Mosaicism for copy number variations in the placenta is even more difficult to interpret than mosaicism for whole chromosome aneuploidy.

Objective: To compare mosaicisms in prenatal chorionic villus samples (CVSs) with corresponding postpartum placental samples.

Method: We collected placentas from 15 consecutive cases of mosaicism detected in CVSs and obtained five standardized samples on each placenta after delivery. All pre- and postnatal placental samples were uncultured and analyzed by high-resolution chromosomal microarray.

Preferences for prenatal tests for Down syndrome: an international comparison of the views of pregnant women and health professionals.

Non-invasive prenatal testing is increasingly available worldwide and stakeholder viewpoints are essential to guide implementation. Here we compare the preferences of women and health professionals from nine different countries towards attributes of non-invasive and invasive prenatal tests for Down syndrome. A discrete choice experiment was used to obtain participants' stated preference for prenatal tests that varied according to four attributes: accuracy, time of test, risk of miscarriage, and type of information.