Salvio Freire

Antioxidant Therapy to Prevent Preeclampsia A Randomized Controlled Trial

OBJECTIVE: To study whether antioxidant supplementation will reduce the incidence of preeclampsia among patients at increased risk. METHODS: A randomized, placebo-controlled, double-blind clinical trial was conducted at four Brazilian sites. Women between 12 0/7 weeks and 19 6/7 weeks of gestation and diagnosed to have chronic hypertension or a prior history of preeclampsia were randomly assigned to daily treatment with both vitamin C (1,000 mg) and vitamin E (400 International Units) or placebo. Analyses were adjusted for clinical site and risk group (prior preeclampsia, chronic hypertension, or both). A sample size of 734 would provide 80% power to detect a 40% reduction in the risk of preeclampsia, assuming a placebo group rate of 21% and &agr;=.05. The &agr; level for the final analysis, adjusted for interim looks, was 0.0458. RESULTS: Outcome data for 707 of 739 randomly assigned patients revealed no significant reduction in the rate of preeclampsia (study drug, 13.8% [49 of 355] compared with placebo, 15.6% [55 of 352], adjusted risk ratio 0.87 [95.42% confidence interval 0.61–1.25]). There were no differences in mean gestational age at delivery or rates of perinatal mortality, abruptio placentae, preterm delivery, and small for gestational age or low birth weight infants. Among patients without chronic hypertension, there was a slightly higher rate of severe preeclampsia in the study group (study drug, 6.5% [11 of 170] compared with placebo, 2.4% [4 of 168], exact P=.11, odds ratio 2.78, 95% confidence interval 0.79–12.62). CONCLUSION: This trial failed to demonstrate a benefit of antioxidant supplementation in reducing the rate of preeclampsia among patients with chronic hypertension and/or prior preeclampsia. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.ClinicalTrials.gov, NCT00097110 LEVEL OF EVIDENCE: I

Tobacco use and secondhand smoke exposure during pregnancy: An investigative survey of women in 9 developing nations:

OBJECTIVES We examined pregnant womens use of cigarettes and other tobacco products and the exposure of pregnant women and their young children to secondhand smoke (SHS) in 9 nations in Latin America, Asia, and Africa. METHODS Face-to-face surveys were administered to 7961 pregnant women (more than 700 per site) between October 2004 and September 2005. RESULTS At all Latin American sites, pregnant women commonly reported that they had ever tried cigarette smoking (range: 78.3% [Uruguay] to 35.0% [Guatemala]). The highest levels of current smoking were found in Uruguay (18.3%), Argentina (10.3%), and Brazil (6.1%). Experimentation with smokeless tobacco occurred in the Democratic Republic of the Congo and India; one third of all respondents in Orissa, India, were current smokeless tobacco users. SHS exposure was common: between 91.6% (Pakistan) and 17.1% (Democratic Republic of the Congo) of pregnant women reported that smoking was permitted in their home. CONCLUSIONS Pregnant womens tobacco use and SHS exposure are current or emerging problems in several low- and middle-income nations, jeopardizing ongoing efforts to improve maternal and child health.

Serum inhibin A and angiogenic factor levels in pregnancies with previous preeclampsia and/or chronic hypertension: are they useful markers for prediction of subsequent preeclampsia?

OBJECTIVE Our objective was to determine whether measurement of placenta growth factor (PLGF), inhibin A, or soluble fms-like tyrosine kinase-1 (sFlt-1) at 2 times during pregnancy would usefully predict subsequent preeclampsia (PE) in women at high risk. STUDY DESIGN We analyzed serum obtained at enrollment (12(0/7) to 19(6/7) weeks) and follow-up (24-28 weeks) from 704 patients with previous PE and/or chronic hypertension (CHTN) enrolled in a randomized trial for the prevention of PE. Logistic regression analysis assessed the association of log-transformed markers with subsequent PE; receiver operating characteristic analysis assessed predictive value. RESULTS One hundred four developed preeclampsia: 27 at 37 weeks or longer and 77 at less than 37 weeks (9 at less than 27 weeks). None of the markers was associated with PE at 37 weeks or longer. Significant associations were observed between PE at less than 37 weeks and reduced PLGF levels at baseline (P = .022) and follow-up (P < .0001) and elevated inhibin A (P < .0001) and sFlt-1 (P = .0002) levels at follow-up; at 75% specificity, sensitivities ranged from 38% to 52%. Using changes in markers from baseline to follow-up, sensitivities were 52-55%. Associations were observed between baseline markers and PE less than 27 weeks (P < or = .0004 for all); sensitivities were 67-89%, but positive predictive values (PPVs) were only 3.4-4.5%. CONCLUSION Inhibin A and circulating angiogenic factors levels obtained at 12(0/7) to 19(6/7) weeks have significant associations with onset of PE at less than 27 weeks, as do levels obtained at 24-28 weeks with onset of PE at less than 37 weeks. However, because the corresponding sensitivities and/or PPVs were low, these markers might not be clinically useful to predict PE in women with previous PE and/or CHTN.

