Dr. Bryant et al., LIMITED CLINICAL UTILITY OF MIDTRIMESTER FETAL MORPHOMETRIC PERCENTILE RANKINGS IN SCREENING FOR BIRTH-WEIGHT ABNORMALITIES, American journal of obstetrics and gynecology, 177(4), 1997, pp. 859-863
OBJECTIVE: Our purpose was to determine whether midtrimester fetal ult
rasonographic morphometric percentile rankings are sensitive screening
tests for preterm labor or birth weight abnormalities. STUDY DESIGN:
Stepwise multiple regression and chi(2) analysis were used to identify
midtrimester fetal measurements predicting birth weight and gestation
al age. Receiver-operator characteristic curves were used to evaluate
abdominal circumference percentiles as a test for large-for-gestationa
l-age and small-for-gestational-age infants. RESULTS: Extremes in abdo
minal circumference and head measurement percentiles were associated w
ith large-and small-for gestational-age infants but not with preterm d
elivery. Abdominal circumference predicted birth weight in regression
analysis; however receiver-operator characteristic curves showed abdom
inal circumference percentiles to be poor screening tests for large-or
small-for-gestational-age infants. The positive predictive value of 1
0th and 90th abdominal circumference percentiles for small-and large-f
or-gestational-age infants was <20%. CONCLUSION: Midtrimester percenti
le rankings offer no clear benefit in targeting fetuses with potential
birth weight abnormalities or risk of preterm delivery and may provid
e clinically misleading information.