Iron and oxidative stress in pregnancy

High dietary micronutrient inadequacy in peri-urban school children from a district in South India: Potential for staple food fortification and nutrient supplementation

Multiple micronutrient deficiencies (MNDs) co-exist, often because of poor intakes and adversely impact health. Habitual diets were assessed in 300 school children (6-17 years old) recruited from two government schools by simple random sampling. Probability of adequacy (PA) for 11 micronutrients and mean probability of adequacy (MPA) was calculated. Haemoglobin, plasma ferritin, folic acid, vitamin B12 and C-reactive protein were estimated. Descriptive statistics and regression analysis were used to estimate magnitude and factors associated with MNDs. The contribution of fortified foods and/or supplements in addressing inadequacies and excessive intakes was modelled. The PA ranged from 0.04 for folate to 0.70 for zinc, and the MPA was 0.27. Prevalence of anaemia (53%), iron deficiency (57%; ID), iron deficiency anaemia (38%; IDA), folate deficiency (24%) and B12 deficiency (43%) was high. Dietary inadequacy of iron, zinc and a low MPA was associated with anaemia and IDA. Inclusion of double fortified salt (DFS), fortified rice (FR) or iron folic acid (IFA) supplements individually in habitual diet reduced probability of iron inadequacy significantly from 82% to ≤13%. Inclusion of DFS and FR simultaneously led to disappearance of iron inadequacy, but risk of excessive intake increased to 16%. Inclusion of DFS, FR and IFA together increased risk of excess iron intake to 40%. Nevertheless, intakes of folate and B12 remained inadequate even with FR and/or IFA. These results indicate a high risk of dietary MNDs in children and suggest need for more systematic intake measurements in representative sample and adjustment of iron dosages to avoid excessive intakes.

Physiological Need for Calcium, Iron, and Folic Acid for Women of Various Subpopulations During Pregnancy and Beyond

Women tend to supplement their diets with multivitamin/mineral (MVM) supplements more often than men, and reports indicate that more than 90% of pregnant women in the United States supplement their diets with prenatal MVMs. Given the widespread use of MVMs among women and given the increasing efforts to unveil the importance of phenotype-specific health determinants, it seems imperative to review what is known about variations in nutrient physiology among women from different ethnic and racial groups and at different reproductive stages of life. In this study, we embark on an assessment of the scientific evidence and knowledge gaps that impact the precise determination of nutrient levels (specifically calcium, iron, and folic acid) that confer benefits to various subpopulations of women in the United States.

Delta-9-tetrahydrocannabinol disrupts mitochondrial function and attenuates syncytialization in human placental BeWo cells

The psychoactive component in cannabis, delta-9-tetrahydrocannabinol, can restrict fetal growth and development. Delta-9-tetrahydrocannabinol has been shown to negatively impact cellular proliferation and target organelles like the mitochondria resulting in reduced cellular respiration. In the placenta, mitochondrial dysfunction leading to oxidative stress prevents proper placental development and function. A key element of placental development is the proliferation and fusion of cytotrophoblasts to form the syncytium that comprises the materno-fetal interface. The impact of delta-9-tetrahydrocannabinol on this process is not well understood. To elucidate the nature of the mitochondrial dysfunction and its consequences on trophoblast fusion, we treated undifferentiated and differentiated BeWo human trophoblast cells, with 20 µM delta-9-tetrahydrocannabinol for 48 hr. At this concentration, delta-9-tetrahydrocannabinol on BeWo cells reduced the expression of markers involved in syncytialization and mitochondrial dynamics, but had no effect on cell viability. Delta-9-tetrahydrocannabinol significantly attenuated the process of syncytialization and induced oxidative stress responses in BeWo cells. Importantly, delta-9-tetrahydrocannabinol also caused a reduction in the secretion of human chorionic gonadotropin and the production of human placental lactogen and insulin growth factor 2, three hormones known to be important in facilitating fetal growth. Furthermore, we also demonstrate that delta-9-tetrahydrocannabinol attenuated mitochondrial respiration, depleted adenosine triphosphate, and reduced mitochondrial membrane potential. These changes were also associated with an increase in cellular reactive oxygen species, and the expression of stress responsive chaperones, HSP60 and HSP70. These findings have important implications for understanding the role of delta-9-tetrahydrocannabinol-induced mitochondrial injury and the role this might play in compromising human pregnancies.

The effect of mother's β-thalassemia minor on placental histology and neonatal outcomes

Objective: β-thalassemia is a prevalent disease in Iran. The adverse effects of anemia on placental and neonatal outcomes have previously been shown. Women require additional iron during pregnancy and the anemia of women with β-thalassemia may adversely affect the neonatal outcome and increase placental abnormalities. In this study, we compared the placental histology and neonatal outcomes among pregnant women with and without β-thalassemia.Material and methods: In this population-based cross-sectional study, 144 pregnant women with β-thalassemia minor (case group) were compared to 142 women without β-thalassemia (control group). Women with singleton pregnancies over 20 weeks of gestation without pregnancy complications, anemia, collagen vascular diseases, or other hemoglobinopathies, all referred to hospitals affiliated to Shiraz University of Medical Sciences from March 2014 to February 2016, were included and maternal and neonatal data were extracted from medical records. After child birth, the placenta was evaluated for macroscopic and microscopic changes.Results: The frequency of LBW was significantly higher in the case group than that in the control group (19.7 vs. 9.7%, respectively) (p = .019). Six in the case group had gross abnormalities of placenta, while none in the control group (p = .03) and the case group had a higher frequency of chorangiosis, calcification, syncytial knot, and umbilical cord position (p < .05).Conclusion: As β-thalassemia increases the chance of placental abnormalities, it is recommended to pay more attention to patients with β-thalassemia, especially during pregnancy, to prevent placental and neonatal adverse outcomes.

Comparison of different doses of daily iron supplementation for anemia prophylaxis in pregnancy: A systematic review

Different doses of iron are used for oral supplementation during pregnancy throughout the world. This objective of this review is to describe the effectiveness and side effect profile of different doses of oral iron supplementation for prophylaxis of anemia among pregnant women. Published literature was searched using keywords "iron," "pregnancy," and "supplementation" and related terms. Gray literature was searched in medical libraries including National Medical Library, Dr. B. B. Dikshit library, and library of ICMR. Intervention studies comparing different doses of oral iron given as prophylaxis for anemia during pregnancy, published till December 2017, were retrieved. Studies done only among anemic patients, and studies comparing oral iron with placebo were excluded. In total, 1588 studies were obtained and 11 of them met the objectives. In global studies, prophylactic dose of 30 mg and above is shown to maintain normal hemoglobin. Among the studies from India, prophylactic dose of 120 mg showed consistent results and 60 mg showed inconsistent results in increasing both hemoglobin and ferritin levels. No significant difference in side effects was reported up to 80 mg iron in global studies and the side effects were comparable with 60 to 240 mg doses in Indian studies. It was evident from the review that a state of clinical equipoise exists for the ideal dose of iron supplementation for the prevention of anemia in pregnancy in terms of efficacy and side effect profile. Robust clinical trial as well as technical consultation is required, especially in Indian setting to explore this question further.

Reactive oxygen species from mitochondria impacts trophoblast fusion and the production of endocrine hormones by syncytiotrophoblasts

The placenta, a tissue that is metabolically active and rich in mitochondria, forms a critical interface between the mother and developing fetus. Oxidative stress within this tissue, derived from the dysregulation of reactive oxygen species (ROS), has been linked to a number of adverse fetal outcomes. While such outcomes have been associated with mitochondrial dysfunction, the causal role of mitochondrial dysfunction and mitochondrially generated ROS in altering the process of placentation remains unclear. In this study, mitochondrial complex I activity was attenuated using 10 nM rotenone to induce cellular oxidative stress by increasing mitochondrial ROS production in the BeWo choriocarcinoma cell line. Increased mitochondrial ROS resulted in a significant decrease in the transcripts which encode for proteins associated with fusion (GCM1, ERVW-1, and ERVFRD-1) resulting in a 5-fold decrease in the percentage of BeWo fusion. This outcome was associated with increased indicators of mitochondrial fragmentation, as determined by decreased expression of MFN2 and OPA1 along with an increase in a marker of mitochondrial fission (DRP1). Importantly, increased mitochondrial ROS also resulted in a 5.0-fold reduction of human placental lactogen (PL) and a 4.4-fold reduction of insulin like growth factor 2 (IGF2) transcripts; hormones which play an important role in regulating fetal growth. The pre-treatment of rotenone-exposed cells with 5 mM N-acetyl cysteine (NAC) resulted in the prevention of these ROS mediated changes in BeWo function and supports a central role for mitochondrial ROS signaling in the maintenance and function of the materno-fetal interface.

