Congenital uterine malformations are associated to increased blood pressure in pregnancy.

OBJECTIVE: To assess the relationship between congenital uterine malformations and blood pressure in pregnancy. STUDY DESIGN: Twenty-four-hour automated ambulatory blood pressure monitoring (readings every 30 min) was performed in 16 normotensive, nonproteinuric, primigravidae with congenital uterine malformations (5 uterus septus, 9 uterus bicornis, 2 uterine didelphys) between 20 and 30 weeks. From the 24-hr blood pressure report, we calculated 24-hr mean, daytime and nighttime means. The results were compared with 16 primigravidae, matched for age and gestation, who were and remained normotensive throughout pregnancy, and tested for statistics with t-test; significance assessed at p < 0.001. RESULTS: Although they were within the normotensive range, all blood pressure measurements considered were significantly higher in pregnant women with congenital uterine malformations, compared to normal pregnant women. Namely, 24-hr, daytime, and nighttime systolic (mean +/- SD) were 121.1 +/- 8.4, 124.4 +/- 8.8, 114.0 +/- 7.7 mmHg, respectively, in women with uterine malformations and 108.0 +/- 7.4, 109.2 +/- 7.3, 102.1 +/- 8.5 mmHg, respectively, in normal pregnant women. Twenty-four-hour diastolic, daytime, and nighttime diastolic (mean +/- SD) 74.1 +/- 10.2, 77.1 +/- 10.6, 68.1 +/- 9.2 mmHg, in women with uterine malformations and 64.1 +/- 5.7, 66.0 +/- 5.7, 58.2 +/- 6.3 mmHg, in normal pregnant women (all differences p < 0.001). Fifteen of the fetuses from women with congenital uterine malformations showed intrauterine growth retardation. No differences were found 6 months after delivery. CONCLUSIONS: Although the blood pressure levels remained within the normotensive range, pregnant women with congenital uterine anomalies have a higher blood pressure than normal women. Elevated blood pressure can result from altered uterine circulation and reduced blood supply to the placenta. This pathogenesis or the poor placentation may result in a foetal growth retardation.     

Blood pressure is elevated in normotensive pregnant women with intrauterine growth restriction

OBJECTIVE: To assess the relationship between blood pressure pattern and intrauterine growth restriction in normotensive pregnant women. STUDY DESIGN: Twenty-four-hour ambulatory blood pressure was consecutively performed between 32 and 34 weeks in 139 normotensive, non-proteinuric, primigravidae with intrauterine growth restriction (IUGR) and in 140 primigravidae, matched for age and gestation, who were and remained normotensive throughout pregnancy and whose fetuses had regular fetal growth, who served as controls. RESULTS: Although all measures were within the normotensive range, blood pressure of mothers with IUGR were significantly higher than controls. Twenty-four-hour mean, daytime, and nighttime systolic were 119.9+/-11.9, 122.6+/-11.7, 114.4+/-13.3 mmHg, in women with IUGR and 108.0+/-7.4, 109.2+/-7.3, 102.1+/-8.5 mmHg, in controls. Twenty-four-hour diastolic average, daytime, and nighttime diastolic (mean+/-S.D.) 78.1+/-9.3, 69.2+/-10.6, 67.2+/-9.0 mmHg, in women with IUGR and 64.1+/-5.7, 66.0+/-5.7, 58.2+/-6.3 mmHg, in normal pregnant women. All differences p<0.0001. CONCLUSIONS: Pregnant women with idiopathic IUGR have blood pressure higher than normal. Although within clinic normotensive range, slightly higher levels of blood pressure can alter uterine and placental perfusion and determine fetal growth restriction.     

The long-term effects of low-dose 17beta-estradiol and dydrogesterone hormone replacement therapy on 24-h ambulatory blood pressure in hypertensive postmenopausal women: a 1-year randomized, prospective study.

