Korean-Specific Parameter Models for Calculating the Risk of Down Syndrome in the Second Trimester of Pregnancy

Abstract

The purpose of the current study was to propose a Korean-specific parameter set for calculating the risk of Down syndrome in the second trimester of pregnancy and to determine the screening performances of triple and quadruple tests in Korean women. Using the data on triple or quadruple screening from three hospitals in Korea during 7 yr, we re-converted the concentrations of four serum markers to multiple of median values according to gestational age and maternal weight. After re-calculating the risk of Down syndrome in each pregnancy by multiplying maternal age-specific risk by the likelihood ratio values for the serum markers, screening performances and optimal cut-off values of triple and quadruple tests were analyzed. Among 16,077 pregnancies, 23 cases had Down syndrome (1.4/1,000 deliveries). Compared to the previous program, the tests with new parameters had improved screening performance. The triple and quadruple tests had detection rates of 65.2% and 72.7%, respectively, at a false-positive rate of 5%. The optimal cut-off value for the quadruple and triple tests was 1:250. We have presented a Korean-specific parameter set for Down syndrome screening. The proposed screening test using this parameter set may improve the performance of Down syndrome screening for Korean women.

Prevalence of Congenital Heart Defects Associated with Down Syndrome in Korea

“…The prevalence of DS in our study was considerably lower than in previous studies conducted in Korea. The prevalence of DS was 14 and 26.7 per 10,000 total births in Shin et al ( 18 ) and Jun et al ( 19 ), respectively. However, since two previous studies were limited to only a few institutions and not nationwide, it may not reflect the overall prevalence of DS in Korea.…”

Triple Test Screening for Down Syndrome: An Egyptian-Tailored Study

“…Using these median analyte values, the grand median MoM for each of the three parameters (without regard for the gestational week) was always 1.00. Figure 1 compares Egyptian medians with those in Korea [15] and a number of Western areas compiled by Vranken et al [16] .…”

“…Weight distribution in our community is different from that in Western, black or Asian communities, and needs to be considered when adjustments to MoMs are to be made. Three formulas were derived and served to adjust measured MoMs to a population median maternal weight of 78.2 kg (compared to 60 kg in a Caucasian-based study [23] and 57.2 kg in a Korean study) [15] . A difference in median weight as small as 2.5 kg was recommended to warrant formula modification to minimize errors in risk calculation [24] .…”

“…It is equivalent to the risk of a 35-year old woman in the absence of serum screening. The risk cut-off of a screening test should be set specifically to each country in consideration of the cost and safety of invasive diagnostic procedures, the prevalence of DS, and the age distribution of pregnant women [15] .…”

Normative Values of Second-Trimester Maternal Serum Markers Using an Automated Assay Platform for Down Syndrome Screening

“…Up to now, only few studies have been reported regarding the reference values of these four second-trimester serum markers analyzed by an automated immunoassay among Asian population. 7,8 Moreover and importantly, no data derived from an automated immunoassay is available for Thai population. Accordingly, the aim of this study was to determine the median values of second trimester serum markers as a function of gestational age (GA) in Thai population using an automated immunoassay.…”