Effect of Maternal Nutritional Status and Mode of Delivery on Zinc and Iron Stores at Birth.

Zinc and iron deficiencies among infants aged under 6 months may be related with nutrient store at birth. This study aimed to investigate the association between zinc and iron stores at birth with maternal nutritional status and intakes during pregnancy. 117 pregnant women were enrolled at the end of second trimester and followed until delivery. Clinical data during pregnancy, including pre-pregnancy body mass index (BMI) and at parturition were collected from medical record. Zinc and iron intakes were estimated from a food frequency questionnaire. Serum zinc and ferritin were determined in maternal blood at enrollment and cord blood. Mean cord blood zinc and ferritin were 10.8 ± 2.6 µmol/L and 176 ± 75.6 µg/L, respectively. Cord blood zinc was associated with pre-pregnancy BMI (adj. ß 0.150; p = 0.023) and serum zinc (adj. ß 0.115; p = 0.023). Cord blood ferritin was associated with pre-pregnancy BMI (adj. ß -5.231; p = 0.009). Cord blood zinc and ferritin were significantly higher among those having vaginal delivery compared to cesarean delivery (adj. ß 1.376; p = 0.007 and 32.959; p = 0.028, respectively). Maternal nutritional status and mode of delivery were significantly associated with zinc and iron stores at birth. Nutrition during preconception and pregnancy should be ensured to build adequate stores of nutrients for infants.

The role of parathyroid hormone during pregnancy on the relationship between maternal vitamin D deficiency and fetal growth restriction: a prospective birth cohort study.

Previous studies have shown conflicting findings regarding the relationship between maternal vitamin D deficiency (VDD) and fetal growth restriction (FGR). We hypothesised that parathyroid hormone (PTH) may be an underlying factor relevant to this potential association. In a prospective birth cohort study, descriptive statistics were evaluated for the demographic characteristics of 3407 pregnancies in the second trimester from three antenatal clinics in Hefei, China. The association of the combined status of vitamin D and PTH with birth weight and the risk of small for gestational age (SGA) was assessed by a multivariate linear and binary logistic regression. We found that declined status of 25-hydroxyvitamin D is associated with lower birth weight (for moderate VDD: adjusted ß = -49·4 g, 95 % CI -91·1, -7·8, P < 0·05; for severe VDD: adjusted ß = -79·8 g, 95 % CI -127·2, -32·5, P < 0·01), as well as ascended levels of PTH (for elevated PTH: adjusted ß = -44·5 g, 95 % CI -82·6, -6·4, P < 0·05). Compared with the non-VDD group with non-elevated PTH, pregnancies with severe VDD and elevated PTH had the lowest neonatal birth weight (adjusted ß = -124·7 g, 95 % CI -194·6, -54·8, P < 0·001) and the highest risk of SGA (adjusted risk ratio (RR) = 3·36, 95 % CI 1·41, 8·03, P < 0·01). Notably, the highest risk of less Ca supplementation was founded in severe VDD group with elevated PTH (adjusted RR = 4·67, 95 % CI 2·78, 7·85, P < 0·001). In conclusion, elevated PTH induced by less Ca supplementation would further aggravate the risk of FGR in pregnancies with severe VDD through impaired maternal Ca metabolism homoeostasis.

Impact of erythrocyte long-chain omega-3 polyunsaturated fatty acid levels in early pregnancy on birth outcomes: findings from a Belgian cohort study.

OBJECTIVE: To examine the association between maternal erythrocyte long-chain omega-3 PUFA (n-3 LCPUFA), measured in early pregnancy, and pregnancy and birth outcomes. STUDY DESIGN: One hundred and eight healthy women with a singleton pregnancy were included. Erythrocyte fatty acids were analyzed using gas chromatography. Gestational length, birth anthropometric measures, and pregnancy-associated complications were collected from hospital medical records. RESULTS: We observed significant positive associations between maternal docosahexaenoic acid (DHA) levels (p = 0.024) and omega-3 index values (p = 0.021) and gestational length in adjusted linear regression models. Each point in maternal DHA level was associated with 2.19 days longer gestational duration (ß = 2.19; 95% CI 0.29-4.09). No consistent associations were found between n-3 PUFA levels and composite pregnancy outcome. CONCLUSION: These findings suggest that the gestational length is positively affected by maternal n-3 LCPUFA status as soon as the early stages of pregnancy.