Differences in the response to iron supplementation on oxidative stress, inflammation, and hematological parameters in nonanemic and anemic pregnant women

Background: Iron supplementation is widely recommended for all pregnant women, irrespective of their iron status. But providing excess iron to nonanemic pregnant women can result in iron overload, which may lead to oxidative stress and inflammation.Objectives: To assess the differential effect of iron supplementation on hematological parameters, oxidative stress, and inflammation in nonanemic and anemic pregnant women.Methods: Forty nonanemic and forty anemic pregnant women were recruited at 12 weeks of gestation. The study subjects were supplemented with iron (60 mg/day for nonanemic pregnant women and 120 mg/day for anemic pregnant women). Fasting state blood samples were collected at 12 and 28 weeks of gestation.Results: Malondialdehyde (MDA)/total antioxidant status (TAS) ratio (MDA/TAS) and high-sensitivity C-reactive protein (hsCRP) were significantly higher in anemic pregnant women before iron supplementation. Iron supplementation to the anemic pregnant women resulted in significant improvement in the hematological profile and ferritin levels. Further, the iron supplementation caused a significant reduction in hsCRP levels although the MDA/TAS ratio remained unaltered. Iron supplementation to nonanemic pregnant women resulted in a significant increase in the levels of MDA/TAS ratio and hsCRP, but there were no changes in hematological profile and serum ferritin levels.Conclusion: Prophylactic iron supplementation in nonanemic pregnant women increased oxidative stress and inflammation. However, in anemic pregnant women, iron supplementation was found to be beneficial as it improved hematological status and decreased inflammation without affecting oxidative stress.

Serum levels of copper, iron, and manganese in women with pregnancy, miscarriage, and primary infertility

BACKGROUND

Iron (Fe), copper (Cu), and manganese (Mn) play a significant role in female reproduction and fetal development. At the same time, high levels of metals may exert toxic effects. Correspondingly, both excess and deficiency of essential trace elements were shown to be associated with female infertility and adverse pregnancy outcome, although the existing data are rather contradictory. Therefore, the objective of the present study was to reveal the potential role of altered iron, copper, and manganese status in female reproductive health problems through assessment of serum metal levels in healthy non-pregnant and pregnant women, as well as patients with miscarriage and primary infertility.

METHODS

A total of 150 healthy controls, 169 pregnant women (II trimester of pregnancy), 75 women with miscarriage, and 91 patients with primary infertility were enrolled. Serum metal levels were assessed using ICP-MS.

RESULTS

Pregnant women are characterized by a significant increase in serum Cu an Mn levels by 40% (p < 0.001) and 16% (p = 0.043) as compared to the controls, respectively. Serum Cu levels in women with miscarriage and infertility were 30% and 35% lower than those in pregnant women (p < 0.001). No significant difference in serum iron levels were observed between the control and pregnant women. Women who had miscarriage were characterized by 13% (p = 0.042) higher serum Fe levels as compared to the pregnant ones. Multiple regression analysis demonstrated that serum copper levels was significantly associated both with pregnancy (β = 0.436; p < 0.001) and reproductive health problems in women (β = -0.272; p < 0.001). The latter was improved significant after adjustment for serum Fe and Mn levels, age, and BMI (β = -0.431; p < 0.001). The model incorporating serum Cu, Fe, Mn, and anthropometric parameters accounted for 23% of variability in reproductive status (p < 0.001).

CONCLUSIONS

It is proposed that the lack of pregnancy-associated increase in metal levels in miscarriage and infertility may be indicative of at least partial role of metal insufficiency in impaired pregnancy and reproductive function in general. However, detailed clinical studies as well as experimental investigations are required for assessment of the potential causes and mechanisms of the observed associations.

Genetic parameters for haemoglobin levels in sows and piglets as well as sow reproductive performance and piglet survival

Genetic parameters were estimated for haemoglobin (Hb) levels in sows and piglets as well as sow reproductive performance and piglet survival. Reproductive traits were available between 2005 and 2014 for 7857 litters from 1029 Large White and 858 Landrace sows. In 2012 and 2013, Hb levels, sow BW and sow back fat depth were measured on 348 sows with 529 litters 5 days prior to farrowing. In addition, Hb levels were available for 1127 one-day-old piglets from 383 litters (a maximum of three piglets per litter) of 277 sows with Hb levels. The average Hb levels in sows (sow Hb), their litters (litter Hb, based on average Hb of three piglets) and individual piglets (piglet Hb) were 112 ± 12.6 g/l, 103 ± 15.3 g/l and 105 ± 21.7 g/l, respectively. Heritabilities for Hb levels were 0.09 ± 0.07 for sow Hb, 0.19 ± 0.11 for litter Hb and 0.08 ± 0.05 for piglet Hb. Estimates for the permanent environment effect of sows were 0.09 ± 0.09 for sow Hb, 0.11 ± 0.12 for litter Hb and 0.12 ± 0.03 for piglet Hb. In comparison, heritabilities for both number of stillborn piglets and pre-weaning survival were lower (0.05 ± 0.01 and 0.04 ± 0.01). Sow BW had no significant heritability, while sow back fat depth was lowly heritable (0.10 ± 0.08). Positive genetic correlations were found between sow Hb and litter Hb (0.64 ± 0.47) and between litter Hb and sow back fat depth (0.71 ± 0.53). Higher litter Hb was genetically associated with lower number of stillborn piglets (-0.78 ± 0.35) and higher pre-weaning survival (0.28 ± 0.33). Negative genetic correlations between sow Hb and average piglet birth weight of the litter (-0.60 ± 0.34) and between piglet Hb and birth weight of individual piglets (-0.37 ± 0.32) indicate that selection for heavier piglets may reduce Hb levels in sows and piglets. Similarly, selection for larger litter size will reduce average piglet birth weight (rg: -0.40 ± 0.12) and pre-weaning survival (-0.57 ± 0.13) and may lead to lower litter Hb (-0.48 ± 0.27). This study shows promising first results for the use of Hb levels as a selection criterion in pig breeding programs, and selection for higher Hb levels may improve piglet survival and limit further reduction in Hb levels in sows and piglets due to selection for larger and heavier litters.

Iron-Related Factors in Early Pregnancy and Subsequent Risk of Gestational Diabetes Mellitus: the Ma'anshan Birth Cohort (MABC) Study

Iron is an essential micronutrient while its excessive load has been related to the etiology of diabetes. We used data of 3289 pregnant women from the Ma'anshan birth cohort (MABC) study in China to examine the associations of three iron-related factors (i.e., serum iron (SI) concentration, hemoglobin level, and use of iron supplements) with risk of gestational diabetes mellitus (GDM). Emphatically explore the potential non-linear relationship between SI concentration and risk of GDM. SI concentration was measured in fasting blood using inductively coupled plasma mass spectrometry (ICP-MS). GDM diagnosis was determined by 75 g oral glucose tolerance test at 24~28 weeks. Restricted cubic splines with three knots were used to examine potential non-linear relationship between SI concentration and GDM risk. We observed a U-shape relation between SI concentration in the first trimester and risk of GDM. In the multivariate-adjusted model, compared with the middle level (ln(SI), 7.1-7.7 μg/L), both the lowest level (ln(SI) ≤ 7.1 μg/L) (odds ratio (OR) = 1.35, 95% confidence interval (CI) = 1.04-1.76) and the highest level (ln(SI) > 7.7 μg/L) (OR = 1.63, 95%CI = 1.16-2.28) increased risk of GDM. Associations of hemoglobin level in the first trimester and risk of GDM attenuated to non-significance after adjustment for pre-pregnancy body mass index (BMI) and blood pressure. Pre-pregnancy iron supplement use was associated with an increased risk of GDM (OR = 1.57, 95%CI = 1.06-2.32). In conclusion, the three iron-related factors are all related to GDM risk on some level.

Iron and fecundity among Tsimane' women of Bolivia

Background and objectives

Iron is critical for women's reproduction, and iron-deficiency anemia is a global health problem for mothers. While public health programs have aimed to correct iron deficiency in reproductive-aged women with supplementation, a small group of studies have shown that too much iron also has negative effects on birth outcomes. We hypothesize that women's iron levels evolved within a narrow optimum, and predict that hemoglobin (Hb) levels would be associated with women's fecundity.

Methodology

We used the publicly available, longitudinal Tsimane' Amazonian Panel Study to test the association between -Hb levels and hazard of having a next birth (a measure of fecundity) among 116 parous, reproductive-aged Tsimane' women of Bolivia. A Cox proportional hazards model was used to model Hb level and other predictors against the event of next birth across the observation period, which began at each woman's previous birth.

Results

The higher the Hb level, the lower the hazard of a woman giving birth within the study observation period (hazard ratio=0.82, P = 0.03). However, there was no evidence that low Hb reduced women's fecundity.

Conclusions and implications

These results demonstrate that high Hb influences women's fecundity. These results supports the growing body of literature showing that iron metabolism is critical for understanding the evolution of women's reproduction. More work is needed to determine the evolved optimal range of iron levels for reproductive-aged women.

Lay summary

Lower chance of pregnancy among Tsimane' women with high Hb levels, suggesting evolved optimal Hb levels in women.

The Impact of Iron Overload and Ferroptosis on Reproductive Disorders in Humans: Implications for Preeclampsia

Iron is an essential element for the survival of most organisms, including humans. Demand for iron increases significantly during pregnancy to support growth and development of the fetus. Paradoxically, epidemiologic studies have shown that excessive iron intake and/or high iron status can be detrimental to pregnancy and is associated with reproductive disorders ranging from endometriosis to preeclampsia. Reproductive complications resulting from iron deficiency have been reviewed elsewhere. Here, we focus on reproductive disorders associated with iron overload and the contribution of ferroptosis-programmed cell death mediated by iron-dependent lipid peroxidation within cell membranes-using preeclampsia as a model system. We propose that the clinical expressions of many reproductive disorders and pregnancy complications may be due to an underlying ferroptopathy (elemental iron-associated disease), characterized by a dysregulation in iron homeostasis leading to excessive ferroptosis.

