Mean, lowest, and highest pulsatility index of the uterine artery and adverse pregnancy outcome in twin pregnancies

OBJECTIVE: The objective of the study was to assess the use of mean, lowest, and highest pulsatility index (PI) of the uterine arteries to screen for adverse pregnany outcome in twin pregnancies. STUDY DESIGN: This was a screening study of 423 twin pregnancies. Relationship between PI at 20-22 weeks and adverse pregnancy outcome was evaluated. RESULTS: Mean, lowest, and highest PI above the 95th centile were significant risk factors for preeclampsia and adverse pregnancy outcome in monochorionic and dichorionic twins. We calculated a sensitivity for preeclampsia for mean, highest, and lowest PI of 35%, 29%, and 27%, respectively. CONCLUSION: Increased mean, lowest, and highest PI is associated with a higher risk of preeclampsia and adverse pregnancy outcome in twins. We observed the highest sensitivity and specificity by using highest PI. The high incidence of preeclampsia in twins makes it attractive to use the PI of the uterine artery for risk stratification in twins.