Anu Kapoor1, Mahesh D. Dudhat2
AIMS AND OBJECTIVES
The purpose of this study was to evaluate the placental thickness by sonography in normal singleton pregnancies at different stages of gestation in order to develop this as a useful tool for gestational age estimation.
MATERIALS AND METHODS
We evaluated 310 normal singleton pregnancies and calculated the fetal gestational age using sonographic biometric criteria for different periods of gestation. Placental thickness was measured by sonography at the site of umbilical cord insertion using the standardized technique. Mean placental thickness along with its standard deviation and 95 % confidence interval was calculated for each week of gestation. We used correlation regression analysis to study the relationship between placental thickness and gestational age.
RESULTS Mean placental thickness (in mm) closely matched the gestational age (in weeks) between 10 to 30 weeks of gestation. We established a nomogram for placental thickness measurements with increasing gestational age.
CONCLUSIONS Placental thickness has a linear relationship with gestational age especially during the second trimester of pregnancy. Placental thickness measurements when used along with fetal biometry can increase the accuracy of predicting gestational age during pregnancy. The regression equation and nomogram developed by us can be used to calculate the gestational age with minimal error.
