Objective: We studied the outcomes of fetuses in whom cystic hygroma was diagnosed in the first trimester of pregnancy through the application of transvaginal ultrasonography.
Study design: In the period 1990 to 1991 22 fetuses with cystic hygroma were found. All fetuses had karyotyping and a complete ultrasonographic search for associated anomalies.
Results: Aneuploidy was found in seven of 22 fetuses: four trisomy 21, two trisomy 18, and one translocation. Monosomy X was absent in this series. In 15 of 22 cases there was a normal karyotype. In 10 of 15 euploid fetuses the small nonseptated hygroma resolved spontaneously. In four of 15 euploid fetuses other malformations were detected with ultrasonography (i.e., polycystic kidneys, coarctation of the aorta, bladder outlet obstruction, and fetal hydrops).
Conclusion: Whenever a cystic hygroma is suspected in the antenatal period, even if of small size, a structured and detailed ultrasonographic examination and fetal karyotyping are recommended.