Risque de trisomie 21 discordant en cas de marqueurs sériques très bas : à propos de cinq cas de triploïdie digynique

Very elevated hCGβ (≥10 multiple of the median) in maternal marker screening for Down syndrome: Frequency, etiologies, outcomes, and guidelines

“…Very high values of maternal serum hCGβ observed at DS screening have been described in case reports or small studies as being associated with fetal disease (as aneuploidy), maternal disease (as renal failure and ovarian choriocarcinoma), or systemic diseases affecting both the fetus and the mother (as preeclampsia). [6][7][8][9][10][11][12][13][14][15][16][17][18][19] We present a F I G U R E 2 Guidelines for patients presenting with maternal serum hCGβ values ≥10 multiple of median at Down syndrome screening.…”

“…High hCG or hCGβ values have been previously reported to be associated with poor prognosis when over 2.5 MoM 6–18 . However, the large distribution profiles of hCG and hCGβ mean that 10%–25% of patients are over the 2.5 MoM cut‐off, instead of the expected 2.5% over a +3 Z ‐score.…”

“…5 High hCG or hCGβ values have been previously reported to be associated with poor prognosis when over 2.5 MoM. [6][7][8][9][10][11][12][13][14][15][16][17][18] However, the large distribution profiles of hCG and hCGβ mean that 10%-25% of patients are over the 2.5 MoM cut-off, instead of the expected 2.5% over a þ3 Z-score. Therefore, additional ultrasound screening or additional management for such a population would not be pertinent in current practice.…”

“…Various publications have reported that high values (over 2 MoM, over 3 MoM or over the 99th percentile) are associated with fetal disease (trisomy 21, severe growth restriction, placental trisomy 16 mosaicism), preeclampsia, or ovarian choriocarcinoma. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] While the guidelines are clearly defined for high MoM values of AFP (secondtrimester DS screening marker), 20 due to the disparity of the anomalies associated with very high hCG or hCGβ and the cut-off taken into account, pregnancy follow-up largely depends on team practices.…”

“…In our series, trisomy 21 was twice as frequent as triploidy, but 13 cases of diandric triploidy were observed and required karyotyping for diagnosis, as also described by Huang et al 13 When NIPT alone would be the preferred option, it should be recalled that triploidy may not be detected using all techniques of NIPT. 14 Indeed, as explained by Benn and Cuckle, the method of NIPT can be an important consideration for screening for sex chromosome abnormalities, microdeletion syndromes, triploidy, molar pregnancies, rare autosomal trisomies, and segmental imbalances. 21 4) When the first three points were assessed, and according to the appearance of the ovaries on ultrasound examination, hGCβ and total hCG controls may help exclude maternal malignancy.…”