VP13.05: Prenatal ultrasound diagnosis of fetal limb skeletal dysplasia

Abstract

To explore the characteristics of fetal limb skeletal deformities by prenatal ultrasound. The prenatal ultrasound results of fetuses with skeletal dysplasia of extremities from October 2016 to January 2019 were retrospectively analysed. A total of 164 cases of abnormal limb skeletal development were detected from 12 weeks to 37 weeks of pregnancy. 15 cases presented with short and angled long bone, short ribs, small thorax, low ossification of skull, short nasal bone or abnormal spine, which were fatal skeletal malformations. There were four cases of fetal limb long bones less than -4SD and 51 cases of club foot. There were 12 cases of overlapping fingers, 4 of which were confirmed to be Trisomy 18. There were seven cases of middle phalangeal bone loss in both hands and 10 cases of dysplasia or deletion of radius with carpal abnormality. In addition, we found three cases of metacarpal and phalangeal abnormalities. Four cases of amniotic band syndrome were characterised by finger shortage, toe shortage, lower extremity abnormality, skull deformation, encephalocele, abdominal fissure, etc. A case of six fingers and six toes with bilateral fetal polycystic kidney and occipital encephalocele was confirmed as Meckel–Gruber syndrome after delivery. Two cases of cleft hand and foot were found. There were four cases of lower extremity rigidity, two cases of which were combined with femur less than -2SD, excessive amniotic fluid, mild neck edema and bilateral small lung, suspected of Pena Shokeir syndrome. One fetus was diagnosed as spinal stenosis, combined with extremely flat face and absent nasal bone. Postnatal x-ray showed that the terminal finger was short and gene chip examination showed no abnormality, which was a rare abnormality of macular achondroplasia. The common missed cases were polydactyly and syndactyly. Three-dimensional ultrasound is intuitive and can provide more information. Prenatal two-dimensional and three-dimensional ultrasound play an important role in the detection and classification of fetal limb skeletal malformations.