 Hello, everyone. I'm Dr. Lakshmi Johan, JR2 Department of Radio Diagnosis in Dr. D.Y. Partley University School of Medicine, Navey Mumbai. Today, I'm here to present on antinatal approach to skeletal dysplasia. The aim is to conduct step-by-step approach in a suspected case of antinatal skeletal dysplasia. Skeletal dysplasia, also known as osteocondro dysplasia, are a large heterogeneous group of disorders consisting of skeletal abnormalities. The primary etiology is genetic mutation, which usually begins at an early stage of the fetal development and continues to evolve throughout the life. According to Nozology Committee of International Skeletal Displasia study, the latest in the 10th version of Nozology comprises 461 different diseases, which are further divided into 42 groups based on their clinical radiological and molecular phenotype. Fetal skeletal dysplasias are difficult to diagnose in neutro due to numerous factors, including a large number of skeletal dysplasia and their phenotypic variability with overlapping features, absence of precise molecular diagnosis and systemic approach for many disorders, in efficacy of ultrasound to provide an integrated view, variability of time at which finding manifests in some skeletal dysplasia. Their overall prevalence has been reported to be 2.3 to 7.6 per 10,000 births in various studies. Method, a 33-year-old G3P2L1 came for an anomaly scan. Geologic P9R3 ultrasound machine with curvilinear probe was used. Step-by-step fetal anatomical survey was done. In first gravita, the findings were similar as the current case, which was aborted and no tests were done. Second gravita was normal. On anatomical survey of the third gravita, following findings were seen. Here we can see the stippling of the femoral epiphysis. These arrows, green arrows are representing stippling of femoral epiphysis. Stippling means focal bony calcifications which appear dot-like. Here we can see the depress nasal bridge which is known as saddle nose. Saddle nose means collapse of the nasal bridge with decrease in the nasal height. In this case, there was increased frontal nasal angle which was 151 degree. The normal frontal nasal angle in 14-39 weeks of gestation is 126 plus minus 7 degrees. However, in this case, the nasal bone length was normal. Here we can see the flat face. The other findings were polyhydrome news, the upper limb lower and rest of the lower limbs were normal, thorax, pelvis, spine, hand, fore, skull, all were normal. The above positive findings were suspicious of skeletal dysplasia. The patient was advised for further evaluation with amniocentesis exome sequence. In a suspected case of skeletal dysplasia on antenatal scan, a detailed evaluation of skeletal system needs to be performed. The following points need to be evaluated. In upper and lower limbs, the length of the long bones, absinthe, malformation, hypoplasia which are resomelia, mesomelia, resomesomelia, acromelia should be looked for, curvature, degree and the mineralization of the bone and fracture should be looked for. Femur foot length ratio should be normal which is 1. If it is less than 1, it is suggestive of skeletal dysplasia. In thorax, we have to look for markers of pulmonary hypoplasia. Some of these are chest circumference less than 5th percentile, chest abdo circumference ratio less than 5th percentile, chest trunk length ratio less than 0.2 and femoral length and abdominal circumference ratio less than 0.16. We have to look for clidocranial dysplasia which is absence of hypoplastic clavicle, chemtomirlic dysplasia which is absent scapula. In hands and feet, we have to look for polydictile, syndictile and clino-dictile. Others include club feet, hand, rocker bottom feet, etc. In pelvis, achondroplasia, limb pelvic hypoplasia, femoral hypoplasia, unusual feces syndrome should be ruled out. In skull, head circumference and biparital diameter are to be looked upon to exclude macrosyphaly. Head circumference is to abdominal circumference ratio, shape, mineralization, degree of ossification, interorbital distance to exclude hyper and hypotellurism. Brecicephaly, scapicephaly, craniosynthesis should be ruled out. Others include macrognathia, short upper lip, abnormal shaped ear, frontal bossing and cloverleaf skull. In spine, we need to rule out relative length, total length and curvature, mineralization of vertebral bodies and neural arches. In our cases, the following findings were noted. Binder syndrome, which is also known as mexilonasal dysplasia, is a rare congenital condition which develops in the first trimester of pregnancy and is characterized by facial features. Some of these include erinoid face, shortened nose with depressed nasal bridge, flat faces, intermexillary hypoplasia, nasal mucosa atrophy, anterior nasal spine agenesis, a convex upper lip, underdevelopment of frontal sinuses and anomalies of cervical spine. Binder syndrome is phenotype with several causes amongst which most important is chondrodysplasia punctata. In some cases of Binder syndrome, only facial features are present, while in others, full clinical picture of x-linked, brecicephalyngic chondrodysplasia punctata is seen. Chondrodysplasia punctata, this includes various group of disorders in which calcific stippling of cartilage and periarticulars of tissue is seen. It is of two type, resomalic and non-resomalic type. It has very poor prognosis. Some radiological features are very short humerus and relatively short femur with some metaphyzels spleen. Facial features include flat face and small saddle nose. Acytis and polyhydromonous may also be seen. In our case, the following finding was seen on genetic testing. The disease was diagnosed as chondrodysplasia punctata. Inheritance was x-link dominant. Zygocity was heterozygous or hemizygous. Some common skeletal dysplasias and their salient antinatal radiological features include first achondroplasia, which includes short femur length, often less than 5th percentile, trident-shaped hand, frontal bossing, depressed nasal bone. Thanatotrophic dysplasia includes short, thick, bold bones especially of the lower extremities. Thicken soft tissue of extremities, narrow thoracic cavity, comparatively large head with frontal bossing and clover leaves skull may also be seen. In osteogenesis imperfecta, decreased calvarial ossification, fracture which may result in shortening or angulation of the long bones and polyhydromonous are seen. Echondrogenesis includes micromelia, floating head appearance may be seen, micrognathia and macrocephaly can be seen. These are the references. Thank you.