A randomized controlled trial of folic acid intervention in pregnancy highlights a putative methylation-regulated control element at ZFP57.

BACKGROUND: Maternal blood folate concentrations during pregnancy have been previously linked with DNA methylation patterns, but this has been done predominantly through observational studies. We showed recently in an epigenetic analysis of the first randomized controlled trial (RCT) of folic acid supplementation specifically in the second and third trimesters (the EpiFASSTT trial) that methylation at some imprinted genes was altered in cord blood samples in response to treatment. Here, we report on epigenome-wide screening using the Illumina EPIC array (~ 850,000 sites) in these same samples (n = 86). RESULTS: The top-ranked differentially methylated promoter region (DMR) showed a gain in methylation with folic acid (FA) and was located upstream of the imprint regulator ZFP57. Differences in methylation in cord blood between placebo and folic acid treatment groups at this DMR were verified using pyrosequencing. The DMR also gains methylation in maternal blood in response to FA supplementation. We also found evidence of differential methylation at this region in an independent RCT cohort, the AFAST trial. By altering methylation at this region in two model systems in vitro, we further demonstrated that it was associated with ZFP57 transcription levels. CONCLUSIONS: These results strengthen the link between folic acid supplementation during later pregnancy and epigenetic changes and identify a novel mechanism for regulation of ZFP57. This trial was registered 15 May 2013 at www.isrctn.com as ISRCTN19917787.

Association Between Maternal 2nd Trimester Plasma Folate Levels and Infant Bronchiolitis.

Objectives Viral bronchiolitis is the most common cause of infant hospitalization. Folic acid supplementation is important during the periconceptional period to prevent neural tube defects. An area of investigation is whether higher prenatal folate is a risk factor for childhood respiratory illnesses. We investigated the association between maternal 2nd trimester plasma folate levels and infant bronchiolitis. Methods We conducted a retrospective cohort analysis in a subset of mother-infant dyads (n = 676) enrolled in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study and Tennessee Medicaid. Maternal folate status was determined using 2nd trimester (16-28 weeks) plasma samples. Bronchiolitis diagnosis in the first year of life was ascertained using International Classification of Diagnosis-9 codes from Medicaid administrative data. We used multivariable logistic regression to assess the adjusted association of prenatal folate levels and infant bronchiolitis outcome. Results Half of the women in this lower-income and predominately African-American (84%) study population had high levels of folate (median 2nd trimester level 19.2 ng/mL) and 21% of infants had at least one bronchiolitis healthcare visit. A relationship initially positive then reversing between maternal plasma folate and infant bronchiolitis was observed that did not reach statistical significance (poverall = .112, pnonlinear effect = .088). Additional adjustment for dietary methyl donor intake did not significantly alter the association. Conclusions for Practice Results did not confirm a statistically significant association between maternal 2nd trimester plasma folate levels and infant bronchiolitis. Further work is needed to investigate the role of folate, particularly higher levels, in association with early childhood respiratory illnesses.

F2-isoprostanes and fatty acids profile in early pregnancy complicated by pre-existing diabetes.

BACKGROUND: Diabetes and pregnancy are both associated with oxidative stress, characterized by an increase of F2-isoprostanes from the non-enzymatic oxidation of arachidonic acid, a n - 6 polyunsaturated fatty acid (PUFA). We hypothesized that pregnant women with pre-existing diabetes will be characterized by elevated levels of specific F2-isoPs isomers and altered PUFA composition in plasma early pregnancy when compared to normoglycemic controls. METHODS: Plasma samples from 23 women with uncomplicated pregnancies and 11 women with pre-existing diabetes in pregnancy were collected between 12 and 18 weeks of pregnancy (MIROS cohort). Six F2-isoprostanes isomers were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Fatty acids concentrations in plasmatic phospholipids were measured by gas chromatography coupled to a flame ionization detector. RESULTS: F2-isoprostanes, specifically the 8-iso-15(R)-PGF2α levels, were 67% higher in diabetic than normoglycemic pregnancies (p = 0.026). The total n - 6 PUFA and arachidonic acid level did not differ between study groups. In contrast, total n - 3 level was 32% lower in diabetic pregnancies than in controls (p = 0.002); EPA(20:5) and DHA(22:6) being specifically reduced (p = 0.035 and p = 0.003 respectively). Delta-6-desaturase (D6D) activity index, calculated using fatty acid ratios, was 9% lower in pre-existing diabetes than in controls (p = 0.042). CONCLUSIONS: Pre-existing diabetes in early pregnancy displays a distinctive F2-isoprostanes profile when compared to other pathologies of pregnancy, such as preeclampsia, as previously assessed in the same cohort.