OBJECTIVE: The aim of this study was to assess the long-term effects of low-dose oral hormone replacement therapy (HRT) on 24-h blood pressure in hypertensive postmenopausal women. STUDY DESIGN: In this 12-month, prospective study, 66 postmenopausal women with mild or moderate hypertension were randomly assigned to receive either HRT with 1 mg/day micronized 17beta-estradiol sequentially combined with 10 mg/day dydrogesterone for 14 days of each 28-day cycle, or no therapy. Ambulatory blood pressure measurements were recorded for a 24-h period at baseline and after 12 months of treatment or follow-up. RESULTS: Blood pressure did not differ significantly between the groups at baseline. After 12 months, there were falls in 24-h systolic, diastolic and mean arterial blood pressure in both the HRT and control groups; only the fall in mean arterial blood pressure in the HRT group achieved statistical significance (-2.0 +/- 0.8 mmHg, p < 0.01). While there was no significant decrease in daytime systolic or mean arterial blood pressure in either group, a significant decrease in diastolic blood pressure (-1.8 +/- 10 mmHg, p < 0.001) was observed in the HRT group. Night-time systolic and mean arterial blood pressure also decreased significantly (p < 0.001) in the HRT group (-3.0 +/- 1.5 mmHg and -2.2 +/- 0.6 mmHg, respectively), but no significant change was observed in the control group. Conclusion: Low-dose oral HRT caused significant falls in both daytime and night-time ambulatory blood pressure in postmenopausal women with mild or moderate hypertension.     

Magnesium sulfate effectively reduces blood pressure in an animal model of preeclampsia.

OBJECTIVE: We tested the ability of magnesium sulfate to reduce hypertension and neonatal growth retardation in an animal model of preeclampsia. STUDY DESIGN: On day 17 of pregnancy, osmotic minipumps were inserted subcutaneously to continuously deliver either vehicle (saline control group), or N-nitro-L-arginine methyl ester (L-NAME) (50 mg/kg/day), or L-NAME (50 mg/kg/day) in combination with magnesium sulfate (60 mg/kg/day). Prior to insertion, blood pressure and heart rate were monitored with a pneumatic tail cuff device. Blood pressure measurements were repeated on days 18, 20, and 21 of pregnancy. Blood was obtained on days 17 and 21, along with urine, to assess magnesium levels and degree of proteinuria. Pups were weighed and measured at 48 hours postpartum. RESULTS: Rats receiving L-NAME developed hypertension within 24 hours of implantation (108 +/- 3.9 vs. 123 +/- 3.4 mmHg, p < 0.05). Magnesium sulfate, given along with L-NAME did not prevent mean blood pressure from increasing, but reduced it by day 21 compared to L-NAME given alone (107 +/- 3.4 vs. 122 +/- 8.7 mmHg, respectively, p < 0.05). Magnesium sulfate reduced neonatal growth retardation by improving the weight of the pups compared to pups from maternal rats given L-NAME alone (6.1 +/- 0.1 vs. 5.2 +/- 0.3 grams, respectively, p < 0.05). CONCLUSION: Maternal magnesium sulfate reduces blood pressure and increases neonatal size compared to L-NAME without magnesium. These findings support a beneficial effect of magnesium in preeclampsia.     

Effects of isradipine, a new calcium antagonist, on postpartum uterine activity

The effects of a new calcium antagonist, isradipine (PN 200-110) on postpartum uterine activity and the maternal cardiovascular system were investigated. Uterine activity was recorded by a microtip transducer catheter inserted transcervically within 45 min of normal vaginal delivery. 0.5 mg of isradipine was given as a bolus injection during 5 min to 7 women with spontaneous uterine activity and 1 mg was given during a 15-min period to another 8 women with oxytocin-stimulated uterine activity. Matched controls with similar pre-injection activity (+/- 5%) but not given the drug were selected for comparison. The effects of the drug in 3 women (given 1 mg of isradipine) were compared with those in matched controls and in women given 0.25 mg of terbutalin i.v. as a bolus injection. Isradipine had a marked inhibitory effect on both spontaneous and oxytocin-stimulated uterine activity. The inhibitory effect of 1 mg of isradipine seemed comparable to that of 0.25 mg of terbutalin. The inhibition occurred within 1-2 min after the injection and was sustained throughout the study period (2 h). A transient reduction of the systolic (mean maximum decrease 10-15%) and diastolic blood pressure (mean maximum decrease 15-20%) was seen, particularly during the injection period. Hypotension (systolic blood pressure less than 80 mmHg) was not recorded. A moderate increase in pulse rate (mean maximum increase 22-27%) was seen in all cases. The results show that isradipine given as a bolus injection can inhibit early postpartum uterine activity, with minimal side effects.     

