Abstract: Proximal femoral focal deficiency (PFFD) is a rare congenital skeletal malformation characterized by variable underdevelopment of the proximal femur. This report presents a 30-year-old, G4P3+0 woman with a pregnancy complicated by a fetus with left-sided PFFD with breech presentation and small-for-gestational-age features. Delivery was performed by elective cesarean section at 38 weeks showed a female neonate with confirmed unilateral PFFD affecting the left femur, classified as Aitken type D, with no associated congenital anomalies. The parents were referred for pediatric orthopedic, prosthetic, and rehabilitation counselling. This case highlights the importance of meticulous prenatal ultrasonography in detecting rare skeletal anomalies such as PFFD. Even in the absence of advanced imaging, 2D ultrasound can support timely diagnosis, parental counselling, and early multidisciplinary management to improve long-term functional outcomes. Plain Language Summary: Proximal femoral focal deficiency (PFFD) is a very rare condition where the upper thigh bone does not fully develop, causing one leg to be shorter than the other. This may affect a child’s mobility and quality of life as they grow. In this case, PFFD was detected during pregnancy through routine ultrasound at 32 weeks. After birth, the diagnosis was confirmed by X-ray, which showed the left thigh bone was much shorter than the right. No other abnormalities were found. Finding PFFD before birth is important because it gives parents time to receive counselling and allows doctors to plan treatment after delivery. While advanced imaging can improve detection, this case shows that careful use of standard ultrasound can still identify the condition. Early diagnosis helps families access orthopedic, prosthetic, and rehabilitation services that can improve long-term mobility and daily function for affected children. Keywords: fetal detail scan, case report, intrauterine diagnosis, prenatal ultrasound, proximal femoral focal deficiency, skeletal dysplasia
Arioseno et al. (Sun,) studied this question.