Plasma folate, vitamin B(12), and homocyst(e)ine concentrations in preeclamptic and normotensive Peruvian women

Association of serum homocysteine with vitamin B12 and folate levels in women with pre-eclampsia in a tertiary health care center in Nepal

BACKGROUND

Pre-eclampsia is a syndrome that chiefly includes the development of new-onset hypertension and proteinuria after 20 weeks of pregnancy. Pre-eclampsia is one of the major causes of mortality and morbidity in Nepal. Hyperhomocysteinemia may be a cause of the endothelial dysfunction provoked by oxidative stress in pre-eclampsia. This study was designed to evaluate the association of homocysteine with Vitamin B12 and folate in patients with pre-eclampsia.

METHOD

An observational cross sectional study was performed in the Gynecology and Obstetrics Department of TUTH involving seventy two subjects with pre-eclampsia. Blood pressure, urinary protein levels, serum homocysteine, Vitamin B12 and folate levels were compared in both mild and severe forms of pre-eclampsia. Concentration of Vitamin B12 and folate were measured using Vitros ECI and homocysteine was measured using CLIA. SPSS 23.0 was used to analyze the data. Tests were performed with Mann Whitney Test and Spearman's rank correlation test. A p-value < 0.05 was considered statistically significant.

RESULTS

This study showed no significant difference in age and weeks of gestation in both mild and severe forms of pre-eclampsia. Mean concentration of homocysteine was higher (13.1 ± 6.4 micromol/L) in severe Pre-eclampsia as compared to mild cases (7.6 ± 2.8 micromol/L). Mean concentration of folate was lower in severe cases (35.4 ± 24.1 micromol/L) when compared with mild cases of pre-eclampsia (57 ± 23.4 micromol/L).

CONCLUSION

Homocysteine levels were increased in severe Pre-eclampsia when compared with mild pre-eclampsia and this finding can be used to predict and prevent complications in patients with pre-eclampsia.

Genetically predicted circulating concentrations of micronutrients and risk of hypertensive disorders of pregnancy: a Mendelian randomization study

PURPOSE

Epidemiological studies examining the association between circulating micronutrients and the risk of hypertensive disorders during pregnancy (HDP) have produced inconsistent results. Therefore, we conducted a Mendelian randomization (MR) analysis to evaluate the potential causal relationship between micronutrients and HDP.

METHODS

Nine micronutrients (beta-carotene, vitamin B6, vitamin B12, calcium, zinc, selenium, copper, folate, and phosphorus) were selected as the exposure factors. Summary data for gestational hypertension (14,727 cases and 196,143 controls) and preeclampsia/eclampsia (7212 cases and 174,266 controls) were extracted from the FinnGen consortium. The MR analysis employed the inverse variance weighted method and conducted a range of sensitivity analyses.

RESULTS

The inverse variance weighted method indicated no significant causal relationship between nine genetically predicted micronutrient concentrations and gestational hypertension, as well as preeclampsia/eclampsia. Sensitivity analyses suggested the absence of pleiotropy.

CONCLUSION

There is no strong evidence to support the causation between circulating micronutrients and hypertensive disorder during pregnancy.

Prevalence of vitamin B complex deficiencies in women in reproductive age, pregnant, or lactating woman in Brazil: a systematic review and meta-analysis protocol

BACKGROUND

Vitamin B deficiencies are involved with several outcomes in fertility and pregnancy. In Brazil, the national prevalence rates of these micronutrient deficiencies in women of reproductive age were not known. This study aims to systematically identify, select, evaluate, analyze, and report the prevalence rates of vitamin B complex deficiencies in women of reproductive age in Brazil and identify variables that may modify the outcome rates.

METHODS

A systematic review will be conducted guided by the following question: "What is the prevalence of vitamin B deficiencies in women of reproductive age in Brazil?". The studies will be identified and selected from a literature search using electronic databases, consultation with researchers/specialists, and reference lists of eligible studies and reviews on the topic. Major eligibility criteria include observational cross-sectional and cohort studies carried out in Brazil and performed in women 10-49 years old, or pregnant and lactating mothers, and investigated the deficiency of vitamin B complex by laboratory test. Two reviewers independently will perform the screening and selection of the studies, data extraction, and risk of bias assessment. For the data report, a narrative approach will be used to present the characteristics of the included studies and individual findings. A random meta-analysis model will be implemented to summarize the individual prevalence rates in a global value if the studies are sufficiently homogeneous.

DISCUSSION

This study aims to identify the national and regional prevalence rates of vitamin B complex deficiencies in women of reproductive age; allow the policymakers discuss, plan, and implement public policies to screen; and prevent and/or treat these malnutrition conditions. This also aims to know the rates of nutritional deficiencies over the years, serving as an indirect indicator of the socioeconomic and dietary patterns of the population. Specifically for folate, this study allows to compare the prevalence rates of deficiency of this vitamin before and after the mandatory fortification of wheat and corn flours implemented since 2004 in Brazil, in this specific population. The evidence gathered may highlight the need for population-based studies to investigate the deficiency of these vitamins.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020188474.

Biological Role of Folic Acid in Pregnancy and Possible Therapeutic Application for the Prevention of Preeclampsia

The rationale and importance of folic acid supplementation during pregnancy for fetal congenital defect prevention are accepted worldwide. Moreover, a sufficient plasma concentration of folates can reduce the incidence of spontaneous abortions, and support the normal expansion of placental blood vessels, ensuring physiological placental blood flow, thus promoting appropriate fetal growth and development. Furthermore, there is emerging evidence that long-term supplementation with folic acid can effectively prevent preeclampsia. Preeclampsia is unique to the human species in complications during pregnancy, which contributes to maternal and perinatal mortality worldwide. In the pathogenesis of preeclampsia abnormal placental invasion, the excess of antiangiogenic factors and maternal-placental syndrome play a key role. Increased blood levels of homocysteine during pregnancy are associated with the risk of preeclampsia. Moreover, hyperhomocysteinemia has been proposed to be an independent risk factor for preeclampsia. Folate supplementation helps to decrease elevated levels of homocysteine; thus, the role of folic acid supplementation in pregnancy is even more important. Multiple reports suggest that folate administration decreases the level of serum homocysteine and, therefore, reduce the risk and severity of preeclampsia. However, the association between folic acid supplementation and the decreased risk of preeclampsia has been investigated with controversial conclusions. Currently, the optimal dose of folic acid that is effective for preeclampsia prevention remains uncertain. In this review, we aim to summarize the accumulated knowledge on the role of folic acid in the pathogenesis of preeclampsia, and the possible impact of folate supplementation on the decreased risk of preeclampsia.

Thyroid Dysfunction, Vitamin B12, and Folic Acid Deficiencies Are Not Associated With Cognitive Impairment in Older Adults in Lima, Peru

Background: Reversible etiologies of cognitive impairment are common and treatable, yet the majority of mild cognitive impairment (MCI) and dementia research in Latin America has focused on irreversible, neurodegenerative etiologies. Objective: We sought to determine if thyroid dysfunction and vitamin B12 and folate deficiencies are associated with cognitive disorders among older adults with memory complaints in Lima, Peru. Methods: This was a retrospective review of patients who presented for cognitive evaluations to a multidisciplinary neurology clinic in Lima, Peru from January 2014 to February 2020. We included individuals aged ≥60 years, native Spanish-speakers, with at least a primary school educational level and a complete clinical assessment. Patients had either subjective cognitive decline (SCD), MCI, or dementia. One-way ANOVA and multiple logistic regression analyses were performed. Results: We included 720 patients (330 SCD, 154 MCI, and 236 dementia); the dementia group was significantly older [mean age SCD 69.7 ± 4.1, dementia 72.4 ± 3.7 (p = 0.000)] and had lower folate levels than SCD patients. The MCI group had higher free T3 levels compared with SCD patients. Those with lower TSH had greater dementia risk (OR = 2.91, 95%CI: 1.15-6.86) but not MCI risk in unadjusted models. B12 deficiency or borderline B12 deficiency was present in 34% of the dementia group, yet no clear correlation was seen between neuropsychological test results and B12 levels in our study. There was no association between MCI or dementia and thyroid hormone, B12 nor folate levels in adjusted models. Conclusion: Our findings do not support an association between metabolic and endocrine disorders and cognitive impairment in older Peruvians from Lima despite a high prevalence of B12 deficiency. Future work may determine if cognitive decline is associated with metabolic or endocrine changes in Latin America.

