A systematic review of randomized controlled trials of prenatal and postnatal vitamin A supplementation of HIV-infected women

We searched the Cochrane Library, MEDLINE, EMBASE, AIDSearch, and Gateway to assess the effect of prenatal and/or postnatal vitamin A supplementation on the risk of mother-to-child transmission (MTCT) of HIV and other pregnancy outcomes. We included 5 trials totaling 7528 women (4 trials of prenatal and 1 trial of postnatal supplementation). Overall, there was no evidence of an effect of prenatal and/or postnatal vitamin A supplementation on the risk of MTCT of HIV (Relative Risk [RR] 1.06, 95% Confidence Interval [CI] 0.89-1.26). However, prenatal vitamin A supplementation significantly improved birth weight (weighted mean difference 89.78; 95% CI, 84.73-94.83), but there was no evidence of an effect on stillbirths (RR 0.99; 95% CI, 0.68-1.43), preterm births (RR 0.88; 95% CI, 0.65-1.19), death before 24 months among live births (RR 1.08; 95% CI, 0.91-1.29), and maternal death (RR 0.83; 95% CI, 0.59-1.17). The available evidence does not support vitamin A supplementation of HIV-infected pregnant and lactating women, despite improvement in birth weight.     

A Meta-Analysis on the Efficacy and Safety of Combined Vitamin C and E Supplementation in Preeclamptic Women

Objective: To evaluate whether vitamin C and E co-supplementation of women at risk of preeclampsia can reduce maternal and neonatal disorders. Method: Electronic databases were searched up to May 2008 to find studies investigating pregnancy outcomes in women at risk of preeclampsia following exposure to combined vitamin C and E supplementation. The outcomes of interest were gestational hypertension, preeclampsia, preterm delivery, small for gestational age, and low birth weight. The relative risk (RR) and confidence interval (CI) for the individual studies were pooled and heterogeneity analysis was performed. Results: Seven studies involving 5969 pregnant women at risk of preeclampsia were included: 2982 received vitamin C and E and 2987 received placebo. The RRs are 1.3 (95% CI of 1.08–1.57, p = 0.0066) for gestational hypertension, 0.7 (95% CI of 0.58–1.08, P = 0.1653) for preeclampsia, 1.12 (95% CI of 0.96–1.32, p = 0.141) for preterm delivery, 1.04 (95% CI of 0.94–1.15, p = 0.4789) for small for gestational age, and 1.13 (95% CI of 1.004–1.27, p = 0.0429) for low birth weight. Conclusion. Combined vitamin C and E supplementation not only have no potential benefit in improvement of maternal and neonatal outcome but increase the risk of gestational hypertension in women at risk of preeclampsia and low birth weight in neonates.     

Effect of folic acid supplementation during pregnancy on gestational hypertension/preeclampsia: A systematic review and meta-analysis

Objective: To evaluate the effect of folic acid supplementation during pregnancy on the risk of gestational hypertension/preeclampsia. Methods: A systematic review and meta-analysis were conducted. Medline, Embase, Scopus, and the Web of Science were searched from inception to December 2014. Results: Out of 1224 potentially relevant studies, 13 studies met our inclusion criteria (2 randomized controlled trials (RCTs), 10 cohort studies, and 1 case–control study). The pooled relative risk (RR) and 95% confidence interval (CI) of the two RCTs were 0.62 (0.45–0.87) in the trial arm as compared with the placebo arm. The pooled RR was 0.92 (95% CI: 0.79–1.08) for nine cohort studies with available data on folic acid supplementation in pregnancy and gestational hypertension/preeclampsia. Pooled RR was 0.88 (95% CI: 0.76–1.02) for eight cohort studies with available data on folic acid supplementation and preeclampsia. Conclusion: Whether folic acid supplementation in pregnancy can prevent the occurrence of gestational hypertension/preeclampsia remains uncertain.     