Urinary kallikrein quantity and activity of normal pregnant women and toxemia patients in third trimester

In this study, urinary kallikrein quantity and activity were measured by the kallikrein direct RIA and kininogenase activity with human low molecular weight kininogen in 32 non pregnant healthy women, 20 normal 3rd trimester pregnant women and 18 3rd trimester hypertension type toxemia patients. There was no significant difference in urinary kallikrein quantity between non pregnant women (n = 32, 64.0 +/- 6.3 micrograms/day, mean +/- SE) and normal pregnant women (n = 20, 68.1 +/- 10.1 micrograms/day). There was a significant difference (p less than 0.001) between non pregnant women and toxemia patients (n = 18, 22.5 +/- 3.3 micrograms/day). There was a significant difference (p less than 0.001) between toxemia patients and normal pregnant women. There was a significant difference (p less than 0.05) in urinary kallikrein activity between non pregnant women (n = 32, 496.2 +/- 57.2 micrograms kinin/day) and normal pregnant women (n = 20, 319.5 +/- 48.1 micrograms kinin/day). There was a significant difference (p less than 0.0001) between non pregnant women and toxemia patients (n = 18, 82.6 +/- 13.6 micrograms kinin/day). There was a significant difference (p less than 0.01) between normal pregnant women and toxemia patients. There were no correlation in both urinary kallikrein quantity and activity between severe type toxemia patients (systolic blood pressure greater than or equal to 160mmHg or diastolic blood pressure greater than or equal to 110mmHg) and mild type toxemia patients (160mmHg greater than systolic blood pressure greater than or equal to 140mmHg and 110mmHg greater than diastolic blood pressure greater than or equal to 90mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Misoprostol compared with methylergometrine for the prevention of postpartum haemorrhage: a double-blind randomised trial.

OBJECTIVE: To compare the efficacy and side effects of misoprostol, compared with methylergometrine, for the prevention of postpartum haemorrhage. DESIGN: A double-blind, randomised clinical trial of 200 women with apparently normal pregnancies. SETTING: University teaching hospital. PARTICIPANTS: Two hundred women with apparently normal pregnancies. METHODS: After the baby had been born, all women received two capsules by mouth and the contents of an ampule by intravenous injection. Each woman only received one active product. The capsules contained either a total of 600 microg misoprostol or placebo, and the ampule 200 microg of methylergometrine or placebo. MAIN OUTCOME MEASURES: Need for further oxytocic drugs, blood pressure, the presence of side effects, mean haemoglobin and haematocrit three days after delivery. RESULTS: Two hundred women completed the study (100 received methylergometrine and 100 misoprostol). Postpartum haemorrhage occurred in 4.3% of the methylergometrine group and 8.3% of the misoprostol group (P = 0.57). The need for further oxytocic drugs was 4.4% and 12.8% after methylergometrine and misoprostol, respectively (P = 0.065). One hour after the birth of the baby there was no difference in the mean systolic blood pressure (117 +/- 12 mmHg versus 115 +/- 11 mmHg) (P = 0.26) or the mean diastolic blood pressure (72 +/- 10 mmHg versus 71 +/- 11 mmHg for the groups receiving methylergometrine or misoprostol, respectively) (P = 0.97). The mean temperature in the misoprostol group rose to 37.4 degrees C, compared with 37 degrees C in the methylergometrine group (P < 0.0001). In the misoprostol group 34% developed fever (> 38 degrees C) compared with 3% in the methylergometrine group (P < 0.0001). Shivering (visual analogue score > or = 8) also occurred more often after misoprostol (42%) than after methylergometrine (8.5%) (P < 0.0001). The haemoglobin level (g/dL) on the third postpartum day was similar for both groups ( 11.0 and 11.2 for methylergometrine and misoprostol, respectively) (P = 0.39). CONCLUSIONS: This study suggests that although protection from postpartum haemorrhage using parenteral methylergometrine and oral misoprostol is nearly equal, misoprostol is associated with more side effects.     

Ambulatory blood pressure monitoring during pregnancy: validation of the TM-2420 monitor

To validate the accuracy of the TM-2420 ambulatory blood pressure monitor in pregnant women, its measurements were compared with those taken simultaneously by two trained observers using a random zero sphygmomanometer. Each of 30 pregnant women had her blood pressure measured three times. The mean differences between the monitor and the averaged observer measurements were -0.53 +/- 2.7 mmHg for systolic blood pressure, -5.4 +/- 5.3 mmHg for Korotkoff phase 4 (P less than .001), and 0.87 +/- 3.7 mmHg for phase 5 diastolic blood pressure. The TM-2420 ambulatory monitor provides reliable estimates of systolic and Korotkoff phase 5 diastolic blood pressures during pregnancy.     

