Treatment of hypertension in pregnancy: effect of atenolol on maternal disease, preterm delivery, and fetal growth.

OBJECTIVE: To assess the impact of antihypertensive therapy initiated early in pregnancy on maternal and fetal outcomes. METHODS: A retrospective review of patients treated in early pregnancy with atenolol was conducted. Therapy was directed by measurements of cardiac output. Fetal growth was analyzed with reference to prior pregnancy outcome, treatment inconsistent with standards present at the end of the study period, and year of treatment. Data were analyzed by paired and unpaired t-test, analysis of variance for multiple comparisons, and linear regression. RESULTS: Two hundred thirty-five pregnancies at risk for preeclampsia were studied. Ten percent (n = 22) received additional therapy with furosemide; 20% (n = 48) with hydralazine. Six and one half percent had treatment inconsistencies. Fifty-five percent had greater than 100 mg of proteinuria at baseline. One patient developed severe preeclampsia. Only 2.1% delivered before 32 weeks; 4.7% delivered before 34 weeks. Low percentile birth weight was strongly associated with a prior pregnancy with intrauterine growth restriction (P = 0.001), treatment inconsistency (P <.001), and a pregnancy earlier in our treatment experience (P <.001). Percentile birth weight increased from the 20th at the beginning of the study period to the 40th by the end (P = 0.002). CONCLUSION: Early intervention with antihypertensive therapy was associated with a low rate of severe maternal hypertension and preterm delivery. The failure to adjust therapy in response to an excessive fall in cardiac output or increase in vascular resistance was associated with reduced fetal growth.

The relationship between hemodynamics and inflammatory activation in women at risk for preeclampsia.

OBJECTIVE: This study evaluated: 1) whether women with risk factors for preeclampsia had a hyperdynamic circulation and increased markers of endothelial and inflammatory activation; and 2) whether hemodynamically directed therapy was associated with a change in markers. METHODS: A controlled experimental study was performed for two groups: 1) women at risk for preeclampsia (high risk); and 2) women at low risk (controls). Tumor necrosis factor-alpha (TNF-alpha), TNF-alpha receptors 1 and 2, vascular cell adhesion molecule-1, cellular fibronectin, and cardiac output were measured at or before 24 weeks' gestation and at 6-8 week intervals. High-risk subjects with cardiac output greater than 7.4 L/minute were treated with atenolol. Atenolol therapy was not randomized. Therefore, the longitudinal data were descriptive. Data were analyzed by the t test, Wilcoxon rank sum test, chi(2) test, multivariable linear regression, and the standard two-stage test. RESULTS: There were 46 high-risk subjects and 25 controls. Maternal age, gestational age, and parity did not differ between the groups. Cardiac output (P <.001) and vascular cell adhesion molecule-1 (P =.02) at baseline were significantly increased in the high-risk group. A total of 42 women in the high-risk group received atenolol for high cardiac output. There was a slower rise in TNF-alpha receptor 1 in the treated group compared with the controls (P <.001). CONCLUSION: Women with risk factors for preeclampsia had a hyperdynamic circulation and endothelial activation. Hemodynamically directed therapy in women at risk was associated with a slower rise in TNF-alpha receptor 1 compared with low-risk women who were not treated, suggesting a relationship between hemodynamics and inflammatory activation.

Low-dose, short-acting, angiotensin-converting enzyme inhibitors as rescue therapy in pregnancy.

OBJECTIVE: To assess the risks and potential benefits of low-dose angiotensin-converting enzyme (ACE) inhibitor treatment in pregnancies complicated by severe hypertension. METHODS: A retrospective review of pregnant women treated with ACE inhibitors was conducted. Hemodynamics before and after treatment were assessed by using Doppler technique to measure cardiac output. Data were analyzed by using the Wilcoxon signed-rank test. Maternal and neonatal outcomes were assessed by chart review and phone interview. RESULTS: Ten pregnancies were identified in which ACE inhibitor therapy was initiated in pregnancy for severe, unresponsive vasoconstricted hypertension; three were complicated by severe chronic hypertension, 4 by renal insufficiency, and 3 by severe preeclampsia. Treatment was limited to a low-dose, short-acting ACE inhibitor (captopril, 12.5 to 25 mg/day). Treatment was associated with an increase in cardiac output from 5.7 +/- 1.5 L/minute to 7.4 +/- 1.4 L/minute (P<.01) and a reduction in total peripheral resistance from 1770 +/- 670 to 1222 +/- 271 dyne. sec. cm(-5) (P =.005). No fetal or neonatal complications were observed. The probability of observing one or more adverse neonatal outcome in this sample, based on an assumed true risk of 5% and 10%, was calculated to be 12% and 50%, respectively. CONCLUSION: Low-dose captopril therapy was associated with improvement in maternal hemodynamics and, in cases complicated by severe hypertension and renal insufficiency, successful continuation of pregnancy. Fetal and neonatal complications were not experienced, but complication rates of 5-10% could have been missed because of the small number of exposed pregnancies.

Maternal hemodynamics and pregnancy outcome in women with prior orthotopic liver transplantation.

