Sonographically detectable changes in placental structures in pregnancy. 5. Statistical comparison of the frequency distribution of placental stages 0-3 in newborn infants in a pregnancy of less than 37 weeks duration

The analysis of sonographically provable changes of placental structures in 97 pregnant women (202 examination) shows in cases with a duration of pregnancy less than 37 gestational weeks that stage 0 could be found statistically significant more frequent until the 32nd week of pregnancy, stage 1 in the whole pregnancy, stage 2 and 3 between the 29. and 36. gestational week. Stage 0 and 1 don't effect prematurity; however stages 2 and 3 could be proved before the 32nd or 34th week of pregnancy in 41 or 100% of examination respectively and effect a premature birth. Stage 2 could be proved 2,8 times more frequent and stage 3 4 times more frequent in premature babies than in newborns with a normal duration of pregnancy.