Nomogram of Placental Thickness, Placental Volume and Placental Vascular Indices in Healthy Pregnant Women between 12 and 20 Weeks of Gestation
Vitaya Titapant MD*, Panida Cherdchoogieat MD*
Affiliation : * Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To generate the nomogram of placental thickness, volume, and vascular indices in healthy pregnant women
between 12 to 20 weeks of gestation.
Material and Method: An experimental cross sectional study of pregnant women, which were categorized into nine groups
according to their gestational age ranging from 12 to 20 weeks of gestation, was done. Placental parameters that included
placental thickness, volume, and vascular indices were measured using a Voluson E8 ultrasound machine. The measurements
were correlated with gestational age.
Results : Two hundred ninety four subject were included in this study. The study indicated that the placental thickness
and volume significantly increased with gestational age (rp = 0.481, p<0.001 and rp = 0.837, p<0.001). The correlation
between the placental volume and gestational age can be formulated according to this equation: Placental volume (cm3) =
e7.584-42.45(GA ); R2 = 0.76. Nonetheless, there is a very low correlation between the vascularization index (VI), vascularization
flow index (VFI), and the gestational age (rp = 0.162, p = 0.005 and rp = 0.158, p = 0.007). The flow index (FI) was shown
to have no correlation with gestational age (rp = -0.067, p = 0.254).
Conclusion : From the present study, the placental thickness and placental volume significantly increased with gestational
age. The VI and VFI showed poor correlation with gestational age while the FI had no correlation with the gestational age.
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Keywords : Gestational age, Healthy pregnant women, Placental thickness, Placental volume, Placental vascular indices
