Screening for trisomies by cfDNA testing of maternal blood in twin pregnancy: update of The Fetal Medicine Foundation results and meta-analysis

OBJECTIVES

To report on the routine clinical implementation of cell-free DNA (cfDNA) analysis of maternal blood for trisomies 21, 18 and 13 in twin pregnancy and to define the performance of the test by combining our results with those identified in a systematic review of the literature.

METHODS

The data for the prospective study were derived from screening for trisomies 21, 18 and 13 in twin pregnancies at 10 + 0 to 14 + 1 weeks' gestation. Two populations were included; first, self-referred women to the Fetal Medicine Centre in London or Brugmann University Hospital in Brussels and, second, women selected for the cfDNA test after routine first-trimester combined testing at one of two National Health Service hospitals in England. This dataset was used to determine the performance of screening for the three trisomies. Search of MEDLINE, EMBASE, CENTRAL (The Cochrane Library), ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (ICTRP) was carried out to identify all peer-reviewed publications on clinical validation or implementation of maternal cfDNA testing for trisomies 21, 18 and 13 in twin pregnancy. A meta-analysis was then performed using our data and those in the studies identified by the literature search.

RESULTS

In our dataset of 997 twin pregnancies with a cfDNA result and known outcome, the test classified correctly 16 (94.1%) of the 17 cases of trisomy 21, nine (90.0%) of the 10 cases of trisomy 18, one (50.0%) of the two cases of trisomy 13 and 962 (99.4%) of the 968 cases without any of the three trisomies. The literature search identified seven relevant studies, excluding our previous papers because their data are included in the current study. In the combined populations of our study and the seven studies identified by the literature search, there were 56 trisomy-21 and 3718 non-trisomy-21 twin pregnancies; the pooled weighted detection rate (DR) and false-positive rate (FPR) were 98.2% (95% CI, 83.2-99.8%) and 0.05% (95% CI, 0.01-0.26%), respectively. In the combined total of 18 cases of trisomy 18 and 3143 non-trisomy-18 pregnancies, the pooled weighted DR and FPR were 88.9% (95% CI, 64.8-97.2%) and 0.03% (95% CI, 0.00-0.33%), respectively. For trisomy 13, there were only three affected cases and two (66.7%) of these were detected by the cfDNA test at a FPR of 0.19% (5/2569).

CONCLUSIONS

The performance of cfDNA testing for trisomy 21 in twin pregnancy is similar to that reported in singleton pregnancy and is superior to that of the first-trimester combined test or second-trimester biochemical testing. The number of cases of trisomies 18 and 13 is too small for accurate assessment of the predictive performance of the cfDNA test. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Analysis of cell-free DNA in maternal blood in screening for aneuploidies: updated meta-analysis

OBJECTIVES

To review clinical validation or implementation studies of maternal blood cell-free (cf) DNA analysis and define the performance of screening for fetal trisomies 21, 18 and 13 and sex chromosome aneuploidies (SCA).

METHODS

Searches of PubMed, EMBASE and The Cochrane Library were performed to identify all peer-reviewed articles on cfDNA testing in screening for aneuploidies between January 2011, when the first such study was published, and 31 December 2016. The inclusion criteria were peer-reviewed study reporting on clinical validation or implementation of maternal cfDNA testing in screening for aneuploidies, in which data on pregnancy outcome were provided for more than 85% of the study population. We excluded case-control studies, proof-of-principle articles and studies in which the laboratory scientists carrying out the tests were aware of fetal karyotype or pregnancy outcome. Pooled detection rates (DRs) and false-positive rates (FPRs) were calculated using bivariate random-effects regression models.

RESULTS

In total, 35 relevant studies were identified and these were used for the meta-analysis on the performance of cfDNA testing in screening for aneuploidies. These studies reported cfDNA results in relation to fetal karyotype from invasive testing or clinical outcome. In the combined total of 1963 cases of trisomy 21 and 223 932 non-trisomy 21 singleton pregnancies, the weighted pooled DR and FPR were 99.7% (95% CI, 99.1-99.9%) and 0.04% (95% CI, 0.02-0.07%), respectively. In a total of 563 cases of trisomy 18 and 222 013 non-trisomy 18 singleton pregnancies, the weighted pooled DR and FPR were 97.9% (95% CI, 94.9-99.1%) and 0.04% (95% CI, 0.03-0.07%), respectively. In a total of 119 cases of trisomy 13 and 212 883 non-trisomy 13 singleton pregnancies, the weighted pooled DR and FPR were 99.0% (95% CI, 65.8-100%) and 0.04% (95% CI, 0.02-0.07%), respectively. In a total of 36 cases of monosomy X and 7676 unaffected singleton pregnancies, the weighted pooled DR and FPR were 95.8% (95% CI, 70.3-99.5%) and 0.14% (95% CI, 0.05-0.38%), respectively. In a combined total of 17 cases of SCA other than monosomy X and 5400 unaffected singleton pregnancies, the weighted pooled DR and FPR were 100% (95% CI, 83.6-100%) and 0.004% (95% CI, 0.0-0.08%), respectively. For twin pregnancies, in a total of 24 cases of trisomy 21 and 1111 non-trisomy 21 cases, the DR was 100% (95% CI, 95.2-100%) and FPR was 0.0% (95% CI, 0.0-0.003%), respectively.