Associations between prenatal exposure to bisphenol a and neonatal outcomes in a Taiwanese cohort study: Mediated through oxidative stress?

This study determined whether maternal bisphenol A (BPA) exposure influences birth outcomes through oxidative stress and estimated the daily intake of BPA through breast milk for infants. One hundred and eighty-six pregnant women without pregnancy complications were enrolled and maternal urine was collected in the third trimester. Postnatal breast milk was collected in the first and third months after delivery. Concentrations of BPA were determined through ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Generalized additive model-penalized regression splines and a multivariable regression model were employed to determine the effects of BPA exposure and oxidative stress levels on birth outcomes. A causal mediation analysis was conducted to clarify the mediation effects of oxidative stress due to maternal BPA exposure on birth outcomes. The daily intake of BPA in breast milk was calculated using probabilistic risk assessment methods. The geometric means (geometric standard deviation) of BPA levels for maternal urine and first- and third-month breast milk were 2.19 (2.88) μg/g creatinine., 1.35 (3.53) ng/g, and 3.17 (2.97) ng/g, respectively. No significant mediation existed among maternal BPA exposure, oxidative stress level, and neonatal head circumference. Three percent of 1-monthold babies and 1% of 3-month-old babies exceeded the BPA tolerable daily intake of 4 μg/kg-bw/day proposed by the European Food Safety Authority. This study revealed the BPA exposure profile for pregnant women and infants in northern Taiwan. The marginally significant correlation between maternal BPA exposure and neonatal head circumference should be considered.

The sex-specific association between maternal paraben exposure and size at birth

Parabens are a group of esters of parahydroxybenzoic acid and are utilized as antimicrobial preservatives in the majority of personal care products (PCPs). Epidemiological studies regarding the adverse effects of parabens on fetuses are still limited. The aim of this study was to determine the association between maternal paraben exposure and birth outcomes. One hundred and ninety-nine pregnant women were enrolled, and maternal urine was collected in the third trimester. The urine concentrations of four parabens (methyl (MP), ethyl (EP), propyl (PP), and butyl (BP)) were determined by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Generalized additive model-penalized regression splines and a multivariable regression model were employed to determine the association between paraben exposure levels and birth outcomes. A causal mediation analysis was conducted to determine the mediation effect of oxidative stress on birth outcomes. The geometric means of urinary MP, EP, PP, and BP were 51.79, 1.26, 4.21, and 1.25 μg/g cre., respectively. In the penalized regression splines, sex-specific associations between maternal MP levels and birth outcomes were observed; a downward curvature was observed between the MP level and birth weight, length, head circumference, and thoracic circumference among female newborns. Pregnant women in the group with MP levels above the third quartile had neonates with significantly lower body weight (β = -215.98 g, p value = 0.02) compared to those in the group with MP levels lower than the third quartile. No significant mediation of oxidative stress was observed between maternal MP exposure and female birth weight. The estimated proportion mediated ranged from -6% to 15%. The negative association between maternal paraben exposure and female birth outcomes in relation to child development should be carefully considered.

Prepregnancy Obesity, Maternal Dietary Intake, and Oxidative Stress Biomarkers in the Fetomaternal Unit

Background

Obesity and pregnancy increase levels of maternal oxidative stress (OS). However, little is known about the maternal, placental, and neonatal OS status.

Objective

To analyze the relation between prepregnancy obesity and the expression of OS markers and antioxidant capacity in the fetomaternal unit and their association with dietary intake.

Methods

This cross-sectional study included 33 women with singleton, noncomplicated pregnancies. Two groups were formed: women with prepregnancy body mass index (pBMI) within normal range (18.5-24.9 kg/m², n = 18) and women with pBMI ≥ 30 kg/m², suggestive of obesity (n = 15). Dietary and clinical information was obtained by questionnaire and from clinical records. Total antioxidant capacity (TAC) and malondialdehyde (MDA) concentration were measured on maternal and cord serum by colorimetric techniques, and placental expression of glutathione peroxidase 4 (GPx4) was measured by immunohistochemistry.

Results

Placental GPx4 expression was lower in the group with pBMI suggestive of obesity than in the normal weight group (ß = -0.08, p = 0.03, adjusted for gestational age and magnesium intake). Concentrations of TAC and MDA in maternal and cord blood were not statistically different between groups (p>0.05). Cord MDA concentration was related to maternal MDA concentration (ß = 0.40, p < 0.01), vitamin A intake (tertile 2: ß = -0.04, p = 0.40, tertile 3: ß = 0.13, p = 0.03, vs tertile 1), and placental GPx4 expression (ß = -0.09, p = 0.02).

Conclusion

Prepregnancy obesity is associated with a decrease in GPx4 expression in the placenta, which is related to OS in the newborn. The influence of micronutrient intake on OS biomarkers highlights the importance of nutritional assessment during pregnancy and adequate prenatal care.

Iron deficiency in late pregnancy and its associations with birth outcomes in Chinese pregnant women: a retrospective cohort study

Background

Several biomarkers are used to measure iron deficiency (ID) during pregnancy, but the prevalence of ID and its association with adverse birth outcomes shows inconsistent results. The aim of this study was to examine the prevalence of ID in third trimester using multiple indicators of iron status and the relationship with birth outcomes in Chinese population.

Methods

We conducted a retrospective observational cohort study of 11,581 pregnant women between 2016 and 2017 in Changzhou City, Jiangsu Province, China. We obtained the data (maternal characteristics and birth outcomes) and the concentrations of ID biomarkers from our hospitalization information system and laboratory information system, respectively. Using serum ferritin (SF), serum transferrin (ST) and their ratio as criteria of ID, we investigated associations between birth outcomes and late pregnancy ID.

Results

The prevalence of ID in our study was 51.82% as defined by low SF (< 12 μg/L), 54.43% as defined by high ST (> 4 g/L) and 53.90% as defined by high ratio of ST/SF (Log 10 transform > 5.52). Maternal ST/SF ratio was associated with higher mean birth weight (97.04 g; 95% CI, 74.28, 119.81 for the highest vs. lowest quartile). Third trimester maternal ID, defined by ST/SF ratio, was associated with lower risks of preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) infants, higher risks of macrosomia and large for gestational age (LGA) babies (for PTB: OR = 0.53, 95% CI, 0.36-0.77; for LBW: OR = 0.44, 95% CI, 0.31-0.62; for SGA: OR = 0.69, 95% CI, 0.57-0.83; for macrosomia: OR = 1.39, 95% CI, 1.13-1.70; for LGA: OR = 1.20, 95% CI, 1.04-1.39).

Conclusions

ID in the third-trimester of pregnancy are frequent in Chinese women. Our findings suggest that the ratio of ST/SF measured in late pregnancy could be useful as a significant predictor of unfavorable birth outcomes.

MiR-195 modulates oxidative stress-induced apoptosis and mitochondrial energy production in human trophoblasts via flavin adenine dinucleotide-dependent oxidoreductase domain-containing protein 1 and pyruvate dehydrogenase phosphatase regulatory subunit

OBJECTIVE

Preeclampsia is a severe pregnancy-specific syndrome defined as newly onset hypertension and proteinuria. Abnormal placental development has been generally accepted as the initial cause of the disorder. Recently, miR-195 was identified as one of the downregulated small RNAs in preeclamptic placentas.

METHODS

The potential targets of miR-195 in human trophoblast cells were screened by isobaric tags for relative and absolute quantification-based mass spectrum analysis. Localization of miR-195 and its targets was examined by in-situ hybridization and immunohistochemistry in human placenta. Real-time PCR, western blotting and luciferase assay were used for target validation. Apoptosis was accessed by Annexin V/PI costaining, whereas mitochondrial function by ATP measurement and tetramethylrhodamine ethyl ester fluorescence.

RESULTS

Two mitochondria-associated proteins, flavin adenine dinucleotide-dependent oxidoreductase domain-containing protein 1 (FOXRED1) and pyruvate dehydrogenase phosphatase regulatory subunit (PDPR), were identified as targets of miR-195. Overexpression of miR-195 in HTR8/SVneo cells resulted in enhanced apoptosis, decreased mitochondrial membrane potential and cellular ATP content upon hydrogen peroxide stimulation. The effects could be partially rescued by FOXRED1 or PDPR. In preeclamptic patients, lowered circulating level of miR-195 were found at early-to-mid gestation and term pregnancy, and marked increase in FOXRED1 and PDPR expression were observed in the placenta when compared with gestational week-matched controls. In addition, chronic hydrogen peroxide stimuli suppressed miR-195 expression in trophoblast cells.

CONCLUSION

MiR-195 could suppress mitochondrial energy production via targeting FOXRED1 and PDPR, and lead to trophoblast cell apoptosis under oxidative stress. In preeclamptic placenta, lowered level of miR-195 might be induced by chorionic oxidative stress and subsequently form a compensation mechanism to defend the disturbed energy production and cell apoptosis upon oxidative stress.

