Stunted growth Candida albicans in human amniotic fluid in vitro.

The interaction of human AF with the pathogenic yeast Candida albicans was studied in vitro in 262 samples from early midtrimester and term gestations. Among 111 fluids collected between 15 and 18 weeks, 84% (93) manifested growth-inhibiting activity on 10(2) fungal cells/ml at 24 hr. This phenomenon persisted to a similar extent in late pregnancy. It could not be explained by a lack of nutrients in AF, since the addition of TSB failed to influence the proportion of active fluids. Depletion of the yeast cell glycogen reserve potentiated the degree of fungistasis achieved in several samples (p = 0.0009). Supplementation with either SDB or a physiologic concentration of carbon dioxide effected a complete reversal (p less than 0.0001). Preliminary data as well as overall results suggest that the absolute transferrin content and its pH-dependent saturation with iron are key factors invovled in the growth-inhibiting activity. Germ tube formation was unrestricted in 115 second trimester fluids studied. Human AF probably helps to prevent congenital candidiasis, and this protective function must be better defined.