Association between abnormal maternal serum levels of vitamin B12 and preeclampsia: a systematic review and meta-analysis

CONTEXT

Some evidence has shown an association between maternal vitamin B12 levels and the development of preeclampsia in pregnant women, but the relationship between preeclampsia and vitamin B12 is not clear.

OBJECTIVE

The aim of this systematic review was to compare serum vitamin B12 levels in women with preeclampsia with those in normotensive pregnant women.

DATA SOURCES

The PubMed/MEDLINE, Scopus, and Web of Science databases were searched up to August 2019, along with the reference lists of included articles.

STUDY SELECTION

The literature was searched for observational studies that investigated vitamin B12 levels in women with preeclampsia.

DATA EXTRACTION

Data were extracted independently by 2 authors. Data were pooled using a random-effects model.

RESULTS

Vitamin B12 levels in women with preeclampsia were significantly lower than those in healthy women (mean, -15.24 pg/mL; 95%CI, -27.52 to -2.954; P < 0.015), but heterogeneity between studies was high (I2 = 97.8%; P = 0.0103). Subgroup analyses based on folic acid supplementation, homocysteine concentrations, and gestational age at the time of sampling for vitamin B12 assessment did not identify the sources of heterogeneity.

CONCLUSIONS

Women with preeclampsia had significantly lower vitamin B12 concentrations than normotensive pregnant women.

Maternal Hypertensive Disorders in Pregnancy and Postpartum Plasma B Vitamin and Homocysteine Profiles in a High-Risk Multiethnic U.S., Population

Background: Hypertensive disorders of pregnancy are a recognized risk factor of a woman's future cardiovascular risk. The potential role of micronutrients in mitigating hypertensive disorders is not fully understood. This study examined maternal postpartum plasma B vitamin profiles by hypertensive disorders of pregnancy in a high-risk multiethnic U.S. population. Materials and Methods: The analyses included 2584 mothers enrolled within 3 days postpartum at the Boston Medical Center. Hypertensive disorders of pregnancy included gestational hypertension and pre-eclampsia disorders (pre-eclampsia, eclampsia, hemolysis, elevated liver enzymes, and/or low platelets syndrome) as documented in the medical records. Plasma folate, vitamin B12, and homocysteine levels were measured in blood samples collected at enrollment. Kernel density plots and multivariable regressions were used to examine the relationship between hypertensive disorders and postpartum B vitamin profiles. Results: Of the 2584 mothers, 10% had pre-eclampsia disorders that were associated with significantly lower plasma folate (adjusted beta coefficient (aβ): -0.10; 95% CI: -0.22 to -0.06) and increased homocysteine (aβ: 0.08; 95% CI: 0.04-0.13), but not with vitamin B12 concentrations. These associations remained robust after adjusting for a range of pertinent covariables and were more pronounced in non-Hispanic Black women compared with other groups. However, gestational hypertension was not significantly associated with any postpartum biomarker. Conclusions: We found that pre-eclampsia disorders, but not gestational hypertension, was associated with lower folate and higher homocysteine levels postpartum, especially among Black mothers. This finding, if further confirmed, may have implications for postpartum care, including attention to maternal micronutrient status to reduce and prevent hypertensive disorders in pregnancy-associated consequences in subsequent pregnancies and lifespan. Registration date: July 25, 2017; Registry website: https://clinicaltrials.gov/ct2/show/NCT03228875.

The Role of Nitric Oxide, ADMA, and Homocysteine in The Etiopathogenesis of Preeclampsia-Review

Preeclampsia is a serious, pregnancy-specific, multi-organ disease process of compound aetiology. It affects 3–6% of expecting mothers worldwide and it persists as a leading cause of maternal and foetal morbidity and mortality. In fact, hallmark features of preeclampsia (PE) result from vessel involvement and demonstrate maternal endothelium as a target tissue. Growing evidence suggests that chronic placental hypoperfusion triggers the production and release of certain agents that are responsible for endothelial activation and injury. In this review, we will present the latest findings on the role of nitric oxide, asymmetric dimethylarginine (ADMA), and homocysteine in the etiopathogenesis of preeclampsia and their possible clinical implications.

Higher maternal plasma folate, vitamin B12 and homocysteine levels in women with preeclampsia

Micronutrients like vitamin B₁₂ and folate play an important role in nucleic acid metabolism, cell growth, and are important determinants of fetal growth. The present study examined the levels of maternal and cord plasma folate, vitamin B₁₂, homocysteine, and their association with birth outcome in women with preeclampsia (PE). This study includes 450 normotensive control (NC) and 350 women with PE. PE women were further classified into women delivering at term (n = 224) and preterm (n = 126). Maternal and cord blood was collected at delivery. The levels of maternal vitamin B₁₂ (p < 0.05), folate (p < 0.01), and homocysteine (p < 0.01) were higher in the PE group as compared to the NC group. Maternal folate levels were higher in both term and preterm groups, while vitamin B₁₂ levels were higher only in the preterm group as compared to NC group. In contrast, homocysteine was higher only in the term PE group. Similar changes were also observed in the cord plasma. There was a positive association of maternal plasma homocysteine with systolic (r = 0.151, p = 0.000, n = 578) and diastolic blood pressure (r = 0.213, p = 0.000, n = 578) in the whole cohort. A negative association of maternal folate with systolic blood pressure (r = -0.105, p = 0.048, n = 352) while a positive association with baby weight in the NC group (r = 0.116, p = 0.029, n = 352). The present study suggests that maternal and cord micronutrient levels are altered in women with PE.

Supplementation of folic acid in pregnancy and the risk of preeclampsia and gestational hypertension: a meta-analysis

OBJECTIVES

We aimed to systematically assess the relationship between folic acid supplementation in pregnancy and risk of preeclampsia and gestational hypertension.

METHODS

The relevant studies were included by retrieving the Embase, PubMed and Cochrane library databases. Data extraction was conducted by two investigators independently. The risk ratio (RR) and 95% confidence interval (CI) were used as effect indexes to evaluate the relationship between folic acid supplementation and risk of gestational hypertension or preeclampsia. A subgroup analysis was performed according to the supplementation patterns of folic acid. The homogeneity of the effect size was tested across the studies, and publication biases were examined.

RESULTS

In total, 13 cohort studies and 1 randomized controlled trial study was included, containing 160,562 and 149,320 women with and without folic acid supplementation during pregnancy. Pooled results showed that risk of gestational hypertension was not associated with the supplementation of folic acid. However, folic acid supplementation during pregnancy could significantly reduce the risk of preeclampsia. Moreover, the results of subgroup analysis showed that the decreased preeclampsia risk was associated with supplementation of multivitamins containing folic acid rather than folic acid alone.

CONCLUSIONS

Our findings indicate that the supplementation of multivitamins containing folic acid during pregnancy could significantly lower preeclampsia risk.

Joint effect of maternal plasma homocysteine and prepregnancy obesity on child blood pressure: a prospective birth cohort study

BACKGROUND/OBJECTIVES

Elevated homocysteine (Hcy) is a known cardiovascular risk factor. However, its role in intergenerational cardiometabolic risk is unknown. We hypothesized that maternal elevated Hcy can act alone or in combination with maternal prepregnancy obesity to increase child systolic blood pressure (SBP).

METHODS

This study included 1279 mother-child pairs who were enrolled at birth and followed prospectively up to age 9 years from 2003 to 2014 at the Boston Medical Center. Child SBP percentile was calculated according to US reference data and elevated SBP was defined as SBP⩾75th percentile.

RESULTS

A U-shaped relationship between maternal Hcy and her child SBP was observed. The risk for child elevated SBP was higher among those in the lowest quartile (Q1, odds ratio (OR): 1.27; 95% confidence interval (CI): 0.94-1.72), and highest quartile (Q4, OR: 1.34; 95% CI: 1.00-1.81) as compared with those in quartiles 2 and 3. The highest risk of child elevated SBP was found among children born to obese mothers with Hcy in Q4 (OR: 2.22; 95%CI: 1.35-3.64), compared with children of non-obese mothers with Hcy in Q2-Q3. This association was independent from maternal folate and vitamin B12 status, and was not mediated by gestational age or size at birth.

