Placental thickness and Transcerebellar diameter for accurate estimation of gestational age in the second trimester (A cross sectional study)

Abstract

Objective: To assess the accuracy of combined measurementof placental thickness and transcerebellar diameter in estimation of fetal gestational age in second trimester.Patients and Methods: A cross sectional study was conducted at ultrasound unit, department of obstetrics and gynecology,Ain shams University Maternity Hospital in the period betweenJanuary 2020 and March 2020.The population studied included161 pregnant ladies at 14 to 26 weeks.Trans-abdominal ultrasound (Samsung H60, Convex Pro = CV1 = 8MHz - probe 4.9MHz) was used to asses placental thickness and transcerebellardiameter.Results: Our results showed that there is positive correlationbetween Placental thickness and gestational age r= 0.44 whichis highly significant (P value < 0.001). Also highly statisticallysignificant positive correlation between TCD and G.A (P value < 0.001) r= 0.92. Statistical analysis of our results showedthat trans-cerebellar diameter was more accurate than placentalthickness for accurate estimation of gestational age with almostperfect agreement (0.91) between gestational age by last menstrual period and gestational age by trans-cerebellar diameter.Conclusion: Client’s aged 32.8 ±3.4. More than half had primary infertility with mean duration of 4.6 ± 2.4. Female factorinfertility was the commonest cause of infertility. The pregnancy rate per embryo transfer was 36.4%, miscarriage rate was9.1%, while the live rate was 27.3%. The mean VAS scores at1hour, 6 hours, 24 hours and at embryo transfer were 7.1 ± 2.8,4.6 ±1.4, 2.8 ±1.2 and 1.0 ± 0.9 respectively. The mean Likertscore was 2.4 ± 0.9.Conclusion: Both placental thickness and TCD are useful fetalbiometric parameters that can be used for assessment of gestational age. Although placental thickness is positively correlatedto G.A, it is not as accurate as TCD. Unfortunately, combineduse of placental thickness and TCD is not superior to TCDalone in accurate estimation of gestational age.