World Health Organisation multicentre randomised trial of supplementation with vitamins C and E among pregnant women at high risk for pre-eclampsia in populations of low nutritional status from developing countries

Objective  To determine if vitamin C and E supplementation in high-risk pregnant women with low nutritional status reduces pre-eclampsia.
Design  Multicentred, randomised, controlled, double-blinded trial.
Setting  Antenatal care clinics and Hospitals in four countries.
Population  Pregnant women between 14 and 22 weeks' gestation.
Method  Randomised women received 1000 mg vitamin C and 400 iu of vitamin E or placebo daily until delivery.
Main outcome measures  Pre-eclampsia, low birthweight, small for gestational age and perinatal death.
Results  Six hundred and eighty-seven women were randomised to the vitamin group and 678 to the placebo group. Groups had similar gestational ages (18.1; SD 2.4 weeks), socio-economic, clinical and demographical characteristics and blood pressure at trial entry. Risk factors for eligibility were similar, except for multiple pregnancies: placebo group (14.7%), vitamins group (11.8%). Previous pre-eclampsia, or its complications, was the most common risk factor at entry (vitamins 41.6%, placebo 41.3%). Treatment compliance was 87% in the two groups and loss to follow-up was low (vitamins 2.0%, placebo 1.3%). Supplementation was not associated with a reduction of pre-eclampsia (RR: 1.0; 95% CI: 0.9–1.3), eclampsia (RR: 1.5; 95% CI: 0.3–8.9), gestational hypertension (RR: 1.2; 95% CI: 0.9–1.7), nor any other maternal outcome. Low birthweight (RR: 0.9; 95% CI: 0.8–1.1), small for gestational age (RR: 0.9; 95% CI: 0.8–1.1) and perinatal deaths (RR: 0.8; 95% CI: 0.6–1.2) were also unaffected.
Conclusion  Vitamins C and E at the doses used did not prevent pre-eclampsia in these high-risk women.     

Progesterone supplementation for preventing preterm birth: a systematic review and meta-analysis

AIM: The aim of this study is to assess the role of progesterone in preterm birth prevention. METHODS: A MEDLINE search (from 1966 to the present; date of last search January 2005) was performed - using the key words progesterone, pregnancy, preterm birth, preterm labor, and randomized, controlled trial - in order to identify randomized, controlled trials in which progesterone (either intramuscular or vaginal administration) was compared with placebo or no treatment. Data were extracted and a meta-analysis was performed. RESULTS: Seven randomized, controlled trials were identified. Women who received progesterone were statistically significantly less likely to give birth before 37 weeks (seven studies, 1020 women, RR = 0.58, 95% CI = 0.48-0.70), to have an infant with birth weight of < or =2.5 kg (six studies, 872 infants, RR = 0.62, 95% CI = 0.49-0.78), or to have an infant diagnosed with intraventricular hemorrhage (one study, 458 infants, RR = 0.25, 95% CI = 0.08-0.82). CONCLUSIONS: For progesterone supplementation to be advocated for women at the risk of preterm birth, the prolongation of gestation demonstrated in this meta-analysis must translate into improved infant outcomes, including a reduction in mortality. There is currently insufficient information to allow recommendations regarding the optimal dose, route, and timing of administration of progesterone supplementation.     

Acetylsalicylic Acid for the Prevention of Preeclampsia and Intra-uterine Growth Restriction in Women with Abnormal Uterine Artery Doppler: A Systematic Review and Meta-analysis

