Clínica de Diagnóstico por Imagem – CDPI, Rio de Janeiro - Brazil.

Introduction

Hydrops fetalis is characterised by generalised soft tissue edema (anasarca). It is a non-specific finding in a wide variety of fetal and maternal disorders, including metabolic, hepatic, gastrointestinal, pulmonary, cardiovascular, neoplasms (sacrococcygeal teratoma, placental chorangioma, etc) and immune. The diagnosis can be made early by ultrasound. Janiaux et al (1990) reported chromosomal defects in 16% of 600 fetuses with non-immune hydrops (trisomy 21 in 35% of the cases). Nicolaides et al 1992 found 12% of chomosomal abnormalities in 214 fetuses with hydrops, mainly trisomy 21.

Esophageal atresia is a congenital failure of the full esophageal lumen to develop. There is an associated tracheoesophageal fistula in 90% of the cases. The diagnosis can be made by ultrasound when polyhydramnios is associated with a small fetal stomach in repeated scans. Nicolaides et al (1992) found in 20 fetuses with no visible stomach, trisomy 18 in 85% of them (in all cases there were additional abnormalities).

Case report

We report the prenatal diagnosis of hydrops fetalis and esophageal atresia associated with trisomy 21. A 38-year-old healthy primigravida woman was admitted for evaluation to our ultrasound unit at 18 week's gestation because suspected hydrothorax. The diagnosis of trisomy 21 was made by amniocentesis in the same week. Sonography at 18 weeks revealed a small hydrothorax, which was no observed at 22 and 27 weeks. A new scan at 32 weeks revealed hydrops fetalis. Short femur, polyhydramnios and no stomach were observed in all scans. The heart was normal and fetal face was typical of trisomy 21. The termination of the pregnancy was carried out at 32 weeks by Cesarean section. A male infant weighing 2.960 g (apgar 1 at 1 min) died 4 hours later. The autopsy confirmed the ultrasound fidings.

Images 1, 2: Axial ultrasound view (18 weeks) shows hydrothorax (arrows). The stomach was not visualized.

Image 3: Coronal view (18 weeks) shows hydrothorax.

Images 4, 5: Axial and coronal scan of fetal body (32 weeks). Note edema of body wall (blue arrow) and important bilateral hydrothorax (red arrow).

Images 6, 7: Image 6 - ascites (red arrow) and skin edema (blue arrow) in a 32 week fetus with trisomy 21. Image 7 - polyhydramnios.

Images 8, 9: 3D view of the fetal face with microghnathia.

References

• Janiaux E et al.: Nonimmune hydrops fetalis associated with genetic abnormalities. Obstet Gynecol 75: 568-72, 1990.
• Nicolaides et al.: Ultrasonographically detectable markers of fetal chromosomal abnormalities. Lancet 340: 704-7, 1992.
• Nicolaides et al.: Fetal gastrointestinal and abdominal wall defects: associated malformations and chromosomal defects. Fetal Diagn Ther 7:102-15, 1992.