The authors present 6 observations of in utero detected abdominal wall defect : 2 laparoschisis and 4 omphaloceles. In three cases the diagnosis have been done prior week 20, by systematic AFP assay for amniocentesis performed for cytogenetic or metabolic reasons; the pregnancy was terminated. In three other cases, the pregnancy was complicated by hydramnios after week 30; amniocentesis for AFP and echography were performed to detect fetal malformations after associated with hydramnios. The detected abdominal wall anomaly was not alone: two fetus had an abnormal caryotype (trisomy 18), three other presented a polymalformative syndrome, a Beckwith-Wiedemann syndrome was discussed for the last child. The in utero diagnosis of omphalocele or laparoschisis implicates difficulties for genetic counselling, particularly if the diagnosis is done prior week 20. These anomalies can be treated with surgical management, but frequency of associated malformations must be underlined. it is important for genetic counselling to know the family history, the amniotic fluid cells caryotype, and an ultrasound scanning performed to reveal any other malformations.