Placental thickness measurement by ultrasonography and it’s correlation with gestational age in normal and intrauterine growth retarded pregnancy

Abstract

Introduction- Ultrasonography is modality of choice for fetal evaluation, estimation of gestational age and detection of fetal growth restriction in pregnancies. This study was conducted with the aim of evaluating placental thickness, its role in estimation of gestational age of the fetus and in predicting normal and fetal growth restriction as outcome.

Material and Methods- Using Ultrasonography placental thickness was measured at cord insertion site from 18th to 40th weeks of gestation. Study participants were categorized as normal and intra uterine growth restriction based on birth weight of newborns. Correlation of placental thickness with gestational age was calculated and compared in both groups to find any significant difference.

Result- A positive correlation was observed between placental thickness and gestational age in both groups. Pearson’s correlation coefficient (r) was calculated for both groups. It was 0.3221 and 0.7450 in intra uterine growth restriction and normal group respectively. In normal group placental thickness (mm) corresponds to gestational age (weeks) upto 32nd weeks. After that mean placental thickness remains nearly stationary upto 40th weeks with average thickness 31 mm. In 18th , 19th and 26th weeks of gestation, placental thickness was more in IUGR group (22.5±4.2 ,28.1±5.2 and 31±5.5) as compared to normal group (18.7±1.6, 19.6±1.9 and 26±3.1).

Conclusion- Measured placental thickness at the umbilical cord insertion site can be used as an early sonographic parameter in detection of intrauterine growth restriction in singleton normal pregnancies.