One‐stop clinic for assessment of risk for trisomy 21 at 11–14 weeks: a prospective study of 15 030 pregnancies

The results of a chromosomal test by genetic amniocentesis in 58 cases with an increased nuchal translucency (NT; C3 mm thickness) revealed 47 cases showing a normal karyotype (81%) and 11 cases (19%) showing an abnormal karyotype. However, the cases of a normal karyotype with increased NT also included those with fetal abnormalities. Among the 49 cases in which NT was observed during the first trimester and then subsequently disappeared, chromosomal abnormalities were observed in five, and fetal abnormalities other than chromosomal abnormalities were observed in two. Meanwhile, all nine cases in which an increased NT remained or in which NT continued to increase in size during the second trimester were diagnosed as having cystic hygroma, and chromosomal abnormalities were found in six cases (67%). It should be noted that the shape of increased NT includes NT with a notch (notched NT) and NT without a notch (smooth NT). Among the 20 cases of notched NT, chromosomal abnormalities were observed in eight (40%), and cystic hygroma was observed in nine (45%). On the other hand, among the 38 cases of smooth NT, chromosomal abnormalities were observed in three (7.9%), but no cystic hygroma was observed. Our results confirm that increased NT does not always indicate a fetal abnormality. Whether NT thickness should be measured as a screening tool for fetal abnormalities remains controversial. However, increased NT may be detected by chance, because a maternal-fetal medical examination using ultrasonography is usually performed in Japan. It is therefore considered to be extremely important to establish a system in which cases are referred to obstetricians who are licensed clinical genetic specialists to obtain appropriate genetic counseling whenever increased NT is clinically observed.

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“…In addition, NT measurement has is one of the items of the screening test for Down syndrome (Bindra et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Does increased nuchal translucency indicate a fetal abnormality? A retrospective study to clarify the clinical significance of nuchal translucency in Japan

et al. 2008

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“…The most commonly used test for genetic diagnosis is amniocentesis, but the rate of spontaneous fetal loss related to amniocentesis averages about one in every 200 [2] procedures. Because of this risk, serum analyte testing has become an important, noninvasive first step in detecting patients at risk for congenital abnormalities.Current studies done on first trimester maternal serum screening has shown that the double marker test helps to identify 90 % of women at risk for Down syndrome, 94 % of all major chromosomal defects such as Patau syndrome, Edward syndrome, triploidy and Turner syndrome, and 60 % of other chromosomal defects, such as deletions, partial trisomies, unbalanced translocations, and sex chromosome aneuploidies other than turners [3]. Some of the advantages of first-trimester biochemical screening over second trimester biochemical screening include providing clinicians and patients with the substantial advantage of an earlier diagnosis, higher detection rates for fetal Down syndrome i.e; 90 % [4] or even higher, compared to 80 % for the second trimester quadruple test [5,6] and 70 % for the older triple screening test [7], and detection of most major chromosome abnormalities other than trisomy 21.…”

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confidence: 99%

First Trimester Maternal Serum Screening Using Biochemical Markers PAPP-A and Free β-hCG for Down Syndrome, Patau Syndrome and Edward Syndrome

Shiefa¹,

Amargandhi²,

Bhupendra³

et al. 2012

Ind J Clin Biochem

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The first trimester screening programme offers a noninvasive option for the early detection of aneuploidy pregnancies. This screening is done by a combination of two biochemical markers i.e. serum free b-human chorionic gonadotrophin (free b-hCG) and pregnancy associated plasma protein A (PAPP-A), maternal age and fetal nuchal translucency (NT) thickness at 11 ? 0-13 ? 6 weeks of gestation. A beneficial consequence of screening is the early diagnosis or trisomies 21, 18 and 13. At 11 ? 0-13 ? 6 weeks, the relative prevalence of trisomies 18 and 13 to trisomy 21 are found to be one to three and one to seven, respectively. All three trisomies are associated with increased maternal age, increased fetal NT and decreased PAPP-A, but in trisomy 21 serum free b-hCG is increased whereas in trisomies 18 and 13 free b-hCG is decreased.Prenatal screening for trisomies based on the analysis of biochemical markers in maternal serum has become an established part of obstetric practice in many countries. Resent interest in prenatal screening for trisomies has focused on the first trimester. Of the biochemical markers that have been investigated, only maternal serum free b-human chorionic gonadotrophin (free b-hCG) and pregnancy associated plasma protein-A (PAPP-A) has been shown to be of value. The goal of first trimester maternal serum screening programs is to identify women at increased risk of having a baby affected with Down syndrome, Patau syndrome, and Edward syndrome defects and those that will benefit from the testing.The association between advancing maternal age [1] and increased risk of trisomy 21 (Table 1) is well known, and pregnant women older than 35 years at delivery are routinely offered invasive prenatal diagnostic testing. The most commonly used test for genetic diagnosis is amniocentesis, but the rate of spontaneous fetal loss related to amniocentesis averages about one in every 200 [2] procedures. Because of this risk, serum analyte testing has become an important, noninvasive first step in detecting patients at risk for congenital abnormalities.Current studies done on first trimester maternal serum screening has shown that the double marker test helps to identify 90 % of women at risk for Down syndrome, 94 % of all major chromosomal defects such as Patau syndrome, Edward syndrome, triploidy and Turner syndrome, and 60 % of other chromosomal defects, such as deletions, partial trisomies, unbalanced translocations, and sex chromosome aneuploidies other than turners [3]. Some of the advantages of first-trimester biochemical screening over second trimester biochemical screening include providing clinicians and patients with the substantial advantage of an earlier diagnosis, higher detection rates for fetal Down syndrome i.e; 90 % [4] or even higher, compared to 80 % for the second trimester quadruple test [5,6] and 70 % for the older triple screening test [7], and detection of most major chromosome abnormalities other than trisomy 21. It also acts as a nonspecific marker for other birth defects inclu...

