[Sonographically detectable changes in placental structures in pregnancy. 3. Statistical, comparison of the frequency distribution of placenta stages 0-3 in newborn infants with a birth weight of less than 2,500 grams].

The utilisation of sonographically provable changes of placental structures in 131 pregnant woman (277 examinations) shows in cases with newborn infants with a weight of birth under 2500 gram than the stage 0 is found significant frequent to the 32. week of pregnancy, the stage 1 to the 40. week of pregnancy, the stage 2 between the 29. and 40. week of pregnancy and the stage 3 between the 31. and 40. week of pregnancy. The stages 0, 1 and 2 influence in comparison with the newborn infants with a weight of birth between 2500 gram and 3999 gram not the weight in newborn infants under 2500 gram. The stage 3 will prove frequent in 13,5 times before the 34. week of pregnancy as in the comparison group with normal weight of birth.