Three-dimensional placental volume and mean grey value: Normal ranges in a Turkish population and correlation with maternal serum biochemistry and Doppler parameters.

The aim of this study is to evaluate the relationship between three-dimensional (3D) ultrasound measurements of placenta at 11-13(6) weeks' gestation and maternal serum levels of pregnancy associated plasma protein-A (PAPP-A), free beta human chorionic gonadotrophin (fβhCG), Doppler parameters in early pregnancy. This prospective study consisted of 334 singleton pregnancies at 11-13(6) weeks' gestation. Placental volume and placental volumetric mean grey values were evaluated. The placental volume (cm(3)) was analysed using the Virtual Organ Computer-aided AnaLysis (VOCAL) imaging program and 3D histogram was used to calculate the volumetric mean grey value (%). Mean maternal age was 28.35 ± 7.55. Mean gestational age was 12.29 ± 0.68 weeks. Placental volume was 77.04 ± 35.74 cm(3). Mean grey value of the placenta was 34.38 ± 8.02%. Correlation analysis revealed that placental volume was significantly correlated with the crown-rump length (r = 0.173, p = 0.002), gestational week (r = 0.116, p = 0.036), ductus venosus pulsatility index (r = -0.101, p = 0.04) and maternal weight (r = 0.099, p = 0.037). There was a significant relation between the mean grey value of the placenta and maternal age (r = 0.131, p = 0.02), nuchal translucency (r = -0.109, p = 0.048), PAPP-A (r = 0.108, p = 0.04) and fβhCG (r = 0.104, p = 0.042). Volumetry of the placenta can be carried out with a high percentage of 1st trimester pregnancies. Volumetry during the 1st trimester could be helpful because of the less advanced state of placentation. This examination is easy to perform and the measurements can be acquired correctly and quickly.