Key points are not available for this paper at this time.
This study provides estimates of risks for a wide range of chromosomal defects taking into account maternal age as well as the gestation at assessment. The estimates make it possible to counsel patients presenting at different stages of pregnancy. At the same time, they offer the possibility of evaluating the efficacy of biochemical and ultrasonographic markers in identifying fetuses with chromosomal defects.
Snijders et al. (Sun,) studied this question.