EP08.47: Evaluation and interest of bone maturation during fetal ultrasound

Fetal bone maturation is important during postnatal radiographic diagnosis in context of fetopathological examination to determine chronological bone age, estimate intrauterine growth retardation (IUGR), term of uterine fetal death (UFD), or to guide fetal pathology. We studied feasibility of studying standardised bone maturation during an ultrasound examination (US) by transposing ossification points described according to D. Eurin atlas. Feasibility of fetal US to estimate and check gestational age and bone maturation on a series of 100 eutrophic fetuses whose pregnancy is progressing and with physiological growth. US are staged of 14 steps throughout pregnancy at chronological terms using known classifications and technically through the use of 3D/4D bone echo software and high frequency probe. From 100 fetuses presenting progressive terms: we were able to highlight 14 beginning following steps (+/- 1GW): 12-13 GW: P1 hands, P2 of hallux; 14-15GW: mineralisation C6-S2, middle phalanges hands except P2 5th finger; 16GW: P2 of 5th finger, P1 toe phalanges; 17-18GW: ischium, cervical vertebral bodies, P2 toe phalanges, 3 sacral vertebrate; 20GW: upper semi-circular canals (SCC); 22GW: lower incisors, 4 sacral vertebrate; 23GW: calcaneum; 24GW: total SCC, upper and lower incisors; 25-26GW: lower canines, 5 sacral vertebrate; 27-29GW: talus, sternum; 31-32GW: molars, hyoid bone; 32-35GW: lower femoral (Béclard); 35-37GW: upper tibial (Todt); 39GW: superior humerus, cuboid, coccyx. Algorithm for synthesis of estimated age is in progress. Bone maturation can be accessible in fetal US, but depends on approach, gestational age and echogenicity. Main difficulty is to see dental germs which is easier to visualise in postnatal profile radiography. Estimating bone age can be interesting in cases of IUGR and UFD but also in some hormonal pathologies such as diabetes or Graves' disease presenting advances in bone maturation, but also for some constitutional bone diseases before carrying out a Bone CT. IA recognizing and evaluation could be interesting in this project.