Clinical significance of normalization of uterine artery pulsatility index with maternal heart rate for the evaluation of uterine circulation in pregnancy-induced hypertension.
OBJECTIVE
To investigate whether the use of normalized pulsatility index (PI) improves evaluation of the fetal prognosis in pregnancy-induced hypertension (PIH).


METHODS
Eighty women with uncomplicated pregnancies and 46 women with PIH (33 with pre-eclampsia and 13 with gestational hypertension) were included in the study. Uterine artery PI and normalized PI were analyzed in relation to two neonatal parameters: incidence of small-for-gestational age infants and incidence of Cesarean section for non-reassuring fetal status.


RESULTS
In normal pregnancy, the normalized uterine artery PIs (mean +/- SD) at 25, 31, and 39 weeks of gestation were 0.70 +/- 0.15, 0.71 +/- 0.16, and 0.65 +/- 0.13, respectively. Using non-normalized PI, 10 of 46 PIH cases had increased PI; however, with normalization, two pre-eclampsia cases were added to the group with elevated PI, giving a total of 12. The incidences of small-for-gestational age infants and Cesarean section due to non-reassuring fetal status were higher in the elevated normalized uterine artery PI group. The use of normalized PI appeared to reduce the false-negative results in pre-eclampsia and PIH. After normalization, sensitivity, positive predictive value and negative predictive value of PI for small-for-gestational age infants and Cesarean section due to non-reassuring fetal status were improved in cases with pre-eclampsia and PIH. The incidence of these complications was low in gestational hypertension.


CONCLUSIONS
Normalization of the PI may improve predictive values for small-for-gestational age infants and delivery by cesarean section due to non-reassuring fetal status in PIH.
Ochi
H
H
Department of Obstetrics and Gynecology, Ehime University School of Medicine, Shitsukawa, Shigenobu, Ehime, Japan. hohakase@m.ehime-u.ac.jp
Kusanagi
Y
Y
Katayama
T
T
Matsubara
K
K
Ito
M
M
D000328:Adult; D001158:Arteries / Q000502:physiology; D005260:Female; D005865:Gestational Age; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D021041:Placental Circulation / Q000502:physiology; D011225:Pre-Eclampsia / Q000503:physiopathology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D011673:Pulsatile Flow / Q000502:physiology; D012680:Sensitivity and Specificity; D014599:Uterus / Q000098:blood supply*