CONCLUSIONS

In this prospective birth cohort, we observed a U-shaped association between maternal Hcy levels and child elevated SBP. Maternal high Hcy (Q4) and prepregnancy obesity jointly increased the risk of child elevated SBP by more than two-fold.

Associations of Maternal Vitamin B12 Concentration in Pregnancy With the Risks of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis of Individual Participant Data

Vitamin B12 (hereafter referred to as B12) deficiency in pregnancy is prevalent and has been associated with both lower birth weight (birth weight <2,500 g) and preterm birth (length of gestation <37 weeks). Nevertheless, current evidence is contradictory. We performed a systematic review and a meta-analysis of individual participant data to evaluate the associations of maternal serum or plasma B12 concentrations in pregnancy with offspring birth weight and length of gestation. Twenty-two eligible studies were identified (11,993 observations). Eighteen studies were included in the meta-analysis (11,216 observations). No linear association was observed between maternal B12 levels in pregnancy and birth weight, but B12 deficiency (<148 pmol/L) was associated with a higher risk of low birth weight in newborns (adjusted risk ratio = 1.15, 95% confidence interval (CI): 1.01, 1.31). There was a linear association between maternal levels of B12 and preterm birth (per each 1-standard-deviation increase in B12, adjusted risk ratio = 0.89, 95% CI: 0.82, 0.97). Accordingly, B12 deficiency was associated with a higher risk of preterm birth (adjusted risk ratio = 1.21, 95% CI: 0.99, 1.49). This finding supports the need for randomized controlled trials of vitamin B12 supplementation in pregnancy.

Renal Handling of Homocysteine During Normal Pregnancy and Preeclampsia

OBJECTIVE

Maternal plasma homocysteine decreases in normal pregnancy and is significantly increased in preeclampsia. The goal of this study was to investigate the role of the maternal kidney in the changes of plasma homocysteine during normal pregnancy and preeclampsia.

METHODS

Plasma and 24-hour urine samples were collected in the same women before, during (first, second, and third trimesters), and after normal pregnancy; and in a separate cross-sectional study of normal pregnant, preeclamptic and nonpregnant women and homocysteine concentrations were measured.

RESULTS

Longitudinally, maternal plasma homocysteine decreased significantly by the first trimester compared with prepregnancy and postpartum levels (5.6 +/- 1.8 versus 6.8 +/- 0.5 and 7.4 +/- 0.4 microM, respectively, P<.05 by analysis of variance) and paralleled a significant increase in the renal clearance of homocysteine (2.9 +/- 0.4 versus 1.8 +/- 0.2 and 1.6 +/- 0.2 L/24 hours, respectively, P<.001). In addition, plasma homocysteine was significantly elevated in preeclampsia compared with normal pregnancy (4.4 +/- 0.6 versus 3.2 +/- 0.2 microM, P<.04); however, renal clearance was not different (1.2 +/- 0.1 versus 1.0 +/- 0.1 L/24 hours, P=.55).

CONCLUSION

Increases in renal clearance contribute to the decrease in plasma homocysteine during normal pregnancy. However, changes in renal handling do not appear to contribute to the increase in plasma homocysteine in preeclampsia.

Prevalence of vitamin B-12 insufficiency during pregnancy and its effect on offspring birth weight: a systematic review and meta-analysis

BACKGROUND

Vitamin B-12 and folate are micronutrients essential for normal embryogenesis. Vitamin B-12 insufficiency in pregnancy is high in certain parts of the world, such as India, and although this has been linked to low birth weight (LBW) in these populations, the relation between vitamin B-12 and birth weight (BW) elsewhere is unknown.

OBJECTIVES

We performed a systematic review to assess 1) the worldwide prevalence of vitamin B-12 insufficiency in pregnancy and 2) its association with BW.

DESIGN

A search of 5 electronic databases was performed to identify eligible articles. Random-effects meta-analysis was conducted according to geographic regions and pregnancy trimesters for the prevalence subreview and by categorical measures of BW.

RESULTS

A total of 57 and 23 articles were included for the prevalence and BW subreviews, respectively. The pooled estimates of vitamin B-12 insufficiency were 21%, 19%, and 29% in the first, second, and third trimesters, respectively, with high rates for the Indian subcontinent and the Eastern Mediterranean. The large heterogeneity between studies was partially addressed by creating a standardized score for each study (mean vitamin B-12 insufficiency ÷ cutoff value), which internally corrected for geographic region, trimester, and assay type. Twelve of the 13 longitudinal studies included showed a decrease in mean or median vitamin B-12 across trimesters. Pooled analysis showed nonsignificantly lower maternal vitamin B-12 concentrations in LBW than in normal-BW infants and higher odds of LBW with lower vitamin B-12 values (adjusted OR: 1.70; 95% CI: 1.16, 2.50), but studies from India largely contributed to the latter.

CONCLUSIONS

Our review indicates that vitamin B-12 insufficiency during pregnancy is common even in nonvegetarian populations and that concentrations of vitamin B-12 decrease from the first to the third trimester. There is no consistent association between vitamin B-12 insufficiency and LBW. However, given the long-term risks of LBW, this observation warrants further cohort studies and randomized controlled trials.

Folic acid supplementation: what is new? Fetal, obstetric, long-term benefits and risks

The association between folic acid supplementation, prior to conception and/or during pregnancy and pregnancy outcomes, has been the subject of numerous studies. The worldwide recommendation of folic acid is at least 0.4 mg daily for all women of reproductive age, and 4–5 mg in high-risk women. In addition, evidence shows that folic acid supplementation could modulate other adverse pregnancy outcomes, specifically, in pregnancies complicated by seizure disorders, preeclampsia, anemia, fetal growth restriction and autism. This review summarizes the available national and international guidelines, concerning the indications and dosage of folic acid supplementation during pregnancy. In addition, it describes the potential preventive benefits of folic acid supplementation on multiple maternal and fetal outcomes, as well as potential risks.

Increased homocysteine levels exist in women with preeclampsia from early pregnancy

OBJECTIVE

The present prospective study examines the levels of maternal plasma folate, vitamin B12 and homocysteine in normotensive control (NC) women and women with preeclampsia (PE) from early pregnancy till delivery.

METHODS

The present study includes 126 NC and 62 PE women. Maternal blood was collected at 3 time points during pregnancy (T1 = 16th-20th weeks, T2 = 26th-30th weeks and T3 = at delivery). Levels of folate, vitamin B12 and homocysteine were estimated by the chemiluminescent microparticle immunoassay technology.

RESULTS

Maternal plasma folate levels were similar between NC and PE women at all the time points across gestation. Maternal plasma vitamin B12 levels were significantly higher in PE (p < 0.05) as compared with NC at T2. Maternal plasma homocysteine levels were higher in PE as compared with NC at all the time points, i.e. T1, T2 (p < 0.05 for both) and T3 (p < 0.01).

CONCLUSION

Our results indicate that higher homocysteine levels exist in women with PE from early pregnancy and continue till delivery.

Folic acid supplementation and dietary folate intake, and risk of preeclampsia

BACKGROUND/OBJECTIVES

Folic acid supplementation has been suggested to reduce the risk of preeclampsia. However, results from few epidemiologic studies have been inconclusive. We investigated the hypothesis that folic acid supplementation and dietary folate intake before conception and during pregnancy reduce the risk of preeclampsia.

SUBJECTS/METHODS

A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. A total of 10,041 pregnant women without chronic hypertension or gestational hypertension were enrolled.

RESULTS

Compared with nonusers, folic acid supplement users had a reduced risk of preeclampsia (OR=0.61, 95% CI: 0.43-0.87). A significant dose-response of duration of use was observed among women who used folic acid supplemention during pregnancy only (P-trend=0.007). The reduced risk associated with folic acid supplement was similar for mild or severe preeclampsia and for early- or late-onset preeclampsia, although the statistical significant associations were only observed for mild (OR=0.50, 95% CI: 0.30-0.81) and late-onset (OR=0.60, 95% CI: 0.42-0.86) preeclampsia. The reduced risk associated with dietary folate intake during pregnancy was only seen for severe preeclampsia (OR=0.52, 95% CI: 0.31-0.87, for the highest quartile of dietary folate intake compared with the lowest).