Low serum folate status in the second trimester increase the risk of low birthweight in Chinese women.

AIM: This study aimed to explore the influence of maternal folate and vitamin B12 (B12) status during pregnancy on the incidence of low birthweight (LBW) infants. METHODS: A total of 6203 eligible women registered in seven hospitals in southern China, and 230 cases with singleton live births and 382 controls were matched for further analyses. The concentrations of serum folate and B12 were detected with chemiluminescence microparticle immunoassay on ARCHITECT i2000-1. Conditional logistic regression was used to evaluate the effects of folate and B12 levels on LBW. RESULTS: Maternal serum folate levels increased basically with increasing the period of folic acid supplementation (P trend <0.001). Moreover, maternal serum folate and B12 levels gradually decreased with the increase of gestational age (P < 0.001). Conditional logistic regressions analysis results showed increased odds ratios (OR) for LBW from the fourth to first folate quartiles (P trend <0.01) in the second trimester. Compared with the women in the highest quartile, those in the lowest quartile of serum folate in the second trimester were found with higher risk of LBW (adjusted OR = 1.67, 95% confidence interval [CI]: 1.02-2.73). However, no significant association was observed between serum folate and LBW in the first trimester or third trimester. In addition, serum B12 exhibited no significant association with LBW. CONCLUSIONS: Low serum folate levels in the second trimester significantly increases the risk of LBW amongst Chinese women with singleton pregnancies.

Labor induction versus expectant management at early term in pregnancies with second trimester elevated human chorionic gonadotropin or alpha fetoprotein.

AIM: Elevated human chorionic gonadotropin (HCG) and alpha fetoprotein (AFP) have been linked to placental dysfunction and associated morbidities. We aimed to compare the induction of labor with expectant management at term in those pregnancies for the prevention of neonatal and maternal morbidities. METHODS: Women with second trimester HCG ≥ 2 and/or AFP ≥ 2 multiples of the median, without additional maternal or fetal complications, from their 38th gestational week were offered the choice of labor induction or expectant management. The primary outcomes were maternal composite outcome (composed of cesarean deliveries, pre-eclampsia or placental abruption) and neonatal composite outcome (composed of antenatal or neonatal death, Apgar score at 5 min < 7, admission to the neonatal intensive care unit, need for phototherapy, respiratory abnormalities, birth trauma or neonatal infection). RESULTS: Of 305 women, 124 women chose to undergo labor induction, and 181 women chose expectant management. The composite maternal outcome in the expectant management group was twice the rate of the labor induction group, although it did not reach statistical significance (18 [10%] vs 6 [5%]; P = 0.1; relative risk [expectant/induced] 2.04; 95% confidence interval 0.8-5.0). Increased rate of phototherapy led to increased neonatal composite outcomes in the labor induction group compared with the expectant management group (34 [27%] vs 27 [15%], respectively = 0.007). CONCLUSION: In pregnancies with elevated AFP and/or HCG, early term labor induction initiated a trend towards improvement in maternal outcome but increased the rate of mild neonatal morbidity. The statistical insignificance of the large effect on the maternal outcome might reflect the lack of statistical power. Further research is needed to address this limitation.

Maternal haemoglobin concentration and risk of preterm birth in a Chinese population.