CONCLUSIONS

Screening by analysis of cfDNA in maternal blood in singleton pregnancies could detect > 99% of fetuses with trisomy 21, 98% of trisomy 18 and 99% of trisomy 13 at a combined FPR of 0.13%. The number of reported cases of SCA is too small for accurate assessment of performance of screening. In twin pregnancies, performance of screening for trisomy 21 is encouraging but the number of cases reported is small. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Diagnostic accuracy of cancer antigen 125 for endometriosis: a systematic review and meta-analysis

BACKGROUND

The development of a non-invasive and accurate diagnostic biomarker for endometriosis is urgently needed.

OBJECTIVE

Evaluate the diagnostic accuracy of serum cancer antigen 125 (CA 125) for endometriosis.

SEARCH STRATEGY

We searched EMBASE, MEDLINE, and Web of Science from inception to January 2016.

SELECTION CRITERIA

Diagnostic accuracy studies of serum CA 125 (index test) for histologically confirmed endometriosis (reference standard) were included.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, extracted study characteristics and data. Methodological quality was assessed using Quality Assessment of Comparative Diagnostic Accuracy Studies (QUADAS-2) checklist.

MAIN RESULTS

Twenty-two studies (16 cohort, six case-control), 3626 participants, were identified. Bivariate hierarchical models were used to pool accuracy data of 14 studies (2920 participants) using CA 125 ≥ 30 units/ml. Pooled specificity was 93% (95% CI 89-95%) and sensitivity 52% (95% CI 38-66%). CA 125 was significantly more sensitive for the diagnosis of moderate or severe endometriosis compared with minimal disease (63%, 95% CI 47-77% versus 24%, 95%CI 19-32%, P-value = 0.001).

CONCLUSIONS

CA 125 performs well as a rule-in test facilitating expedited diagnosis and ensuring investigation and treatment can be confidently tailored for the management of endometriosis. Unfortunately, a negative test, CA 125 < 30 units/ml, is unable to rule out endometriosis.

TWEETABLE ABSTRACT

Blood test CA 125: a rule-in test for the diagnosis of women presenting with symptoms of endometriosis.

First-trimester uterine artery Doppler and adverse pregnancy outcome: a meta-analysis involving 55,974 women

OBJECTIVES

To determine the accuracy with which uterine artery Doppler in the first trimester of pregnancy predicts pre-eclampsia and fetal growth restriction, particularly early-onset disease.

METHODS

We searched MEDLINE (1951-2012), EMBASE (1980-2012) and the Cochrane Library (2012) for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of first-trimester uterine artery Doppler to predict adverse pregnancy outcome and performed data extraction to construct 2 × 2 tables. We synthesized sensitivity and specificity for various Doppler indices using a bivariate random-effects model.

RESULTS

From 1866 citations, we identified 18 studies (55,974 women). The sensitivity and specificity of abnormal uterine artery flow velocity waveform (FVW) in the prediction of early-onset pre-eclampsia were 47.8% (95% CI: 39.0-56.8) and 92.1% (95% CI: 88.6-94.6), and in the prediction of early-onset fetal growth restriction were 39.2% (95% CI: 26.3-53.8) and 93.1% (95% CI: 90.6-95.0), respectively. The sensitivities for predicting any pre-eclampsia and fetal growth restriction were 26.4% (95% CI: 22.5-30.8) and 15.4% (95% CI: 12.4-18.9), respectively, and the specificities were 93.4% (95% CI: 90.4-95.5%) and 93.3% (95% CI: 90.9-95.1), respectively. The number needed to treat (NNT) with aspirin to prevent one case of early-onset pre-eclampsia fell from 1000 to 173 and from 2500 to 421 for background risks varying between 1% and 0.4%, respectively.

CONCLUSIONS

First-trimester uterine artery Doppler is a useful tool for predicting early-onset pre-eclampsia, as well as other adverse pregnancy outcomes. Based on the NNT, abnormal uterine artery Doppler in low-risk women achieves a sufficiently high performance to justify aspirin prophylaxis in those who test positive.