CONCLUSIONS

Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia. Future studies are needed to confirm the associations.

A combined supplementation of omega-3 fatty acids and micronutrients (folic acid, vitamin B12) reduces oxidative stress markers in a rat model of pregnancy induced hypertension

Objectives

Our earlier studies have highlighted that an altered one carbon metabolism (vitamin B₁₂, folic acid, and docosahexaenoic acid) is associated with preeclampsia. Preeclampsia is also known to be associated with oxidative stress and inflammation. The current study examines whether maternal folic acid, vitamin B₁₂ and omega-3 fatty acid supplementation given either individually or in combination can ameliorate the oxidative stress markers in a rat model of pregnancy induced hypertension (PIH).

Materials and Methods

Pregnant Wistar rats were assigned to control and five treatment groups: PIH; PIH + vitamin B₁₂; PIH + folic acid; PIH + Omega-3 fatty acids and PIH + combined micronutrient supplementation (vitamin B₁₂ + folic acid + omega-3 fatty acids). L-Nitroarginine methylester (L-NAME; 50 mg/kg body weight/day) was used to induce hypertension during pregnancy. Blood Pressure (BP) was recorded during pregnancy and dams were dissected at d20 of gestation.

Results

Animals from the PIH group demonstrated higher (p<0.01 for both) systolic and diastolic BP; lower (p<0.01) pup weight; higher dam plasma homocysteine (p<0.05) and dam and offspring malondialdehyde (MDA) (p<0.01), lower (p<0.05) placental and offspring liver DHA and higher (p<0.01) tumor necrosis factor–alpha (TNF–ά) levels as compared to control. Individual micronutrient supplementation did not offer much benefit. In contrast, combined supplementation lowered systolic BP, homocysteine, MDA and placental TNF-ά levels in dams and liver MDA and protein carbonyl in the offspring as compared to PIH group.

Conclusion

Key constituents of one carbon cycle (folic acid, vitamin B₁₂ and DHA) may play a role in reducing oxidative stress and inflammation in preeclampsia.

Erythrocyte folate content and serum folic acid and homocysteine levels in preeclamptic primigravidae teenagers living at high altitude

OBJECTIVE

To measure erythrocyte folate content and serum folic acid and homocysteine (Hcy) levels in preeclamptic primigravidae teenagers living at high altitude.

METHODS

Measured analytes were compared to those found in normal teen controls.

RESULTS

Teenagers complicated with preeclampsia displayed significantly lower hematocrit and erythrocyte folic acid levels with higher serum Hcy levels as compared to controls (36.40 ± 4.90 vs. 38.99 ± 2.89 %, 493.80 ± 237.30 vs. 589.90 ± 210.60 ng/mL, and 7.29 ± 2.52 vs. 5.97 ± 1.41 μmol/L, respectively, p < 0.05). There was a non-significant trend for lower serum folic acid levels among preeclampsia teenagers. Serum and erythrocyte folic acid levels positively correlated in preeclampsia teenagers, and levels of both analytes inversely correlated with Hcy levels.

CONCLUSION

This pilot study found that teenagers complicated with preeclampsia living at higher altitude displayed lower erythrocyte folate content in addition to higher serum Hcy levels. More research is warranted to determine the clinical implications of these findings.

Folic Acid Supplementation During Early Pregnancy and the Risk of Gestational Hypertension and Preeclampsia

Emerging evidence has suggested that folic acid–containing multivitamins may markedly reduce the risk of gestational hypertension or preeclampsia. We examined whether maternal supplementation with folic acid alone during early pregnancy can prevent the occurrence of gestational hypertension and preeclampsia. The data are from a large population-based cohort study established to evaluate the effectiveness of the campaign to prevent neural tube defects with folic acid supplementation in China. We selected participants who were registered in 2 southern provinces, had exact information on folic acid use, and were not affected by chronic hypertension or diabetes mellitus before 20 weeks gestation. A logistic regression model was used to adjust for the effects of the main potential confounders, including age, body mass index, education, occupation, parity, and multiple births. The study size had 99.9% power (α=0.05) to detect a decrease of 10% over the unexposed rate of 9.4% for gestational hypertension. Among the 193 554 women (47.9% took folic acid, 52.1% did not), the overall incidence of gestational hypertension and preeclampsia was 9.5% and 2.5%, respectively. The incidence of gestational hypertension and preeclampsia was 9.7% and 2.5% for women who took folic acid, and 9.4% and 2.4% for women who did not use it. The adjusted risk ratio associated with folic acid use was 1.08 (95% confidence interval, 1.04–1.11) for gestational hypertension and 1.11 (95% confidence interval, 1.04–1.18) for preeclampsia. Our findings suggest that daily consumption of 400 μg folic acid alone during early pregnancy cannot prevent the occurrence of gestational hypertension and preeclampsia.

Influence of mineral and vitamin supplements on pregnancy outcome

The literature was searched for publications on minerals and vitamins during pregnancy and the possible influence of supplements on pregnancy outcome. Maternal iron (Fe) deficiency has a direct impact on neonatal Fe stores and birth weight, and may cause cognitive and behavioural problems in childhood. Fe supplementation is recommended to low-income pregnant women, to pregnant women in developing countries, and in documented deficiency, but overtreatment should be avoided. Calcium (Ca) deficiency is associated with pre-eclampsia and intra-uterine growth restriction. Supplementation may reduce both the risk of low birth weight and the severity of pre-eclampsia. Gestational magnesium (Mg) deficiency may cause hematological and teratogenic damage. A Cochrane review showed a significant low birth weight risk reduction in Mg supplemented individuals. Intake of cereal-based diets rich in phytate, high intakes of supplemental Fe, or any gastrointestinal disease, may interfere with zinc (Zn) absorption. Zn deficiency in pregnant animals may limit fetal growth. Supplemental Zn may be prudent for women with poor gastrointestinal function, and in Zn deficient women, increasing birth weight and head circumference, but no evidence was found for beneficial effects of general Zn supplementation during pregnancy. Selenium (Se) is an antioxidant supporting humoral and cell-mediated immunity. Low Se status is associated with recurrent abortion, pre-eclampsia and IUGR, and although beneficial effects are suggested there is no evidence-based recommendation for supplementation. An average of 20-30% of pregnant women suffer from any vitamin deficiency, and without prophylaxis, about 75% of these would show a deficit of at least one vitamin. Vitamin B6 deficiency is associated with pre-eclampsia, gestational carbohydrate intolerance, hyperemesis gravidarum, and neurologic disease of infants. About 25% of pregnant women in India are folate deficient. Folate deficiency may lead to congenital malformations (neural tube damage, orofacial clefts, cardiac anomalies), anaemia and spontaneous abortions, and pre-eclampsia, IUGR and abruption placentae. Pregestational supplementation of folate prevents neural tube defects. A daily supplemental dose of 400 μg/day of folate is recommended when planning pregnancy. In developing countries diets are generally low in animal products and consequently in vitamin B12 content. An insufficient supply may cause reduced fetal growth. In vegetarian women, supplementation of vitamin B12 may be needed. Vitamin A deficiency is prevalent in the developing world, impairing Fe status and resistance to infections. The recommended upper limit for retinol supplements is 3000 IU/day. Vitamin A supplementation enhances birth weight and growth in infants born to HIV-infected women. Overdosing should be avoided. Low concentrations of vitamin C seem to increase the development of pre-eclampsia, and supplementation may be beneficial. Supplementation with vitamin D in the third trimester in vitamin D deficient women seems to be beneficial. The use of vitamins E, although generally considered "healthy", may be harmful to the pregnancy outcome by disrupting a physiologic oxidative gestational state and is consequently not recommended to prevent pre-eclampsia. Further studies on specific substances are needed as the basis for stratified, placebo-controlled analyses.

