Background: The aim of this study is to analyse several theories of pathogenesis of cystic hygroma, its correlation with chromosomal abnormalities and the indicators of poor or good prognosis.
Experimental design: This is a retrospective study that evaluates all cases of cystic hygroma seen during the four-year period from January 1994 to December 1997.
Setting: This study was performed in the center of prenatal diagnosis of institutional hospital in Caserta.
Patients: All cases of fetuses with cystic hygroma were examined in 2100 pregnant female who visited the ambulatory.
Interventions: The modality of diagnosis of this pathology and the presence of abnormal maternal serum levels of alpha-fetoprotein, human chorionic gonadotropin and unconjugated estriol were evaluated. Moreover, the presence of karyotype abnormalities or other non chromosomal abnormalities were also evaluated. Prognostic indicators such as the presence of septae seen by sonography were examined.
Results: Nine fetuses with cystic hygroma were diagnosed sonographically. Septae were identified in six cases. Chromosomal abnormalities were found in five cases. Two cases presented Turner's syndrome and one case Downs' syndrome. There were two cases with associated anomalies. The amniotic fluid alpha-fetoprotein (AFP) levels were high in all cases.
Conclusions: Cystic hygroma is a malformation of the lymphatic system that is diagnosed by ultrasound very well from the first quarter of pregnancy. It is frequently associated with chromosomal and non chromosomal abnormalities. The presence of septae in it and amniotic fluid AFP levels are prognostic indicators.