BackgroundPreeclampsia is a major global cause of maternal, neonatal and perinatal mortality. From studies of placental pathophysiology in women with preeclampsia, a potentially important role of low-dose acetylsalicylic acid (ASA) in the prevention of preeclampsia was expected, but the results from clinical trials have been disappointing. While recent evidence has shown that uterine Doppler can predict preeclampsia as early as in the first trimester of pregnancy, most clinical trials have evaluated ASA in the second and third trimesters.ObjectivesWe performed a meta-analysis to assess the influence of gestational age at the time of introduction of ASA on the incidence of preeclampsia in women at increased risk, on the basis of abnormal uterine artery Doppler.MethodsComputerized searches of randomized controlled trials were conducted to retrieve studies in which pregnant women at increased risk of preeclampsia had been identified on the basis of abnormal uterine Doppler measurements. The trials compared women who received ASA with a control group. The primary outcome was preeclampsia. Secondary outcomes included severe preeclampsia, gestational hypertension, preterm birth, intrauterine growth restriction, placental abruption, birth weight and gestational age at delivery. Statistical analyses used fixed effects of risk ratio (RR) with the Mantel-Haenszel method and 95% confidence intervals.ResultsNine randomized controlled trials with a total of 1317 women met the inclusion criteria. ASA treatment beginning in early gestation was associated with a greater reduction in the incidence of preeclampsia than treatment beginning in late gestation: ASA treatment started at ≤16 weeks’ gestation resulted in RR 0.48 (95% CI 0.33 to 0.68), at 17–19 weeks RR 0.55 (95% CI 0.17 to 1.76), and at ≥ 20 weeks RR 0.82 (95% CI 0.62 to 1.09). ASA treatment started before 16 weeks was also linked with a significant reduction in the incidence of severe preeclampsia (RR 0.10; 95% CI 0.01 to 0.74), gestational hypertension (RR 0.31; 95% CI 0.13 to 0.78) and IUGR (RR 0.51; 95% CI 0.28 to 0.92).ConclusionASA treatment initiated early in pregnancy is an efficient method of reducing the incidence of preeclampsia and its consequences in women with ultrasonographic evidence of abnormal placentation diagnosed by uterine artery Doppler studies.     

High body mass index and hypercholesterolemia: risk of hypertensive disorders of pregnancy.

OBJECTIVE: To examine the relationship between pregravid body mass index (BMI), elevated cholesterol level, and the development of hypertensive disorders of pregnancy. METHODS: We studied 15,262 women who gave birth between 1991 and 1995. Pregravid exposures including BMI and self-reported history of elevated cholesterol were ascertained by biennial mailed questionnaires. Gestational hypertension or preeclampsia was confirmed by medical record review according to standard criteria. Proportional hazards analysis was used to adjust for potential confounding variables. RESULTS: We confirmed 216 cases of gestational hypertension and 86 cases of preeclampsia. The risk of gestational hypertension increased as pregravid BMI increased (P < .01). Compared with women with a pregravid BMI of 21-22.9 kg/m2, the relative risk (RR) of gestational hypertension was 1.6 (95% confidence interval [CI] 1.0, 2.3) for women with BMI of 23-24.9 kg/m2, 2.0 (95% CI 1.3, 3.0) for BMI 25-29.9 kg/m2, and 2.6 (95% CI 1.6, 4.4) for BMI over 30 kg/m2. Leaner women (BMI less than 21 kg/m2) had a reduced risk (RR 0.7, 95% CI 0.4, 1.0). For preeclampsia, the RR of women with pregravid BMI over 30 kg/m2 was 2.1 (95% CI 1.0, 4.6) (P for trend 0.09). A history of elevated cholesterol was not associated with the risk of gestational hypertension (RR 0.9, 95% CI, 0.6, 1.4). In contrast, the RR of preeclampsia in women with a history of elevated cholesterol was 2.0 (95% CI 1.2, 3.3). CONCLUSION: Pregravid BMI and hypercholesterolemia could identify women at higher risk for hypertensive disorders during pregnancy.     

Blood loss at cesarean delivery in women on magnesium sulfate for preeclampsia

Objective: To evaluate the effect of magnesium sulfate for prevention of eclampsia on blood loss at time of cesarean delivery (CD).

