Analysis of middle cerebral artery peak systolic velocity in monochorionic twin pregnancies as a method for identifying spontaneous twin anaemia-polycythaemia sequence.

A regular Doppler control evaluation of middle cerebral artery peak systolic velocity is needed in order to identify twin anaemia polycythaemia sequence in monochorionic twin pregnancies. Here, we present a clinical case of spontaneous TAPS, and we review the diagnostic criteria and management strategies for this syndrome.

New contingent sequential screening model for Down syndrome based on the combined test associated with modified genetic sonography.

OBJECTIVE: The aim of this study is to evaluate the possibility of implementing a contingent sequential screening test for Down syndrome (DS) based on the combined test (CT) associated with modified genetic sonography (MGS). We evaluate sensitivity (Sen), false positive rate (FPR), and economic costs. METHOD: We compiled data from the results of a prospective screening programme for DS during a 5-year study period (July 2005-December 2011). Pregnancies were offered the CT as the first step in the contingent sequential test. We identified an intermediate risk group (1/101-1/1000) using CT results, and offered these individuals a MGS (major malformation and nuchal fold). RESULTS: A total of 19 440 pregnancies (103 chromosome abnormalities and 66 cases of DS) were administered the CT. We performed a MGS on 99.6% of individuals in the intermediate risk group (2188/2197); in this group, we observed 22 chromosome abnormalities (17 DS). The CT provided a Sen for DS of 80.30% (95%CI: 68.68-89.07) (53/66), and a Sen for all chromosome abnormalities of 76.70% (95%CI: 67.34-84.46) (79/103), with a FPR of 3.79% (95%CI: 3.52-4.05) (732/19 374). The contingent sequential strategy produced a Sen for DS of 81.82% (95%CI: 70.39-90.24) (54/66) and a Sen for all chromosome abnormalities of 79.61% (95%CI: 70.54-86.91) (82/103), with a FPR of 1.16% (95%CI: 1.02-1.33) (224/19 457). The economic costs of the CT and the contingent sequential model were 9 70 275 Euros and 9 41 716 Euros, respectively. CONCLUSIONS: We present a new sequential contingent strategy for DS screening and demonstrate its usefulness for reducing FPR while maintaining a high level of Sen for DS, without requiring an increase in economic costs.

Stepwise sequential screening for Down's syndrome (combined test associated with modified genetic sonography) in pregnant women with low risk for chromosomal disorders.

OBJECTIVE: To assess the sensitivity (Sen) and false positive ratio (FPR) of stepwise sequential screening [1st step: combined test (CT), 2nd step: modified genetic sonography (major malformation and nuchal fold, MGS)] as a screening method for Down's syndrome (DS) in the general population of pregnant women. METHODS: Prospective study. During a 5-year study period (July 2005 to June 2010), 17,911 pregnant women were screened for DS using a stepwise sequential screening method (CT+MGS). We evaluated the Sen and FPR (95% CI) of the two chromosomal disorder screening methods for DS: CT and CT+MGS. RESULTS: Seventeen thousand nine hundred and eleven cases were analysed, including 67 with chromosome abnormalities and 45 with DS. The Sen of CT for DS was 80% (95% CI; 68.3-91.7) (36/45) with a FPR of 4.2% (95% CI; 3.9-4.5) (752/17, 866). The Sen of CT+MSG for DS was 93.3 (95% CI; 85.9-99) (42/45) with a FPR of 4.8% (95% CI; 4.5-5.1) (860/17, 866). CONCLUSIONS: MGS coupled with CT increases the Sen of DS diagnosis by 13.3% (95% CI; 2.7-25.9), with an increase in FPR of 0.6% (95% CI; 0.5-0.7).

Role of fetal echocardiography in stepwise sequential screening for chromosomal disorders (combined test associated with modified genetic sonography).