Pharmacokinetics and pharmacodynamics of ritodrine after intramuscular administration to pregnant women

To define the pharmacokinetics and pharmacodynamics of ritodrine after intramuscular injection, we administered 5 or 10 mg ritodrine into the gluteus or deltoid muscles of 12 pregnant volunteers. Six women received 5 mg and six received 10 mg into each muscle group on different days. We withdrew blood samples before and 12 times in the 6 hours after ritodrine injection. Blood pressure and heart rate were recorded at each time. Ritodrine was measured by high-performance liquid chromatography. Peak ritodrine concentrations (mean +/- SD) after a single 5 mg injection in the deltoid or gluteus were 38 +/- 13 and 26 +/- 8 ng/ml, respectively. After a 10 mg dose in the deltoid or gluteus, peak concentrations were 59 +/- 30 and 47 +/- 22 ng/ml, respectively. Although higher, the peak plasma concentrations after injections into the deltoid were not significantly greater than those after injection into the gluteus. None of the pharmacokinetic parameters differed according to dose or injection site. The pharmacodynamic effects of ritodrine were unaffected by injection site, but ritodrine caused a dose-related increase in heart rate and systolic blood pressure and a dose-related decrease in diastolic blood pressure. After a 10 mg injection, the maximal changes in heart rate, systolic, and diastolic blood pressure were 22%, 10%, and 19%, respectively. However, mean blood pressure was not altered by either the 5 or 10 mg dose. These findings indicate that there are few differences in pharmacokinetic parameters between deltoid and gluteal injection of ritodrine. The single intramuscular injection of 5 or 10 mg ritodrine results in labor-inhibiting concentrations with clinically insignificant cardiovascular effects.     

Individual differences in equol production capability modulate blood pressure in tibolone-treated postmenopausal women: lack of effect of soy supplementation.

OBJECTIVES: Equol, a gut bacterial metabolite of the isoflavone daidzein, has been associated with beneficial health effects. Recent studies indicate that women with intestinal capacity to convert daidzein to equol also have the capacity to alter steroid metabolism and bioavailability of estrogens. METHODS: We evaluated whether individual equol production capability, while not consuming soy supplement, was associated with lower blood pressure in postmenopausal women using tibolone. In addition, in a randomized, placebo-controlled, cross-over trial we assessed the effect of soy supplementation on blood pressure in both equol-producing (n = 20) and non-equol-producing (n = 20) women using tibolone. Blood pressure was recorded with a validated oscillometric technique. RESULTS: The circulating equol levels rose 20-fold in the equol producers and 1.9-fold in the non-equol producers. At baseline, systolic blood pressure (129.9 +/- 2.6 vs. 138.5 +/- 3.1 mmHg, p = 0.02), diastolic blood pressure (72.2 +/- 1.5 vs. 76.6 +/- 1.3 mmHg, p = 0.01) and mean arterial blood pressure (93.5 +/- 1.7 vs. 99.9 +/- 1.8 mmHg, p = 0.007) were lower in equol producers compared to non-equol producers. Soy supplementation had no effect on blood pressure in either group, whereas the baseline differences persisted. CONCLUSIONS: Postmenopausal women using tibolone characterized as equol producers had lower blood pressure compared to non-equol producers. Soy supplementation for 2 months had no blood pressure-lowering effect.     

The effect of hospitalisation on ambulatory blood pressure in pregnancy

METHODS: Twenty-four-hour ambulatory blood pressure monitoring was performed on 40 women (20 hypertensive, 20 normotensive) on a hospitalised and non-hospitalised day. Mean blood pressure differences were calculated for the awake, sleeping and 24-hour periods on both days. RESULTS: Mean heart rate was higher at home (1.79, p = 0.04) than in hospital, but there were no significant differences in mean systolic (1.30 mmHg, p = 0.06), diastolic (0.78 mmHg, p = 0.21) or mean arterial blood pressure (0.81 mmHg, p = 0.19) between the hospitalised and non hospitalised day for the group overall. Nevertheless, the range of individual responses was wide (-8.5 mmHg to 15.4 mmHg mean arterial blood pressure). Hypertensive women receiving antihypertensive therapy had significantly greater differences in mean arterial blood pressure between the hospital and non-hospital day when compared to the rest of the group (5.8 mmHg, compared to 3.3 mm Hg, p = 0.02). CONCLUSIONS: Although hospitalisation does not significantly lower blood pressure in pregnant women as a group, women receiving antihypertensive therapy demonstrate significant differences in blood pressure between hospital and home. Based on conventional blood pressure measurements alone, these women may be at risk of either under treatment, or over treatment, of blood pressure.     

