[Contribution of array CGH in the management of fetal nuchal translucency]

OBJECTIVES

Increased nuchal translucency and cystic hygroma have a neonatal prognosis, when the karyotype is normal, which depends on the findings during the medical follow-up. Array comparative genomic hybridization (aCGH) has been systematically included in this follow-up by prenatal diagnosis teams. There are no guidelines and little information on the advantages of carrying out this test systematically. The aim of our study is to evaluate the contribution of the aCGH in the medical follow-up.

METHODS

Fifty-one patients were included during 18 months and followed till the end of their pregnancy in prenatal diagnosis centers in Brest and Amiens. Inclusion criterion was a nuchal translucency above 3,5mm on the first trimester ultrasound. A fetal DNA ChromoQuant and aCGH analysis on chorionic villi sampling, and an ultrasound at 18 weeks of gestation were performed during the follow-up.

RESULTS

The aCGH was decisive in only 2 cases. The ultrasound at 18 weeks gestation seemed to be more sensible in the detection of an abnormality. When the aCGH relieved an abnormality, the ultrasound permitted already to detect the presence of a deformity. In 10 cases, the aCGH could not be interpreted on the chorionic villi sampling. In 9 cases, an amniocentesis was performed in order to obtain this result.

CONCLUSION

Given the results of this study, the aCGH was rarely determinant or decisive on the realization of a therapeutic abortion. These elements make us reflect on the necessity of maintaining this test before 14 weeks of gestation or propose it as a second-line test after the ultrasound shows signs at 18weeks of gestation.

[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.