Sirenomelia apus after trimethoprim exposure: first-trimester ultrasound diagnosis-a case report

Abstract

We report the early prenatal ultrasound diagnosis of sirenomelia apus at 12+4 weeks in a patient with trimethoprim exposure in the vulnerable period. First-trimester scan revealed a malformed fetus with one femur, one small tibia, no feet, intraabdominal unilocular cystic structure, and two-vessel umbilical cord with allantoic cyst.

Ultrasound visualization with two/three/four-dimensions was helpful in the process of parental counseling.

Keywords

• Sirenomelia apus
• trimethoprim
• exposure: first-trimester
• ultrasound diagnosis