OBJECTIVES: To evaluate the contribution made by fetal echocardiography in identifying Down's syndrome (DS) and other chromosomal disorders in a stepwise sequential screening method (first step: combined test (CT), second step: modified genetic sonography (MGS) (major malformation and nuchal fold)), for DS in the general population of pregnant women. METHODS: Prospective study. During a 5-year study period (July 2005-June 2010) 17,911 pregnant women underwent CTs with MGS (with fetal cardiac morphological evaluation performed by obstetricians in a tertiary hospital) as a screening method for DS. We evaluated the sensitivity and false positive rate (FPR) (95% confidence interval (CI)) of three screening methods for DS and all chromosomal disorders: CT, CT + MGS, and CT + fetal echocardiography. RESULTS: A total of 17,911 cases were analyzed with 67 chromosome disorders and 45 DS cases being found. For DS, the CT sensitivity was 80% (95% CI; 68.3-91.7) (36/45) and 79.1% (95% CI; 69.4-88.8) (53/67) for all chromosome disorders, with a FPR of 4.2% (95% CI; 3.9-4.5) (752/17,866) and 4.1% (95% CI; 3.8-4.4) (735/17,844), respectively. For CT + MSG and CT + fetal echocardiography, the sensitivity for DS was 93.3% (95% CI; 85.9-0.99) (42/45) and 95.5% (95% CI; 90.5-0.99) (64/67) for all chromosome disorders. The FPR for CT + MSG was 4.8% (95% CI; 4.5-5.1) (860/17,866) and 4.6% (95% CI; 4.3-4.9) (836/17,844), respectively. The FPR of CT + fetal echocardiography was 4.4% (95% CI; 4.1-4.7) (792/17,866) for DS screening and 4.3% (95% CI; 4-4.6) (770/17,844) for chromosome abnormality screening. CONCLUSIONS: Fetal echocardiography is highly capable of identifying DS and other chromosomal disorders as a part of genetic sonography in stepwise sequential screening.

First trimester contingent test as a screening method for Down's syndrome. A prospective study in the general population.

OBJECTIVES: To evaluate the possibility of implementing a contingent test as a screening method for Down's syndrome (DS) in the first trimester of pregnancy, and assess its sensitivity (Sen) and false positive rate (FPR). METHODS: Prospective study covering a 4-year study period (July 2006-June 2010). Pregnant women were offered a combined test (CT) as the first step of a contingent test. An intermediate risk group is identified in the CT (1/101 and 1/1000) and offered an ultrasound assessment of secondary s (nasal bone, ductus venosus, tricuspid regurgitation). RESULTS: CTs were performed on 10,452 pregnant women (24 cases of DS). In the intermediate risk group, which had 7 cases of DS, we performed secondary ultrasound marker assessment on 98.1% (1,017/1,036). The CT and the contingent test had a Sen of 83% (95% CI; 67.9-98) (20/24) and 70.8% (95% CI; 52.6-88.9) (17/24) with an FPR of 3% (95% CI; 2.7-3.3) (316/10,430) and 2% (95% CI; 1.7-2.3) (220/10,408), respectively. CONCLUSIONS: With the contingent test, we managed to reduce the FPR, but the Sen was too low for use as a screening method for DS.

Contribution of "modified genetic sonography" to the combined test as a screening method for chromosomal abnormalities.

OBJECTIVES: We propose to assess the contribution of "modified genetic sonography" (MGS) to the combined test (CT) as a method of stepwise sequential screening (1st step: CT, 2nd step: MGS) for chromosome abnormalities in the general population of pregnant women. METHODS: Prospective study. During a 4 year study period (July 2005-June 2009) 16,548 pregnancies underwent a CT combined with MGS (major malformation and nuchal fold) as a screening method for chromosome abnormalities. We assessed sensitivity and false positive rate (FPR) (95% CI). RESULTS: We offered a chromosome abnormalities screening test to 96.6% of pregnancies (15,995 cases). 14,160 cases are analyzed (1st step: CT, 2nd step: MGS) including 49 chromosome abnormalities and 35 Down's syndrome (DS). The sensitivity of CT for DS was 77.1% [95% CI, 63.2-91] (27/35) and 77.5% for all chromosome abnormalities [95% CI, 65.8-89.2] (38/49) with a FPR of 4.4% [95% CI, 4.1-4.7]. If MGS was combined with CT, the sensitivity for DS was 91.4% [95% CI, 82.1-99] (32/35) and 93.8% for all chromosome abnormalities [95% CI, 87-99] (46/49) for a FPR of 5.1% [95% CI, 4.7-5.5]. CONCLUSIONS: The addition of an MGS to combined first-trimester screening test for aneuploidy improved sensitivity by 14.3% while only increasing the FPR by 0.7%.