A low COMT activity haplotype is associated with recurrent preeclampsia in a Norwegian population cohort (HUNT2)

The etiology of preeclampsia is complex, with susceptibility being attributable to multiple environmental factors and a large genetic component. Although many candidate genes for preeclampsia have been suggested and studied, the specific causative genes still remain to be identified. Catechol-O-methyltransferase (COMT) is an enzyme involved in catecholamine and estrogen degradation and has recently been ascribed a role in development of preeclampsia. In the present study, we have examined the COMT gene by genotyping the functional Val108/158Met polymorphism (rs4680) and an additional single-nucleotide polymorphism, rs6269, predicting COMT activity haplotypes in a large Norwegian case/control cohort (n(cases)= 1135, n(controls)= 2262). A low COMT activity haplotype is associated with recurrent preeclampsia in our cohort. This may support the role of redox-regulated signaling and oxidative stress in preeclampsia pathogenesis as suggested by recent studies in a genetic mouse model. The COMT gene might be a genetic risk factor shared between preeclampsia and cardiovascular diseases.

Peripartum pulmonary embolism

Pregnancy is an example of Virchow's triad predisposing to the development of venous thromboembolism (VTE). Specific risk factors for antepartum and postpartum VTE have been identified. The diagnosis of pulmonary embolism in pregnancy is complicated by the physiologic changes of pregnancy as well as physicians' apprehension about ordering radiologic studies during pregnancy because of concerns with fetal well-being. Therapy for VTE is complicated by pregnancy physiology affecting medication pharmacokinetics and bioavailability, and the unpredictable occurrence of labor during therapeutic anticoagulation.

Pre-eclampsia: connecting angiogenic and metabolic pathways

Pre-eclampsia is a hypertensive disease of pregnancy with a worldwide incidence of 5-8%. This review focuses on recent developments in pre-eclampsia research related to angiogenesis and metabolism. We first address the 'angiogenic imbalance' theory, which hypothesizes that pre-eclampsia results from an imbalance of factors that promote or antagonize angiogenesis, such as soluble fms-like tyrosine kinase (sFlt1), 2-methoxyestradiol (2-ME) and catechol-O-methyltransferase (COMT). Next, we analyze the association between pre-eclampsia and dysfunctional metabolism of both homocysteine and placental glycogen. We hope that illuminating some of the various connections existing between angiogenesis and metabolism in pre-eclampsia will facilitate the update or reconsideration of old models of pathogenesis.

Methylenetetrahydrofolate reductase677 C→T polymorphism and plasma folate in relation to pre-eclampsia risk among Peruvian women

OBJECTIVES

Pre-eclampsia is an important cause of maternal and fetal morbidity and mortality worldwide. Hyperhomocyst(e)inemia in pregnancy is associated with an increased risk of pre-eclampsia in most studies. Nutritional and genetic factors regulate homocyst(e)ine levels. A missense mutation 677 C-->T in the gene for methylenetetrahydrofolate reductase (MTHFR) has been associated with an increased pre-eclampsia risk in some, although not most, previously studied populations.

METHODS

To further understand the role of this polymorphism in the etiology of pre-eclampsia, we genotyped a total of 125 pre-eclamptics and 179 normotensive pregnant Peruvian women.

RESULTS

The wild-type allele frequency among cases and controls was 54% and 58%, respectively. Twenty percent of cases and 17% of controls were homozygous for the 677 C-->T MTHFR genotype (T/T). After adjustment for confounding by covariates including maternal age, nulliparity, pre-pregnancy body mass index and use of prenatal vitamins, women homozygous for the 677 C-->T MTHFR genotype (T/T) experienced a modest, statistically non-significant increased risk of pre-eclampsia (adjusted OR 1.6, 95% CI 0.7, 3.8). Maternal folate deficiency was associated with a statistically non-significant doubling in risk of pre-eclampsia in this population (adjusted OR 2.0, 95% CI 0.9, 4.3).

CONCLUSIONS

There was no evidence to suggest that pre-eclampsia risk is positively associated with the T/T genotype overall, or in the context of folate deficiency.

Inherited thrombophilia and preeclampsia within a multicenter cohort: the Montreal Preeclampsia Study

OBJECTIVE

We sought to evaluate the association between inherited thrombophilia and preeclampsia.

STUDY DESIGN

From a multicenter cohort of 5337 pregnant women, we prospectively identified 113 women who developed preeclampsia and selected 443 control subjects who did not have preeclampsia or nonproteinuric gestational hypertension. Blood samples were tested for DNA polymorphisms affecting thrombophilia (factor V Leiden mutation, prothrombin G20210A mutation, methylenetetrahydrofolate reductase C677T polymorphism), homocysteine, and folate levels, and placentae underwent pathological evaluation.

RESULTS

Thrombophilia was present in 14% of patients and 21% of control subjects (adjusted logistic regression odds ratio, 0.6; 95% confidence interval, 0.3-1.3). Placental underperfusion was present in 63% of patients vs 46% of control subjects (P < .001) and was more frequent in women with folate levels in the lowest quartile (P = .04), but was not associated with thrombophilia.

CONCLUSION

We did not find evidence to support an association between inherited thrombophilia and increased risk of preeclampsia. Placental underperfusion is associated with preeclampsia, but this does not appear to be consequent to thrombophilia.

Exposure-measurement error is frequently ignored when interpreting epidemiologic study results

INTRODUCTION

One important source of error in study results is error in measuring exposures. When interpreting study results, one should consider the impact that exposure-measurement error (EME) might have had on study results.

METHODS

To assess how often this consideration is made and the form it takes, journal articles were randomly sampled from original articles appearing in the American Journal of Epidemiology and Epidemiology in 2001, and the International Journal of Epidemiology between December 2000 and October 2001.

RESULTS

Twenty-two (39%) of the 57 articles surveyed mentioned nothing about EME. Of the 35 articles that mentioned something about EME, 16 articles described qualitatively the effect EME could have had on study results. Only one study quantified the impact of EME on study results; the investigators used a sensitivity analysis. Few authors discussed the measurement error in their study in any detail.

CONCLUSIONS

Overall, the potential impact of EME on error in epidemiologic study results appears to be ignored frequently in practice.

Combining mid-trimester maternal plasma homocysteine with uterine artery doppler velocimetry: is it useful?

OBJECTIVE

To investigate the possible association between mid-trimester maternal plasma homocysteine concentration, uterine artery Doppler measurements in a two-stage screening strategy, and outcome of pregnancy.

MATERIALS AND METHODS

This prospective observational study was conducted on healthy women undergoing screening for pre-eclampsia by uterine artery Doppler velocimetry at 20-22 and 24-26 weeks of gestation. Abnormal uterine artery blood flow was defined as an average resistance index (RI) > 0.58 and/or bilateral early diastolic notch. Homocysteine measurement was performed by two competitive immunoassay methods involving two steps at 20-22 and 24-26 weeks' gestation.

RESULTS

Sixty women enrolled. Abnormal Doppler findings were found in 18 of 60 (30%) women at 20-22 weeks of gestation. This proportion was reduced to 10% (6/60) at 24-26 weeks of gestation, and two of these six women developed pre-eclampsia later in pregnancy. There was no significant difference in the maternal plasma homocysteine levels in women with abnormal Doppler findings when compared with controls at first and second visits (p > 0.05).

CONCLUSION

Mid-trimester maternal homocysteine concentration is not elevated in women with abnormal uterine artery Doppler findings in a two-stage screening method.

Adult Weight Change, Weight Cycling, and Prepregnancy Obesity in Relation to Risk of Preeclampsia

BACKGROUND

Preeclampsia has been shown to be associated with obesity, with other risk factors for cardiovascular disease, and with subsequent cardiovascular disease itself. However, the possible association with weight gain and weight cycling has not been evaluated.

METHODS

In this prospective study of a cohort of 1644 pregnant women, we assessed adult weight change, intentional weight cycling, and prepregnancy obesity in relation to preeclampsia risk. Net weight change from age 18 years to the period 3 months before conception was determined for each participant. Weight cycling was defined as intentional weight loss and unintentional regain of at least 15 pounds during periods not related to pregnancy or lactation. We used multivariate regression procedures to calculate risk ratios (RRs) and 95% confidence intervals (CIs).