Methods: We conducted an electronic based search using the following databases: MEDLINE, PUBMED and the Cochrane Library. The search terms were “magnesium sulfate”, “preeclampsia” and “randomized”. Inclusion criteria were randomized controlled trials of women with preeclampsia who delivered with or without magnesium sulfate therapy for seizure prophylaxis. Only trials with placebo or no treatment comparison groups were included. Primary outcome was postpartum hemorrhage. Secondary outcomes were estimated blood loss, change in hemoglobin, blood transfusion and eclampsia.

Results: Five trials met inclusion criteria. The incidence of postpartum hemorrhage was similar between the two groups [magnesium sulfate: 754/4482 (17%); no magnesium sulfate: 775/4427 (18%); RR 0.97, 95% CI 0.88–1.06]. There was no statistical difference between any of the other blood loss outcomes reported in the included studies. The rate of eclampsia with magnesium sulfate was significantly lower than with placebo (42/5604, 0.7%, versus 107/5600, 1.9%; RR 0.40, 95% CI 0.28–0.57).

Conclusions: Magnesium sulfate does not appear to affect blood loss intrapartum and postpartum in women with preeclampsia. Magnesium sulfate, therefore, should be continued during CD, given the benefit of seizure prophylaxis without any increased risk of hemorrhage.     

Lower risk of adverse perinatal outcomes in natural versus artificial frozen–thawed embryo transfer cycles: a systematic review and meta-analysis

This systematic review of literature and meta-analysis of observational studies reports on perinatal outcomes after frozen embryo transfer (FET). The aim was to determine whether natural cycle frozen embryo transfer (NC-FET) in singleton pregnancies conceived after IVF decreased the risk of adverse perinatal outcomes compared with artificial cycle frozen embryo transfer (AC-FET). Thirteen cohort studies, including 93,201 cycles, met the inclusion criteria. NC-FET was associated with a lower risk of hypertensive disorders in pregnancy (HDP) (RR 0.61, 95% CI 0.50 to 0.73), preeclampsia (RR 0.47, 95% CI 0.42 to 0.53), large for gestational age (LGA) (RR 0.93, 95% CI 0.90 to 0.96) and macrosomia (RR 0.82, 95% CI 0.69 to 0.97) compared with AC-FET. No significant difference was found in the risk of gestational hypertension and small for gestational age. Secondary outcomes assessed were the risk of preterm birth (RR 0.83, 95% CI 0.79 to 0.88); post-term birth (RR 0.48, 95% CI 0.29 to 0.80); low birth weight (RR 0.84, 95% CI 0.80 to 0.89); caesarean section (RR 0.84, 95% CI 0.77 to 0.91); postpartum haemorrhage (RR 0.39, 95% CI 0.35 to 0.45); placental abruption (RR 0.61, 95% CI 0.38 to 0.98); and placenta accreta (RR 0.18, 95% CI 0.10 to 0.33). All were significantly lower with NC-FET compared with AC-FET. In assessing safety, NC-FET significantly decreased the risk of HDP, preeclampsia, LGA, macrosomia, preterm birth, post-term birth, low birth weight, caesarean section, postpartum haemorrhage, placental abruption and placenta accreta. Further randomized controlled trials addressing the effect of NC-FET and AC-FET on maternal and perinatal outcomes are warranted. Clinicians should carefully monitor pregnancies achieved by FET in artificial cycles prenatally, during labour and postnatally.     