The aim was to examine the relationship between maternal haemoglobin (Hb) concentrations and risk of preterm birth by secondary analysis of data from a randomised controlled trial. This analysis included 10,430 women who were at least 20 years old and no more than 20 weeks of gestation. Results revealed neither first- nor second-trimester Hb concentrations were associated with the risk of preterm births. However, the risk of preterm birth increased when the Hb level was low (<130 g/L) in the first but high (≥130 g/L) in the second trimester, regardless of supplement type (iron-containing: AOR: 2.26, 95% CI: 1.37-3.73; non-iron-containing: AOR: 2.16, 95% CI: 1.11-4.21). In conclusion, maternal Hb concentrations were not associated with the risk of preterm birth. A low-Hb level in the first trimester but coupled with a high Hb level in the second was associated with an elevated risk of preterm birth. Impact statement What is already known on this subject: The relationship between maternal Hb concentration and preterm birth remains inconclusive. Some studies have shown an association between a low- or a high-Hb level and an increased risk of preterm birth. Others have not found such an association. Yet others have shown a U-shaped relationship. What do the results of this study add: Overall, maternal Hb concentrations in first or second trimester were not statistically associated with the risk of preterm birth. However, women with a low Hb concentration in the first trimester together with a high Hb concentration in the second trimester had an increased risk of preterm birth, compared to women who had a higher Hb concentration in the first trimester that remained similar during the second trimester. What are the implications are of these findings for clinical practice and/or further research: Our finding helps identify mothers who are at risk of having a preterm delivery. Investigating the underlying clinical causes of the unfavourable change in Hb levels and close follow-up to these women may help improve birth outcomes.

Maternal Vitamin D Status in the Late Second Trimester and the Risk of Severe Preeclampsia in Southeastern China.

The association between maternal vitamin D deficiency and the risk of severe preeclampsia is still debated. In the present study, we aimed to evaluate vitamin D status in Chinese pregnant women and investigate its correlation with the odds of developing severe preeclampsia. A cohort study was performed on 13,806 pregnant women who routinely visited the antenatal care clinics and subsequently delivered at the Wuxi Maternity and Child Health Hospital. All the subjects in the cohort had their serum 25-hydroxyvitamin D (25(OH)D) concentrations measured during pregnancy. A high prevalence of maternal vitamin D deficiency (25(OH)D < 50 nmol/L) was found. Pregnant women who had different BMIs before pregnancy had significantly different serum concentrations of 25(OH)D. There was also a significant difference in the serum 25(OH)D concentration among pregnant women of different ages. The serum 25(OH)D concentration was significantly lower in pregnant women who subsequently developed severe preeclampsia compared with those who did not. Maternal vitamin D deficiency at 23-28 weeks of gestation was strongly associated with increased odds for severe preeclampsia after adjusting for relevant confounders (adjusted OR, 3.16; 95% CI, 1.77-5.65). Further studies are required to investigate whether vitamin D supplementation would reduce the risk of severe preeclampsia and improve pregnancy outcomes.

Clinical and Metabolic Response to Selenium Supplementation in Pregnant Women at Risk for Intrauterine Growth Restriction: Randomized, Double-Blind, Placebo-Controlled Trial.

Data on the effects of selenium supplementation on clinical signs and metabolic profiles in women at risk for intrauterine growth restriction (IUGR) are scarce. This study was designed to assess the effects of selenium supplementation on clinical signs and metabolic status in pregnant women at risk for IUGR. This randomized double-blind placebo-controlled clinical trial was performed among 60 women at risk for IUGR according to abnormal uterine artery Doppler waveform. Participants were randomly assigned to intake either 100 µg selenium supplements as tablet (n = 30) or placebo (n = 30) for 10 weeks between 17 and 27 weeks of gestation. After 10 weeks of selenium administration, a higher percentage of women in the selenium group had pulsatility index (PI) of <1.45) (P = 0.002) than of those in the placebo group. In addition, changes in plasma levels of total antioxidant capacity (TAC) (P < 0.001), glutathione (GSH) (P = 0.008), and high-sensitivity C-reactive protein (hs-CRP) (P = 0.004) in the selenium group were significant compared with the placebo group. Additionally, selenium supplementation significantly decreased serum insulin (P = 0.02), homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (P = 0.02), and homeostatic model assessment for B-cell function (HOMA-B) (P = 0.02) and significantly increased quantitative insulin sensitivity check index (QUICKI) (P = 0.04) and HDL-C levels (P = 0.02) compared with the placebo. We did not find any significant effect of selenium administration on malondialdehyde (MDA), nitric oxide (NO), fasting plasma glucose (FPG), and other lipid profiles. Overall, selenium supplementation in pregnant women at risk for IUGR resulted in improved PI, TAC, GSH, hs-CRP, and markers of insulin metabolism and HDL-C levels, but it did not affect MDA, NO, FPG, and other lipid profiles.Clinical trial registration number http://www.irct.ir : IRCT201601045623N64.

