Background Ultrasound is commonly used for the antenatal assessment of a fetus and it can provide functional and haemodynamic data in addition to anatomical details. The accuracy of the former is dependant on angle of insonation, maternal habitus and fetal position. Phase contrast cardiovascular magnetic resonance (PC CMR) has emerged as a clinical tool for blood flow quantification but its use in the foetus has been hampered by the need for gating with the fetal heart beat. Previously described metric optimized gating (MOG) technique has been successfully used to measure fetal blood flow in late gestation foetuses on a 1.5T MRI magnet. However, there is increasing interest in performing foetal cardiac imaging using 3.0T MRI. We describe our pilot data of fetal blood flow measured in 3.0T MRI using MOG technique. Methods Fetal blood flows were quantified in 5 subjects at late gestational age (35-38 weeks) of which were two normal and three pregnancies with ventricular size discrepancy. The data were obtained on 1.5T and 3.0T (Siemens Avanto and TRIO, respectively) within the same day using a previously described protocol. After MOG reconstruction of PC MR data, blood flow was quantified by using Q flow (Medis, NL) and adjusted for fetal mass. Reproducibility of flow measurements at the two field strengths was assessed by Pearson correlation coefficient (R 2 ), linear regression and Bland Altman analysis.