First‐trimester combined screening for trisomy 21 at 7–14 weeks' gestation

Wright, Dave; Spencer, Kevin; Tørring, Niels; Petersen, Olav Bjørn; Christou, Aliki; Kallikas, J.; Nicolaides, Kypros H.

doi:10.1002/uog.7755

Cited by 106 publications

(150 citation statements)

References 12 publications

Supporting

Mentioning

138

Contrasting

Unclassified

Order By: Relevance

“…The performance is better at 9-10 weeks than at 13 weeks because the difference in PAPP-A between trisomic and euploid pregnancies is greater in earlier gestations [43,44]. Although the difference in free bhCG between trisomic and euploid pregnancies increases with gestation, the magnitude of the difference is smaller than that of the opposite relation of PAPP-A.…”

Section: Multiple Of Median (Mom)mentioning

confidence: 94%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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...

show abstract

Section: Multiple Of Median (Mom)mentioning

confidence: 94%

“…Screening for biochemical testing and ultrasound scanning can also be carried out in two separate visits, with the first done at 9-10 weeks and the second at 12 weeks [44,47,48]. It has been estimated that this approach would improve the detection rate from 90 % to 93 to 94 %.…”

Section: Multiple Of Median (Mom)mentioning

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

View full text Add to dashboard Cite

show abstract

“…These measurements are combined in a screening algorithm to produce likelihood ratios, which are multiplied by a priori maternal age-related risks, resulting in individual pregnancy-specific risks (1,2 ). This panel of tests has been demonstrated to have detection rates of Ն90%, with false-positive rates of 5% (3)(4)(5).…”

mentioning

confidence: 99%

Evaluation of a Dried Blood Spot Assay to Measure Prenatal Screening Markers Pregnancy-Associated Plasma Protein A and Free β-Subunit of Human Chorionic Gonadotropin

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The performance is better at 9 to 10 weeks than at 13 weeks because the difference in PAPP-A between trisomic and euploid pregnancies is greater in earlier gestations (Cuckle and van Lith, 1999;Spencer et al, 2003a;Kagan et al, 2008a;Wright et al, 2010). Although the difference in free β-hCG between trisomic and euploid pregnancies increases with gestation, the magnitude of the difference is smaller than that of the opposite relation of PAPP-A.…”

Section: First Trimestermentioning

confidence: 95%

Aneuploidy and Anomaly Screening

Elkady¹,

Dawlatly²,

Ahmed³

et al. 2017

Mastering Single Best Answer Questions for the Part 2 MRCOG Examination

View full text Add to dashboard Cite

Effective screening for major aneuploidies can be provided in the first trimester of pregnancy. Screening by a combination of fetal nuchal translucency and maternal serum free-β-human chorionic gonadotrophin and pregnancy-associated plasma protein-A can identify about 90% of fetuses with trisomy 21 and other major aneuploidies for a false-positive rate of 5%. Improvement in the performance of first-trimester screening can be achieved by firstly, inclusion in the ultrasound examination assessment of the nasal bone and flow in the ductus venosus, hepatic artery and across the tricuspid valve, and secondly, carrying out the biochemical test at 9 to 10 weeks and the ultrasound scan at 12 weeks.

show abstract

First‐trimester combined screening for trisomy 21 at 7–14 weeks' gestation

Abstract: K E Y W O R D S: ConclusionThe performance of first-trimester biochemical screening for trisomy 21 is best at 9-10 weeks rather than at 7-8 or 11-14 weeks.

Cited by 106 publications

References 12 publications

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

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

Evaluation of a Dried Blood Spot Assay to Measure Prenatal Screening Markers Pregnancy-Associated Plasma Protein A and Free β-Subunit of Human Chorionic Gonadotropin

Aneuploidy and Anomaly Screening

Contact Info

Product

Resources

About