CHICAGO — A retrospective study of 1,300 women at 24 weeks' gestation suggests that early preeclampsia and late preeclampsia may be two different hemodynamic forms of disease.
Early preeclampsia was associated with normal prepregnancy BMI, high total vascular resistance (TVR), and bilateral notching of the uterine artery on Doppler evaluation, and late preeclampsia was associated with high prepregnancy BMI and low TVR, Dr. Barbara Vasapollo of University of Rome Tor Vergata reported in a presentation at the World Congress on Ultrasound in Obstetrics and Gynecology.
“This is not the first study to suggest that early and late preeclampsia are two different entities, but it is the first to demonstrate that they are two different hemodynamic entities in the latent phase,” Dr. Vasapollo said in an interview.
Researchers reviewed data on 1,345 nulliparous normotensive women who had undergone uterine artery Doppler and maternal echocardiography to determine TVR at 24 weeks' gestation between 1999 and 2007.
Of these patients, 155 had bilateral notching of the uterine artery, and 107 of this group developed preeclampsia (defined as blood pressure greater than 140/90 mm Hg and proteinuria greater than 300 mg/dL).
Thirty-two patients developed late preeclampsia (more than 34 weeks' gestation), and 75 developed early preeclampsia (less than 34 weeks' gestation).
Significantly more early preeclampsia patients (60%) showed bilateral notching of the uterine artery than late preeclampsia patients (15.6%) at the 24 weeks' examination.
TVR was significantly lower in the group who subsequently developed late preeclampsia than in the group who developed early preeclampsia (741 dyn-s/cm
Dr. Vasapollo said the findings are consistent with other research that links late preeclampsia with maternal constitutional factors such as BMI and early preeclampsia with defective trophoblast invasion (Hypertension 2008; 51:970–5, 989–90).
TVR appears to be one of the most reliable predictors of early or late preeclampsia, she said.
“The ROC curves built to predict early and late preeclampsia show a very good sensitivity and specificity,” according to a study by Dr. Vasapollo and her colleagues. “When considering early severe complications, almost all preeclamptic women show a TVR of greater than 1,400,” she noted (Hypertension 2008;51:1020–6).
Dr. Vasapollo and her colleagues plan to investigate a preventive pharmacologic approach to treatment that is guided by maternal hemodynamics.