Klippel-Trénaunay-Weber Syndrome: Prenatal Diagnosis and Review of the Literature.

Klippel-Trénaunay-Weber syndrome (KTW) is a rare congenital disease, representing a challenge in prenatal diagnosis due to overlapping characteristics with other syndromes and no specific genetic markers known to date. We have collected all the cases present in the literature on the prenatal diagnosis of KTW, emphasizing common ultrasound findings that can guide the clinician and genetics to the prenatal counseling. Thus, we collected all the information about the postnatal prognosis and the necessity for treatment. Our review of 44 cases highlights the typical common features: hemihypertrophy, predominantly affecting the right leg, with cystic lesions extending to the trunk or upper limbs and rare internal organ involvement. Prenatal complications, including hydrops and polyhydramnios, emphasize the need for a careful ultrasound follow-up. Despite no identified genetic mutation, genetic counseling and invasive testing are recommended. Mortality rate due to a severe complication known as Kasabach-Merritt syndrome, underlines the importance of early diagnosis and accurate management strategies. Prenatal diagnosis of KTW, guided by ultrasound findings and genetic counseling, could help with informed decision-making and optimal care planning.