Screening Pregnant Women at 22-24 Weeks for Gestational Hypertension or Intrauterine Growth Retardation by Doppler Ultrasound Followed by 24-Hour Blood Pressure Recording

Abstract

Objective: To improve the efficacy of screening patients at increased risk of hypertension or intrauterine growth retardation, we combined the assessment of increased uteroplacental resistance with a second-line screening using 24-h blood pressure monitoring.

Methods: Doppler assessment of uterine artery flow (resistance index, diastolic notch) at 20 and at 24 weeks gestation and 24-h ambulatory blood pressure were determined in 48 consecutive patients. Mean 24-h diastolic blood pressure (M24-h DBP) was used as a measure to describe the overall pressure regimen for each patient. Based on a cutoff of 68 mm Hg, the series was divided into two groups: 18 high-risk patients with abnormal M24-h DBP (higher than 68 mm Hg). and 30 low-risk patients (equal to or lower than 68 mm Hg). The results were blinded to clinicians.

Main Outcome Measures: The development of gestational hypertension, preeclampsia, and intrauterine growth retardation (IUGR).

Results: None of the 18 pathological M24-h DBP as compared to 25/30 in the normal DBP group had a normal pregnancy outcome. The group with abnormal 24-h DBP monitoring delivered earlier and smaller infants than did the normal 24-h DBP group. Sensitivity of combining these two methods to detect gestational hypertension was 79% and positive predictive value was 83%, whereas the respective indices for IUGR were 90% and 50%.

Conclusions: Screening patients with increased uteroplacental resistance with 24-h blood pressure recording improves the efficacy of the Doppler screening to identify patients at risk of an abnormal outcome of pregnancy.

Key Words:

• Hypertension in pregnancy
• Intrauterine growth retardation
• 24-h ambulatory blood pressure monitoring
• Uterine Doppler waveform analysis