Am 18wks pregnant, did my second us, they said that my baby's weight dropped from the 20th percentile to the 7th.placenta is good.is that dangerous?

What did they tell: U? The 7th percentile if you have accurate dates is very worrisome for iugr or worse and i assume you have another us set up in a few weeks as the fetal anatomy needs to be checked closely and if you are really at the 7th % , you need to be having everything explained at length to you by them and what the plan will; be if the growth continues to drop, good luck but you really need to ask your doc.