RESULTS

Relative to women with stable weight (gained or lost < 2.5 kg) women who gained 5.0-9.9 kg experienced a 2.6-fold increased risk of preeclampsia (95% CI = 1.0-6.7). The corresponding risk ratio (RR) for women who gained > or = 10 kg was 5.1 (2.2-12.2). Intentional weight cycling, after controlling for weight at age 18 years, adult weight change, and other risk factors, was not associated with increased risk of preeclampsia (RR = 1.1; CI = 0.6-1.8). RRs increased monotonically with increasing prepregnancy body mass index greater than 19.8 kg/m. After adjusting for confounders, the RR for prepregnancy overweight women and obese women were 1.7 (0.6-4.9) and 3.4 (1.5-7.6) respectively.

CONCLUSIONS

These results suggest that adult weight gain and prepregnancy overweight and obesity status are associated with an increased risk of preeclampsia.

Functional variants of the lipoprotein lipase gene and the risk of preeclampsia among non-Hispanic Caucasian women

Hypertriglyceridemia is an important pathophysiologic feature of preeclampsia, a common vascular disorder of pregnancy. Three well-documented functional variants (N291S, S447X, and D9N) of the lipoprotein lipase gene were related to hypertriglyceridemia. Results from the only two studies concerning the relationship between these variants and preeclampsia risk have been inconsistent. We investigated this relationship in a case-control study including 144 preeclamptic and 290 normotensive pregnant women (all non-Hispanic Caucasians). We estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for maternal age, pre-pregnancy body mass index, and parity. After adjusting for covariates, women with the 291 N/S or S/S genotype had significantly increased risk of preeclampsia (OR 6.9, 95% CI 1.9-25.4) compared with women with the common 291N/N genotype. The 447 S/X or X/X genotype was not significantly associated with preeclampsia risk. The frequency of the 9N variant allele was 1.8% in controls, while this allele was not observed among cases. Haplotype 9D/291S/447S was strongly associated with higher risk of preeclampsia as compared with the most common haplotype 9D/291N/447S (adjusted OR 6.6, 95% CI 1.7-25.0). Results from our study support the thesis that abnormal lipid metabolism is important in the pathogenesis of preeclampsia.

Folate and human reproduction

The influence of folate nutritional status on various pregnancy outcomes has long been recognized. Studies conducted in the 1950s and 1960s led to the recognition of prenatal folic acid supplementation as a means to prevent pregnancy-induced megaloblastic anemia. In the 1990s, the utility of periconceptional folic acid supplementation and folic acid food fortification emerged when they were proven to prevent the occurrence of neural tube defects. These distinctively different uses of folic acid may well be ranked among the most significant public health measures for the prevention of pregnancy-related disorders. Folate is now viewed not only as a nutrient needed to prevent megaloblastic anemia in pregnancy but also as a vitamin essential for reproductive health. This review focuses on the relation between various outcomes of human reproduction (ie, pregnancy, lactation, and male reproduction) and folate nutrition and metabolism, homocysteine metabolism, and polymorphisms of genes that encode folate-related enzymes or proteins, and we identify issues for future research.

A case-control study of oxidized low density lipoproteins and preeclampsia risk

Diffuse vascular endothelial dysfunction, secondary to oxidative stress, is an important pathological feature of preeclampsia. Oxidative conversion of low density lipoproteins (LDL) to oxidized-LDL (Ox-LDL) is considered an important step in transforming macrophages into lipid-laden foam cells destined to develop into early atherosclerotic-like lesions. In our study of 95 women with preeclampsia and 100 controls, we evaluated the association between maternal plasma Ox-LDL concentrations and preeclampsia risk. Ox-LDL concentrations were measured using a solid phase two-site enzyme immunoassay. Plasma lipids were measured using standard enzymatic procedures. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for confounders. Plasma Ox-LDL concentrations were positively correlated with cholesterol, triglyceride (TG), and LDL concentrations in cases and controls, (Spearman's r ranging from 0.39-0.48, p-values all <0.01). There was no evidence of an increased risk of preeclampsia across increasing quartiles of Ox-LDL. The ORs for successive quartiles, with the lowest as the reference group, were as follows: 1.0, 1.1, 0.6, and 1.2. Women with extremely high concentrations of Ox-LDL (> or =73 U/L, the upper decile), as compared with those with lower values (<73 U/L) had a 2.7-fold increased risk of preeclampsia (95% CI 1.0-6.8). Women with high Ox-LDL and high TG concentrations (> or =284 mg/dl), as compared with those without these two factors, had a 9.6-fold increased preeclampsia risk (95% CI 2.0-45.6). Elevated Ox-LDL, particularly in conjunction with elevated TG, appears to be a risk factor of preeclampsia.

Elevated plasma homocysteine concentrations in severe preeclampsia and eclampsia

Homocysteine is an essential amino acid required for the growth of cells and tissues in the human body. Maternal hyperhomocysteinemia is associated with a number of placenta-mediated diseases such as preeclampsia. The aim of this study was to evaluate the plasma level of homocysteine and its association with severity of preeclampsia. A case-control study was performed with 32 mild preeclamptic patients, 25 severe preeclamptic patients, 16 eclamptic patients and 34 controls. Maternal plasma homocysteine concentration was measured prospectively at antenatal period by high-performance liquid chromatography. There were no significant differences in demographic characteristics between the study and control groups. Mean plasma levels of homocysteine in women with severe preeclampsia (16.7 +/- 10.1 micromol/l, mean +/- S.D., n = 25) and eclampsia (16.5 +/- 9.6 micromol/l, mean +/- S.D., n = 16) were significantly higher than those in mild preeclampsia (7.7 +/- 2.4 micromol/l, mean +/- S.D., n = 32) and controls (6.7 +/- 1.6 micromol/l, mean +/- S.D., n = 34) (p < 0.0001). It should be noted that plasma levels of homocysteine are not significantly different between mild preeclampsia and controls. In conclusion, plasma homocysteine concentrations are increased in severe preeclampsia and eclampsia, but not in mild preeclampsia.

Oxidative stress, diet, and the etiology of preeclampsia

BACKGROUND

A current theory holds that oxidative stress, ie, an imbalance between maternal prooxidants and antioxidants, is a component of preeclampsia. It is uncertain whether such an imbalance occurs before clinical recognition of the syndrome or whether it is related to diet.

OBJECTIVE

We measured urinary excretion of the isoprostane 8-iso-prostaglandin F(2alpha), which is an indicator of oxidative damage to lipids, and the total antioxidant power, which is a global measure of antioxidant status, at the entry to prenatal care. We also examined the relation of these indexes to diet during pregnancy.

DESIGN

A cohort of 307 gravidae from Camden, NJ, was studied from entry to prenatal care (at 15.0 +/- 0.49 wk gestation). Measures of the maternal diet were obtained by 24-h recall.

RESULTS

Risk of preeclampsia was increased 5-fold with higher urinary isoprostane excretion and decreased 3-fold with higher total antioxidant power. Over the course of pregnancy, there were significant trends for an association of higher isoprostane excretion with increased consumption of energy-adjusted fat, polyunsaturated fat, and polyunsaturated fatty acids (n-3, n-6, and linoleic and linolenic fatty acids), whereas total antioxidant power was not related to diet.

CONCLUSIONS

Increased urinary excretion of isoprostane and decreased antioxidant production is an imbalance that is consistent with oxidative stress, and it precedes clinical recognition of preeclampsia. The maternal diet is an underlying factor that provides an environment for free radical generation.

Placental malaria and pre-eclampsia through the looking glass backwards?

Placental malaria and pre-eclampsia occur frequently in women in developing countries and are leading causes of fetal growth restriction. Reduced placental perfusion, loss of placental integrity and endothelial cell dysfunction are characteristics of both conditions, and several common factors can be implicated in their causation as well as leading to a cascade of responses with pathophysiological effects. Discrimination between risk factors which result in a loss of endothelial integrity from pathogenic factors which occur as a consequence of this is essential for understanding the potential influence of malaria on pre-eclampsia. This article summarises the evidence linking the two conditions in relation to their epidemiological, immunological, haematological and biochemical characteristics as well as the pathological similarities and differences related to placental structure and function. The potential similar role for nitric oxide synthase involvement in both placental malaria and pre-eclampsia is considered. Several research implications are highlighted which follow from this analysis. We consider that there is no clear dividing line between pathogenic mechanisms related to both conditions, a better understanding of which should be of benefit to millions of women in developing countries.

