[The antenatal diagnosis before 20 weeks of an omphalocoele and a failure of development of the abdominal wall (author's transl)].

We report 2 cases of malformations occuring in the region of the umbilicus which were diagnosed by amniocenteses before the 20th week of pregnancy (with levels of alphafetoprotein) and echography. Failure of development of the abdominal wall was only diagnosed for certain after the therapeutic abortion had been carried out. The omphalocoele was diagnosed for certain by echography at the 19th week after anencephaly and spina bifida had been eliminated in spite of an abnormally high rise in the level of amniotic fluid alphafetoprotein (100.000 microgram/l). We have not found any similar cases in the literature at this gestational age. These observations prove the value of combining the estimation of alphafetoprotein level in the amniotic fluid when making antenatal diagnoses because of the age of the mother (after the age of 38), with echography specially directed to searching for such apparent morphological abnormalities.