English

Abstract

BACKGROUND An important part of human placental development is the extensive modification of maternal vasculature by trophoblasts. Fetal growth retardation (FGR) and preeclampsia (PE) are associated with deficient trophoblastic invasion and modification of the uterine spiral arteries leading to small-caliber vessels of high resistance which impairs placental blood flow, creating a hypoxic environment and subsequent oxidative stress. FGR and pre-eclampsia are important causes of maternal and perinatal morbidity and mortality and it is important to identify such ‘at risk’ pregnancies during routine antenatal care. Ultrasonography (USG) and colour-Doppler are readily available tools that may be used for identifying such ‘at risk’ pregnancies. The purpose of this study was to evaluate the accuracy of 2-D sonographic placental volumetry, umbilical arterial doppler and uterine arterial doppler in predicting adverse fetomaternal outcomes and compare the accuracy of these three tests with each other in terms of sensitivity and specificity. METHODS A total of 100 women were randomly selected from the antenatal clinics, and were subject to serial ultrasounds at 12 - 16 weeks, 20 - 24 weeks, and 28 - 32 weeks. The 2-D sonographic placental volume, umbilical and uterine arterial resistivity index (RI), and pulsatility index (PI) were measured. The pregnancies were followed up till delivery and the measurements were plotted against the actual placental weight and development of FGR and/or pre-eclampsia. RESULTS In pregnancies with FGR or pre-eclampsia, the placental volumes were low, and correspondingly the uterine and umbilical arterial RI and PI were high (increased impedance) as compared to the normal pregnancies. For the prediction of adverse outcomes, a receiver operating curve (ROC) analysis showed that placental volume and umbilical artery RI and PI had high sensitivity in the 1st-trimester, and high specificity in the 2nd-trimester. CONCLUSIONS 2-D sonographic placental volumetry and umbilical arterial Doppler studies may be used as 1st-trimester screening tools to predict adverse fetomaternal outcomes. These patients may be subjected to more intensive follow-up to minimize maternal and perinatal morbidity and mortality. KEYWORDS Doppler Ultrasonography; Fetal Growth Retardation; Placenta; Pre-eclampsia; Umbilical Arteries; Uterine Artery