Effects of timolol and acetazolamide on intraocular pressure elevation following argon laser iridotomy.

To study the effect of hypotensive agents on intraocular pressure elevation following argon laser iridotomy, 0.5% timolol maleate topically and acetazolamide 125 mg orally were given in 39 eyes, one hour prior to laser iridotomy, with 29 eyes serving as the control. The mean pressure two hours after laser iridotomy was 18.9 +/- 7.2 mmHg in the control group and 12.8 +/- 3.9 mmHg in the pretreated group. Ocular pressure was elevated from the baseline pressure of the prelaser status in two eyes (5%) only in the timolol-acetazolamide treated group and in 16 eyes (55%) in the control group. The pressure elevation two hours after laser iridotomy was significantly less in the timolol-acetazolamide pretreated group.     

Norepinephrine, adrenocorticotropin, cortisol and beta-endorphin in women suffering from fear of labor: responses to the cold pressor test during and after pregnancy

BACKGROUND: Women suffering from fear of labor have reduced pain tolerance during a cold pressor test (CPT) during and after pregnancy. METHODS: We compared levels of norepinephrine, adrenocorticotropin (ACTH), cortisol and beta-endorphin before and during the CPT up to 60 min in 20 normotensive women with and 20 without fear of labor at 37.4 +/- 0.2 (mean +/- SE) gestational weeks and at 41.9 +/- 1.6 weeks after delivery. RESULTS: Baseline levels of norepinephrine in the pregnant fear group (1.63 +/- 0.18 nmol/L) were higher (p = 0.068) than in controls (1.38 +/- 0.14 nmol/L) but after delivery they were lower in the fear group (1.75 +/- 0.31 nmol/L vs. 2.31 +/- 0.26 nmol/L, p = 0.064). ACTH, cortisol and beta-endorphin did not differ between pregnant and nonpregnant groups. The CPT caused a 28.4% smaller response in norepinephrine in the pregnant fearful women than in controls, whereas the responses of ACTH and beta-endorphin were similar between groups during and after pregnancy. The CPT caused no significant response in cortisol. Pregnant fearful women had higher diastolic blood pressure (85.6 +/- 4.5 mmHg, mean +/- SE) than the controls (74.9 +/- 3.4 mmHg, p = 0.065). CONCLUSIONS: Women with fear of labor were characterized by changes in norepinephrine but not in ACTH, cortisol or beta-endorphin before and during the CPT, indicating a normal pituitary-adrenal axis function.     

A randomized, placebo-controlled, double-blind study evaluating leuprolide acetate depot treatment before myomectomy

Eighteen premenopausal women with symptomatic leiomyomata uteri were enrolled in a stratified, randomized, double-blind, placebo-controlled study evaluating the efficacy of leuprolide acetate (LA) depot treatment before myomectomy. Stratification was based on pretreatment uterine volume (less than 600 cm3 versus greater than or equal to 600 cm3). Nine women received intramuscular (IM) depot LA 3.75 mg every 4 weeks for 12 weeks (group A); nine women received IM placebo with the same injection schedule (group B). All women underwent myomectomy within 4 weeks of their last injection. Mean total intraoperative blood loss was 213 +/- 44 mL (mean +/- standard error of the mean [SEM]) in group A and 302 +/- 43 mL in group B. When data from patients with large uteri (pretreatment uterine volumes of 600 cm3 or greater) were analyzed, mean total blood loss was 189 +/- 44 mL in group A and 390 +/- 20 mL in group B. These data suggest that leuprolide depot treatment before myomectomy may decrease intraoperative blood loss in women with large leiomyomata uteri.     

The possible role of endothelial cells in hypertensive disorders during pregnancy.

