Garchet-Beaudron Aurélie, Dreux Sophie, Leporrier Nathalie, Oury Jean-François, Muller Françoise
Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, Paris, France.
Prenat Diagn. 2008 Dec;28(12):1105-9. doi: 10.1002/pd.2145.
To analyze the value of Down syndrome (DS) second-trimester maternal serum screening in large series of twin pregnancies.
Prospective study of second-trimester maternal serum markers [alpha fetoprotein (AFP) and free beta-human chorionic gonadotrophin (beta-hCG)] in 11,040 twin pregnancies, 27 of which were trisomy 21-affected. Comparison with 64,815 singleton pregnancies, of which 86 were trisomy 21-affected. Markers were expressed in multiple of median (MoM) corrected by a previously defined coefficient (2.1 for AFP and 2.07 or 2.16 for free beta-hCG, dichorionic or monochorionic, respectively).
Trisomy 21 frequency was 1/649 for twins and 1/754 in singletons (NS). Mean detection rate was 63% (71% when both twins were affected and 60% when one was affected), versus 74.4% in singletons. False-positive rates were 10.8% in twins versus 10.3% in singletons (NS). No significant differences in MoM AFP and free beta-hCG values were noted between twins and singletons (0.92 and 0.78 for AFP and 1.54 and 2.68 for free beta-hCG, respectively).
Our study demonstrates that second-trimester DS maternal serum marker screening can be performed in twin pregnancies.
分析孕中期母血清筛查在大量双胎妊娠中对唐氏综合征（DS）的筛查价值。
对11040例双胎妊娠进行孕中期母血清标志物[甲胎蛋白（AFP）和游离β-人绒毛膜促性腺激素（β-hCG）]的前瞻性研究，其中27例为21-三体综合征。与64815例单胎妊娠进行比较，其中86例为21-三体综合征。标志物以中位数倍数（MoM）表示，并通过先前定义的系数进行校正（AFP为2.1，游离β-hCG在双绒毛膜或单绒毛膜双胎中分别为2.07或2.16）。
双胎妊娠中21-三体综合征的发生率为1/649，单胎妊娠中为1/754（无统计学差异）。平均检出率为63%（当两个胎儿均受影响时为71%，当一个胎儿受影响时为60%），单胎妊娠的检出率为74.4%。双胎妊娠的假阳性率为10.8%，单胎妊娠为10.3%（无统计学差异）。双胎和单胎之间MoM AFP和游离β-hCG值无显著差异（AFP分别为0.92和0.78，游离β-hCG分别为1.54和2.68）。
我们的研究表明，孕中期DS母血清标志物筛查可用于双胎妊娠。
