DOPPLER ASSESSMENT OF THE FETAL RIGHT AND LEFT PULMONARY-ARTERIES IN RELATION TO FETAL POSITION AND GESTATIONAL-AGE

Aim of the study: To analyse the feasibility of colour and spectral Do ppler assessment of blood flow in the fetal right (RPA) and left (LPA) main pulmonary arteries in relation to fetal position and to gestatio nal age. Study design: The fetal position was a priori divided into 3 types, depending on whether the fetal heart was visualised apically (T ype 1), from the right side (Type 2) or from the left side (Type 3). T hree groups A (19-25 weeks' gestation), B (26-32) and C (33-39) includ ing 33 consecutive pregnancies each, were examined to document the fet al position as well as the rare of the successful Doppler examinations of the RPA and/or LPA. Results: The fetal position Type 2 was most co mmon throughout gestation (in group A=42%, B=36%, C=51%) followed by t he type 3 and then type 1. The rate of successful Doppler records from the RPA and LPA depended on the fetal position: In Type 2 RPA in 98%; in Type 3, LPA in 100%; but the apical approach was not effective (<4 0%). Depending on gestational age, the success rates for a Doppler exa mination of at least one vessel were high (>85%), whereas successful e xamination of both vessels was unlikely (12%). Conclusions: In the sec ond half of pregnancy, independent of fetal position, Doppler examinat ion of at least one pulmonary artery is successful in most cases, wher eas the assessment of bath vessels is rather difficult.