Impact of air pollution on low birth weight in Spain: An approach to a National Level Study

BACKGROUND

According to the WHO, low birth weight (<2500 gr) is a primary maternal health indicator as the cause of multiple morbi-mortality in the short and long-term. It is known that air pollution from road traffic (PM₁₀, NO₂) and O₃ have an important impact on low birth weight (LBW), but there are few studies of this topic in Spain. The objective of this study is to determine the possible exposure windows in the gestational period in which there is greater susceptibility to urban air pollution and to quantify the relative risks (RR) and population attributable risks (PAR) of low birth weight associated with pollutant concentrations in Spain.

METHODS

We calculated the weekly average births with low birth weight (ICD-10: P07.0-P07.1) for each Spanish province for the period 2001-2009, using the average weekly concentrations of PM₁₀, NO₂ and O₃, measured in the capital cities of the provinces. The estimation of RR and PAR were carried out using generalized linear models with link Poisson, controlling for the trend, seasonality and auto-regressive character of the series and for the influence of temperature during periods of heat waves and/or cold. Finally, a meta-analysis was used to estimate the global RR and PAR based on the RR obtained for each of the provinces.

RESULTS

The RR for the whole of Spain is 1.104 (CI95%: 1.072, 1.138) for the association between LBW and PM₁₀, and 1.091 (CI95%: 1.059, 1.124) for the association between NO₂ and LBW. Our results suggest that 5% of low birth weight births in the case of PM₁₀ and 8% in the case of NO₂ could have been avoided with a reduction of 10 μg/m³ in the concentrations of these pollutants.

CONCLUSIONS

The impact of the results obtained- with 6105 cases attributable to PM₁₀ and up to 9385 cases attributable to NO₂ in a period of 9 study years- suggest the need to design structural and awareness public health measures to reduce air pollution in Spain.

Micronutrient supplementation in pregnancy: Who, what and how much?

Pregnancy represents a period of major physiological and metabolic change, aiming to ensure proper fetal growth and development, as well as maternal preservation. This review focuses on maternal nutrition, and particularly on micronutrient deficiencies and supplementation during pregnancy. Nutrient deficiencies and consequences in pregnant women are presented, with an overview of current recommendations for dietary supplementation in pregnancy, even considering the risk of micronutrient overload. Appropriate universal supplementation and prophylaxis/treatment of nutritional needs currently appear to be the most cost-effective goal in low-income countries, thus ensuring adequate intake of key elements including folate, iron, calcium, vitamin D and A. In high-income countries, a proper nutritional assessment and counselling should be mandatory in obstetric care in order to normalize pregestational body mass index, choose a healthy dietary pattern and evaluate the risk of deficiencies.

Prenatal Iron Deficiency and Replete Iron Status Are Associated with Adverse Birth Outcomes, but Associations Differ in Ghana and Malawi

BACKGROUND

Previous literature suggests a U-shaped relation between hemoglobin concentration and adverse birth outcomes. There is less evidence on associations between iron status and birth outcomes.

OBJECTIVE

Our objective was to determine the associations of maternal hemoglobin concentration and iron status with birth outcomes.

METHODS

We conducted a secondary data analysis of data from 2 cohorts of pregnant women receiving iron-containing nutritional supplements (20-60 mg ferrous sulfate) in Ghana (n = 1137) and Malawi (n = 1243). Hemoglobin concentration and 2 markers of iron status [zinc protoporphyrin and soluble transferrin receptor (sTfR)] were measured at ≤20 weeks and 36 weeks of gestation. We used linear and Poisson regression models and birth outcomes included preterm birth (PTB), newborn stunting, low birth weight (LBW), and small-for-gestational-age.

RESULTS

Prevalence of iron deficiency (sTfR >6.0 mg/L) at enrollment was 9% in Ghana and 20% in Malawi. In early pregnancy, iron deficiency was associated with PTB (9% compared with 17%, adjusted RR: 1.63; 95% CI: 1.14, 2.33) and stunting (15% compared with 23%, adjusted RR: 1.44; 95% CI: 1.09, 1.94) in Malawi but not Ghana, and was not associated with LBW in either country; replete iron status (sTfR <10th percentile) was associated with stunting (9% compared with 15%, adjusted RR: 1.71; 95% CI: 1.06, 2.77) in Ghana, but not PTB or LBW, and was not associated with any birth outcomes in Malawi. In late pregnancy, iron deficiency was not related to birth outcomes in either country and iron-replete status was associated with higher risk of LBW (8% compared with 16%, adjusted RR: 1.90; 95% CI: 1.17, 3.09) and stunting (6% compared with 13%, adjusted RR: 2.14; 95% CI: 1.21, 3.77) in Ghana, but was not associated with birth outcomes in Malawi.

CONCLUSIONS

The associations of low or replete iron status with birth outcomes are population specific. Research to replicate and extend these findings would be beneficial. These trials were registered at clinicaltrials.gov as NCT00970866 (Ghana) and NCT01239693 (Malawi).

Influence of tobacco smoke on zinc, cadmium, iron, iron-binding proteins, and low-weight anti-oxidant status in pregnancy

Pregnancy and tobacco smoking (TS) each can cause increases in reactive oxygen species (ROS) production; this, in turn, can lead to disorders in iron management and disruption of the pro- and anti-oxidant balance. The aim of the study was to analyze the influence of TS and Cd on Fe, Zn, and anti-oxidant levels (i.e. glutathione [GSH], metallothionein [MT]) in the blood of pregnant women. The study reported here evaluated 110 blood samples from pregnant women in their 1st, 2nd and 3rd trimester. Concentrations of ferritin and transferrin were measured in the serum; Zn, Fe and cotinine in the plasma, that of Cd in whole blood, that for glutathione in red blood cell lysates, and levels of metallothionein both in the plasma and in lysates prepared from isolated erythrocytes. The results indicated there was a decrease in Zn and increase in Cd and metallothionein levels in pregnant women smokers as compared to in nonsmoking counterparts. Differences in intracellular MT concentration were noted both in smoking and nonsmoking women during pregnancy while there were no changes in extracellular MT level. A decline in circulating ferritin and a rise in transferrin during pregnancy was observed in all groups. Based on the results, it was concluded that exposure to TS-associated xenobiotics like Cd could result in higher MT levels in erythrocytes and in pregnant smokers, the major anti-oxidant mechanism that is in place is one being mediated by MT and not by reduced GSH.

Maternal dietary patterns and risk of adverse pregnancy (hypertensive disorders of pregnancy and gestational diabetes mellitus) and birth (preterm birth and low birth weight) outcomes: a systematic review and meta-analysis

OBJECTIVE

Epidemiological studies have indicated that dietary patterns during pregnancy are associated with adverse pregnancy and birth outcomes such as hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), preterm birth (PTB) and low birth weight (LBW). However, the results of these studies are varied and inconsistent. The present study aimed to assess the association between dietary patterns and the risk of adverse pregnancy and birth outcomes.

DESIGN

Systematic review and meta-analysis. Seven databases were searched for articles. Two reviewers performed the study selection and data extraction. A random-effects model was used to estimate pooled effect sizes of eligible studies.

SETTING

Studies conducted all over the world were incorporated.

SUBJECTS

The review focused on pregnant women.

RESULTS

A total of twenty-one studies were identified. Adherence to a healthy dietary pattern (intake of vegetables, fruits, legumes, whole grains) was significantly associated with lower odds (OR; 95 % CI) of pre-eclampsia (0·78; 0·70, 0·86; I2=39·0 %, P=0·178), GDM (0·78; 0·56, 0·99; I2=68·6 %, P=0·013) and PTB (0·75; 0·57, 0·93; I2=89·6 %, P=0·0001).

CONCLUSIONS

Our review suggests that dietary patterns with a higher intake of fruits, vegetables, legumes, whole grains and fish are associated with a decreased likelihood of adverse pregnancy and birth outcomes. Further research should be conducted in low-income countries to understand the impact of limited resources on dietary intake and adverse pregnancy and birth outcomes.

Oxidative stress in healthy pregnancy and preeclampsia is linked to chronic inflammation, iron status and vascular function

Background

During normal pregnancy, placental oxidative stress (OS) is present during all three trimesters and is necessary to obtain normal cell function. However, if OS reaches a certain level, pregnancy complications might arise. In preeclampsia (PE), a dangerous pregnancy specific hypertensive disorder, OS induced in the ischemic placenta causes a systemic inflammatory response and activates maternal endothelial cells. In this study, we aimed to quantify superoxide concentrations (as a measure of systemic OS) using electron paramagnetic resonance (EPR) and correlate them to markers of systemic inflammation, iron status and vascular function.

Methods

Fifty-nine women with a healthy pregnancy (HP), 10 non-pregnant controls (NP) and 28 PE patients (32±3.3weeks) were included. During HP, blood samples for superoxide, neutrophil to lymphocyte ratio (NLR), mean platelet volume (MPV) and iron status were taken at 10, 25 and 39 weeks. Vascular measurements for arterial stiffness (carotid-femoral pulse wave velocity (CF-PWV), augmentation index (AIx), augmentation Pressure (AP)) and microvascular endothelial function (reactive hyperemia index (RHI)) were performed at 35 weeks. In PE, all measurements were performed at diagnosis. CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) was used as spin probe for EPR, since the formed CM radical corresponds to the amount of superoxide.