Vitamin D deficiency and supplementation in pregnancy in a multiethnic population-based cohort.

BACKGROUND: To investigate ethnic differences in vitamin D levels during pregnancy, assess risk factors for vitamin D deficiency and explore the effect of vitamin D supplementation in women with deficiency in early pregnancy. METHODS: This is a population-based, multiethnic cohort study of pregnant women attending Child Health Clinics for antenatal care in Oslo, Norway. Serum-25-hydroxyvitamin D [25(OH)D] was measured in 748 pregnant women (59% ethnic minorities) at gestational weeks (GW) 15 (SD:3.6) and 28 (1.4). Women with 25(OH)D <37 nmol/L at GW 15 were for ethical reasons recommended vitamin D3 supplementation. Main outcome measure was 25(OH)D, and linear regression models were performed. RESULTS: Severe deficiency (25(OH)D <25 nmol/L) was found at GW 15 in 45% of women from South Asia, 40% from the Middle East and 26% from Sub-Saharan Africa, compared to 2.5% in women from East Asia and 1.3% of women from Western Europe. Women from South Asia, the Middle East and Sub-Saharan Africa had mean values that were -28 (95 % CI:-33, -23), -24 (-29, -18) and -20 (-27, -13) nmol/L lower than in Western women, respectively. Ethnicity, education, season and intake of vitamin D were independently associated with 25(OH)D. At GW 28, the mean 25(OH)D had increased from 23 (SD:7.8) to 47 (27) nmol/L (p < 0.01) in women who were recommended vitamin D supplementation, with small or no change in women with sufficient vitamin D levels at baseline. CONCLUSIONS: Vitamin D deficiency was prevalent among South Asian, Middle Eastern and African women. The serum levels of 25(OH)D increased significantly from GW 15 to 28 in vitamin D deficient women who received a recommendation for supplementation. This recommendation of vitamin D supplementation increased vitamin D levels in deficient women.

Evaluation of lead and essential elements in whole blood during pregnancy: a cross-sectional study.

AIM: Physiological concentrations of some elements fluctuate during pregnancy due to the increased requirements of growing fetus and changes in the maternal physiology. The aim of the study is to evaluate the distribution at different stages of pregnancy in healthy Chinese women and to show the association between trace elements and gestational age-specific reference intervals. METHODS: A cross-sectional study was performed in 1089 pregnant women and 677 nonpregnant control women. Five element concentrations, including Cu, Zn, Ca, Mg, Pb in the blood were determined by atomic absorption spectrometry. Spearman's rank correlation test was used to assess the relationship between weeks of gestation and blood element concentrations. RESULTS: The mean levels of Cu and Mg were 23.64 ± 4.69 µmol/L and 1.36 ± 0.12 mmol/L, respectively, in the control women. While 0.68 % of all pregnant women showed Cu levels below the normal ranges, the levels of Mg were comparable in different groups. Though the overall mean blood zinc and Ca concentrations (83.84 ± 17.50 µmol/L and 1.60 ± 0.15 mmol/L, respectively) increased gradually with the progress of gestation, the Zn and Ca deficiency levels (16.6 and 3.6 %, respectively) decreased with the advance of gestation. Compared with nonpregnant group, the concentrations of Cu, Zn, Ca, Mg, Pb during the different stages of pregnancy, as a whole, were significantly different. Positive correlations were observed between weeks of gestation and blood Cu, Ca, Pb concentrations (r = 0.301, 0.221, 0.223; P < 0.05). There was a negative correlation blood Mg concentrations and weeks of gestation (r = -0.321; P < 0.05). A weak positive correlation was noted between Zn concentrations and weeks of gestation (r = 0.125; P < 0.05). CONCLUSION: The importance of Cu and Mg deficiency and supplementation is well realized, but, Zn/Ca deficiency and Pb exposure is still exist; the overall deficiency of pregnant women was not so optimistic. During pregnancy, the established reference values will provide an important guidance for the reasonable supplementation of essential elements and surveillance of lead overexposure.