Effects of maternal micronutrient supplementation on fetal loss and under-2-years child mortality: long-term follow-up of a randomised controlled trial from Guinea-Bissau

A number of trials on maternal multi-micronutrient supplementation (MMS) have found a benefical effect on birth weight, but few have demonstrated a beneficial effect on infant survival. We examined the effect of two different preparations of antenatal MMS on fetal loss and under-2-years child mortality, as compared with iron-folic acid supplementation among 2,100 pregnant women in Guinea-Bissau. Women receiving a 1xRDA MMS preparation (consisting of 14 vitamins and minerals) had a marginally reduced risk of fetal loss (Relative risk (RR) 0.65, 95% CI 0.40; 1.05), and women receiving a 2xRDA MMS preparation had a similar effect (RR 0.67, 95% CI 0.42; 1.08), the pooled effect being 0.66 (95% CI 0.44; 0.99). None of the supplements reduced under-2-years mortality or the combination of fetal loss and under-2-years mortality. There was a marginally negative effect of both the 1xRDA (RR 2.10, 95% CI 0.99; 4.46) and the 2xRDA (RR 2.02, 95% CI 0.95; 4.32) MMS preparation on mortality specifically between 92-365 days of age.     

Second-trimester maternal serum alpha-fetoprotein and risk of adverse pregnancy outcome(1)

OBJECTIVE: To determine the risk of adverse pregnancy outcome by maternal serum alpha-fetoprotein (MSAFP) level. METHODS: We followed 77,149 pregnant women and their infants from MSAFP screening in the 15th to 20th week of gestation until 1 year after birth. Information on pregnancy outcome was obtained from national registries. The relative risks (RRs) and 95% confidence intervals (CIs) for adverse pregnancy outcome were estimated according to the level of MSAFP, with adjustment for confounders. RESULTS: A total of 638 pregnancies resulted in spontaneous abortion, 289 in stillbirth, and 437 in infant death. Compared with women with MSAFP levels at 0.75-1.24 multiples of the median (MoM), those with MSAFP levels greater than or equal to 2.5 MoM had an increased risk of spontaneous abortion (RR 12.5; 95% CI 9.7, 16.1), preterm birth (RR 4.8; 95% CI 4.1, 5.5), small for gestational age (RR 2.8; 95% CI 2.4, 3.2), low birth weight (RR 5.8; 95% CI 5.0, 6.6), and infant death (RR 1.9; 95% CI 1.2, 2.8). Women with MSAFP levels below 0.25 MoM had an increased risk of spontaneous abortion (RR 15.1; 95% CI 9.3, 24.8), preterm birth (RR 2.2; 95% CI 1.3, 3.8), and stillbirth (RR 4.0; 95% CI 1.0, 16.0); those with levels less than 0.5 MoM had an increased risk of infant death (RR 1.9; 95% CI 1.2, 3.0). The increased risk of infant death remained after the subtraction of recognized conditions associated with extreme MSAFP values. CONCLUSION: Pregnant women with extreme MSAFP values in the second trimester have an increased risk of fetal and infant deaths. Obstet Gynecol 2001;97:277-82.     

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 alpha=.05. The alpha 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.     

Periodontal disease and pregnancy outcomes: state-of-the-science

To examine the existing evidence on the relationship between periodontal disease and adverse pregnancy outcomes, we conducted a systematic review of studies published up to December 2006. Studies published in full text were identified by searching computerized databases (e.g., MEDLINE, EMBASE). A meta-analysis was performed to pool the effect size of the clinical trials. Forty-four studies were identified (26 case-control studies, 13 cohort studies, and 5 controlled trials). The studies focused on preterm low birth weight, low birth weight, preterm birth, birth weight by gestational age, miscarriage or pregnancy loss, preeclampsia, and gestational diabetes mellitus. Of the chosen studies, 29 suggested an association between periodontal disease and increased risk of adverse pregnancy outcome (odds ratios [ORs] ranging from 1.10 to 20.0) and 15 found no evidence of an association (ORs ranging from 0.78 to 2.54). A meta-analysis of the clinical trials suggested that oral prophylaxis and periodontal treatment may reduce the rate of preterm low birth weight (pooled risk ratio (RR): 0.53, 95% confidence interval [CI]: 0.30-0.95, P < 0.05), but did not significantly reduce the rates of preterm birth (pooled RR: 0.79, 95% CI: 0.55-1.11, P > 0.05) or low birth weight (pooled RR: 0.86, 95% CI: 0.58%1.29, P > 0.05). The authors conclude that periodontal disease may be associated with increased risk of adverse pregnancy outcomes. More methodologically rigorous studies are needed in this field. Currently, there is insufficient evidence to support the provision of periodontal treatment during pregnancy for the purpose of reducing adverse pregnancy outcomes. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to state that the published literature is not vigorous to clinically link periodontal disease and/or its treatment to specific adverse pregnancy outcomes, and explain that more rigorous studies with world-wide agreed-upon definitions are particularly needed before periodontal disease treatment can be recommended.     