Effectiveness of a clinically integrated e-learning course in evidence-based medicine for reproductive health training: a randomized trial

CONTEXT

For evidence-based practice to embed culturally in the workplace, teaching of evidence-based medicine (EBM) should be clinically integrated. In low-middle-income countries (LMICs) there is a scarcity of EBM-trained clinical tutors, lack of protected time for teaching EBM, and poor access to relevant databases in languages other than English.

OBJECTIVE

To evaluate the effects of a clinically integrated e-learning EBM course incorporating the World Health Organization (WHO) Reproductive Health Library (RHL) on knowledge, skills, and educational environment compared with traditional EBM teaching.

DESIGN, SETTING, AND PARTICIPANTS

International cluster randomized trial conducted between April 2009 and November 2010 among postgraduate trainees in obstetrics-gynecology in 7 LMICs (Argentina, Brazil, Democratic Republic of the Congo, India, Philippines, South Africa, Thailand). Each training unit was randomized to an experimental clinically integrated course consisting of e-modules using the RHL for learning activities and trainee assessments (31 clusters, 123 participants) or to a control self-directed EBM course incorporating the RHL (29 clusters, 81 participants). A facilitator with EBM teaching experience was available at all teaching units. Courses were administered for 8 weeks, with assessments at baseline and 4 weeks after course completion. The study was completed in 24 experimental clusters (98 participants) and 22 control clusters (68 participants).

MAIN OUTCOME MEASURES

Primary outcomes were change in EBM knowledge (score range, 0-62) and skills (score range, 0-14). Secondary outcome was educational environment (5-point Likert scale anchored between 1 [strongly agree] and 5 [strongly disagree]).

RESULTS

At baseline, the study groups were similar in age, year of training, and EBM-related attitudes and knowledge. After the trial, the experimental group had higher mean scores in knowledge (38.1 [95% CI, 36.7 to 39.4] in the control group vs 43.1 [95% CI, 42.0 to 44.1] in the experimental group; adjusted difference, 4.9 [95% CI, 2.9 to 6.8]; P < .001) and skills (8.3 [95% CI, 7.9 to 8.7] vs 9.1 [95% CI, 8.7 to 9.4]; adjusted difference, 0.7 [95% CI, 0.1 to 1.3]; P = .02). Although there was no difference in improvement for the overall score for educational environment (6.0 [95% CI, -0.1 to 12.0] vs 13.6 [95% CI, 8.0 to 19.2]; adjusted difference, 9.6 [95% CI, -6.8 to 26.1]; P = .25), there was an associated mean improvement in the domains of general relationships and support (-0.5 [95% CI, -1.5 to 0.4] vs 0.3 [95% CI, -0.6 to 1.1]; adjusted difference, 2.3 [95% CI, 0.2 to 4.3]; P = .03) and EBM application opportunities (0.5 [95% CI, -0.7 to 1.8] vs 2.9 [95%, CI, 1.8 to 4.1]; adjusted difference, 3.3 [95% CI, 0.1 to 6.5]; P = .04).

CONCLUSION

In a group of LMICs, a clinically integrated e-learning EBM curriculum in reproductive health compared with a self-directed EBM course resulted in higher knowledge and skill scores and improved educational environment.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12609000198224.

Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of computed tomography (CT) angiography in the evaluation of patients with an episode of acute gastrointestinal haemorrhage.

METHODS

Systematic review and meta-analysis to estimate pooled accuracy indices. A bivariate random effects model was adjusted to obtain a summary receiver-operating characteristic (sROC) curve and the corresponding area under the curve (AUC).

RESULTS

Twenty-two studies were included and provided data on 672 patients (range of age 5-74) with a mean age of 65 years. The overall sensitivity of CT angiography for detecting active acute GI haemorrhage was 85.2 % (95 % CI 75.5 % to 91.5 %). The overall specificity of CT angiography was 92.1 % (95 % CI 76.7 % to 97.7 %). The likelihood ratios for positive and negative test results were 10.8 (95 % CI 3.4 to 34.4) and 0.16 (95 % CI 0.1 to 0.27) respectively, with an AUC of 0.935 (95 % CI 0.693 to 0.989). The sources of heterogeneity explored had no significant impact on diagnostic performance.

CONCLUSIONS

CT shows high diagnostic accuracy and is an excellent diagnostic tool for detection and localising of intestinal bleeding sites. It is highly available, provides fast detection and localisation of the bleeding site, and is minimally invasive.

KEY POINTS

• CT angiography is increasingly used for investigating severe gastrointestinal bleeding. • This systematic review and meta-analysis updates previous ones. • In patients with massive gastrointestinal bleeding, CT angiography/MDCT detects bleeding accurately. • CT angiography is useful in locating the bleeding site and determining appropriate treatment.