Increased pulsatility index of uterine artery Doppler between 26 and 28 weeks of gestation and adverse perinatal outcomes

Objective: To compare adverse perinatal outcomes in pregnant women with or without normalization of the mean pulsatility index (PI) uterine artery Doppler between 24 and 28 weeks of gestation.

Methods: Retrospective cohort which pregnant women were divided into three groups: normal uterine artery Doppler between 20-24 and 26-28 weeks (controls), abnormal uterine artery Doppler between 20-24 and normal between 26-28 weeks (anUtA), and abnormal uterine artery Doppler between 20-24 and 26-28 weeks (aaUtA). To compare adverse perinatal results between the groups Chi-square test was used. Binary logistic regression was used to assess the ability of uterine artery Doppler to predict birthweight < 10th and composite perinatal outcomes.

Results: Birthweight was significantly lower in the aaUtA compared to anUtA (2687 vs 3248 grams, p = 0.0479). A significant negative correlation was observed between the mean PI uterine artery Doppler during the 3rd trimester and birthweight (r = -0.13, R² = 0.035, p = .0192). The prevalence of composite perinatal outcomes was significantly higher in aaUtA compared to anUtA (25.9 vs 0%, p = .013). Mean PI uterine artery Doppler during the 3rd trimester was significant predictor for birthweight < 10th (OR: 2.74, CI 95% = 1.03-7.3), but the protodiastolic notch and the association between mean PI uterine artery Doppler and protodiastolic notch were not.

Conclusion: Maintenance of altered uterine artery Doppler during the 3rd trimester was associated with higher prevalence of composite perinatal outcomes and lower birthweight compared to its late normalization. Although modest, uterine artery Doppler in the 3rd trimester proved to be predictor of birthweight < 10th.