First-trimester Down syndrome screening: Free β-human chorionic gonadotropin and pregnancy-associated plasma protein A

Krantz, David; Larsen, John W.; Buchanan, Philip D.; Macri, James N.

doi:10.1016/s0002-9378(96)70436-2

Cited by 100 publications

(56 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We confirmed the difference due to race and showed that median concentrations of serum free b-hCG were higher in Chinese compared with other groups. In our study, the free b-hCG median concentrations in Chinese were 27%-68% higher than those provided with the DELFIA Free hCGb kit, 39%-124% higher than the results by Krantz et al (22), 35%-68% higher than those reported by Spencer (23) and 20%-44% higher than results from Pettersson et al (14). Our study showed that free b-hCG median concentrations in Chinese were higher than found in other studies.…”

Section: Discussioncontrasting

confidence: 72%

Determination of median levels of the free β subunit of human chorionic gonadotropin in women from mainland China using a new time-resolved fluoroimmunoassay

Tang

Wu²,

Yin³

et al. 2009

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Article in press -uncorrected proof Determination of median levels of the free b subunit of human chorionic gonadotropin in women from mainland China using a new time-resolved fluoroimmunoassay ) chelates only. Methods: We developed a two-site, one-step assay using two monoclonal antibodies (MAbs) against free b subunit and b subunit with Eu 3q chelates as labels. Using the present assay, we evaluated 24,634 normal serum samples in Chinese pregnant women during 8-20 weeks of gestation. Results: The detection limit using this assay was -0.05 ng/mL. The within-run and between-run imprecision was -6.0% and 7.0% using control material. Free b-hCG concentrations measured using the current assay in 999 maternal serum samples correlated well with those obtained by samarium (Sm 3q )-labeled DELFIA free hCGb assay (rs0.987). The medians for 8-20 weeks for maternal serum free b-hCG were higher in the women from mainland China compared to reports from other countries. Conclusions: The present assay is suitable for use in biochemical screening of women in mainland China. Our study on the median concentrations of free b-hCG will help establish reference values that are specific for ethnic populations from the Chinese mainland. These will be useful for studying the importance of ethnic factors in biochemical screening.

show abstract

Section: Discussioncontrasting

confidence: 72%

Determination of median levels of the free β subunit of human chorionic gonadotropin in women from mainland China using a new time-resolved fluoroimmunoassay

Tang

Wu²,

Yin³

et al. 2009

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

show abstract

“…With the use of a combination of free β-human chorionic gonadotropin and pregnancy-associated plasma protein A with maternal age, detection rates of 60% to 70% for Down syndrome have been reported. 12,13 With the use of a combination of first-trimester serum analytes with nuchal translucency and maternal age, detection rates of approximately 90% have been reported. 14,15 In the United States, the First-and SecondTrimester Evaluation of Risk for Aneuploidy trial, sponsored by the National Institutes of Health, is comparing first-trimester nuchal translucency and serum screening with second-trimester serum screening.…”

Section: Reliability Of First-trimester Ultrasonographic Screening Fomentioning

confidence: 99%

Prenatal informed consent for sonogram: the time for first‐trimester nuchal translucency has come.

