Trimester-Specific Urinary Strontium Concentrations during Pregnancy and Longitudinally Assessed Fetal Growth: Findings from a Prospective Cohort.

BACKGROUND: Studies have claimed that strontium (Sr) is associated with fetal growth, but the research evidence is insufficient. OBJECTIVES: Our study aimed to evaluate associations of trimester-specific urinary Sr concentrations with fetal growth parameters and birth size indicators. METHODS: In this prospective cohort, 9015 urine samples (first trimester: 3561, 2nd trimester: 2756, 3rd trimester: 2698) from 3810 mothers were measured for urinary Sr levels using inductively coupled plasma mass spectrometry (ICP-MS) and adjusted to urine specific gravity. We calculated standard deviation scores (SD-scores) for ultrasound-measured fetal growth parameters (head circumference, abdominal circumference, femur length, and estimated fetal weight) at 16, 24, 31, and 37 wk of gestation and birth size indicators (birth weight, birth length, and Ponderal index). Generalized linear models and generalized estimating equations models were used. Models were adjusted for potential covariates (gestational age, maternal age, body mass index, parity, passive smoking during pregnancy, education, folic acid supplements use, physical activity, maternal and paternal height, and infant sex). RESULTS: Positive associations of naturally logarithm-transformed Sr concentrations with fetal growth parameters and birth size indicators were observed. With each doubling increase in the urinary ln-Sr level in all 3 trimesters resulting in a percent change in SD-scores fetal growth parameters at 24, 31, and 37 wk of gestation and birth size indicators, 5.09%-8.23% in femur length, 7.57%-11.53% in estimated fetal weight, 6.56%-10.42% in abdominal circumference, 6.25% in head circumference, 5.15%-7.85% in birth weight, and 5.71%-9.39% in birth length, respectively. Most of the above statistical results could only be observed in male fetuses. CONCLUSIONS: Our findings suggest a potential association between Sr concentration and increased fetal growth, but these results and underlying mechanisms need further confirmation and clarification.

Association of Selenium Levels with Gestational Diabetes Mellitus: An Updated Systematic Review and Meta-Analysis.

Several studies have investigated the association between selenium levels and gestational diabetes mellitus (GDM); however, their results are not conclusive. This systematic review and meta-analysis aimed to update and draw conclusions regarding the evidence from published studies that investigated selenium levels in relation to GDM. PubMed, Google Scholar, Cochrane Library and ScienceDirect were searched for studies related to selenium and GDM, published from the inception of each database through to July 2022. The meta-analysis was conducted by measuring the standardized mean difference (SMD) between the selenium levels of women with GDM and those pregnant without GDM (control group). Stratified meta-analysis, meta-regression analysis and reporting bias were applied. The "meta" package in the open-access software R was used to analyze all of the data. A total of 12 studies, including 940 pregnant women with GDM and 1749 controls met this study's inclusion criteria. The selenium levels were significantly lower in women with GDM compared with the control group (SMD = -0.66; 95% confidence interval (CI): (-1.04, -0.28); p ≤ 0.001). Due to significant heterogeneity (I2 = 94%, Cochrane Q = 186.7; p ≤ 0.0001), the random-effects model was followed. The stratified meta-analysis showed that the selenium levels were lower in the cases compared with the normal controls in the third trimester (SMD = -1.85 (-3.03, -0.66); p ≤ 0.01). The same trend was observed in the studies published before the year 2014 (SMD = -0.99 (-1.70, -0.28); p ≤0.01) and those published in or after 2014 (SMD = -0.45 (-0.90, 0.00); p = 0.05). None of the investigated covariates in the meta-regression analysis (each study's geographic location, trimester of selenium quantification, World Bank economic classification, method of selenium determination, study design, study quality score, publication year and study's sample size) were significantly associated with the selenium SMD. The current evidence indicates that selenium levels are lower among women with GDM in comparison to those without GDM; however, after the correction of the reporting bias, the result was no longer significant. Further studies with more prospective designs are needed to confirm this evidence and explain the function of selenium in GDM throughout pregnancy.

Association of Vitamin D in Different Trimester with Hemoglobin during Pregnancy.

