Two pregnancies at risk for Fanconi’s anemia have been monitored by a cytogenetic method in the first trimester of gestation. The rate of chromosome breakage was evaluated in spontaneous mitoses from a direct preparation of trophoblasts in one case and from mitoses obtained from standard cultures and from mitoses treated with diepoxybutane in both cases. Cytogenetic studies were carried out also at 16 weeks from amniotic fluid cells in one case, and in fibroblasts sampled from the aborted fetus in the other. In all the experimental conditions the mean frequency of breaks/cell was in the range of controls, suggesting that the fetuses were unaffected by Fanconi’s anemia. In one case the results have been confirmed by chromosome analysis at birth.