A diastolic notch is a blood flow pulse similar to the diastolic of the heart, in the uterine artery
. It reflects the relationship between the vessels and muscles of the uterus
with the growing placenta. It is usual for this to be seen until 22 weeks of gestation, but it disappears later. Presence of an early diastolic notch in the uterine artery in the third trimester is an indication of the perinatal outcome. It is an indicator of preeclampsia
or fetal growth retardation and increased rate of operative delivery due to fetal distress
followed by prolonged perinatal care. I think that you should be under constant supervision of your doctor and follow advice. Wish you a safe delivery.