OBJECTIVE: To clarify the role of endothelial cells in pregnancy-related hypertensive disorders, we studied the cytotoxic effect of sera from normal pregnant women and from gravidas with various hypertensive complications of pregnancy. METHODS: We obtained serum samples from 84 Japanese women: 17 with preeclampsia, ten with gestational hypertension, six with chronic hypertension, five with chronic hypertension with superimposed preeclampsia, 21 normal gravidas, and 25 healthy nonpregnant women. Endothelial cell injury was measured by the release of radiolabeled chromium from the cells into the culture medium. RESULTS: The mean (+/- standard error of the mean) values of chromium 51 release in preeclampsia, gestational hypertension, chronic hypertension, chronic hypertension with superimposed preeclampsia, normal pregnancy, and healthy nonpregnant women were: 21.9 +/- 2.1, 10.0 +/- 2.0, 9.2 +/- 2.3, 12.9 +/- 0.8, 8.4 +/- 1.4, and 7.3 +/- 1.6%, respectively. Normal pregnant and nonpregnant subjects did not differ with respect to endothelial cell injury. Sera from women with preeclampsia demonstrated significantly greater endothelial cell injury than did sera from normal gravidas. Subjects with the three other categories of hypertensive disorders did not differ significantly from normal gravidas. CONCLUSION: Preeclampsia is characterized by the presence of a serum factor cytotoxic to endothelial cells. Therefore, the mechanism responsible for the increase in blood pressure differs between women with preeclampsia and those with other hypertensive disorders in pregnancy.     

Should continuous hydralazine infusions be utilized in severe pregnancy-induced hypertension?

Intravenous hydralazine therapy in severe preeclampsia-eclampsia may be administered by either continuous intravenous infusion or intermittent bolus therapy. We studied the hemodynamic effects of continuous intravenous hydralazine infusion in seven patients with severe pregnancy-induced hypertension. The starting infusion dose was 5 mg/hr and was increased every 15 to 20 minutes by 1 to 2 mg/hr to obtain a 20% reduction in mean arterial blood pressure. The initial mean systolic and diastolic blood pressures were 208.3 +/- 24.8 and 124.3 +/- 11.6 mmHg, respectively. The comparable mean levels following hydralazine therapy was 144 +/- 13.6 and 87 +/- 11.6 mmHg. This decline was obtained at a mean hydralazine dose of 16.04 +/- 3.65 mg/hr. Despite an increase in cardiac output, the rapid uncontrolled decline in blood pressure resulted in five of the seven patients developing fetal distress requiring cesarean delivery. If hydralazine therapy is to be used in severe preeclampsia-eclampsia, we advocate avoidance of continuous intravenous therapy.     

Magnesium sulfate and promethazine do not interact to cause hypotension in gravid ewes

The purpose of this study was to determine whether magnesium sulfate and promethazine interact to cause hypotension in gravid ewes. Fifteen experiments were performed in five chronically instrumented animals between 125 and 130 days of timed gestation (term = 145 days). In one group of experiments each animal received magnesium sulfate (4 gm intravenous bolus followed by 4 gm/hr intravenous infusion) then promethazine (50 mg intravenously). In a second group each animal received magnesium sulfate then saline solution as a control. In a third group each animal received saline solution then promethazine. Infusion of magnesium sulfate increased the mean (+/- SEM) serum magnesium concentration to 5.7 +/- 0.6 and 6.6 +/- 0.6 mg/dl in the magnesium sulfate-promethazine and magnesium sulfate-saline solution groups, respectively. Magnesium sulfate slightly decreased maternal mean arterial pressure (p less than 0.05) and increased cardiac output (p less than 0.05) in both the magnesium sulfate-promethazine and magnesium sulfate-saline solution groups. Otherwise there were no significant changes in maternal mean arterial pressure or cardiac output in any group. Promethazine increased maternal heart rate (p = 0.0001) in both the magnesium sulfate-promethazine and saline solution-promethazine groups. Magnesium sulfate increased uterine blood flow (p less than 0.01) in both the magnesium sulfate-promethazine and magnesium sulfate-saline solution groups, but promethazine blunted the increase in uterine blood flow associated with magnesium sulfate. Similarly, magnesium sulfate decreased uterine vascular resistance (p less than 0.01) in both the magnesium sulfate-promethazine and magnesium sulfate-saline solution groups, but promethazine eliminated the decrease in uterine vascular resistance associated with magnesium sulfate. Maternal and fetal arterial blood gas and acid-base values did not change in any group, except that there was a small, near-significant decrease (p = 0.06) in fetal pH 10 minutes after promethazine was given in the magnesium sulfate-promethazine group. We conclude that magnesium sulfate and promethazine did not interact to cause maternal hypotension in normovolemic gravid ewes. However, promethazine increased maternal heart rate and blunted the increase in uterine blood flow associated with magnesium sulfate.     