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“…Quando utilizada juntamente com a idade materna e marcadores bioquímicos do primeiro trimestre, tem uma sensibilidade de 90%, passando a 95% quando acrescida da avaliação do osso próprio do nariz, para um falso positivo de 5% [12][13][14] .…”

Section: Introductionunclassified

Evolução perinatal e pediátrica de crianças com translucência nucal aumentada e cariótipo normal

Vieira¹,

Silva²,

Faria³

et al. 2013

Rev. Bras. Ginecol. Obstet.

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(45,6%). Nos fetos com cariótipo normal, houve um abortamento na 15ª semana gestacional com pentalogia de Cantrel, um óbito na 24ª semana com diversas anomalias estruturais, um óbito neonatal sem causa definida e dois casos de comunicação intraventricular (CIV) detectados no ECO fetal. Na avaliação ecocardiográfica pós-natal, persistiu um caso de CIV e foi diagnosticado um caso de comunicação interatrial (CIA) e persistência do canal arterial (PCA). Entre os 40 casos sobreviventes, apenas 1 criança apresentou atraso no desenvolvimento da fala e outra apresentou quadro de autismo. Os demais casos resultaram em desenvolvimento neuropsicomotor normal. CONCLUSÃO: No acompanhamento dos fetos com TN aumentada e cariótipo normal, os pais podem ser mais bem aconselhados de que, frente a um exame morfológico-ecocardiográfico do 2° trimestre sem alterações, a probabilidade de a criança nascer viva e bem é alta (93,5%). Abstract PURPOSE:To analyze the perinatal and pediatric outcome of fetuses that showed nuchal translucency (NT) above the 95th percentile (P95) and a normal karyotype in order to obtain data allowing better maternal prenatal counseling. METHODS: fetuses from a tertiary obstetric service with an NT above P95 and a normal karyotype were analyzed between 2005 and 2011. We analyzed gestational ultrasound follow-up, fetal and postnatal echocardiography (ECHO), weight, length and Apgar score at birth, and neuropsychomotor development by the Ages and Stages Questionnaire (ASQ) up to July 2012. RESULTS: During this period, there were 116 cases of nuchal translucency above the 95th percentile, and the fetal karyotype was determined in 79 of them (68%). Forty-three analyses were normal (54.4%) and 36 were altered (45.6%). Among the fetuses with a normal karyotype, one was miscarried at 15 weeks of gestation with Cantrel pentalogy and one died at 24 weeks with several structural abnormalities. There was one neonatal death of unknown cause and two cases of intraventricular communication (IVC) detected by fetal ECHO. Postnatal echocardiography revealed the persistence of IVC in one case and one case of atrial septal defect (ASD) and patent ductus arteriosus (PDA). Of the 40 surviving children, only 1 showed delayed speech development and another presented autism. The remaining cases resulted in normal neurodevelopment. CONCLUSION: During the monitoring of fetuses with increased NT and a normal karyotype, parents can be best advised that when a 2 nd trimester morphologicalechocardiography ultrasound study is normal, the probability of the child being born alive and well is high (93.5%).

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One‐stop clinic for assessment of risk for trisomy 21 at 11–14 weeks: a prospective study of 15 030 pregnancies

Abstract: Screening for trisomy 21 by a combination of maternal age, fetal NT and maternal serum biochemistry at 11-14 weeks can be provided in an OSCAR setting and is associated with a detection rate of about 90% for a false-positive rate of 5%.

Cited by 219 publications

References 30 publications

Does increased nuchal translucency indicate a fetal abnormality? A retrospective study to clarify the clinical significance of nuchal translucency in Japan

Does increased nuchal translucency indicate a fetal abnormality? A retrospective study to clarify the clinical significance of nuchal translucency in Japan

First Trimester Maternal Serum Screening Using Biochemical Markers PAPP-A and Free β-hCG for Down Syndrome, Patau Syndrome and Edward Syndrome

Evolução perinatal e pediátrica de crianças com translucência nucal aumentada e cariótipo normal

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