Objective: The main objective of the study is to determine the correlation of sonographic mean placental thickness in mm with the composite mean 2nd and 3rd trimester gestational age in weeks estimated by ultrasound.
Study Design: Cross sectional.
Place and Duration of Study: Radiology department, Military hospital, AFIRI Rawalpindi for the period of six months from 10/10/13 to 10/5/14.
Material and Methods: The instrument used in this study was Aloka SSI 5500 ultrasound equipment with 3.5MHz curvilinear transducer. A total of 200 women were included through radiology outdoor with singleton pregnancy in 2nd and 3rd trimester. The fetuses were observed for gestational age estimation using bi-parietal diameter (BPD) and femur length (FL) in the second trimester and BPD, FL and abdominal circumference (AC) in the third trimester. The composite average of the gestational age estimated by the various growth parameters were taken for each fetus and was calculated automatically by the ultrasound software. The placenta was localized in longitudinal section and its antero-posterior thickness measured at the level of insertion of the umbilical cord
Results: A total of 200 women with singleton pregnancy in 2nd and 3rd trimester were included in this study. The mean age of the women was 25.43±2.63 years, average gestational age and placental thickness was 26.18±7.91 weeks and 29.10±7.027 mm. Total of 104(52%) patients were in2nd trimester and 96(48%) were in 3rd trimester. A linear relationship was observed between gestational age and placental thickness. There were 104 women with 2nd trimester, correlation between placental thickness and gestational age was positive and significant (r=0.959 and p=0.0005) , similarly 96 women with 3rd trimester, correlation between placental thickness and gestational age was positive and significant (r=0.858 and p=0.0005). Strong positive correlation between placental thickness and gestational age was observed (r= 0.985 and p= 0.0005).
Conclusion: Positive correlation suggested that as placental thickness increases, the fetal weight also increases so that the placental growth directly influences the fetal weight.
Gestational age, Placenta, Second trimester, Ultrasonography