Results

Superoxide concentration remains stable during pregnancy (p = 0.92), but is significantly higher compared to the NP controls (p<0.0001). At 25 weeks, there is a significant positive correlation between superoxide and ferritin concentration. (p = 0.04) In PE, superoxide, systemic inflammation and iron status are much higher compared to HP (all p<0.001). During HP, superoxide concentrations correlate significantly with arterial stiffness (all p<0.04), while in PE superoxide is significantly correlated to microvascular endothelial function (p = 0.03).

Conclusions

During HP there is an increased but stable oxidative environment, which is correlated to ferritin concentration. If superoxide levels increase, there is an augmentation in arterial stiffness. In PE pregnancies, systemic inflammation and superoxide concentrations are higher and result in a deterioration of endothelial function. Together, these findings support the hypothesis that vascular function is directly linked to the amount of OS and that measurement of OS in combination with vascular function tests might be used in the prediction of PE.

Genetic and non-genetic risk factors for pre-eclampsia: umbrella review of systematic reviews and meta-analyses of observational studies

OBJECTIVE

To summarize evidence from the literature on genetic and non-genetic risk factors associated with pre-eclampsia (PE), assess the presence of statistical bias in the studies and identify risk factors for which there is robust evidence supporting their association with PE.

METHODS

PubMed and ISI Web of Science were searched from inception to October 2016, to identify systematic reviews and meta-analyses of observational studies examining associations between genetic or non-genetic risk factors and PE. For each meta-analysis, the summary-effect size was estimated using random-effects and fixed-effects models, along with 95% CIs and the 95% prediction interval. Between-study heterogeneity was expressed using the I² statistic, and evidence of small-study effects (large studies had significantly more conservative results than smaller studies) and evidence of excess significance bias (too many studies with statistically significant results) were estimated.

RESULTS

Fifty-eight eligible meta-analyses were identified, which included 1466 primary studies and provided data on 130 comparisons of risk factors associated with PE, covering a wide range of comorbid diseases, genetic factors, exposure to environmental agents and biomarkers. Sixty-five (50%) associations had nominally statistically significant findings at P < 0.05, while 16 (12%) were significant at P < 10^-6 . Sixty-five (50%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 10 (8%) and 26 (20%) associations, respectively. The only non-genetic risk factor with convincing evidence for an association with PE was oocyte donation vs spontaneous conception, which had a summary odds ratio of 4.33 (95% CI, 3.11-6.03), was supported by 2712 cases with small heterogeneity (I²  = 26%) and 95% prediction intervals excluding the null value, and without hints of small-study effects (P for Egger's test > 0.10) or excess of significance (P > 0.05). Of the statistically significant (P < 0.05) genetic risk factors for PE, only PAI-1 4G/5G (recessive model) polymorphism was supported by strong evidence for a contribution to the pathogenesis of PE. Eleven factors (serum iron level, pregnancy-associated plasma protein-A, chronic kidney disease, polycystic ovary syndrome, mental stress, bacterial and viral infections, cigarette smoking, oocyte donation vs assisted reproductive technology, obesity vs normal weight, severe obesity vs normal weight and primiparity) presented highly suggestive evidence for an association with PE.

CONCLUSIONS

A large proportion of meta-analyses of genetic and non-genetic risk factors for PE have caveats that threaten their validity. Oocyte donation vs spontaneous conception and PAI-1 4G/5G polymorphism (recessive model) showed the strongest consistent evidence for an association with risk for PE. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Effects of micronutrients on placental function: evidence from clinical studies to animal models

Micronutrient deficiencies are common in pregnant women due to low dietary intake and increased requirements for fetal development. Low maternal micronutrient status is associated with a range of pregnancy pathologies involving placental dysfunction, including fetal growth restriction (FGR), small-for-gestational age (SGA), pre-eclampsia and preterm birth. However, clinical trials commonly fail to convincingly demonstrate beneficial effects of supplementation of individual micronutrients, attributed to heterogeneity and insufficient power, potential interactions and lack of mechanistic knowledge of effects on the placenta. We aimed to provide current evidence of relationships between selected micronutrients (vitamin D, vitamin A, iron, folate, vitamin B12) and adverse pregnancy outcomes, combined with understanding of actions on the placenta. Following a systematic literature search, we reviewed data from clinical, in vitro and in vivo studies of micronutrient deficiency and supplementation. Key findings are potential effects of micronutrient deficiencies on placental development and function, leading to impaired fetal growth. Studies in human trophoblast cells and rodent models provide insights into underpinning mechanisms. Interestingly, there is emerging evidence that deficiencies in all micronutrients examined induce a pro-inflammatory state in the placenta, drawing parallels with the inflammation detected in FGR, pre-eclampsia, stillbirth and preterm birth. Beneficial effects of supplementation are apparent in vitro and in animal models and for combined micronutrients in clinical studies. However, greater understanding of the roles of these micronutrients, and insight into their involvement in placental dysfunction, combined with more robust clinical studies, is needed to fully ascertain the potential benefits of supplementation in pregnancy.

Dietary Iron Fortification Normalizes Fetal Hematology, Hepcidin, and Iron Distribution in a Rat Model of Prenatal Alcohol Exposure

BACKGROUND

Prenatal alcohol exposure (PAE) causes neurodevelopmental disability. Clinical and animal studies show gestational iron deficiency (ID) exacerbates PAE's behavioral and growth deficits. In rat, PAE manifests an inability to establish iron homeostasis, increasing hepcidin (maternal and fetal), and fetal liver iron while decreasing brain iron and promoting anemia. Here, we hypothesize dietary iron fortification during pregnancy may mitigate alcohol's disruption of fetal iron homeostasis.

METHODS

Pregnant Long-Evans rats, fed iron-sufficient (100 ppm iron) or iron-fortified (IF; 500 ppm iron) diets, received either 5 g/kg alcohol (PAE) or isocaloric maltodextrin daily on gestational days (GD) 13.5 through 19.5. Maternal and fetal outcomes were evaluated on GD20.5.

RESULTS

PAE reduced mean fetal weight (p < 0.001) regardless of maternal iron status, suggesting iron fortification did not improve fetal growth. Both PAE (p < 0.01) and IF (p = 0.035) increased fetal liver iron. In fetal brain, PAE (p = 0.015) affected total (p < 0.001) and nonheme iron (p < 0.001) such that iron fortification normalized (p = 0.99) the alcohol-mediated reductions in brain iron and nonheme iron. Iron fortification also improved fetal hematologic indices in PAE including hemoglobin, hematocrit, and mean cell volume (ps<0.001). Iron fortification also normalized hepcidin expression in alcohol-exposed maternal and fetal liver. Neither diet nor PAE affected transferrin (Tf) and ferritin (FTN) content in fetal liver, nor Tf or transferrin receptor in fetal brain. However, IF-PAE fetal brains trended to less FTN content (p = 0.074), suggesting greater availability of nonstorage iron. In PAE, hepcidin levels were linearly related to increased liver iron stores and decreased red blood cell count and brain iron.

CONCLUSIONS

Maternal oral iron fortification mitigated PAE's disruption of fetal iron homeostasis and improved brain iron content, hematologic indices, and hepcidin production in this rat PAE model. Clinical studies show maternal ID substantially enhances fetal vulnerability to PAE, and our work supports increased maternal dietary iron intake may improve fetal iron status in alcohol-exposed pregnancies.

Maternal iron nutriture as a critical modulator of fetal alcohol spectrum disorder risk in alcohol-exposed pregnancies

Alcohol consumption during pregnancy places the fetus at risk for permanent physical, cognitive, and behavioral impairments, collectively termed fetal alcohol spectrum disorder (FASD). However, prenatal alcohol exposure (PAE) outcomes vary widely, and growing evidence suggests that maternal nutrition is a modifying factor. Certain nutrients, such as iron, may modulate FASD outcomes. Untreated gestational iron deficiency (ID) causes persistent neurodevelopmental deficits in the offspring that affect many of the same domains damaged by PAE. Although chronic alcohol consumption enhances iron uptake and elevates liver iron stores in adult alcoholics, alcohol-abusing premenopausal women often have low iron reserves due to menstruation, childbirth, and poor diet. Recent investigations show that low iron reserves during pregnancy are strongly associated with a worsening of several hallmark features in FASD including reduced growth and impaired associative learning. This review discusses recent clinical and animal model findings that maternal ID worsens fetal outcomes in response to PAE. It also discusses underlying mechanisms by which PAE disrupts maternal and fetal iron homeostasis. We suggest that alcohol-exposed ID pregnancies contribute to the severe end of the FASD spectrum.

