Background: Accurate estimation of gestational age is a highly influential component of antenatal care. Therefore, searching for other parameters supplementing well-known biometric parameters for calculating gestational age is necessary. Hence, we evaluated the placental thickness by ultrasonography at the level of insertion of the umbilical cord to estimate and correlate with the gestational age.

Methods: A cross-sectional observational study was conducted on 200 antenatal women with a normal singleton pregnancy between 11 and 40 weeks. Routine antenatal ultrasonography was done, along with regular biometric parameters, and the placental thickness was also measured for calculating the gestational age.

Results: From 11 to 40 weeks, there is a progressive increase in placental thickness with gestational age. There was a more significant positive correlation (r=0.983) at 11 to 35 weeks of gestational age; however, the correlation was not between 36 and 40 weeks.

Conclusions: Ultrasonographic measurement of placental thickness can be considered for estimating the gestational age from 11 to 35 weeks.