Higher Maternal Plasma n-3 PUFA and Lower n-6 PUFA Concentrations in Pregnancy Are Associated with Lower Childhood Systolic Blood Pressure.

BACKGROUND: Suboptimal maternal diet during pregnancy might lead to fetal cardiovascular adaptations with persistent consequences in the offspring. OBJECTIVE: We assessed the associations of maternal polyunsaturated fatty acid (PUFA) concentrations during pregnancy with childhood blood pressure. METHODS: In a population-based prospective cohort study among 4455 mothers and their children, we measured maternal second-trimester n-3 (ω-3) and n-6 (ω-6) PUFA concentrations in plasma glycerophospholipids and expressed n-3 and n-6 PUFAs as proportions of total PUFAs (wt%). Childhood blood pressure was measured at the median age of 6.0 y (95% range: 5.7-7.9 y). We used linear regression models to assess the associations of maternal PUFA wt% with childhood blood pressure at 6 y. RESULTS: Higher total maternal n-3 PUFA wt% and, specifically, docosahexaenoic acid (DHA; 22:6n-3) wt% were associated with lower childhood systolic blood pressure [differences: -0.28 (95% CI: -0.54, -0.03) and -0.29 mm Hg (95% CI: -0.54, -0.03) per SD increase of total n-3 PUFAs and DHA wt%, respectively], but not with childhood diastolic blood pressure. Total maternal n-6 PUFA wt% was positively associated with childhood systolic blood pressure [differences: 0.36 mm Hg (95% CI: 0.09, 0.62) per SD increase of total n-6 PUFA wt%], but not with childhood diastolic blood pressure. A higher n-6:n-3 PUFA ratio was associated with higher childhood systolic blood pressure (P < 0.05). Pregnancy and childhood characteristics only partly explained the observed associations. CONCLUSIONS: Higher maternal plasma n-3 PUFA and lower n-6 PUFA concentrations during pregnancy are associated with a lower systolic blood pressure in childhood. Further studies are needed to replicate these findings, explore the underlying mechanisms, and examine the long-term cardiovascular consequences.

Maternal PUFA status and offspring allergic diseases up to the age of 18 months.

Studies have suggested that maternal PUFA status during pregnancy may influence early childhood allergic diseases, although findings are inconsistent. We examined the relationship between maternal PUFA status and risk of allergic diseases in early childhood in an Asian cohort. Maternal plasma samples from the Growing Up in Singapore Towards Healthy Outcomes mother-offspring cohort were assayed at 26-28 weeks of gestation for relative abundance of PUFA. Offspring (n 960) were followed up from 3 weeks to 18 months of age, and clinical outcomes of potential allergic diseases (rhinitis, eczema and wheezing) were assessed by repeated questionnaires. Skin prick testing (SPT) was also performed at the age of 18 months. Any allergic disease with positive SPT was defined as having any one of the clinical outcomes plus a positive SPT. The prevalence of a positive SPT, rhinitis, eczema, wheezing and any allergic disease with positive SPT was 14·1 % (103/728), 26·5 % (214/808), 17·6 % (147/833), 10·9 % (94/859) and 9·4 % (62/657), respectively. After adjustment for confounders, maternal total n-3, n-6 PUFA status and the n-6:n-3 PUFA ratio were not significantly associated with offspring rhinitis, eczema, wheezing, a positive SPT and having any allergic disease with positive SPT in the offspring (P>0·01 for all). A weak trend of higher maternal n-3 PUFA being associated with higher risk of allergic diseases with positive SPT in offspring was observed. These findings do not support the hypothesis that the risk of early childhood allergic diseases is modified by variation in maternal n-3 and n-6 PUFA status during pregnancy in an Asian population.

Assessing the relationship between perfluoroalkyl substances, thyroid hormones and binding proteins in pregnant women; a longitudinal mixed effects approach.

