Correlation of Thickness of the Placenta in the Second and Third Trimesters with Crown-rump Length in the First Trimester for the Estimation of Fetal Age

Introduction: Few studies have been done estimating the fetal age using the placental thickness and correlated it with other fetal measures, but no studies have correlated with crown-rump length (CRL), which is considered to be accurate in estimating gestational age.If thickness of the placental done in second and third trimesters correlates with CRL, then it is used for determining the gestational age, mainly for those who missed the dating scan.Objectives: To correlate dating scan CRL with the thickness of placenta in the second and third trimesters to estimate the fetal gestational age. Materials and methods:The following represents a prospective study of observation among 200 single pregnant women with or without any maternal or fetal problems between 7 and 36 weeks of gestational age in the Department of Obstetrics and Gynecology, Aarupadai Veedu Medical College and Hospital, Puducherry.The CRL was taken in the dating scan, and the thickness of the placenta was taken in the second and third trimesters, and gestational age was measured.The correlation derived by CRL in predicting gestational age of the fetus was compared with the correlation derived by placental measurements taken in the second and third trimester scans.Results: When crown CRL is measured in the early trimester scan and compared to placental measurements in both the second and third trimesters, there is a statistically significant association with correlation coefficients of 0.94 and 0.38 in the calculating gestational age.In comparison, the thickness of the placenta evaluated during the second trimester is more significant than the third trimester.Conclusion: As a result, for people who missed the dating scan in the first trimester, the thickness of placenta measured during the second trimester of pregnancy can be utilized to determine the fetal age.