Ultrasonographic Measurement Of Placental Thickness And Its Correlation With Gestational Age In Normal Pregnancy

Abstract

BACKGROUND & OBJECTIVES: Ultrasonography is the most effective method to estimate the gestational age. Placenta is a materno-foetal organ which is a reflection of health and size of the foetus. PT can be used as a new parameter to estimate the gestational age of the foetus. In our present study we measured the placental thickness at the level of umbilical cord insertion to determine its relationship with GA of foetus, BPD & FL in normal singleton pregnancy between 12 – 24 weeks. METHOD OF COLLECTION OF DATA: This was a cross sectional study consisting of 201 normal antenatal women who were referred to the Department of Radio diagnosis from antenatal clinic, Department of OBG, Shri B.M. Patil Medical College Hospital and Research Center, Bijapur from December 2014 – June 2016. All the subjects were enrolled with detailed oral and written consents. Normal singleton pregnancies of gestational ages from 12 to 24 wks were included in the study. PT, in mm, was calculated by averaging the three best measurements for each case at the level of umbilical cord insertion. Correlation of mean PT with GA, BPD & FL was calculated. Data was compiled in MS excel sheet and analysed using SPSS software, chi square test and Pearson’s correlation coefficient were applied considering value of P <0.05 as statistically significant. RESULT: In the total study group of 201 normal singleton pregnancies from 12 to 24 wks of gestation, age ranged between 18 yrs to 37 yrs with majority in age group XI between 21-25 yrs. Anterior placenta was noted to be the most common location amongst the study sample. Lateral location of the placenta was found to be more accurate in measuring the placental thickness, however anterior, posterior & fundal locations also showed significant correlation. PT taken at individual weeks of gestation almost matched with GA, BPD & FL with few negative correlation in some weeks in which PT was less than 1mm w.r.t, gestation in wks. To prove that there was a correlation between PT with GA, BPD & FL the Pearson correlation coefficient was found to be r = 0.98 and the p value was <0.001, thereby establishing a positive correlation between the variables. CONCLUSION: It was observed that PT (in mm) correlated well with GA, BPD & FL (in weeks) from 12 to 24 wks of gestation. And also the thickness of the placenta and growth pattern did not vary relative to the placental locations.