The mechanisms involved in thyroid homeostasis are complex, and perfluoroalkyl substances (PFASs) have been indicated to interfere at several levels in this endocrine system. Disruption of the maternal thyroid homeostasis during early pregnancy is of particular concern, where subclinical changes in maternal thyroid hormones (THs) may affect embryonic and foetal development. The present study investigated associations between THs, thyroid binding proteins (TH-BPs) and PFAS concentrations in pregnant women from Northern Norway. Women participating in The Northern Norway Mother-and-Child contaminant Cohort Study (MISA) donated a blood sample at three visits related to their pregnancy and postpartum period (during the second trimester, 3 days and 6 weeks after delivery) in the period 2007-2009. Participants were assigned to quartiles according to PFAS concentrations during the second trimester and mixed effects linear models were used to investigate potential associations between PFASs and repeated measurements of THs, TH-BPs, thyroxin binding capacity and thyroid peroxidase antibodies (anti-TPOs). Women within the highest perfluorooctane sulfonate (PFOS) quartile had 24% higher mean concentrations of thyroid stimulating hormone (TSH) compared to the first quartile at all sampling points. Women within the highest quartiles of perfluorodecanoate (PFDA) had 4% lower mean concentrations of triiodothyronine (T3) and women within the highest quartile of perfluoroundecanoate (PFUnDA) had 3% lower mean concentrations of free triiodothyronine (FT3). Further, the difference in concentrations and the changes between three time points were the same for the PFAS quartiles. Thyroxin binding capacity was associated with all the THs and TH-BPs, and was selected as a holistic adjustment for individual changes in TH homeostasis during pregnancy. Finally, adjusting for maternal iodine status did not influence the model predictions. Findings in the present study suggest modifications of TH homeostasis by PFASs in a background exposed maternal population. The variation in levels of THs between PFAS quartiles was within normal reference ranges and may not be of clinical significance in the pregnant woman. However, subtle individual changes in maternal THs may have significant consequences for foetal health.

The Northern Norway Mother-and-Child Contaminant Cohort (MISA) Study: PCA analyses of environmental contaminants in maternal sera and dietary intake in early pregnancy.

BACKGROUND: Although predictors of contaminants in serum or whole blood are usually examined by chemical groups (e.g., POPs, toxic and/or essential elements; dietary sources), principal component analysis (PCA) permits consideration of both individual substances and combined variables. OBJECTIVES: Our study had two primary objectives: (i) Characterize the sources and predictors of a suite of eight PCBs, four organochlorine (OC) pesticides, five essential and five toxic elements in serum and/or whole blood of pregnant women recruited as part of the Mother-and-Child Contaminant Cohort Study conducted in Northern Norway (The MISA study); and (ii) determine the influence of personal and social characteristics on both dietary and contaminant factors. METHODS: Recruitment and sampling started in May 2007 and continued for the next 31 months until December 2009. Blood/serum samples were collected during the 2nd trimester (mean: 18.2 weeks, range 9.0-36.0). A validated questionnaire was administered to obtain personal information. The samples were analysed by established laboratories employing verified methods and reference standards. PCA involved Varimax rotation, and significant predictors (p≤0.05) in linear regression models were included in the multivariable linear regression analysis. RESULTS: When considering all the contaminants, three prominent PCA axes stood out with prominent loadings of: all POPs; arsenic, selenium and mercury; and cadmium and lead. Respectively, in the multivariate models the following were predictors: maternal age, parity and consumption of freshwater fish and land-based wild animals; marine fish; cigarette smoking, dietary PCA axes reflecting consumption of grains and cereals, and food items involving hunting. PCA of only the POPs separated them into two axes that, in terms of recently published findings, could be understood to reflect longitudinal trends and their relative contributions to summed POPs. CONCLUSIONS: The linear combinations of variables generated by PCA identified prominent dietary sources of OC groups and of prominent toxic elements and highlighted the importance of maternal characteristics.

Vitamin D status in early pregnancy and risk of preeclampsia.

