = 0.899). CONCLUSIONS: Women report similar healthcare experiences following balloon-outpatient compared to PG-impatient IOL, but are more likely to desire the same method next pregnancy if IOL is required. If both options are available, then differences in experience should be shared with women, alongside differences in clinical outcomes as part of their decision-making process.

Retzius space haematoma as a rare cause of concealed retroperitoneal postpartum haemorrhage following spontaneous vaginal delivery.

A 34-year-old woman presented to hospital in shock 8 hours after a spontaneous home vaginal delivery. She is a known carrier of haemophilia A. Examination revealed a tender but firm, central and contracted uterus. There was a small second-degree perineal tear which was not actively bleeding and no other trauma or bleeding visualised in the vault or cervix. Bedside ultrasound showed a large 1 L blood clot anterior to the empty uterus. Exploratory laparotomy was performed which revealed a haematoma in the Retzius space with extension beneath the anterior serosa of the bladder, through the left broad ligament and into the retroperitoneal space. Bleeding from the Santorini plexus was controlled with haemostatic sutures, reinforced with FLOSEAL and intra-abdominal packing. A CT angiogram and relook laparotomy the following day confirmed haemostasis and facilitated removal of intra-abdominal packs. This case demonstrates a very rare cause of postpartum retroperitoneal haemorrhage.