Foetal weight determination using sonographic measurement of placenta thickness

Abstract

BACKGROUND

The placenta is a foetal organ with important metabolic, endocrine and immunologic functions. Foetal weight can be sonologically estimated using a single or combination of foetal growth parameters such as crown-rump length (CRL), biparietal diameter (BPD), abdominal circumference (AC) and femoral length (FL). Placenta thickness measurement is another useful single alternative parameter in foetal weight estimation . 

MATERIALS AND METHOD

A cross sectional prospective study design was adopted. Three hundred and seventy-five (375) pregnant women referred to radiology department of Braithwaite memorial specialist hospital, PortHarcourt for routine obstertric scan were examined using LOGIQ P6 PRO GE Healthcare 3D machine fitted with a 3.5MHz curvilinear probe. The placental thickness (mm) was measured at the level of cord insertion, its mid portion or its widest diameter for the second and third trimesters while the foetal weight was obtained from the ultrasound machine after measuring AC and FL. Pearson correlation and linear regression analysis were used to correlate between obtained variables.  

­RESULT

Mean placenta thicknesses in the second and third trimesters were 22.68±3.28mm and 34.83±4.57mm respectively. ­­­The mean foetal weights in the second and third trimesters were 418.50±240.01grams and 2309.70±779.50grams. A positive statistical correlation was observed between foetal weight and sonographic placenta thickness yielding a Pearson’s correlation coefficient (r) of 0.769 and 0.856 for the second and third trimesters respectively.

CONCLUSION

Placenta thickness can be used as an alternative parameter to estimate the Foetal weight in the second and third trimesters. This will assist clinicians in the monitoring of foetal weight during pregnancy.