The association between vitamin D and hemoglobin has been suggested. Vitamin D can affect erythropoiesis by the induction of erythroid progenitor cell proliferation and enhance iron absorption by regulating the iron-hepcidin-ferroportin axis in monocytes. However, this relationship in pregnant women is scarce. The purpose of this study was to investigate the association between plasma vitamin D levels with hemoglobin concentration in pregnant women considering each trimester and iron supplementation. The data were obtained from Zhoushan Pregnant Women Cohort, collected from 2011 to 2018. Plasma 25(OH)D was measured in each trimester using liquid chromatography−tandem mass spectrometry. Generalized estimating equations and multiple linear regressions were performed. Finally, 2962 pregnant women and 4419 observations in the first trimester were included in this study. Plasma 25(OH)D in first trimester (T1) (ß = 0.06, p = 0.0177), second trimester (T2) (ß = 0.15, p < 0.0001), and third trimester (T3) (ß = 0.12, p = 0.0006) were positively associated with Hb. Association between plasma 25(OH)D levels in T1 and Hb concentration was positively associated with gestational age (ß = 0.005, p = 0.0421). Pregnant women with VD deficiency in T1 (OR = 1.42, 95% CI: 1.07−1.88) or T2 (OR = 1.94, 95% CI: 1.30−2.89) presented an increased risk of anemia, compared with women without VD deficiency. Moreover, the significant relationship between VD and Hb was only observed among women with iron supplementation during pregnancy. Plasma 25(OH)D levels in each trimester were positively associated with Hb concentration. Iron supplementation might be an important factor affecting the relationship between VD and Hb.

The dynamic change of urinary selenium concentration during pregnancy and influencing factors: A longitudinal study.

BACKGROUND: Selenium concentration of one spot urine sample cannot reflect selenium status during whole pregnancy. Studies on variations of urinary selenium concentration at different stages of pregnancy are limited. AIM: To assess variations of urinary selenium concentrations during three trimesters of pregnancy and to explore the influencing factors. METHODS: This study included 2613 pregnant women from a birth cohort study (Wuhan, China) enrolled between October 2014 and October 2016. Selenium concentrations of urine samples collected at three trimesters were measured. We used a generalized linear mixed effects model to observe the changes in urinary selenium concentration during pregnancy and its influencing factors. RESULTS: The median value (range) of gestational weeks at urine sample collection was 11 (9-14), 24 (15-27), and 34 (28-41) respectively. Urine selenium concentration varied across trimesters (geometric mean: 16.34, 17.65 and 18.83 µg/g creatinine, respectively), with an upward trend (ß = -0.145, 95%CI: -0.164, -0.126) (ß = -0.066, 95%CI: -0.083, -0.048). The concentrations of urinary selenium increased with the increasing of educational level [ß (95%CI): ≤ 9 years = -0.105 (-0.163, -0.047); 10-12 years = -0.086(-0.126, -0.047); > 12 years = reference]. Pregnant women who rarely or only took multivitamins in the first trimester [ß (95% CI): rarely = -0.076 (-0.144, -0.007); only in the first three months of pregnancy = -0.104 (-0.170, -0.038); always = reference], or were not exposed to passive smoking during pregnancy（ߠ= -0.093, 95% CI: - 0.173, - 0.014), or exercised three to four days per week for the first three months before delivery（ߠ= -0.074, 95% CI: - 0.140, - 0.008) had lower urinary selenium concentrations. Pregnant women who took calcium supplements after the third month of pregnancy had higher urinary selenium levels（ߠ= 0.114, 95% CI: 0.059, 0.169). CONCLUSIONS: Urine selenium concentrations of pregnant women showed an upward trend across trimesters. Educational level, calcium or multivitamin supplementation, passive smoking, and physical exercise might impact urine selenium levels.

Intensifying Iodine Deficiency Throughout Trimesters of Pregnancy in a Borderline Iodine-Sufficient Urban Area, Ankara, Turkey.

Iodine has long been recognized as an essential micronutrient for maternal thyroid function, as well as fetal growth and development during pregnancy. The current study aimed to evaluate thyroid hormone status, urinary iodine concentration (UIC), thyroid volume, and nodularity in pregnant women, throughout trimesters, in a borderline iodine sufficient, urban area with mandatory table salt iodization. Two-hundred-sixty-five pregnant women ranging from 17 to 45 years participated in this prospective longitudinal study. Thyroid function tests, thyroid volume, nodule growth, and UIC were recorded throughout the first, second, and third trimesters with no intervention. Median UIC was 96, 78, and 60 µg/L in the first, second, and third trimester of pregnancy, respectively (p < 0.001). Mean TSH values increased significantly (i.e. 0.65 mIU/ml, 1.1 mIU/ml, and 1.3 mIU/ml in the first, second, and third trimesters, respectively) (p < 0.001). Mean ± s.d. thyroid volume was significantly higher in the third trimester (14.72 ± 6.8 ml) compared with the first trimester (13.69 ± 5.31 ml) (p < 0.001). An intensifying iodine deficiency (ID) was reported throughout trimesters in this cohort of pregnant women from Ankara. A significant percentage of pregnant women from a borderline iodine sufficient, urban area in Turkey were iodine deficient during all trimesters, and the deficiency increased throughout the pregnancy. Pregnant women should receive iodine supplementation, besides consuming iodized salt in borderline iodine sufficient areas.