The aim of this study is to evaluate the hemodynamics and pregnancy outcome of women with prior orthotopic liver transplantation. Hemodynamic measurements by Doppler technique were performed on pregnant subjects with prior orthotopic liver transplantation. Maternal characteristics, renal function, pregnancy complications, delivery indications, delivery mode, and neonatal outcomes were evaluated. Six pregnancies occurred in 5 women after orthotopic liver transplantation at the University of Washington Medical Center (Seattle, WA) between 1991 and 1999. Four of the 6 pregnancies were complicated by chronic hypertension, fetal growth restriction, and preterm delivery. Two pregnancies had worsening hypertension characterized by vasoconstriction in the second trimester despite antihypertensive therapy. These 2 subjects were administered cyclosporine for maintenance immunosuppression and had greater mean arterial pressures preconception and in the first trimester than the other subjects. One of these pregnancies resulted in fetal demise at 25 weeks' gestation. The other subject was delivered at 28 weeks' gestation for nonreassuring fetal status and superimposed preeclampsia. All pregnancies were complicated by renal insufficiency; however, the 2 subjects with poor obstetric outcome had preconception serum creatinine levels greater than 1.5 mg/dL and creatinine clearances less than 40 mL/min. Pregnancies complicated by second-trimester vasoconstriction and moderate renal insufficiency are at risk for preeclamspia, fetal growth restriction, and fetal demise. Good obstetric outcome can occur in women with mild renal insufficiency and well-controlled chronic hypertension. Improved hypertensive control preconception may decrease the risk for preeclampsia and poor obstetric outcome.

Prevention of preeclampsia: a randomized trial of atenolol in hyperdynamic patients before onset of hypertension.

OBJECTIVE: To determine if assessment of maternal hemodynamics could predict women at risk for the development of preeclampsia, if treatment directed at hemodynamic abnormalities before the onset of hypertension could prevent preeclampsia, and if mothers could be treated in a way that protects fetal growth. METHODS: A double-blinded, randomized controlled trial was conducted. Subjects were considered to be at risk for preeclampsia if their cardiac output was greater than 7.4 L/min before 24 weeks' gestation. Nulliparous and diabetic subjects at risk were treated with 100 mg of atenolol or placebo. Cardiac output was measured by Doppler technique. Inulin and para-aminohippurate clearances were performed. RESULTS: Treatment with atenolol reduced the incidence of preeclampsia from 5 of 28 (18%) to 1 of 28 (3.8%), (P = .04). Nulliparous women determined to be at risk for preeclampsia were similar to diabetic women at risk. Each was significantly heavier and had inulin and para-aminohippurate clearances greater than the control group. Treatment with atenolol was associated with infants weighing 440 g less than infants in the nulliparous placebo group, (P = .02). No effect on birth weight was seen in the diabetic patients. Mothers of the smallest infants who were treated with atenolol could be identified by unexpectedly large reductions in cardiac output. CONCLUSION: Measurement of cardiac output in the second trimester identified women at risk for preeclampsia. Treatment with atenolol decreased the incidence of preeclampsia. Nulliparous and diabetic women at risk for preeclampsia were similar with regard to maternal hemodynamics, maternal weight, and renal function. Treatment with atenolol was associated with reduced infant birth weight.

The maternal hemodynamic effect of indomethacin in normal pregnancy.

The vasodilation of pregnancy is thought by many to be due to increased endothelial production of prostacyclin, a vasodilatory prostanoid. Indomethacin, a potent inhibitor of prostaglandin synthesis, is known to increase the maternal blood pressure response to angiotensin II infusion. We sought to measure directly the hemodynamic effects of a short course of indomethacin. Twenty-three healthy pregnant women with uncomplicated pregnancies between 26-32 weeks' gestation completed the study. Using Doppler technology, we determined cardiac output, stroke volume, and total peripheral resistance before and after three 25-mg doses of indomethacin. Although blood pressure did not change, peripheral resistance rose and stroke volume fell following indomethacin administration. Our findings support the hypothesis that indomethacin interferes with tonic prostaglandin-induced vasodilation in pregnancy. However, the increase in vascular resistance was very slight, suggesting that other vasodilators are also at work in pregnancy. We recommend that indomethacin be used judiciously in hypertensive pregnant patients until more information concerning possible adverse hemodynamic effects becomes available.

Renal vascular hypertension during pregnancy.

We report two women with renal artery stenosis in pregnancy. The first patient presented with severe hypertension in the first and second trimesters characterized by an extremely high vascular resistance (maximum 2455 dyne.second.cm-5). Transluminal angioplasty was performed at 20 weeks' gestation, resulting in resolution of the patient's hypertension. After angioplasty, her vascular resistance fell to 1600 dyne.second.cm-5, but did not reach normal pregnant levels. The pregnancy was carried to term without complication. The second patient's hypertension improved during pregnancy, and she delivered at term without complication. Twelve weeks postpartum, the patient again became severely hypertensive, and transluminal angioplasty was performed.

The effect of maternal hemodynamics on fetal growth in hypertensive pregnancies.

Seventy-six pregnancies in which hypertension complicated pregnancy before 28 weeks' gestation were studied. In 36, hemodynamics were characterized by increased cardiac output and low vascular resistance; in 32, hemodynamics were characterized by high resistance; in eight hemodynamics crossed over from high output to high resistance during pregnancy. High-resistance hypertension was associated with a mean birth weight 1058 gm less than that in the low-resistance group (p = 0.001). The reduction in birth weight was due to a 4-week difference in gestational age (p = 0.001) and lower percentile weights for gestational age, 19th versus 39th (p = 0.005). Infants in the crossover group had low percentile weights and a high rate of intrauterine fetal death.

Measurement of cardiac output in pregnancy by Doppler technique.

Doppler technique of measuring cardiac output was evaluated during pregnancy. In a study of accuracy Doppler technique correlated well with thermodilution, (r = 0.95, y = 1.05x - 0.35). In a study of interoperator variability, the technique was found to be reproducible, (r = 0.92, y = 0.91x + 0.74).