A young adolescent girl with trisomy 13 was admitted twice to the paediatric department: the first time because of haematocolpos due to uterus didelphys and unilateral transverse vaginal septum, and the second time because of heart failure due to ruptured sinus of Valsalva aneurysm. As a consequence of the historical early high mortality rate in trisomy 13, we are not aware of known complications in older patients. With better survival nowadays through childhood, we advise structural ultrasonographic cardiac and female genital screening in trisomy 13 patients reaching adolescent age.