The first trimester uterine artery Doppler: comparison between sagittal and transverse techniques

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality worldwide, affecting about 2-3% of all pregnancies. There is consistent evidence today that starting to take aspirin before the 16th week of gestation manages to halve the prevalence of PE and also reduces the incidence of fetal growth restriction, hence the importance of being able to identify early high-risk pregnant women regarding those outcomes and thus finding candidates for the use of that medication. Therefore, interest in methods of PE screening and prediction has increased in recent years.

A retrospective study was carried out by means of a review of the medical records of pregnant women submitted to the first trimester morphological examination at Mater Dei Healthcare Network from August 2017 to January 2018, which included the Doppler study of the uterine arteries performed using longitudinal and transverse insonation techniques, for calculating PE risk in the way recommended by the Fetal Medicine Foundation. Then, a comparative analysis of uterine artery mean pulsatility index (PI) measured transversally and longitudinally was performed.

The value for the PI in the sagittal plane (1.634 ± 0.52) was highly correlated (ICC = 0.85) and similar to the value found for the cross-section (1.633 ± 0.54), with no statistically significant differences between them (p = .93). Bland Altman's analysis highlighted the existence of a very tight agreement between both methods of measuring PI.

The pulsatility index of uterine arteries can be measured in a reliable and easily reproducible way using both the sagittal and transverse techniques, with no change in the final outcome of preeclampsia screening through the Fetal Medicine Foundation (FMF) algorithm.