OBJECTIVE: We sought to examine the association between maternal serum 25-hydroxyvitamin D (25[OH]D) concentration in early pregnancy and the subsequent diagnosis of preeclampsia (PE). STUDY DESIGN: This was a nested case-control study from 2 prospective Canadian cohorts conducted in Quebec City, Quebec, and Halifax, Nova Scotia, from 2002 through 2010. Participants were pregnant women (n = 169 cases with PE and 1975 controls). Maternal serum was drawn <20 weeks of gestation, and 25(OH)D measurement was performed. Cases were ascertained from medical records. Logistic regression analysis was used to estimate adjusted odds ratios with 95% confidence intervals. RESULTS: Women who developed PE had a significantly lower 25(OH)D concentration at a mean gestational age of 14 weeks compared with women in the control group (mean ± SD 25[OH]D 47.2 ± 17.7 vs 52.3 ± 17.2 nmol/L, P < .0001). Women with 25(OH)D <30 nmol/L compared to those with at least 50 nmol/L had a greater risk of developing PE (adjusted odds ratio, 2.23; 95% confidence interval, 1.29-3.83) after adjustment for prepregnancy body mass index, maternal age, smoking, parity, season and year of blood collection, gestational week at blood collection, and cohort site. Exploratory analysis with cubic splines demonstrated a dose-response relationship between maternal 25(OH)D and risk of PE, up to levels around 50 nmol/L, where the association appeared to plateau. CONCLUSION: Maternal vitamin D deficiency early in pregnancy defined as 25(OH)D <30 nmol/L may be an independent risk factor for PE. The relevance of vitamin D supplementation for women of childbearing age should be explored as a strategy for reducing PE and for promoting a healthier pregnancy.

Mild anemia and pregnancy outcome in a Swiss collective.

BACKGROUND: Over half of all women in the world experience anemia during their pregnancy. Our aim was to investigate the relation between hemoglobin and iron status examined in second trimester and pregnancy outcome. METHODS: In a prospective longitudinal study, 382 pregnant women were included. Blood samples were examined for hematological status and serum ferritin between 16 and 20 weeks and for hemoglobin before delivery. The adverse maternal and perinatal outcomes were determined. Regression analysis was performed to establish if anemia and low serum ferritin are risk factors for pregnancy complications. RESULTS: There was no increase of complications in women with mild anemia and in women with depleted iron stores. The finding showed that mild iron deficiency anemia and depleted iron stores are not risk factors for adverse outcomes in iron supplemented women. CONCLUSIONS: Mild anemia and depleted iron stores detected early in pregnancy were not associated with adverse maternal and perinatal outcomes in iron supplemented women.

Dynamic changes in serum 25-hydroxyvitamin D during pregnancy and lack of effect on thyroid parameters.

BACKGROUND & AIMS: To explore vitamin D status and its dynamic changes during pregnancy in women living in Northeast China. The association between 25-hydroxyvitamin D and serum calcium, phosphate and parathyroid hormone was studied. Because vitamin D deficiency or thyroid dysfunction/autoimmunity during pregnancy may lead to similar adverse events, the relationship between 25-hydroxyvitamin D and thyroid parameters was investigated. METHODS: Serum samples of 50 women (aged 22 to 36 years) were selected retrospectively. The samples were collected at gestational 8 weeks ± 3 days, 20 weeks ± 3 days and 32 weeks ± 3 days for measurement of 25-hydroxyvitamin D, calcium, phosphate, parathyroid hormone, and thyroid parameters. RESULTS: The median 25-hydroxyvitamin D levels were 28.29, 39.23 and 40.03 nmol/L, respectively, from the first to the third trimester. The 25-hydroxyvitamin D concentration during the first trimester was significantly lower than the next two trimesters (p<0.01) and was unchanged between the second and the third trimester. Of these women, 96%, 78% and 76% showed 25-hydroxyvitamin D ≤ 50 nmol/L during each trimester. Season was associated with 25-hydroxyvitamin D during each trimester (p<0.05), and a significant association was found between calcium and 25-hydroxyvitamin D during the first and the second trimesters. Only triiodothyronine was associated with 25-hydroxyvitamin D in the first trimester (p = 0.024), but statistical significance was only a trend (p = 0.063) after excluding abnormal values. No association was observed between 25-hydroxyvitamin D and phosphate, parathyroid hormone, and other thyroid parameters. CONCLUSIONS: Vitamin D deficiency during pregnancy was prevalent in women from Northeast China who did not use supplementation. No significant relationships were observed between 25-hydroxyvitamin D and thyroid parameters during pregnancy.