A case of malformations of the fetal central nervous system following hypervitaminosis A in early pregnancy is reported. The mother was treated with 150 000 IU vitamin A daily during gestation days 19 to 40. Determination of urinary oestriol carried out in the 42nd week of pregnancy revealed a very low excretion (4.2-6.6) mumol/24 h). Induced delivery resulted in a microcephalic child who died after 18 min. The child had multiple malformations of the central nervous system and very small adrenal glands (1.5 g; normal 11 +/- 4 g). The very low urinary oestriol excretion is well explained by the hypoplastic adrenals, which in turn can be related to insufficient ACTH stimulation, a condition similar to anencephaly. The malformations shown in the present case are considered to be related to the high doses of vitamin A given to the mother, and the authors wish to warn against uncritical use of high doses of vitamin A in whomen of childbearing age.