Associations between prenatal lead exposure and birth outcomes: Modification by sex and GSTM1/GSTT1 polymorphism

Maternal lead exposure is associated with poor birth outcomes. However, modifying effects of polymorphism in glutathione S-transferases (GST) gene and infant sex remain unexplored. Our aim was to evaluate whether associations between prenatal lead and birth outcomes differed by maternal GST genes and infant sex. Prospective data of 782 mother-child pairs from Mothers and Children's Environmental Health (MOCEH) study were used. The genotyping of GST-mu 1 (GSTM1) and theta-1 (GSTT1) polymorphisms was carried out using polymerase chain reaction. Multivariable linear regression was used to examine whether the association between blood lead (BPb) level and birth outcomes (birthweight, length, and head circumference) varied by maternal GST genes and sex. We did not find a statistically significant association between prenatal BPb levels and birth outcomes; in stratified analyses, the association between higher BPb level during early pregnancy and lower birthweight (β=-224 per square root increase in BPb; 95% confidence interval (CI): -426, -21; false discovery rate p=0.036) was significant in males of mothers with GSTM1 null. Results were similar for head circumference model (β=-0.78 per square root increase in BPb; 95% CI: -1.69, 0.14, p=0.095), but the level of significance was borderline. Head circumference model showed a significant three-way interaction among BPb during early pregnancy, GSTM1, and sex (p=0.046). For combined analysis with GSTM1 and GSTT1, GSTM1 null and GSTT1 present group showed a significant inverse association of BPb with birthweight and head circumference in males. Our findings of the most evident effects of BPb on the reduced birthweight and head circumference in male born to the mother with GSTM1 null may suggest a biological interaction among lead, GST genes and sex in detoxification process during fetal development.

Variations in serum concentrations of C-reactive protein, ceruloplasmin, lactoferrin and myeloperoxidase and their interactions during normal human pregnancy and postpartum period

BACKGROUND

Serum proteins may provide information about homeostasis of redox status and inflammatory processes also during pregnancy. The aim of the study was to assess the dynamics of changes in serum concentrations of C-reactive protein (CRP), ceruloplasmin (CP), lactoferrin (LF) and myeloperoxidase (MPO) and their interactions during normal pregnancy and the postpartum period.

METHODS

The concentrations of proteins were measured in serum (n=113) from pregnant in consecutive trimesters and in postpartum period (n=28) and in non-pregnant women (n=17), using immunoturbidimetric assays (CRP, CP) and ELISA Kits (LF, MPO).

RESULTS

The concentrations [mg/dl] CP and CRP (mean±SD respectively): second trimester (43.1±6.2; 0.49±0.57), third trimester (44.5±5.8; 0.41±0.37), postpartum (42.39±6.4; 4.15±3.6) were higher than in the first trimester (33.0.5±8.7; 0.31±0.36) or non-pregnant women (24.12±7.4; 0.12±0.13). The increases in concentrations of CP and CRP between the first and the second trimesters were by approximately 35% and 50% respectively and the correlation coefficients in the first trimester and in non-pregnant women were twice higher than in the second trimester and the postpartum period. The concentrations [μg/ml] LF and MPO were no significant differences (mean±SD respectively): first (6.19±4.54; 0.17±0.12), second (5.68±4.4; 0.14±0.08), third (6.34±6.98; 0.17±0.14), the postpartum (4.86±3.64; 0.25±0.4), and non-pregnant (3.9±2.56; 3.2; 0.14±0.05). However, significant correlations were established (p<0.05) between MPO and LF in all groups and between the following ratios CRP/LF vs CP/MPO and CRP/MPO vs CP/LF.

CONCLUSIONS

The concentrations of proteins synthesized by the liver (CP, CRP) dynamically increase during consecutive trimesters of pregnancy unlike neutrophil-derived proteins (LF, MPO). Statistically significant correlations between the proportions of the serum proteins may suggest their combined role for the maintenance of homeostasis during pregnancy.

Randomized control trial comparing effectiveness of weekly versus daily antenatal oral iron supplementation in preventing anemia during pregnancy

AIM

This study was conducted to determine whether weekly antenatal oral iron and folate supplementation is an effective alternative to a daily regimen in non-anemic pregnant women to prevent anemia and iron deficiency during the third trimester.

METHODS

From December 2014 to April 2015, non-anemic pregnant women (n = 292) who presented to the Academic Obstetric Unit, Teaching Hospital Mahamodera Galle, Sri Lanka, at 14-22 weeks gestation and who had been treated with mebendazole 100 mg twice daily for three days were randomly allocated to receive 120 mg elemental iron, 3 mg folic acid and 100 mg vitamin C weekly (n = 149) or 60 mg elemental iron, 1 mg folic acid and 100 mg vitamin C daily (n = 143). Side effects were assessed at four weekly intervals and hemoglobin concentration (Hb), hematocrit and serum ferritin (SF) were measured at 32-36 weeks gestation.

RESULTS

Only 106 participants in each group completed the study. There were no significant differences between the groups in mean duration of supplementation; presupplementation and post-supplementation mean Hb, hematocrit or SF levels; risk of developing anemia, ID or high Hb levels by an intension to treat analysis; and in those who completed the trial. Significantly greater side effects occurred in the daily compared to the weekly supplementation group.

CONCLUSION

In non-anemic pregnant women, a weekly regimen is an effective alternative to a daily regimen for antenatal oral iron and folate supplementation for preventing anemia and iron deficiency during the third trimester.

Maternal and neonatal outcomes related to iron supplementation or iron status: a summary of meta-analyses

BACKGROUND

Iron deficiency is the most abundant nutritional deficiency in the world and is discussed to be associated with adverse pregnancy outcomes. The objective of this review was to perform an umbrella summary of meta-analyses to evaluate the effects and associations of iron supplementation or iron status on maternal and birth/neonatal outcomes.

METHODS

A literature search was conducted on PubMed and Scopus by two reviewers without temporal restriction. Systematic reviews and meta-analyses of studies evaluating (1) the effects of multimicronutrient compared to iron + folic acid supplementations on maternal and birth/neonatal outcomes (2), the association of dietary iron intake or hemoglobin or ferritin status regarding the risk for maternal (gestational diabetes mellitus (GDM)) and birth/neonatal outcomes, and (3) the effects of iron supplementation on pregnancy and birth/neonatal outcomes, were included in this review.

RESULTS

Overall, 16 meta-analyses were included. Multimicronutrient supplements had significant risk reducing effects on low birth weight and small for gestational age compared to iron/folic acid supplements as controls. Furthermore, most of the meta-analyses showed that higher levels of hemoglobin or ferritin increased the risk for GDM. On the other hand, maternal anemia (low hemoglobin levels) was associated with adverse birth/neonatal outcomes. Finally, iron supplementation reduced the risk of iron deficiency and iron deficiency anemia and had some risk reducing effects on low birth weight newborns.

CONCLUSIONS

Our summary of meta-analyses showed that multimicronutrient supplementation had beneficial effects on some neonatal outcomes. Furthermore, higher ferritin levels seem to increase the risk for GDM whereas maternal anemia was associated with adverse birth/neonatal outcomes.

U-shaped curve for risk associated with maternal hemoglobin, iron status, or iron supplementation

Both iron deficiency (ID) and excess can lead to impaired health status. There is substantial evidence of a U-shaped curve between the risk of adverse birth outcomes and maternal hemoglobin concentrations during pregnancy; however, it is unclear whether those relations are attributable to conditions of low and high iron status or to other mechanisms. We summarized current evidence from human studies regarding the association between birth outcomes and maternal hemoglobin concentrations or iron status. We also reviewed effects of iron supplementation on birth outcomes among women at low risk of ID and the potential mechanisms for adverse effects of high iron status during pregnancy. Overall, we confirmed a U-shaped curve for the risk of adverse birth outcomes with maternal hemoglobin concentrations, but the relations differ by trimester. For low hemoglobin concentrations, the link with adverse outcomes is more evident when hemoglobin concentrations are measured in early pregnancy. These relations generally became weaker or nonexistent when hemoglobin concentrations are measured in the second or third trimesters. Associations between high hemoglobin concentration and adverse birth outcomes are evident in all 3 trimesters but evidence is mixed. There is less evidence for the associations between maternal iron status and adverse birth outcomes. Most studies used serum ferritin (SF) concentrations as the indicator of iron status, which makes the interpretation of results challenging because SF concentrations increase in response to inflammation or infection. The effect of iron supplementation during pregnancy may depend on initial iron status. There are several mechanisms through which high iron status during pregnancy may have adverse effects on birth outcomes, including oxidative stress, increased blood viscosity, and impaired systemic response to inflammation and infection. Research is needed to understand the biological processes that underlie the U-shaped curves seen in observational studies. Reevaluation of cutoffs for hemoglobin concentrations and indicators of iron status during pregnancy is also needed.

Comparison of Total Antioxidant Capacity of Saliva in Women with Gestational diabetes mellitus and Non-diabetic Pregnant Women

Background

Pregnancy is considered a stressful event, results in higher levels of oxidative stress and considerable changes in physiological and metabolic functions such as gestational diabetes mellitus (GDM). Due to the cumulative effect of antioxidants and considering the controversies in this area, this study was undertaken to investigate the total antioxidant capacity (TAC) of saliva in pregnant women whit gestational diabetes in comparison to non-diabetic pregnant women.

Material and Methods

In this cross-sectional study (2015-16), a total of 31 women with a diagnosis of GDM and 59 non-diabetic pregnant women were included in the diabetic and control groups, respectively. Salivary samples were collected by spitting method. When all samples were collected, total antioxidant capacity (TAC) was measured with the use of a commercial kit following the manufacturer's instructions. Data were analyzed with descriptive statistics and Mann-Whitney test using SPSS 18.

Results

Average TAC level in the saliva of women with gestational diabetes was 0.10 ± 0.14, with 0.04 ± 0.11 in non-diabetic pregnant women. Nonparametric Mann-Whitney test showed that this difference was statistically significant (P=0.024).

