Systolic, diastolic and mean arterial pressure at 30-33 weeks in the prediction of preeclampsia.

OBJECTIVE

To investigate the potential value of measuring mean arterial pressure (MAP), systolic (sBP) and diastolic (dBP) blood pressure at 30-33 weeks' gestation in the prediction of preeclampsia (PE) developing at or after 34 weeks.

METHODS

Screening study in singleton pregnancies at 30-33 weeks' gestation including 4,294 that were unaffected by PE, gestational hypertension (GH) or delivery of small-for-gestational-age neonates (normal group), 145 that subsequently developed PE [37 cases requiring delivery at 34-37 weeks (intermediate PE) and 108 delivering at or after 38 weeks (late PE)] and 161 that developed GH. The a priori risks for intermediate and late PE from maternal demographic characteristics and medical history were determined. The a posteriori risks were calculated by combining the a priori risks with the likelihood ratios for MAP, sBP and dBP, which were calculated from fitted bivariate gaussian distributions.

RESULTS

The mean multiple of median MAP, sBP and dBP were significantly higher in the intermediate and late PE groups than in the normal group. In screening by a combination of maternal characteristics and MAP, the estimated detection rates of intermediate and late PE, at a false-positive rate of 10%, were 70.3 and 62.0%, respectively. The respective detection rates for sBP were 62.2 and 59.3% and for dBP were 62.2 and 57.4%.

CONCLUSION

Combined testing by maternal characteristics and blood pressure at 30-33 weeks could effectively identify women at high risk for subsequent development of PE.