The effect of methyldopa treatment on uterine, umblical and fetal middle cerebral artery blood flows in preeclamptic patients

Abstract

The purpose of this study was to evaluate the efficacy of methyldopa in the treatment of preeclamptic patients. This study was performed on 24 preeclamptic women who were in between 25-36 weeks of gestational age. 24 healthy pregnant women were taken as control group. Before starting treatment, 24 preeclamptic patients were examined with Doppler ultrasound. Pulsatility index, resistance index, systolic/diastolic ratio of uterine, umblical and fetal middle cerebral arteries were measured. Preeclamptic patients were treated with totally 1 g methyldopa per day. After 7 d, patients were reexamined with Doppler ultrasound. The effect of methyldopa on uterine, umblical and fetal middle cerebral artery blood flows were detected. Only one control with Doppler ultrasound was done to the healthy pregnant women. Before methyldopa treatment to the preeclamptic women, pulsatility index (PI), resistance index (RI) and systolic/diastolic ratio (S/D) on uterine and umblical arteries were significantly higher than the control group. However, fetal middle cerebral artery (MCA) values were significantly lower than the control group. When Doppler results of preeclamptic patients before and after the methyldopa treatment were compared, no significant differences in terms of Pulsatility Index, Resistance IndexI and S/D ratio of umblical and fetal middle cerebral arteries were found. However, the results of uterine artery were significantly lower after the treatment in preeclamptic patients. Treatment with methyldopa lowered the uterine artery resistance in preeclamptic patients but did not effect the resistance of umblical and fetal middle cerebral artery.

Effect of antihypertensive therapy with α‐methyldopa on uterine artery Doppler in pregnancies with hypertensive disorders

“…Our data confirm the findings of previous studies indicating that, before antihypertensive therapy, uterine artery PI and RI are increased in women with pre‐eclampsia but not in women with gestational hypertension, compared to normotensive controls23, 28–32. The impairment of uteroplacental perfusion found in pre‐eclampsia can explain the less favorable fetal and neonatal outcomes observed in these cases compared with pregnancies complicated by gestational hypertension33–35.…”

“…We found that, independent of gestational age, α‐methyldopa therapy had no significant effect on uterine artery Doppler resistance to blood flow in 51 cases of pre‐eclampsia and 29 cases of gestational hypertension. Four smaller studies that previously examined the effect of α‐methyldopa on uterine artery Doppler indices in women with hypertensive disorders of pregnancy yielded conflicting results23–26. The first study by Montan et al 24 included 20 women presenting with pre‐eclampsia in the third trimester.…”

“…In contrast, the study by Rey26 comparing 25 women with pre‐eclampsia (14 on treatment, 11 untreated), 43 women with chronic hypertension (14 on treatment, 29 untreated) and 22 normotensive controls, treated with α‐methyldopa 750 mg daily for a week, found a decrease in uterine artery PI in treated women in both hypertensive groups. Similarly, Günenç et al 23 compared 24 women with pre‐eclampsia treated with 1 g of α‐methyldopa per day for a week, with 20 normotensive pregnant controls. They found that the uterine artery PI, RI and systolic/diastolic ratio were lower after antihypertensive therapy.…”

“…There is a theoretical concern that, particularly in women presenting with pre‐eclampsia, antihypertensive drugs might adversely affect uteroplacental perfusion by reducing maternal peripheral blood pressure when there is already increased uterine artery resistance21, 22. Previous studies investigating the effect of α‐methyldopa on uterine artery Doppler indices in women with hypertensive disorders of pregnancy included small numbers and yielded conflicting results23–26. The aim of this study was to evaluate further the impact of antihypertensive therapy with α‐methyldopa on maternal uterine artery Doppler blood flow indices in hypertensive disorders of pregnancy.…”

Predictive Value of Middle Cerebral Artery to Uterine Artery Pulsatility Index Ratio in Hypertensive Disorders of Pregnancy

“…In a study done by Günenç et al, treatment with methyldopa lowered the uterine artery resistance in preeclamptic patients but did not affect the resistance of umbilical and fetal middle cerebral artery [9]. In two separate studies done by Khalil et al and Muračević et al, they did not find change in flow resistance of umbilical artery after administration of methyldopa [10, 11].…”