Conclusions

Under the limitations of the present study it can be concluded that there is an increase in oxidative stresses during pregnancy, followed by an increase in the total levels of salivary antioxidants to counteract such stresses. Therefore, it is expected that determining the salivary antioxidant levels during pregnancy can be an alternative technique for the early diagnosis of diabetes. Key words:Gestational diabetes mellitus, pregnancy, saliva, total antioxidant capacity.

Redox Properties of Tryptophan Metabolism and the Concept of Tryptophan Use in Pregnancy

During pregnancy, tryptophan (Trp) is required for several purposes, and Trp metabolism varies over time in the mother and fetus. Increased oxidative stress (OS) with high metabolic, energy and oxygen demands during normal pregnancy or in pregnancy-associated disorders has been reported. Taking the antioxidant properties of Trp and its metabolites into consideration, we made four hypotheses. First, the use of Trp and its metabolites is optional based on their antioxidant properties during pregnancy. Second, dynamic Trp metabolism is an accommodation mechanism in response to OS. Third, regulation of Trp metabolism could be used to control/attenuate OS according to variations in Trp metabolism during pregnancy. Fourth, OS-mediated injury could be alleviated by regulation of Trp metabolism in pregnancy-associated disorders. Future studies in normal/abnormal pregnancies and in associated disorders should include measurements of free Trp, total Trp, Trp metabolites, and activities of Trp-degrading enzymes in plasma. Abnormal pregnancies and some associated disorders may be associated with disordered Trp metabolism related to OS. Mounting evidence suggests that the investigation of the use of Trp and its metabolites in pregnancy will be meanful.

Ambient air pollution and low birth weight - are some women more vulnerable than others?

BACKGROUND AND OBJECTIVES

Ambient air pollution is controllable, and it is one of the greatest environmental threats to human health. Studies conducted worldwide have provided evidence that maternal exposure to ambient air pollution during pregnancy enhances the risk of low birth weight at term (TLBW, <2500g among infants born ≥37 completed weeks of gestation), a maker of intrauterine growth restriction (IUGR), and suggest that some subgroups of pregnant women who are smoking, of low or high body-mass index (BMI), low socioeconomic status (SES) or asthma are more vulnerable towards the effect of ambient air pollution. The aim of this commentary is to review the published literature on the association between ambient air pollution and TLBW regarding increased vulnerability for the above-mentioned subgroups.

RESULTS

Although more than fifty epidemiological studies have examined the associations between ambient air pollution and TLBW to date, we only identified six studies that examined the potential effect modification of the association between ambient air pollution and TLBW by the above listed maternal risk factors. Two studies assessed effect modification caused by smoking on the association between ambient air pollution and TLBW. The adjusted odds ratio (OR) for TLBW associated with exposure to ambient air pollution were in one study higher among women who smoked during pregnancy, as compared to the OR of non-smoking women, while in the other study the association was in the opposite direction. The association of ambient air pollution and TLBW were higher among women characterized by extreme BMI (two studies) and low SES compared to non-obese women or women of higher SES (four studies), respectively. Only one study reported the estimated effects among asthmatic and non-asthmatic women and no statistically significant effect modification was evident for the risk of TLBW associated with ambient air pollution.

CONCLUSION AND RECOMMENDATIONS

The current epidemiologic evidence is scarce, but suggests that pregnant women who are smoking, being underweight, overweight/obese or having lower SES are a vulnerable subpopulation when exposed to ambient air pollution, with and increased risk of having a child with TLBW. The limited evidence precludes for definitive conclusions and further studies are recommended.

Safety and benefits of antenatal oral iron supplementation in low-income countries: a review

The World Health Organization recommends universal iron supplementation of 30-60 mg/day in pregnancy but coverage is low in most countries. Its efficacy is uncertain, however, and there has been a vigorous debate in the last decade about its safety, particularly in areas with a high burden of malaria and other infectious diseases. We reviewed the evidence on the safety and efficacy of antenatal iron supplementation in low-income countries. We found no evidence that daily supplementation at a dose of 60 mg leads to increased maternal Plasmodium infection risk. On the other hand, recent meta-analyses found that antenatal iron supplementation provides benefits for maternal health (severe anaemia at postpartum, blood transfusion). For neonates, there was a reduced prematurity risk, and only a small or no effect on birth weight. A recent trial showed, however, that benefits of antenatal iron supplementation on maternal and neonatal health vary by maternal iron status, with substantial benefits in iron-deficient women. The benefits of universal iron supplementation are likely to vary with the prevalence of iron deficiency. As a consequence, the balance between benefits and risks is probably more favourable in low-income countries than in high-income countries despite the higher exposure to infectious pathogens.

Association between Blood Lead Levels and Delta-Aminolevulinic Acid Dehydratase in Pregnant Women

Blood lead levels (BLLs) and delta-aminolevulinic acid dehydratase (ALAD) activity are considered biomarkers of lead exposure and lead toxicity, respectively. The present study was designed to investigate the association between BLLs and ALAD activity in pregnant women from Durango, Mexico. A total of 633 pregnant women aged 13–43 years participated in this study. Blood lead was measured by a graphite furnace atomic absorption spectrometer. ALAD activity was measured spectrophotometrically. Mean blood lead was 2.09 ± 2.34 µg/dL; and 26 women (4.1%) crossed the Centers for Disease Control (CDC) recommended level of 5 µg/dL. ALAD activity was significantly lower in women with levels of lead ≥5 µg/dL compared to those with BLLs < 5 µg/dL (p = 0.002). To reduce the influence of extreme values on the statistical analysis, BLLs were analyzed by quartiles. A significant negative correlation between blood lead and ALAD activity was observed in the fourth quartile of BLLs (r = −0.113; p < 0.01). Among women with blood lead concentrations ≥2.2 µg/dL ALAD activity was negatively correlated with BLLs (r = −0.413; p < 0.01). Multiple linear regression demonstrated that inhibition of ALAD in pregnant women may occur at levels of lead in blood above 2.2 µg/dL.

Assessing perinatal depression as an indicator of risk for pregnancy-associated cardiovascular disease

Cardiovascular conditions associated with pregnancy are serious complications. In general, depression is a well-known risk indicator for cardiovascular disease (CVD). Mental distress and depression are associated with physiological responses such as inflammation and oxidative stress. Both inflammation and oxidative stress have been implicated in the pathophysiology of CVDs associated with pregnancy. This article discusses whether depression could represent a risk indicator for CVDs in pregnancy, in particular in pre-eclampsia and peripartum cardiomyopathy (PPCM).

Evaluation of Malondialdehyde, Superoxide Dismutase and Catalase Activity in Fetal Cord Blood of Depressed Mothers

Objective

The umbilical cord consists of two arteries and one vein and it functions in the transport between the maternal and fetal circulation. Biochemical analysis of fetal cord blood (FCB) during delivery could be beneficial in terms of understanding the fetal environment. In this study, we aimed to investigate oxidative parameters like malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels in FCB during delivery.

Methods

We collected FCB samples during caesarean section. Our study included 33 depressed mothers and 37 healthy controls. We investigated MDA, SOD, and CAT levels in FCB samples.

Results

We found no significant difference between groups in terms of MDA (p=0.625), SOD (p=0.940), and CAT (p=0.413) levels.

Conclusion

Our study reveals probable protective effects of the placenta from oxidative stress. Future studies should include larger samples.

Haemoconcentration risk at the end of pregnancy: effects on neonatal behaviour

OBJECTIVE

To determine the associations between haemoconcentration at the end of pregnancy (third trimester and delivery) and neonatal behaviour in healthy pregnant women supplemented with moderate doses of Fe.

DESIGN

A prospective longitudinal study in which obstetric and clinical history, maternal toxic habits, maternal anxiety and Hb levels were recorded at the third trimester and delivery. Neonatal behaviour was assessed at 48-72 h of age using the Neonatal Behavioral Assessment Scale.

SETTING

Unit of Obstetrics and Gynaecology of the Sant Joan University Hospital in Reus, Tarragona (Spain).

SUBJECTS

A total of 210 healthy and well-nourished pregnant women and their full-term, normal-weight newborns.

RESULTS

The results showed that, after adjusting for confounders, in the third trimester the risk of haemoconcentration (6·2 % of pregnant women) was related to decreased neonatal state regulation (B=-1·273, P=0·006) and alertness (B=-1·848, P=0·006) scores. In addition, the risk of haemoconcentration at delivery (12·0 % of pregnant women) was also related to decreased neonatal state regulation (B=-0·796, P=0·021) and poor robustness and endurance (B=-0·921, P=0·005) scores.

CONCLUSIONS

Our results show that the risk of haemoconcentration at the end of pregnancy is related to the neonate's neurodevelopment (and self-regulation capabilities), suggesting that Fe supplementation patterns and maternal Fe status during pregnancy are important factors for neurodevelopment which may be carefully controlled.