Efficacy of n-3 fatty acids supplementation on the prevention of pregnancy induced-hypertension or preeclampsia: A systematic review and meta-analysis

The efficacy of n-3 fatty acids supplementation on the prevention of pregnancy-induced hypertension or preeclampsia remains unclear. The aim of study was to examine the effect of supplementation with EPA, and/or DHA, and/or ALA during pregnancy on the pregnancy-induced hypertension or preeclampsia. A systematic search was performed on Scopus, PubMed, Web of Science (WoS), Cochrane Library, and Google scholar, which covered the period between 1991 and 2018. The clinical trials with any control groups (i.e. placebo or other supplementation) were selected. The whole process of meta-analysis and data analysis was done using Comprehensive Meta-Analysis (Version 2.0, Biostat). The searched keywords were: “Fatty Acids, Omega-3”, “n-3 Polyunsaturated Fatty Acid” “Eicosapentaenoic Acid”, “Docosahexaenoic Acids”, “n-3 Polyunsaturated Fatty Acid”, “n-3 PUFAs”, “alpha-Linolenic Acid”, “fish oil”, “Nuts”, “nutrient”, or their synonyms “pregnancy induced hypertension” and preeclampsia. In addition, some key journals, according to Scopus report and the references of the original and review articles, were manually searched for possible related studies. The meta-analysis of the 14 comparisons demonstrated that n-3 fatty acids supplementation played a protective role against the risk of preeclampsia (RR, 0.82; 95% CI, 0.70–0.97; p = 0.024; I2 = 19.0%). The analysis of the 10 comparisons revealed that n-3 fatty acid supplements for pregnant women did not mitigate the risk of pregnancy-induced hypertension (RR, 0.98; 95% CI, 0.90–1.07; p = 0.652; I2 = 0%). The n-3 fatty acid supplements are an effective strategy to prevent the incidence of preeclampsia in women with low-risk pregnancies.     

Is low-dose aspirin therapy to prevent preeclampsia more efficacious in non-obese women or when initiated early in pregnancy?

Objective: Late timing of intervention and maternal obesity are potential explanations for the modest effect of aspirin for preeclampsia prevention. We explored whether low-dose aspirin (LDA) is more effective in women at increased risk when initiated before 16 weeks' gestation or given to non-obese women.

Methods: Secondary analysis of a trial to evaluate LDA (60?mg/d) for preeclampsia prevention in high-risk women. Participants were randomized to LDA or placebo between 13 and 26 weeks. We stratified the effect of LDA on preeclampsia by (a) timing of randomization (Results: Of 2503 women, 461 (18.4%) initiated LDA?p value for interaction?=?0.87). Similarly, LDA effect was not better in non-obese (RR: 0.91, 95% CI: 0.7–1.13) versus obese women (RR: 0.89, 95% CI: 0.7–1.13), (p value for interaction?=?0.85).