Supranutritional Maternal Organic Selenium Supplementation during Different Trimesters of Pregnancy Affects the Muscle Gene Transcriptome of Newborn Beef Calves in a Time-Dependent Manner.

Selenium (Se) is an essential micronutrient for growth and immune function in beef cattle. We previously showed that supranutritional maternal organic Se supplementation during late pregnancy improves immune function in their newborn calves; however, the effects of maternal organic Se-supplementation on fetal programming during different pregnancy stages have yet to be elucidated. Herein, we investigated the effects of supranutritional maternal organic Se-supplementation in different pregnancy trimesters on their beef calf's genome-wide transcriptome profiles. Within 12 to 48 h of birth, whole blood and Longissimus dorsi (LD) muscle biopsies were collected from calves born to 40 crossbred Angus cows that received, except for the control group (CTR), Se-yeast boluses (105 mg of Se/wk) during the first (TR1), second (TR2), or third (TR3) trimester of gestation. Whole-blood Se concentrations of newborn calves increased from CTR, TR1, TR2 to TR3, whereas muscle Se concentrations of newborn calves were only increased in TR3 group. We identified 3048 unique differentially expressed genes (DEGs) across all group comparisons (FDR ≤ 0.05 and |log2FC| ≥ 1.5). Furthermore, we predicted 237 unique transcription factors that putatively regulate the DEGs. Independent of supplementation trimester, supranutritional maternal organic Se supplementation downregulated genes involved in adaptive immunity in all trimesters. Dependent on supplementation trimester, genes involved in muscle development were upregulated by TR3 Se supplementation and downregulated by TR1 Se-supplementation, and genes involved in collagen formation were downregulated by TR2 Se-supplementation. Supranutritional maternal organic Se supplementation in the last trimester of pregnancy resulted in upregulation of myosin and actin filament associated genes, potentially allowing for optimal muscle function and contraction. Our findings suggest a beneficial effect of supranutritional maternal organic Se supplementation during late gestation on Se-status and muscle development and function of newborn calves.

Trimester-Specific Reference Ranges for Saturated, Monounsaturated and Polyunsaturated Fatty Acids in Serum of Pregnant Women: A Cohort Study from the ECLIPSES Group.

In the course of pregnancy, increasing importance is being placed on maintaining optimal fatty acid (FA) levels and particularly n-3 PUFAs to ensure correct fetal development. However, reference ranges for FA have been reported in only a few studies. Our objective is to provide quantitative reference intervals for SFAs, MUFAs, and PUFAs (n-6 and n-3) in a large population of healthy pregnant women from a developed country. A prospective study of pregnant women (n = 479) was conducted from the first trimester (T1) to the third trimester (T3). A total of 11 fatty acids were analyzed in serum by gas chromatography mass spectrometry and were expressed as absolute (µmol/L) and relative (percentage of total FA) concentration units. Serum concentrations of SFAs, MUFAs, n-6 PUFAs, n-3 PUFAs, various FA ratios, and the EFA index were determined. The reference intervals (2.5/97.5 percentiles) in absolute values from T1 ranged from 1884.32 to 8802.81 µmol/L for SFAs, from 959.91 to 2979.46 µmol/L for MUFAs, from 2325.77 to 7735.74 µmol/L for n-6 PUFAs, and from 129.01 to 495.58 µmol/L for n-3 PUFAs. These intervals mainly include the values of other studies from European populations. However, reference ranges vary according to some maternal factors. The FA levels proposed, obtained from a large sample of pregnant women, will be a useful tool for assessing the degree of adequacy of FAs in pregnant women and will help to carry out dietary interventions based on certain maternal factors.

Maternal Vitamin D and Newborn Telomere Length.

Nutrition is important during pregnancy for offspring health. Gestational vitamin D intake may prevent several adverse outcomes and might have an influence on offspring telomere length (TL). In this study, we want to assess the association between maternal vitamin D intake during pregnancy and newborn TL, as reflected by cord blood TL. We studied mother-child pairs enrolled in the Maternal Nutrition and Offspring's Epigenome (MANOE) cohort, Leuven, Belgium. To calculate the dietary vitamin D intake, 108 women were asked to keep track of their diet using the seven-day estimated diet record (EDR) method. TL was assessed in 108 cord blood using a quantitative real-time PCR method. In each trimester of pregnancy, maternal serum 25-hydroxyvitamin D (25-OHD) concentration was measured. We observed a positive association (ß = 0.009, p-value = 0.036) between newborn average relative TL and maternal vitamin D intake (diet + supplement) during the first trimester. In contrast, we found no association between average relative TL of the newborn and mean maternal serum 25-OHD concentrations during pregnancy. To conclude, vitamin D intake (diet + supplements), specifically during the first trimester of pregnancy, is an important factor associated with TL at birth.

