Inter- en intraobserver variabiliteit van de cerebroplacentaire ratio bij foetussen tussen de 32 en 40 weken zwangerschapsduur

Doppler ultrasound measurements are increasingly performed in clinical practice to detect signs of fetal compromise and distinguish the healthy fetus from the fetus at risk. These include the measurements of the pulsatility indices (PI) of the umbilical artery (UA) and the middle cerebral artery (MCA), as well as the Cerebro Placental Ratio (CPR – which is calculated by dividing the MCA PI by the UA PI). A low CPR is indicative of placental insufficiency and a marker of adverse outcomes. Although currently only used in clinical practice in the first en second trimester, the Doppler of the uterine artery (UtA) is also gaining more and more attention as a third trimester marker for placental function. However, the test characteristics of these Doppler measurements in the third trimester of pregnancy have not been adequately studied yet. The aim of this study is to assess the inter- and intra-observer variability of Doppler ultrasound measurements in fetuses between 32 and 40 weeks of gestation, including the MCA, UA, UtA and CPR.

We hypothesize that the inter-observer variability of the CPR, MCA, UA and UtA measurement will be less than intra-observer variability due to normal biological variation of cardiovascular control.

Primary outcome will be analysed after data completion of the 40 subjects. No follow up takes place.

Not applicable