Decreased endovascular trophoblast invasion in first trimester pregnancies with high-resistance uterine artery Doppler indices

Abstract

Background: Defective trophoblastic invasion in early pregnancy is involved in the pathogenesis of preeclampsia. This study investigates the relationship between Doppler assessment of uterine artery resistance and endovascular trophoblastic invasion in the first trimester of pregnancy. Methods: Patients undergoing termination of pregnancy for non-medical reasons were categorized as having a low- or high-resistance uterine artery blood flow pattern by transabdominal Doppler ultrasound. Products of conception were examined histologically with regard to the extent of decidual endovascular trophoblast invasion. Results: There were 14 low-resistance and 17 high-resistance uterine artery blood flow pregnancies identified at 10-14 weeks of gestation. Normal intradecidual endovascular trophoblast invasion was identified with a similar frequency in both groups (P = 0.79). However, the proportion of decidual vessels with endovascular trophoblast invasion was significantly higher in the low-resistance pregnancies (49%) compared with the high-resistance ones (34%, P = 0.02). Conclusions: The findings of this study support the use of uterine artery Doppler investigation for the non-invasive assessment of trophoblast invasion in early pregnancy. Further studies are necessary to clarify the biological significance of these observations and their potential clinical applications.