Pulse pressure and risk of preeclampsia: a prospective study

OBJECTIVE: To find whether pulse pressure, a measure of arterial compliance, is associated early in pregnancy with increased risk of developing preeclampsia. METHODS: In a prospective cohort of 576 nulliparas, we examined blood pressures throughout pregnancy and at 6-8 weeks postpartum. Measurements during weeks 7-15, 16-24, and 25-38 of gestation were pooled to find averages for each period. Outcomes assessed were gestational hypertension and preeclampsia. Logistic regression analysis was used to develop relative risks and 95% confidence intervals. RESULTS: We confirmed 34 (5.9%) cases of preeclampsia, 32 (5.6%) cases of gestational hypertension, and 510 normotensive women. Mean systolic and diastolic blood pressures and mean arterial pressures were elevated throughout pregnancy in women who developed hypertensive disorders of pregnancy compared with normotensive women. Pulse pressure at 7-15 weeks was significantly higher in women who developed preeclampsia (45 +/- 6 mmHg) than in those who developed gestational hypertension (41 +/- 7 mmHg, P =.03) and normotensive women (41 +/- 8 mmHg, P =.01). Examined in tertiles, increasing pulse pressure was associated with increasing risk of developing preeclampsia (P for trend =.01) but not gestational hypertension (P for trend =.95). After adjustment for potential confounders, a 1-mmHg rise in early pregnancy pulse pressure was associated with a 6% (95% confidence interval: 1, 10) increase in risk for developing preeclampsia but not gestational hypertension (relative risk: 1%; 95% confidence interval: -1, 6). Beyond 15 weeks' gestation, differences between groups diminished, but women with any hypertensive disorder had higher pulse pressures than women with uncomplicated pregnancies. CONCLUSION: Elevated pulse pressure, indicating poor arterial compliance, was evident early in pregnancies of women who subsequently developed preeclampsia.     

Ambulatory blood pressure in normal Chinese

Noninvasive ambulatory blood pressure monitoring (NABPM) has been playing an increasing role in the diagnosis of hypertension and in the evaluation of antihypertensive drugs. NABPM data for the normal Chinese population has not yet been established. However, data obtained from 25 young male Chinese adults has been analysed. Average ambulatory blood pressure was 120 +/- 8/74 +/- 7 mmHg for the whole-day monitoring. There was an evident diurnal change of blood pressure during the 24-hour monitoring period with higher blood pressure levels being recorded during the daytime, rather than during the nighttime (7.8 +/- 9.7/4.4 +/- 4.8 mmHg; p less than 0.001). Maximal hourly blood pressure averages occurred during the late morning, while minimal hourly blood pressure averages occurred around midnight. The variability in blood pressure was 11 +/- 3/9 +/- 2 mmHg for the daytime and 11 +/- 3/8 +/- 2 mmHg for the nighttime. The incidence of abnormally high blood pressure ranged widely. Eating would raise both the systolic and diastolic blood pressure, while sleep caused a significant fall in blood pressure. This study offers basic data for the study of NABPM in young normotensive Chinese adults.     

Effect of exercise on maternal hemodynamics and placental blood flow in healthy women

Intervillous placental blood flow responses to standardized exercise during late pregnancy were studied using a Xenon technique in 25 healthy women. Thirteen of them were studied twice between the 32nd and 38th weeks of pregnancy, with mean 32 (range 22 to 40) days between the studies. At the end of a 6-min exercise, mean maternal heart rate had risen from 77 +/- 10 (SD) to 154 +/- 11 beats/min, amounting to 63% of maximal oxygen uptake. Stroke volume rose by 9%, cardiac output by 65% and cardiac index by 71% as a consequence of exercise, but peripheral vascular resistance declined by 41%. The placental blood flow was at a similar level after the exercise as before the exercise, being 95 +/- 19 (mean +/- SD) ml/min/100 ml of intervillous space before, 98 +/- 24 one min after, and 93 +/- 16 30 min after the cessation of exercise. No change was found in the level of placental blood flow between the 32-34th and 37-38th weeks of pregnancy. The placental blood flow had a positive correlation with maternal weight, mean arterial blood pressure and with diastolic blood pressure. Maternal heart rate, cardiac output, cardiac index, placental weight and the birth weight of the infant was not correlated with placental blood flow. It is concluded that in normal pregnancy a short submaximal exercise has little effect on placental blood flow measured after exercise.