Diagnostic ultrasound for detection of intrauterine growth retardation.

There were 738 fetal BPD determined in 468 normal obstetric patients between 16 and 43 weeks in whom (1) the size of the uterus on initial examination corresponded to the duration of amenorrhea +/- 1 week and (2) there were no complications during the pregnancy. The mean BPD +/- 2 S.D. was determined for each week. The rate of BPD growth was found to be 0.26 cm. per week from 18 to 38 weeks. One hundred random high-risk obstetric patients in whom the size of the uterus on initial examination corresponded to the weeks of amenorrhea +/- 1 week were studied. Two patterns of suspected IUGR are observed: one shows BPD values more than 2 S.D. below the mean; the other manifests a decreased delta BPD. Combinations of the two may be seen. At delivery seven neonates were identified who were SGA and could not be detected in utero by single BPD measurements.