Relationship between two-dimensional ultrasound measurement of placental thickness and estimated fetal weight

Abstract

Background/Aim: The placenta plays a major role in fetal well-being, and fetal weight is very important to neonatal survival. There probably exists a relationship between placental dimension and fetal size. Data on ultrasound assessed placenta thickness and fetal weight are scanty in the Nigerian literature. This study aimed to establish a relationship between ultrasound estimated placental thickness and fetal weight. Materials and Methods: Four hundred and twenty apparently healthy pregnant women at gestational age 15-40 weeks were sonographically examined, with a 3.5 MHz curvilinear transducer of a Sonoace X6 machine (Medison Co., Korea). Placenta thickness, in millimeters, and fetal weight, in grams, was estimated for each subject. Correlation between the two parameters was assessed. P ≤ 0.05 were considered to be significant. Results: Mean placental thickness (PT) ranged from 22.6 ± 2.5 mm at 15 weeks to 40.9 ± 7.2 mm at 30 weeks, while estimated fetal weight (EFW) ranged from 147.0 ± 16.5 g at 15 weeks to 3.304.8 ± 284.6 g at 40 weeks. The mean values of placenta thickness and EFW throughout gestation were 35.5 ± 7.0 mm and 1555.0 ± 1004 g, respectively. There was significant correlation between placenta thickness and EFW r = 0.668; P = 0.000. Conclusion: The study established a fairly linear relationship between placental thickness and EFW. A normogram of ultrasound estimated placenta thickness and fetal weight is derived.