[Specificities of screening for aneuploidies in twin pregnancies].

Objectives: To determine the most efficient and tailored screening method for aneuploidies in twins for the French population.
Material and Methods: Articles were searched using the PubMed and the Cochrane libraries.
Results: In cases of twin pregnancies, the aneuploidy's risk related to maternal age as well as gestational age must be considered as being the same as in singletons. In bichorionic twins, we have to consider individually the nuchal translucency thickness of each twin. In monochorionic twins, we have to consider a range of risks related to the nuchal translucency measurements of each twins. The additional benefit of maternal serum biochemistry screening in twins is not as established as in singletons.
Conclusion: The most appropriate method of screening for aneuploidies in twin pregnancies is based during the first trimester of pregnancy on the risk related to maternal age combined with those related to the nuchal translucency measurement. In the absence of first-trimester screening, it is possible to offer a screening method based on the second trimester maternal serum biochemistry and/or by a targeted ultrasound.
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