我的ob给了一个产检的list： 6-11w: BP monitoring, urine and weight checks 16-18w: Quad screening (optional test) 20w: ultrasound 27-28w: Blood test for glucose and iron levels, rhogam given if you are a negative blood type 32w: Tubal Consent signed if applies 32-35w: group B strep culture 38-40w: Prenatal visit and pelvic exam 楼上的mm们知道那个是查down syndrom的吗？一般大概什么时候查呢？