AFP and Down syndrome: Based on our results, Down’s syndrome pregnancy is associated with high levels of β-hCG, uE3 and inhibin A and low levels of AFP and uE3, which is completely in agreement with the results of western countries (26), and in NTDs pregnancies, the AFP MoM values were significantly higher than unaffected pregnancy in three age groups, which means that its higher values will significantly increase the final risk of NTDs, which is similar to a report of other countries (27).