a case of neonatal birth with congenital bilateral femoral deficiency undetected in prenatal ultrasound

Background: prenatal ultrasound plays an important role in the early and accurate evaluation of the congenital skeletal and non-skeletal abnormalities of the fetus and is effective in predicting pregnancy outcomes. congenital femoral deficiency (cfd) is a rare complicated and non-hereditary anomaly that includes the hypoplasia of a portion of the femoral bone with shortening the lower limb. case report: the aim of this study was to report a rare case of neonatal cfd, which was not detected in prenatal ultrasound. in this study, we presented the case of a 28-year-old multiparous woman with the gestational age of 39 weeks hospitalized for labor pain. she had a history of two to three irregular prenatal visits and her only pregnancy ultrasound was related to late pregnancy, which reported a healthy live fetus with a cephalic presentation, which was in 35-36 weeks of gestation according to biparietal diameter (bpd) and femur length (fl). finally, normal vaginal delivery occurred and a neonate was born with a severe bilateral cfd with deformity and immobilization of the lower limbs. conclusion: it seems that in order to early diagnosis and appropriate case management, it is necessary to differentiate both femoral and tibial bones in routine ultrasound more precisely plus measuring their length. the case also strongly emphasize the need for ultrasonic examination of fetal anomalies for all pregnant women.