Middle Iron-Enriched Fructose Diet on Gestational Diabetes Risk and on Oxidative Stress in Offspring Rats

Gestational diabetes mellitus (GDM) is associated with increased insulin resistance and a heightened level of oxidative stress (OS). Additionally, high iron consumption could also increase insulin resistance and OS, which could aggravate GDM risk. The aim of this study is to evaluate a high fructose diet (F) as an alternative experimental model of GDM on rats. We also have evaluated the worst effect of a fructose iron-enriched diet (FI) on glucose tolerance and OS status during pregnancy. Anthropometric parameters, plasma glucose levels, insulin, and lipid profile were assessed after delivery in rats fed an F diet. The effects observed in mothers (hyperglycemia, and hyperlipidemia) and on pups (macrosomia and hypoglycemia) are similar to those observed in women with GDM. Therefore, the fructose diet could be proposed as an experimental model of GDM. In this way, we can compare the effect of an iron-enriched diet on the metabolic and redox status of mother rats and their pups. The mothers' glycemic was similar in the F and FI groups, whereas the glycemic was significantly different in the newborn. In rat pups born to mothers fed on an FI diet, the activities of the antioxidant enzyme glutathione peroxidase (GPx) and glutathione-S-transferase in livers and GPx in brains were altered and the gender analysis showed significant differences. Thus, alterations in the glycemic and redox status in newborns suggest that fetuses are more sensitive than their mothers to the effect of an iron-enriched diet in the case of GDM pregnancy. This study proposed a novel experimental model for GDM and provided insights on the effect of a moderate iron intake in adding to the risk of glucose disorder and oxidative damage on newborns.

Can anemia predict perinatal outcomes in different stages of pregnancy?

Objective:

To investigate the effect of anemia on perinatal outcomes as preterm delivery (PTD) and low birth weight (LBW) in the different stages of pregnancy.

Methods:

Medical records of 39,587 Turkish pregnant women who delivered between January 2011 and September 2014 were reviewed. Anemia during pregnancy was defined as hemoglobin (Hb)< 11 g/dl, low birth weight was defined as birth weight <2500 gr and PTD was defined as <37 weeks. The pregnant women were divided into three groups (Hb<10 gr/dl, Hb 10-11 gr/dl, Hb>11 gr/dl). Perinatal outcomes were compared between these anemic and non-anemic groups.

Results:

The anemia prevalence in our study was 25.1%. In the first and second trimester of Hb<10g/dl group LBW ratio was significantly higher (respectively 13.5%, 9.8%, p=0.03; 22.7%, 14.7%, p=0.01). In the second and third trimesters of Hb<10 g/dl group PTD ratio was significantly higher (respectively 29.1%, 19%, p=0.00; 17.7%, 15.4% p=0.02). In the first trimester Hb<10 g/dl group cesarean section rate was significantly higher (respectively 65.2%, 57.6%, p = 0.01).

Conclusions:

LBW infants and preterm birth rate was higher in Hb <10 gr/dl group than non-anemic in the first, second and third trimester. Hb <10 gr/dl group had higher cesarean rate in first trimester. The mean birth weight was significantly lower in anemic pregnant women in the second trimester. Preterm birth and cesarean section rate, in the group of anemic throughout pregnancy was higher than those of non-anemic in the whole pregnancy period.

The reproductive ecology of iron in women

Reproductive ecology focuses on the sensitivity of human reproduction to environmental variation. While reproductive ecology has historically focused on the relationship between energy status and reproductive outcomes, iron status is equally critical to women's reproductive health, given the wide-ranging detrimental effects of iron-deficiency anemia on maternal and infant well-being. This review interprets the vast literature on iron status and women's reproduction through an evolutionary framework. First, it will critique the evidence for iron deficiency caused by blood loss during menstruation, reinterpreting the available data as ecological variation in menses within and between populations of women. Second, it will highlight the scant but growing evidence that iron status is implicated in fertility, a relationship that has deep evolutionary roots. Third, this review proposes a new hypothesis for the transfer of iron from mother to infant via pregnancy and breastfeeding: reproductive iron withholding. In this hypothesis, mothers transfer iron to infants in a manner that helps infants avoid iron-mediated infection and oxidative stress, but trades off with potential risk of maternal and infant iron deficiency. Finally, this review explores two main factors that can modify the relationship between iron status and the gestation-lactation cycle: (1) the relationship between long-term reproductive effort (parity) and iron status and (2) supplementation schemes before and during pregnancy. The review concludes by suggesting continued research into iron homeostasis in women using evolutionary, ecological, and biocultural frameworks.

Pregnancy in women with thalassemia: challenges and solutions

Advances in treatment of thalassemia have led to the aging of thalassemic patients, and consequently concern about successful reproductive outcome is augmented. Although women with thalassemia intermedia only were considered competent of achieving pregnancy, case series reveal the willingness of both thalassemia major and thalassemia intermedia women to have a family. Pregnancy in general is characterized by dynamic multiple-system changes and increased susceptibility to oxidative stress, while homozygous, transfusion-dependent, β-thalassemia patients manifest cardiac, hepatic, endocrine, and metabolic disorders attributable to chronic anoxia and iron overload and thalassemia intermedia, usually nontransfused, is associated with augmented risk of thromboembolic events. Pregnancy in thalassemia should be considered a high risk for both mother and fetus, and favorable outcomes are the result of continuous preconception, antenatal, and postpartum assessment and management by a team of thalassemia experts.

Hepcidin and Iron Metabolism in Pregnancy: Correlation with Smoking and Birth Weight and Length

To estimate the effect of tobacco smoking on iron homeostasis and the possible association between hepcidin and the neonatal birth weight and length, concentrations of serum hepcidin and selected iron markers were measured in 81 healthy pregnant women (41 smokers and 40 nonsmokers). The smoking mothers had significantly lower concentrations of serum hepcidin (p < 0.001), iron (p < 0.001), and hemoglobin (p < 0.05), but higher erythropoietin (p < 0.05) levels compared with non-smoking pregnant women. Logistic regression analysis showed the highest negative impact of the number of cigarettes smoked per day (β = -0.46; p < 0.01) and positive impact of ferritin level (β = 0.47; p < 0.001) on serum hepcidin concentration. The birth weight and the body length of smoking mothers' infants were significantly lower than in tobacco abstinent group (p < 0.001). In multiple regression analysis, birth body weight (β = 0.56; p < 0.001) and length (β = 0.50; p < 0.001) were significantly related to maternal hepcidin values. Tobacco smoking affected hepcidin level in serum of pregnant women in a dose-dependent manner. Low concentrations of iron and hemoglobin in maternal serum coexisting with high level of erythropoietin suggest that smoking could lead to subclinical iron deficiency and chronic hypoxia not only in mothers but also in fetus. Low serum hepcidin concentration in smoking pregnant women might be associated with lower fetal birth weight and length.

High maternal iron status, dietary iron intake and iron supplement use in pregnancy and risk of gestational diabetes mellitus: a prospective study and systematic review

AIM

High iron measured using dietary intake and biomarkers is associated with Type 2 diabetes. It is uncertain whether a similar association exists for gestational diabetes mellitus. The aim of this systematic review was to conduct a cohort study examining first trimester body iron stores and subsequent risk of gestational diabetes, and to include these findings in a systematic review of all studies examining the association between maternal iron status, iron intake (dietary and supplemental) and the risk of gestational diabetes.

METHODS

Serum samples from women with first trimester screening were linked to birth and hospital records for data on maternal characteristics and gestational diabetes diagnosis. Blood was analysed for ferritin, soluble transferrin receptor and C-reactive protein. Associations between iron biomarkers and gestational diabetes were assessed using multivariate logistic regression. A systematic review and meta-analysis, registered with PROSPERO (CRD42014013663) included studies of all designs published in English from January 1995 to July 2015 that examined the association between iron and gestational diabetes and included an appropriate comparison group.

RESULTS

Of 3776 women, 3.4% subsequently developed gestational diabetes. Adjusted analyses found increased odds of gestational diabetes for ferritin (OR 1.41; 95% CI 1.11, 1.78), but not for soluble transferrin receptor (OR 1.00; 95% CI 0.97, 1.03) per unit increase of the biomarker. Two trials of iron supplementation found no association with gestational diabetes. Increased risk of gestational diabetes was associated with higher levels of ferritin and serum iron and dietary haem iron intakes.

CONCLUSIONS

Increased risk of gestational diabetes among women with high serum ferritin and iron levels and dietary haem iron intakes warrants further investigation.

Comparative analysis of iron status and other hematological parameters in preeclampsia

OBJECTIVE

To compare serum ferritin (SF) concentrations and other hematological parameters between patients with preeclampsia (PE) and normal pregnant women of the same gestational period who received supplemental iron during pregnancy.

METHODS

Prospective, comparative, observational pilot study that included 31 women with PE and 30 healthy pregnant women, at 20 weeks' of gestation. Ferritin, iron and complete blood cell count were compared between groups.

RESULTS

In comparison with controls, preeclamptic patients had a higher weight, body mass index, and arterial pressure. Serum ferritin and serum iron were higher in patients with PE (median: 36.5 μg/l vs. 20.9 μg/l and 103.9 μg/dl vs. 90.8 μg/dl) with a significant difference (P = 0.019 and P = 0.345). SF values >40 μg/l correlated with PE (r = 0.281; P = 0.032). A platelet count less than 100 × 10⁹/l was higher in the PE group than in the control group (13% vs. 3%, P = 0.354).

CONCLUSION

Higher SF levels, despite being within normal range, were associated with PE. The incidence of thrombocytopenia was higher in preeclamptic women, however, the remaining hematological parameters were similar in both groups.