Conclusion: LDA for preeclampsia prevention was not more effective when initiated 相似文献   

Pregnant women with the sickle cell trait are not at increased risk for developing preeclampsia

The primary objective of this study was to determine whether having the sickle cell trait is independently associated with preeclampsia. We performed a retrospective cohort study of 1998 pregnant patients who either did or did not have the sickle cell trait. All patients were screened for the sickle trait using the "Sickledex" test. Data on neonatal and maternal outcome, including preeclampsia, and potential confounding variables were abstracted from medical records. Unadjusted, stratified, and multiple logistic regression analyses were used to identify interactions, and confounding between multiple variables and the association between sickle cell trait and preeclampsia. With an anticipated 6.5% rate of preeclampsia, and alpha = 0.05, this cohort study has 80% power to detect a relative risk (RR) of 2.3 for preeclampsia. Univariate analysis revealed that the two cohorts were similar with regard to primiparity, maternal age, chronic diseases, birth weight, and gestational age at delivery, but the sickle cell trait cohort was more likely to have gestational diabetes and had a higher mean body mass index (BMI). In the univariate analysis, the sickle cell trait cohort was not at increased risk for preeclampsia [unadjusted RR = 0.5, 95% CI (0.2-1.6)]. After controlling for potential confounding variables with logistic regression analysis, sickle trait was not independently associated with preeclampsia [adjusted RR = 0.5, 95% CI (0.2- 1.6)]. In contrast to prior work, these data suggest that the sickle cell trait is not an independent risk factor for preeclampsia or postpartum complications. In fact, the data are more consistent with the sickle trait being protective for developing preeclampsia.     

Vitamin C and E supplementation in women at high risk for preeclampsia: a double-blind, placebo-controlled trial

OBJECTIVE: We sought to determine the effect of supplemental antioxidant vitamins C and E on the rate of preeclampsia in high-risk pregnant women. STUDY DESIGN: Women at risk for preeclampsia (previous preeclampsia, chronic hypertension, pregestational diabetes, or multifetal gestation) were recruited at 14 to 20 weeks' gestation and randomly assigned to receive either 1000 mg of vitamin C and 400 IU of vitamin E or placebo daily in addition to their regular prenatal vitamins. The primary outcome was the occurrence of preeclampsia. An estimated sample size of 220 women in each arm was determined to be necessary to demonstrate a 50% reduction in the rate of preeclampsia. RESULTS: Funding was terminated after 109 women had been recruited; 9 were lost to follow-up or withdrew. We analyzed data from the remaining 100 women to look for differences in outcome and to estimate the required sample size for future studies. The rate of preeclampsia was not different: 17.3% in women who received supplemental vitamins C and E, versus 18.8% in the placebo group. Assuming a baseline rate of preeclampsia in the placebo group between 15% and 20%, we can estimate that 500 to 950 women in each arm will be required to show a clinically important reduction in the rate of preeclampsia. CONCLUSION: The potential benefit of vitamin C and E supplementation to prevent preeclampsia in women with clinical risk factors is smaller than we estimated. Future studies of antioxidant vitamin supplementation in this population will require more than 500 women in each arm.     

Manual versus electric vacuum aspiration for first-trimester abortion: a systematic review

Background  As an alternative to electric vacuum aspirations (EVA), there is an increasing interest in using manual vacuum aspiration (MVA).
Objective  To compare the safety, efficacy and acceptability of MVA with those of EVA for first-trimester abortion.
Search strategy  We searched MEDLINE, EMBASE, Cochrane Library and Chinese Biomedical Database in all language, together with reference lists of retrieved papers.
Selection criteria  Randomised controlled trials comparing MVA with EVA for first-trimester abortion were included. The outcomes are complete abortion rate, uterine perforation rate, blood loss, pain perception and acceptability.
Data collection and analysis  Two reviewers independently extracted the data. Results from the trials were combined to calculate relative risks (RRs) or risk differences for dichotomous outcomes and weighted mean differences (WMDs) for continuous outcomes, together with 95% CIs.
Main results  Ten trials were included, involving 1660 women. Generally, the methodological quality was poor. There were no statistically significant differences, comparing MVA with EVA, in complete abortion rate (RR 1.00; 95% CI 0.99–1.02) and participants' satisfaction (RR 1.02; 95% CI 0.87–1.20). In participants with less than 50 days of gestational age, less blood loss (WMD −1.84; 95% CI −2.45 to −1.23) and less severe pain perception (RR 0.04; 95% CI 0.01–0.12) were reported during the MVA procedure, whereas the operation time was shorter (WMD 0.32; 95% CI 0.02–0.63) in the EVA procedure.
Author's conclusions  There is some evidence that MVA is as effective and acceptable as EVA and might be safer than EVA.     

