Follow-up of infants with amniotic fluid trisomy 20 mosaicism.

The finding of trisomy 20 mosaicism in amniotic fluid is a cause of considerable anxiety for both physicians and parents. Although the significance of this finding is still not clear, some reassurance can be given to prospective parents, since the outcome has been normal in all reported pregnancies carried to term. Follow-up information on psychomotor development of these infants is needed in order to provide better genetic counseling to these families. We have followed three infants who have had normal growth and psychomotor development up to approximately 2 years.