Which ultrasound or biochemical markers are independent predictors of small‐for‐gestational age?

LW Law, TY Leung, DS Sahota… - … in Obstetrics and …, 2009 - Wiley Online Library
LW Law, TY Leung, DS Sahota, LW Chan, TY Fung, TK Lau
Ultrasound in Obstetrics and Gynecology: The Official Journal of …, 2009Wiley Online Library
Objectives To investigate which ultrasound or biochemical markers in both the first and the
second trimesters are the best predictors for fetal growth and small‐for‐gestational age
(SGA). Methods This was a prospective study of 619 Chinese women with a singleton
pregnancy. At 11 to 13+ 6 weeks, fetal crown–rump length (CRL), placental volume (PlaV),
uterine artery pulsatility index (UtA‐PI), and the maternal serum levels of pregnancy‐
associated plasma protein‐A (PAPP‐A) and free β‐human chorionic gonadotropin (β‐hCG) …
Objectives
To investigate which ultrasound or biochemical markers in both the first and the second trimesters are the best predictors for fetal growth and small‐for‐gestational age (SGA).
Methods
This was a prospective study of 619 Chinese women with a singleton pregnancy. At 11 to 13 + 6 weeks, fetal crown–rump length (CRL), placental volume (PlaV), uterine artery pulsatility index (UtA‐PI), and the maternal serum levels of pregnancy‐associated plasma protein‐A (PAPP‐A) and free β‐human chorionic gonadotropin (β‐hCG) were measured. Fetal biparietal diameter, femur length, abdominal and head circumference, PlaV and UtA‐PI were then measured at 18–22 weeks. All markers were transformed to gestational age‐specific Z‐scores or multiples of the median (MoM). Birth weights were also transformed to Z‐scores using the individualized gestational age‐related optimal weight based on a locally derived nomogram. The relationship between all markers and the customized birth weight were examined, and their predictive powers for SGA were examined by regression analysis.
Results
Univariate analysis revealed that all markers except free β‐hCG correlated with birth weight Z‐score. After multiple linear regression analysis, only PlaV, UtA‐PI and CRL in the first trimester, and PlaV and UtA‐PI in the second trimester, stood out as independent markers. Logistic regression analysis showed that PlaV was the only independent first‐trimester predictor of SGA, and in the second trimester both PlaV and UtA‐PI were independent predictors. The sensitivity of these first‐ and second‐trimester markers in predicting SGA were 41% and 45%, respectively, at a false‐positive rate of 20%. Combining them did not significantly improve prediction of SGA.
Conclusions
Among the various known ultrasound and biochemical markers, only the first‐trimester PlaV and the second‐trimester PlaV plus UtA‐PI are independent predictors for SGA. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
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