Diffusion imaging may predict reversible brain lesions in eclampsia and severe preeclampsia: initial experience

OBJECTIVE The purpose of this study was to validate diffusion-weighted magnetic resonance imaging in the prediction of the evolutive course of brain edema and to establish its pathophysiologic presence in patients with eclampsia/severe preeclampsia. STUDY DESIGN Seventeen patients with a clinical diagnosis of severe eclampsia/preeclampsia and T2 hyperintense brain lesions on routine magnetic resonance imaging were evaluated at hospital admission and 8 weeks later. RESULTS Brain edema was reversible in 13 patients and irreversible in 4 patients, as indicated on follow-up magnetic resonance imaging. Sixteen of 17 patients were differentiated accurately into reversible and irreversible groups on the basis of diffusion imaging on hospital admission. Diffusion-weighted magnetic resonance imaging demonstrated a significant increase in water mobility in abnormal regions compared with normal-appearing brains in patients in the reversible group (1.34+/-0.10 mm(2) vs 0.79+/-0.08 mm(2)/s x 10(-3), P<.001). In the irreversible group, restricted water diffusion was present, which was consistent with cytotoxic edema and early brain infarction in 3 of 4 patients. CONCLUSION Diffusion-weighted magnetic resonance imaging can predict successfully the evolutive course of brain edema in an acute setting in these patients. Our findings indicate that brain edema is vasogenic, although ischemic/cytotoxic edema was observed less commonly.

Antioxidant Supplementation and Premature Rupture of the Membranes: A Planned Secondary Analysis

OBJECTIVE The purpose of this study was to determine if antioxidant supplementation during pregnancy reduces the incidence of premature rupture of the membranes (PROM). STUDY DESIGN A placebo-controlled, double-blind trial was conducted. PROM and preterm PROM (PPROM) were planned secondary outcomes of the trial. Women between 12(0/7) and 19(6/7) weeks of gestation and diagnosed to have chronic hypertension or a prior history of preeclampsia were randomized to daily treatment with both vitamin C (1000 mg) and E (400 IU) or placebo. RESULTS Outcome data for PROM were available for 697 of 739 patients. The rates of PROM (37/349 [10.6%] vs 19/348 [5.5%]; adjusted risk ratio [RR] 1.89 [95.42% CI, 1.11-3.23]; P = .015), and PPROM (16/349 [4.6%] vs 6/348 [1.7%]; RR 2.68 [1.07-6.71]; P = .025) were increased in the antioxidant group. CONCLUSION Contrary to expectations, vitamins C and E supplementation in this dose combination may be associated with an increased risk of PROM and PPROM.

The impact of prior preeclampsia on the risk of superimposed preeclampsia and other adverse pregnancy outcomes in patients with chronic hypertension

OBJECTIVE We sought to compare the rates of superimposed preeclampsia and adverse outcomes in women with chronic hypertension with or without prior preeclampsia. STUDY DESIGN We conducted secondary analysis of 369 women with chronic hypertension (104 with prior preeclampsia) enrolled at 12-19 weeks as part of a multisite trial of antioxidants to prevent preeclampsia (no reduction was found). Outcome measures were rates of superimposed preeclampsia and other adverse perinatal outcomes. RESULTS Prepregnancy body mass index, blood pressure, and smoking status at enrollment were similar between groups. The rates of superimposed preeclampsia (17.3% vs 17.7%), abruptio placentae (1.0% vs 3.1%), perinatal death (6.7% vs 8.7%), and small for gestational age (18.4% vs 14.3%) were similar between groups, but preterm delivery <37 weeks was higher in the prior preeclampsia group (36.9% vs 27.1%; adjusted risk ratio, 1.46; 95% confidence interval, 1.05-2.03; P = .032). CONCLUSION In women with chronic hypertension, a history of preeclampsia does not increase the rate of superimposed preeclampsia, but is associated with an increased rate of delivery at <37 weeks.

Exposure of pregnant women to indoor air pollution: a study from nine low and middle income countries

Objective. We studied exposure to solid fuel and second‐hand tobacco smoke among pregnant women in south Asia, Africa and Latin America. Design. Prospective cross‐sectional survey. Setting. Antenatal clinics in Argentina, Brazil, Ecuador, Guatemala, Uruguay, Democratic Republic of Congo, Zambia, India and Pakistan. Sample. A total of 7,961 pregnant women in ten sites in nine countries were interviewed between October 2004 and September 2005. Methods. A standardized questionnaire on exposure to indoor air pollution (IAP) and second‐hand smoke was administered to pregnant women during antenatal care. Main outcome measures. Exposure to IAP and second‐hand tobacco smoke. Results. South Asian pregnant women commonly reported use of wood (49.1–89.7%), crop residue and animal dung as cooking and heating fuel. African pregnant women reported higher use of charcoal (85.4–93.5%). Latin American pregnant women had greater use of petroleum gas. Among south Asian women, solid fuel use and cooking on an open flame inside the home were common. There was a significant association between solid fuel use and allowing smoking within the home at the Asian sites and in Zambia (p < 0.05). Conclusions. Pregnant women from low/middle income countries were commonly exposed to IAP secondary to use of solid fuels. Among these populations, exposure to second‐hand tobacco smoke was also common. This combination of exposures likely increases the risk of poor pregnancy outcomes among the most vulnerable women. Our study highlights the importance of further research on the combined impact of IAP and second‐hand tobacco smoke exposures on adverse maternal and perinatal outcomes.