Screening for Down's syndrome in the first trimester: Combined risk calculation, methodology, and validation of a web‐based system

Abstract

The system described here fulfills the requirement for an appropriately validated risk calculation package, is fully user configurable with easy access through a web-based system allowing extension of the screening program to multiple centers.

The Swedish Pregnancy Register – for quality of care improvement and research

“…The web‐based system uses an algorithm based on likelihood ratios of established serum markers including free beta subunit of human chorionic gonadotropin, and pregnancy‐associated plasma protein A and nuchal translucency from Gaussian distributions in normal and affected pregnancies 4. The first trimester risk assessment system is available for certified units and users throughout the country.…”

“…To promote improved quality of care in pregnancy and childbirth, the Swedish Pregnancy Register (www.graviditetsregistret.se) was started in 2013 by merging the Maternal Health Care Register 1, 2 (established in 1999) and the National Quality Register for Prenatal Diagnosis 3, 4 (established in 2006) and by initiation of collecting information from deliveries. Today the Pregnancy Register includes data on pregnancy and childbirth, starting at the first visit to antenatal care, where demographic, reproductive and maternal health data are collected.…”

Nuchal translucency measurement: are qualitative and quantitative quality control processes related?

“…7,8 This combined strategy is now widely available, and its efficiency has been confirmed in different settings and different countries. [9][10][11][12][13][14][15] However, quality assurance of this simple but critical measurement is mandatory for a satisfactory screening performance to be achieved. 3,[16][17][18][19][20][21][22] Two types of quality assurance processes for NT measurement have been described.…”

Assessment of sonographer nuchal translucency measurement performance – central tendency and dispersion

“…Variation between published expected median NT in unaffected pregnancy models in the first trimester is illustrated by Figure 1. All models were quadratic and based on CRL except for that of Lam et al which was based on gestational age but was also determined within our local Chinese population [19][20][21]. Expected median NT for the Sweedish population reported by Kublickas et al was lower than experts at the FMF with the differences increasing as CRL increased [14,20].…”

“…All models were quadratic and based on CRL except for that of Lam et al which was based on gestational age but was also determined within our local Chinese population [19][20][21]. Expected median NT for the Sweedish population reported by Kublickas et al was lower than experts at the FMF with the differences increasing as CRL increased [14,20]. Despite this difference the dispersion of NTMoM measurements in the unaffected populations as determined by the SD of the log distribution was reported as being 0.0914 similar to 0.097 in our own study and other studies suggesting that there was not any excessive measurement dispersion [13,21].…”