The value of ultrasonic placental grading: no correlation with intrauterine growth retardation or with maternal smoking.

In a prospective study the usefulness of placental grading in detecting IUGR has been evaluated. Those who were echoscopically examined within one week before delivery were taken into the study (n = 137). Changes in placental tissue increased clearly as pregnancy progressed and in 42% (57/137) the placentae reached Grade III. Increasing placental grading is associated with normal maturation of the placenta. Post partum examination of the placenta correlated well with the echoscopic picture (accuracy = 80.5%). No relationship was found in an unselected group between Grade III and IUGR at term. When a Grade III placenta was first seen before 36 weeks, in three out of five cases a growth retarded neonate was born. The effects of maternal smoking habits during pregnancy on birth weight and placenta were examined. There were no significant differences in mean placental weight, placental ratio and placental grading as the amount of cigarettes increased. The mean birth weight and birth weight percentile decreased significantly when the mother smoked more than 10 cigarettes per day.