Our result of prenatal screening for Down’s syndrome during the first trimester showed that the MOM values of free beta-human chorionic gonadotropin (free β-hCG) and pregnancy- associated plasma protein A (PAPP-A) (both in unaffected pregnancies and three age groups) were higher than those which had been reported by the western countries (22), but were similar to a systematic review and meta-analysis of a predominantly Chinese case (23). Here, PAPPA is linked to Down syndrome.