What information is permitted by cytodiagnosis was tested with reference to 2182 vaginal smear examinations in 882 pregnant women at the end of pregnancy. There is no cytological smear type from which the degree of fetal maturity can be determined beforehand with satisfactory certainty; in practice, one must work with diagnosis by exclusion, which, however, can be of great help: If a "before term" smear type is found, a genuine post-term birth can be excluded on the basis of the cytological examination alone with high degree of probability (98.3%). With an "at term" type of smear the birth of an immature child is nor very probable (1.7%); but an over-maturity may already exist (6.9%). A genuine post-term infant can only be expected in barely half of the cases (45.7%) with a "post-term" cell picture. A satisfactory assessment of the probable date of birth is only possible with the "at term" type of smear: in the great majority of cases (80.8%) a birth within 5 days can be counted on with this type of smear. The possibilities of "term cytology" in "programmed births" are referred to.