Preeclampsia and fetal growth

OBJECTIVE: To determine if the influence of preeclampsia on birth size varies with clinical manifestations of the disease, and to evaluate whether maternal factors, such as smoking, modify the effect of preeclampsia on fetal growth. METHODS: Among 12,804 deliveries in a population of approximately 239,000 over a 3-year period, 307 live singleton infants were born after preeclamptic pregnancies. We compared those with a sample of 619 control infants. Preeclampsia was defined as increased diastolic blood pressure (BP) (increase of at least 25 mmHg to at least 90 mmHg) and proteinuria after 20 weeks' gestation. Clinical manifestations were classified according to BP and proteinuria into subgroups of mild, moderate, or severe (including cases with eclampsia and hemolysis, elevated liver enzymes, low platelets [HELLP] syndrome) preeclampsia, and according to gestational age at onset, as early or late preeclampsia. Birth size was expressed as the ratio between observed and expected birth weights, and infants smaller than two standard deviations from expected birth weights were classified as small for gestational age (SGA). RESULTS: Preeclampsia was associated with a 5% (95% confidence interval [CI] 3%, 6%) reduction in birth weight. In severe preeclampsia, the reduction was 12% (9%, 15%), and in early-onset disease, birth weight was 23% (18%, 29%) lower than expected. The risk of SGA was four times higher (relative risk [RR] = 4.2; 95% CI 2.2, 8.0) in infants born after preeclampsia than in control pregnancies. Among nulliparas, preeclampsia was associated with a nearly threefold higher risk of SGA (RR = 2.8; 1.2, 5.9), and among paras, the risk of SGA was particularly high after recurrent preeclampsia (RR = 12.3; 3.9, 39.2). In relation to preeclampsia and maternal smoking, the results indicated that each factor might contribute to reduced growth in an additive manner. CONCLUSION: Severe and early-onset preeclampsia were associated with significant fetal growth restriction. The risk of having an SGA infant was dramatically higher in women with recurrent preeclampsia. Birth weight reduction related to maternal smoking appeared to be added to that caused by preeclampsia, suggesting that there is no synergy between smoking and preeclampsia on growth restriction.     

Calcium Supplementation During Pregnancy for Preventing Hypertensive Disorders Is not Associated with Changes in Platelet Count,Urate, and Urinary Protein: a Randomized Control Trial

Objective. To test the hypothesis that calcium supplementation inhibits the underlying pathological processes in women with preeclampsia. Methods. Seven hundred and eight nulliparous women were enrolled in a WHO randomized double-blind trial, who received 1.5 g of calcium or placebo from 20 weeks of pregnancy or earlier. Platelet count, serum urate, and urinary protein/creatinine ratio were measured at or near 35 gestational weeks. Results. No difference was detected in rates of abnormal platelet count (relative risk [RR] 1.18; 95% confidence interval [CI], 0.63 to 2.18), serum urate level (1.0; 0.64 to 1.57) or urine protein/creatinine ratio (1.01; 0.76 to 1.34). This was consistent with the main trial finding of no difference in the incidence of ‘dipstick’ proteinuria between women receiving calcium and those receiving placebo (8312 women; RR, 1.01; 95% CI, 0.88 to 1.15). Conclusions. An effect of calcium supplementation in the second half of pregnancy on the rate of abnormal laboratory measures associated with preeclampsia was not demonstrated.