[First-trimester cystic hygroma: prenatal diagnosis and fetal outcome].

OBJECTIVES: To describe the ultrasonographic (US) and fetal karyotyping data of fetuses with cystic hygroma diagnosed in the first trimester.

PATIENTS & METHODS: Maternal and fetal data of 69 consecutive fetal cystic hygroma were analysed between 2002 and 2009.

RESULTS: The mean size of the cystic hygroma was 6.3 mm ± 2.4 mm. US abnormalities were present in 54% of cases (37/69) (essentially hydrops fetalis in 45%), with an unfavourable prognosis (P=0.006). Chromosomal abnormalities were present in 53% of cases (36/68) (including 44% of Down syndrome). The rate of unfavourable outcome of pregnancy was 71% of cases (49/69) and was associated with the oldest mothers (P=0.011). In the chromosomally normal pregnancies, there were 59% (19/32) fetus with no apparently abnormalities. Among these 19 children, 13 have been followed up until an average age of 5 years and a half, the infant development was strictly normal.

DISCUSSION AND CONCLUSION: The current results suggest to look for the poor prognosis data: nuchal thickness superior to 6 to 6,5 mm, presence of a hydrops fetalis and/or US abnormalities, fetal karyotyping and/or US evolution of cystic hygroma.