Fetal biparietal diameter and head circumference measurements: results of a longitudinal study in Zimbabwe.

In a longitudinal study in Harare, Zimbabwe, 1233 biparietal diameter and 857 head circumference measurements were obtained from the fetuses of 190 women. Weekly mean values and the two standard deviations were calculated for both the biparietal diameter and head circumference from 12 to 40 weeks of pregnancy. There was little difference between these values and some Caucasian and African standards. Comparison was also made of the weekly biparietal diameter growth rate between our results and those from one study in West Africa. The possible reasons for the differences are explained.