Chasen¹,

Skupski²,

McCullough³

et al. 2001

J of Ultrasound Medicine

View full text Add to dashboard Cite

ltrasonographic screening in pregnancy has been and continues to be a matter of controversy. For the past 20 years, second-trimester ultrasonographic screening has been debated. Even today, the American College of Obstetricians and Gynecologists does not endorse this as a standard of care. Nonetheless, secondtrimester ultrasonography is widely offered. In 1989, two of us (F.A.C. and L.B.M.) made the argument that "the standard of care demands that prenatal informed consent for sonogram be accepted as an indication for the prudent use of obstetric ultrasonography performed by qualified personnel." 1 The purpose of this editorial is to extend that argument to first-trimester ultrasonographic screening for aneuploidy using nuchal translucency determination. Reliability of First-Trimester Ultrasonographic Screening for AneuploidyThe term nuchal translucency refers to the ultrasonographic measurement of nuchal skin late in the first trimester. A specific feature of neonates with Down syndrome is redundant nuchal skin. This has also been noted with other autosomal trisomies as well as Turner syndrome. 2 Nuchal edema occurs in the fetus as well, and varying degrees of this are visible ultrasonographically. These range from slight thickening of nuchal skin to cystic hygromas, which are congenital malformations in which dilated lymphatic channels form a soft tissue mass, typically in the posterior neck.Benacerraf et al 3 reported an association between increased nuchal skin fold thickness in the second trimester and Down syndrome in 1985. Although this is a useful second-trimester marker for Down syndrome, only approximately 20% to 30% of fetuses with Down syndrome will have increased nuchal skin fold thickness. 4 Nicolaides et al 5 described an association with first-trimester nuchal edema and aneuploidy in 1992. Subsequently, numerous studies described increased nuchal translucency in most fetuses with Down syndrome and other forms of aneuploidy between 10 and 14 weeks. Most early studies defined increased nuchal translucency using a single cutoff, usually 3.0 mm. 6 A problem with using a single cutoff in defining abnormal nuchal translucency is the fact that nuchal translucency increases with gestational age in fetuses without abnorAbbreviations CVS, chorionic villus sampling; FMF, Fetal Medicine Foundation

show abstract

“…87,88 The combination of free β-hCG, PAPP-A, and maternal age yields detection rates in the first trimester that are similar to those of secondtrimester screening with 2 biochemical markers. 89,90 The detection rates for trisomy 21 are approximately 60% together with maternal age at a 5% false-positive level.…”

Section: First-trimester Biochemical Screeningmentioning

confidence: 99%

Sonographic screening for fetal aneuploidy: first trimester.

Souter¹,

Nyberg²

2001

J of Ultrasound Medicine

View full text Add to dashboard Cite

Objectives. Screening for fetal aneuploidy is now possible during the first trimester using sonographic and biochemical markers. The aim of this review was to summarize the efficacy and use of nuchal translucency in screening for fetal aneuploidy, especially fetal Down syndrome, and other anomalies. Methods. We reviewed available literature regarding first-trimester screening. This includes more than 16 studies of nuchal translucency as a marker for fetal aneuploidy published since 1995. Results. Although early studies showed wide variation in detection of fetal Down syndrome when using nuchal translucency, more recent studies showed sensitivities of approximately 70% to 80%, for a 5% false-positive rate. Increased nuchal translucency has also been found to be a marker for other aneuploidies, including trisomy 18, trisomy 13, and Turner syndrome. Maternal serum biochemical screening can be used as a test for aneuploidy during the first trimester. The 2 maternal serum markers that appear to be most useful in the late first trimester are the free β subunit of human chorionic gonadotropin and pregnancy-associated plasma protein A. Together with maternal age, these markers yield a detection rate for trisomy 21 of approximately 60%, for a 5% false-positive rate. Because sonographic and biochemical markers appear to be largely independent, their combined risk results in improved detection rates compared with either method alone. As a result, the combination of nuchal translucency, biochemical markers, and maternal age has achieved a detection rate of approximately 85%, for a 5% false-positive level for detection of trisomy 21. A newly proposed "integrated" approach using a panel of first-and second-trimester markers suggests that further improvement in the screening performance is possible. A number of questions regarding first-trimester screening remain. We address some of these questions: Is first-trimester screening more effective than second-trimester screening? How to account for intrauterine lethality? Is earlier diagnosis important, and will it be accepted by patients? Is first-trimester screening cost-effective? How should first-trimester screening be interpreted with second-trimester tests? Conclusions. Despite encouraging data and general enthusiasm for first-trimester screening for fetal Down syndrome and other aneuploidies, a number of questions remain about its implementation in the United States. Multicenter studies currently under way should help answer some of these questions.

show abstract

First-trimester Down syndrome screening: Free β-human chorionic gonadotropin and pregnancy-associated plasma protein A

Cited by 100 publications

References 23 publications

Determination of median levels of the free β subunit of human chorionic gonadotropin in women from mainland China using a new time-resolved fluoroimmunoassay

Determination of median levels of the free β subunit of human chorionic gonadotropin in women from mainland China using a new time-resolved fluoroimmunoassay

Prenatal informed consent for sonogram: the time for first‐trimester nuchal translucency has come.

Sonographic screening for fetal aneuploidy: first trimester.

Contact Info

Product

Resources

About