Mapping the Theories of Preeclampsia: The Role of Homocysteine

OBJECTIVE

We conducted a systematic review to examine the hypothesized mechanism through which homocysteine could lead to preeclampsia.

DATA SOURCES

We searched MEDLINE, EMBASE, BIOSIS, SciSearch, and bibliographies of primary and review articles, and we contacted experts.

METHODS OF STUDY SELECTION

Of the 25 relevant primary articles, 8 studies measured total serum homocysteine concentrations before the clinical onset of preeclampsia (1,876 women), whereas 17 measured it afterward (1,773 women). Meta-analytic techniques were used to examine consistency, strength, temporality, dose-response, and plausibility of the disease mechanisms implicating folate, vitamin B(6), vitamin B(12), genetic polymorphisms, oxidative stress, and endothelial dysfunction in the pathway linking hyperhomocysteinemia to preeclampsia.

TABULATION, INTEGRATION, AND RESULTS

Overall, there were higher serum homocysteine concentrations among pregnant women with preeclampsia than among those with uncomplicated pregnancies, but the results were heterogeneous (P = .12; I(2) = 38.8%). Among studies with temporality, the size of association was smaller than that among those without (weighted mean difference 0.68 mumol/L versus 3.36 mumol/L; P < .006). There was no dose-response relationship between homocysteine concentration and severity of preeclampsia. The mechanisms underlying hyperhomocysteinemia (folate and vitamin B(12) deficiency and genetic polymorphisms) were not found to be plausible, but markers of oxidative stress and endothelial dysfunction were higher in hyperhomocysteinemia.

CONCLUSION

Homocysteine concentrations are slightly increased in normotensive pregnancies that later develop preeclampsia and are considerably increased once preeclampsia is established. However, because of a lack of consistency in data, dose-response relationship, and biologic plausibility, the observed association cannot be considered causal from the current literature.

Long-term ovo-lacto vegetarian diet impairs vitamin B-12 status in pregnant women

A well-planned vegetarian diet has been stated to be adequate during pregnancy. The aim of the present study was to compare serum vitamin B-12 and homocysteine concentrations in pregnant women (n = 109) consuming vegetarian and Western diets and to evaluate the adequacy of current dietary reference intakes of vitamin B-12 for these women. Pregnant women adhering to vegetarian diets for at least 3 y, with subgroups of ovo-lacto vegetarians (OLVs; n = 27), low-meat eaters (LME, n = 43), and women eating an average Western diet (control group, n = 39), were recruited. Dietary vitamin B-12 intake, serum vitamin B-12, and plasma total homocysteine (tHcy) concentrations were measured in wk 9-12, 20-22, and 36-38 of pregnancy. During pregnancy serum vitamin B-12 concentrations of ovo-lacto vegetarians (P < 0.001) and low-meat eaters (P = 0.050) were lower than those of the control group. We observed the combination of low serum vitamin B-12 concentrations and elevated plasma tHcy in 22% of ovo-lacto vegetarians, in 10% of low-meat eaters, and in 3% of controls (P = 0.003). In OLVs, serum vitamin B-12 predicted 60% of the plasma tHcy variation (P < 0.001), but in LMEs and controls only <10% (NS). Serum vitamin B-12 concentrations increased and plasma tHcy decreased sharply with increasing dietary intake of vitamin B-12 toward a cutoff point of 3 mug/d. Pregnant women consuming a long-term predominantly vegetarian diet have an increased risk of vitamin B-12 deficiency. Current recommended dietary intakes urgently need reevaluation.

Offspring sex ratio at population level versus early and late onset preeclampsia

Male dominance being higher at preterm than term delivery was described in a population-based study by Vatten and Skjaerven [Early Hum. Dev. 76 (2004) 47]. A so-called "reversion" and "cross-over" in the sex ratio took place in preeclamptic gestations. These phenomena occurred earlier and stronger when associated with perinatal mortality and are in line with the overripeness ovopathy concept.

Thrombophilia and pregnancy complications

OBJECTIVE

This systematic review examines the strength of the association between thrombophilia and recurrent pregnancy loss and other serious obstetric complications. Study design Electronic databases and manual bibliography searches were used to identify studies evaluating the association between thrombophilia and pregnancy loss, preeclampsia, fetal growth retardation, and placental abruption.

RESULTS

Thrombophilic disorders are associated with an increased risk of fetal loss in the majority of case control and cohort studies. The risk is increased throughout pregnancy, but may be higher in the second and third trimester. The common pathologic finding of placental infarction suggests unexplained fetal loss may result from uteroplacental insufficiency and thrombosis. Thrombophilic disorders are not consistently associated with preeclampsia, fetal growth retardation, or placental abruption. Preliminary data suggest prophylactic anticoagulation may improve outcome in thrombophilic women with unexplained recurrent fetal loss.

CONCLUSION

Women with thrombophilia have an increased risk of pregnancy loss and possibly other serious obstetric complications, although definition of the magnitude of risk will require prospective longitudinal studies. Preliminary data suggesting prophylactic anticoagulation may improve gestational outcome provide a rationale for prospective randomized trials in thrombophilic women with unexplained recurrent fetal loss.

Metformin, pre-eclampsia, and pregnancy outcomes in women with polycystic ovary syndrome

AIMS

Was metformin during pregnancy in women with polycystic ovary syndrome (PCOS) associated with pre-eclampsia, and was it safe for mother and neonate?

METHODS

In the current study, pre-eclampsia and other pregnancy outcomes were prospectively studied in 90 women with PCOS who conceived on metformin 1.5-2.55 g/day, and had > or = 1 live birth (97 pregnancies, 100 live births) compared with 252 healthy women (not known to have PCOS) with > or = 1 live birth, consecutively delivered in a community obstetrics practice.

RESULTS

Women with PCOS were older than controls (33 +/- 5 vs. 29 +/- 6 years, P < 0.0001), more likely to be > 35 years old at conception (23 vs. 13%, P = 0.028), much heavier (93 +/- 23 vs. 72 +/- 18 kg, P < 0.0001, BMI 33.8 +/- 7.8 kg/m2 vs. 25.6 +/- 5.9, P < 0.0001), and more likely to be Caucasian (97 vs. 90%, P = 0.05), but there were similar numbers with preconception Type 2 diabetes mellitus [2/90 (2.2%) vs. 1/252 (0.4%), P = 0.17]. Pre-eclampsia in PCOS (5/97 pregnancies, 5.2%), did not differ (P = 0.5) from controls (9/252, 3.6%), nor did it differ (P = 1.0) in PCOS vs. control primigravidas [2/45 (4.4%) vs. 4/91 (4.4%)]. Development of gestational diabetes in PCOS did not differ from controls [9/95 pregnancies (9.5%) vs. 40/251 (15.9%), P = 0.12]. Of the 100 live births to 90 women with PCOS, there were no major birth defects. Mean +/- sd birth weight of the 80 live births > or = 37 weeks gestation in women with PCOS (3414 +/- 486 g) did not differ from controls' 206 live births > or = 37 weeks (3481 +/- 555 g), P = 0.34, nor did the percentage of > or = 37 week gestation neonates > or = 4000 g (12.5 vs. 17.5%, P = 0.3) or > or = 4500 g (1.3 vs. 2.9%, P = 0.7).

CONCLUSIONS

Metformin is not associated with pre-eclampsia in pregnancy in women with PCOS, and appears to be safe for mother and fetus.

Hyperhomocysteinemia, Pregnancy Complications, and the Timing of Investigation

OBJECTIVE

To assess associations between vitamin-dependent homocysteine metabolism and vascular-related pregnancy complications by considering interval between delivery and postpartum investigation and maternal age.

