First trimester detection of trisomy 16 using combined biochemical and ultrasound screening

Abstract

What's already known about this topic? Four previously reported cases of trisomy 16 have shown reduced levels of pregnancy‐associated plasma protein‐A during first trimester screening for trisomy 21. Isolated increases in free β human chorionic gonadotrophin and nuchal translucency were observed in these four cases. What does this study add? During first trimester screening for aneuploidy, we observed a further 28 cases of trisomy 16, all of which had reduced levels of pregnancy‐associated plasma protein‐A consistent with previous reported cases. Increased free β human chorionic gonadotrophin and increased nuchal translucency were not a consistent finding in our 28 cases.

First trimester screening for other trisomies than trisomy 21, 18, and 13

“…Regarding T16 our results are in agreement with a recent publication based on 32 cases, showing a median PAPP‐A of 0.13 MoM, a median FβhCG of 1.18 MoM, and a median nuchal translucency of 1.1 MoM . Also for T22 our findings are coherent with previous results showing low median PAPP‐A MoM and NT median MoM around 1.0 .…”

“…However, this association may represent ascertainment bias since systematic screening for these aneuploidies is uncommon. Recent data from cFTS show that while nuchal translucency is not significantly increased in cases of placental T16 or T20, the serum levels of the biochemical markers are affected in a combination of increased FβhCG MoM and decreased PAPP‐A MoM in the first and second trimesters …”

Increased Nuchal Translucency and Early Growth Retardation Related to Confined Placental Mosaicism of Trisomy 16 in a Dichorionic Twin

“…In a study by Spencer et al, CPM of trisomy 16 was noted in 16 cases, and NT increased by greater than 2.5 mm in 3 cases. One case with severe cystic hygroma exhibited increased NT (8.8 mm) [7]. In our case, fetal NT increased to 3.7 mm.…”

“…These authors confirmed that the overall median level of PAPP-A in 32 cases significantly decreased to 0.125 multiple of the median (MoM). The overall median MoM of free β-hCG was 1.18 and did not exhibit any special pattern [7].…”

“…Moreover, IUGR and placental structure abnormalities detected by ultrasonographic examination during the second trimester have been  K.-S. Kyeong et al associated with CPM of trisomy 16 [6]. In a recent study, pregnancy-associated plasma protein-A (PAPP-A) levels were reduced in CPM of trisomy 16 as determined by maternal serum aneuploidy screenings during the first trimester [7]. In addition, Christine et al reported the possibility of early growth retardation in CPM of trisomy 16 during the first trimester [8].…”