Nomogram of fetal right portal vein diameter at gestational age 30 to 35 weeks and prediction of small for gestational age at birth

Abstract

Aim: To construct the nomogram of fetal right portal vein (RPV) diameter at 30 to 35 weeks' gestation in Thai pregnant population and the use of RPV measurement to predicting small for gestational age (SGA) fetus. Methods: A prospective, cross-sectional study of singleton pregnancies at antenatal visit between 30 and 35 +6 weeks of gestation in single center, Bhumibol Adulyadej Hospital (BAH) was conducted from January to August 2020. Ultrasonography of fetal biometry and RPV diameter measurement were performed as well as immediate newborn birth weight measurement. The nomogram of fetal RPV was developed for standardization for Thai people. Results: A total of 219 singleton pregnant women were enrolled and ultrasonographic measurement of RPV and fetal biometry was obtained. Mean maternal age and gestational period were 29.4 years and 33.0 weeks, respectively. One third of participants were classified as obese. RPV diameter ranged from 1.85 to 6.07 mm and increased linearly with gestational age. The optimal threshold of RPV diameter for diagnosis SGA was less than 3.06 mm with area under ROC curve at a level of 0.613 (95%CI 0.496 to 0.731). Sensitivity and specificity were 38.46% and 83.94%, respectively. There was no fetal death or neonatal morbidity in the present study. Conclusion: RPV diameter increases in size depending on gestational age. RPV diameter at 30 to 35 +6 weeks gestation was a useful measurement for SGA prediction. RPV measurements greater than 3.06 mm strongly indicated normal fetal growth.

How to enhance the applicability of a risk prediction model for term small‐for‐gestational‐age neonates in clinical settings?

“…Our model is considered among the best performers compared with many past reports, which largely focused on the period in late pregnancy close to term (35-37 weeks of gestation) 28,29 and confined to preterm or high-risk pregnancies 30,31 that limited their clinical use for prevention. Others have also used features such as the diameter and/or the blood flow of the right portal vein, 32,33 but with low predictability and sensitivity. Doppler velocimetry that measures the blood flow between the uterus and the placenta has been shown to predict SGA with superb specificity and sensitivity.…”

Altered Right Portal and Umbilical Vein Doppler Parameters in Fetal Macrosomia Resulting from Pregestational andGestational Diabetic Mothers: A Prospective Case-Control Study

“…[1][2][3] After explaining the physiologic blood distribution, Doppler investigation of these vessels has been performed in some fetal disorders such as fetal growth restriction (FGR) and macrosomia, where these vessels' blood flow may be theoretically affected. [4][5][6][7][8] The left portal vein is dominant because it is the continuation of the umbilical cord in fetal life and portal vein studies have mostly focused on the left portal vein. 6,9 Fetal abdominal circumference (AC) is important in the diagnosis of fetal macrosomia and FGR and the estimation of fetal weight.…”