METHODS

Case-control study performed at the University Medical Center Nijmegen in the Netherlands. Patients had experienced pregnancy-induced hypertension (n = 37), preeclampsia (n = 144), hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome (n = 104), recurrent early pregnancy loss (n = 544), abruptio placentae (n = 135), intrauterine growth restriction (n = 144), or intrauterine fetal death (n = 104). Controls comprised 176 women with uncomplicated obstetric histories. Oral methionine loading tests and fasting vitamin profiles were performed more than 6 weeks after delivery. Odds ratios and 95% confidence intervals were calculated after logistic regression analysis.

RESULTS

Hyperhomocysteinemia was associated with an approximately 2-fold to 3-fold increased risk for pregnancy-induced hypertension, abruptio placentae, and intrauterine growth restriction. Cobalamin deficiency was associated with HELLP syndrome, abruptio placentae, intrauterine growth restriction, and intrauterine fetal death. Pyridoxal 5-phosphate deficiency increased the risk for pregnancy-induced hypertension 4-fold. These associations lost their significance after adjustment for time interval and maternal age. High red cell folate was associated with a decreased risk for abruptio placentae and intrauterine growth restriction. An increased creatinine concentration was associated with pregnancy-induced hypertension, preeclampsia, HELLP syndrome, and abruptio placentae.

CONCLUSION

Hyperhomocysteinemia and vitamin deficiencies are largely determined by the interval between delivery and postpartum investigation and by maternal age. Time interval and maternal age should be considered in the risk estimation for vascular-related pregnancy complications.

High-density lipoprotein and homocysteine levels correlate inversely in preeclamptic women in northern Nigeria

BACKGROUND

Preeclampsia/eclampsia is one of the most common complications of pregnancy. It is a cause of high morbidity for both mother and fetus, especially in developing countries. In a recent survey conducted in Gombe, Nigeria, eclampsia was found to be a major cause of maternal mortality (24.2%), second only to obstetric hemorrhage (27.1%). Previous studies have produced contradictory findings regarding total homocysteine (tHcy) levels in women with preeclampsia/eclampsia and there is little information about the relationship between particular serum lipids and tHcy. The objective of this study in Gombe was to compare the levels of serum lipids and homocysteine in healthy pregnant women and women with preeclampsia/eclampsia in Nigeria.

METHODS

The experimental subjects included 43 women with preeclampsia/eclampsia and 130 healthy pregnant women served as controls. The criteria for preeclampsia/eclampsia included the following: hypertension (blood pressure > 140/90 mmHg), total protein (> 190 mg/g creatinine), and edema. Blood sera obtained from patients and controls attending the prenatal clinics at the Specialist Hospital and the Federal Medical Center in Gombe were analyzed for tHcy, total cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, antioxidant capacity, folate, and vitamin B-12.

RESULTS

The mean tHcy concentration for the preeclamptic/eclamptic women was greater than that of the controls (10.1 vs. 8.4 micromol/l, respectively, p = 0.01). The mean concentrations of LDL-cholesterol and triacylglycerols were not different between the two groups. However, the mean HDL-cholesterol level was higher in the healthy pregnant women compared with the preeclamptic/eclamptic women (1.64 vs. 1.42 mmol/l, respectively, p = 0.02). The HDL-cholesterol concentration was correlated inversely with the tHcy concentration (p = 0.001, r = 0.51). Total homocysteine was not linked with either serum folate or vitamin B-12.

CONCLUSIONS

These results show that preeclampsia/eclampsia is associated with increased tHcy levels and that HDL levels are depressed in Nigerian women with this hypertensive, pregnancy associated disorder.

Hyperhomocyst(e)inemia and elevated soluble vascular cell adhesion molecule-1 concentrations are associated with an increased risk of preeclampsia

Hyperhomocyst(e)inemia (HHcy) is a risk factor of endothelial dysfunction and preeclampsia. Soluble vascular cell adhesion molecule-1 (sVCAM-1), a specific marker of endothelial dysfunction, is elevated in preeclampsia. Few have assessed the joint contribution of these biomarkers in predicting preeclampsia. We assessed the extent to which HHcy and elevated sVCAM-1 are independently and jointly associated with preeclampsia. We conducted a case-control analysis of 100 preeclampsia cases and 100 controls to test our study hypothesis. Maternal plasma was collected before labor onset. Total plasma homocysteine (tHcy) was measured using high-performance liquid chromatography with electrochemical detection procedures. Plasma sVCAM-1 was determined using ELISA. Using the distribution of each analyte among controls, elevated tHcy was defined as plasma tHcy >6.6 micromol/l and elevated sVCAM-1 was defined as plasma concentrations >845 ng/ml (i.e., values above the median). Odds ratios (OR) and 95% confidence intervals (CIs) were calculated. Compared with women without elevated tHcy and without elevated sVCAM-1 (the referent group), those with elevated sVCAM-1 alone had a 4.1-fold increased risk of preeclampsia (95% CI 1.2-13.8). The OR for women with elevated tHcy alone was 2.2 (95% CI 0.6-7.9). The OR for women with elevated tHcy and sVCAM-1 was 13.2 (95% CI 4.1-42.2). Elevated tHcy and sVCAM-1 together were strongly associated with an increased risk of preeclampsia. Larger, prospective studies are needed to confirm these findings and to determine the extent to which elevated tHcy and sVCAM-1 together in early pregnancy are predictive of preeclampsia risk.

Hematological parameters and cobalamin status in infants born to smoking mothers

Hematological parameters, serum cobalamin and folate levels, and the concentrations of the functional markers plasma methylmalonic acid and total homocysteine were determined in 173 newborns and 46 infants at 6 weeks to see whether maternal smoking influences the hematological parameters and the vitamin status of the newborn. At birth, there was a strong inverse correlation between the number of cigarettes smoked per day during pregnancy and red blood cell count (r = -0.56, p = 0.001) and hemoglobin level (r = -0.52, p = 0.003) in the newborns. Neonates born to smoking mothers had lower red blood cell counts and lower hemoglobin and serum cobalamin levels as compared with infants born to nonsmoking mothers. At 6 weeks, maternal smoking significantly predicted the methylmalonic acid and total homocysteine levels, suggesting an influence from smoking on the cobalamin function in these infants.

Family history of hypertension and diabetes in relation to preeclampsia risk in Peruvian women

In a case-control study of 169 preeclamptics and 201 controls, we assessed maternal parental history of chronic hypertension and diabetes in relation to preeclampsia risk among Peruvian women. Participants provided information on parental history of the two conditions and other covariates during postpartum interviews. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for confounding by age, parity and prepregnancy adiposity. In this population, women were more likely to know the diabetes status of their parents than their hypertension status. Compared with women without a parental history of hypertension, women with a parental history of hypertension experienced a 20% increased risk of preeclampsia (OR = 1.2; 95% CI 0.7-2.2) that did not reach statistical significance. Women with a positive parental history for diabetes had a 3.4-fold increased risk of preeclampsia (95% CI 1.4-8.4). Women with a positive parental history of both hypertension and diabetes, as compared with those whose parents had neither condition, experienced a 4.6- fold increased risk of preeclampsia (OR = 4.6; 95% CI 0.9-23.0). Our results are generally consistent with the thesis that parental history of hypertension and diabetes reflects genetic and behavioral factors whereby women may be predisposed to an increased risk of preeclampsia.

Factors regulating trophoblast migration and invasiveness: possible derangements contributing to pre-eclampsia and fetal injury

Impaired trophoblast invasiveness and spiral arterial remodelling, which results in poor placental perfusion during early pregnancy, is believed to cause fetal injury and growth retardation, and also endothelial cell activation/dysfunction in a susceptible mother, leading to clinical manifestations of pre-eclampsia. This article briefly reviews the regulatory roles of certain locally active factors in trophoblast migration and invasiveness. This background is then used to discuss and debate whether derangements or dysfunction of some of these factors can manifest as early serum markers predictive of the disease, as opposed to the intermediate and late stage markers which may reflect manifestations and consequences of the disease. Of particular significance are the observed derangements in uPA/uPAR/PAI system, IGFBP-1, HGF, HB-EGF and TGFbeta, factors which are known to regulate trophoblast migration and invasiveness in situ. An emphasis is placed on the need for longitudinal studies in order to identify predictive serum markers which may help strategies for prevention or amelioration of fetal injury and pre-eclampsia.