Placenta grade III means your placenta is showing signs of maturity, which is actually normal na makikita towards the end ng pregnancy, usually around 36 weeks onwards! A few of us moms talked about this during our checkups, and our doctors said it's nothing to worry about kasi it just means the placenta is doing its job well and ready na for delivery. Best talaga na i-clarify ito with your OB though para ma-explain niya in detail kung ano exactly ang nakikita nila sa ultrasound, since every pregnancy is unique and they'll know best kung normal pa ba for how far along you are.