First trimester screening for Down syndrome using nuchal translucency, maternal serum pregnancy‐associated plasma protein A, free‐β human chorionic gonadotrophin, placental growth factor, and α‐fetoprotein

Abstract

The performance of FTS can be enhanced by adding PlGF and AFP. Even without nuchal translucency, the test would perform well.

Spina bifida screening in the first trimester using ultrasound biparietal diameter measurement adjusted for crown‐rump length or abdominal circumference

“…First trimester maternal serum free β‐hCG levels in OSB have been reported to be reduced in two series, and a published model found that adding both AFP and free β‐hCG to BPD MoM based on CRL increased detection from 50% to 58% for a 5% false‐positive rate . When screening for Down's syndrome in the first trimester, performance can be enhanced by the addition of maternal serum AFP, with or without PlGF . Centres using such protocols will be able to take advantage of the AFP measurement to achieve improved OSB detection.…”

Position statement from the Chromosome Abnormality Screening Committee on behalf of the Board of the International Society for Prenatal Diagnosis

“…Predicted performance is based on published statistical parameters for NT, pregnancy‐associated plasma protein‐A (PAPPA), freeβ, and human chorionic gonadotrophin (hCG), NB, TR and DV, NF, NBL, and PT, and ANOMALY; meta‐analysis for placental growth factor (PlGF) and alpha fetoprotein (AFP) based on publications cited in Ref. ; and a standardized maternal age distribution . Rates are based on prevalence at birth.…”

Rethinking second‐trimester Down‐syndrome screening in the cell‐free DNA era

“…Centers currently using a version of the combined test enhanced by the addition of nasal bone determination will have higher marginal costs when changing protocol because the detection rate advantage of cfDNA testing is smaller. Those currently using a version of the combined test enhanced by additional maternal serum markers, placental growth factor and AFP will need fewer additional funds but will have higher marginal costs.…”