[Cystic hygroma of the neck. Antenatal diagnosis, prognostic factors, management. 42 cases].

The authors report a series of 42 cases of cystic hygroma of the fetal neck diagnosed antenatally. Cystic hygroma is one of the signs suggestive of chromosomal or congenital abnormalities that occur very early and are very specific. A diagnosis can be made from the ninth week of amenorrhoea onwards by vaginal ultrasound. 73% of the karyotypes that were obtained were abnormal. The large majority (54% = have Turner's Syndrome, but there are some of the karyotypes that are normal. Our figures correspond with those in the literature. Several factors were analysed to show the influence of this pathology on the prognosis which is overall awful (only 11.5% of infants were born alive an only 7.5% survived). Factors for a good prognosis would be a normal karyotype and the spontaneous resolution of cystic hygroma in the second trimester of the pregnancy. Hydrops is a factor of poor prognosis and it occurs in 60% of cases of cystic hygroma but unfortunately 30% of cases where the karyotype is normal have severe malformations (bone, kidney and digestive tract). The resolution of the cystic hygroma in the second trimester of pregnancy does not exclude an abnormal karyotype or a severe congenital malformation associated with the condition. As cases do recur in the same family there is an indication that a suspicion that the condition can be an autosomic, recessive or even dominant condition. The authors advise that the diagnosis should be made early and thoroughly in order to carry out chorionic villus sampling to determine the karyotype early before the very important sign for abnormality disappears as it may.