Screening for pre-eclampsia by using changes in uterine artery Doppler indices with advancing gestation

The aim of the study was to assess the relationship of changes in uterine artery (UtA) Doppler pulsatility indices (PI) between first and second trimesters and the subsequent development of pre-eclampsia.

A retrospective study of singleton pregnancies undergoing both first and second trimesters UtA Doppler screening between 2002 and 2009 was conducted. Multiples of median of UtA Doppler PI were used for developing indices describing UtA changes between the two trimesters. Receiver-operating characteristics curves (ROC) were calculated for multiple comparisons.

Three thousand five hundred sixty women had UtA Doppler screening in the first and second trimesters. Eleven women were excluded because of termination of pregnancy before 24 weeks. Out of the 3549 women recruited, 126 developed Pre-eclampsia (PE; 22 early PE delivered <34 weeks and 41 preterm PE delivered <37 weeks). The best index for predicting pre-eclampsia was the difference between the mean second trimester and mean first trimester UtA PI (areas under the ROC for early PE and preterm PE of 0.851 and 0.786, respectively).

Changes of UtA resistance between the first and second trimesters can be calculated as the difference between UtA PI at these gestations. The data of this study demonstrate that the difference in mean PI is the best index in predicting early PE and preterm PE.