Iodine monitoring models contribute to avoid adverse birth outcomes related more than adequate iodine intake.

BACKGROUND: Iodine plays an important role in pregnancy. How to maintain adequate iodine intake amongst pregnant women in each trimester of pregnancy to prevent adverse birth outcomes in central China is a challenge for clinical practice. METHODS: 870 pregnant women and their infants were enrolled in the study. Urinary iodine concentration (UIC) was measured using an inductively coupled plasma mass spectrometry (ICP-MS). Maternal and newborn information were obtained during follow-up. Multinomial logistic regression models were established. RESULTS: Median UIC of pregnant women was 172 ± 135 µg/L which is currently considered to be sufficient. Multivitamin supplements containing iodine, iodized salt intake and frequent milk intake were significantly associated with higher UIC. Multivariate logistic regression analysis showed that multivitamin supplements containing iodine and milk consumption were risk factors for more than adequate iodine (UIC ≥ 250 µg/L). Iodine-rich diet was significantly related to heavier birthweight, larger head circumference and longer femur length of the newborns while more than adequate iodine intake (UIC ≥ 250 µg/L) was a risk factor for macrosomia. Logistic regression models based on potential risk factors involving iodine containing supplements and iodine-rich diet were established to predict and screen pregnant women with high risk of more than adequate iodine intake among local pregnant women in different trimesters and guide them to supplement iodine reasonably to prevent the risk. CONCLUSIONS: Multivitamin supplements containing iodine and milk consumption were risk factors for maternal UIC ≥ 250 µg/L which was a risk factor for macrosomia. Iodine monitoring models were established to provide guidance for pregnant women to reduce the risk of more than adequate iodine intake, thereby contributing to reduce the risk of having a macrosomia.

Systematic review and meta-analysis of vitamin D deficiency in different pregnancy on preterm birth: Deficiency in middle pregnancy might be at risk.

BACKGROUND: Current studies suggest that vitamin D deficiency during pregnancy can produce a certain effect for preterm birth (PTB), but there is no research showing whether vitamin D deficiency has a consistent effect in different pregnancies; thus, we conducted a systematic review and meta-analysis of 24 observational studies, grouping them according to the gestational age at the time of serum sampling, to investigate whether vitamin D deficiency in different periods of gestation has different effects on PTB and to provide an evidence-based basis for pregnant women to measure and supplement vitamin D. METHODS: The databases PubMed-Medline, EMBASE, the Cochrane Library, Web of Science, EBSCO, CBM, and CNKI were searched until February 2020. Two researchers independently assessed the eligibility and quality of studies, and STATA 12.0 software was used for meta-analysis. RESULT: Seven cohort studies, 13 case-control studies, and 4 cross-sectional studies were included from 2500 articles by inclusion and exclusion criteria. After adjusting for age, race, and other confounding factors, meta-analysis results showed that vitamin D deficiency in the first trimester, the second trimester, and the third trimester did not increase the risk of PTB (odds ratio (OR) = 1.01, 95% confidence interval (CI) (0.88, 1.16), P = .867; OR = 1.12, 95%CI (0.92, 1.37), P = .249; OR = 1.05, 95%CI (0.87, 1.27), P = .602). However, there was moderate heterogeneity in the study of vitamin D deficiency in the second trimester, and subgroup analysis suggested that vitamin D deficiency in the second trimester may increase the risk of PTB (OR = 1.33, 95%CI (1.15, 1.54), P = .000). A sensitivity analysis of the second trimester showed that excluding any 1 study did not significantly change the results. CONCLUSIONS: Vitamin D deficiency in early and late pregnancy may not be associated with PTB, while vitamin D deficiency in middle pregnancy is likely to have an important effect on PTB. Vitamin D levels should be measured in the second trimester of pregnancy, and vitamin D supplements should be provided if necessary.

Maternal selenium status plays a crucial role on clinical outcomes of pregnant women with COVID-19 infection.

Adequate maternal selenium level is essential for immune response and healthy pregnancy. This study aimed to shed light on the selenium status of pregnant women with COVID-19 and the effects of potential deficiency in serum selenium levels. Totally 141 pregnant women, 71 of them were COVID-19 patients, in different trimesters were included in the study. Maternal serum selenium levels, demographic and clinical parameters were determined. Serum selenium levels of pregnant women in the second (p: .0003) and third (p: .001) trimesters with COVID-19 were significantly lower than in the healthy group. Maternal selenium level was found to be negatively correlated with gestational week (p < .0001, r: -.541), D-dimer (p: .0002, r: -.363) and interleukin-6 (IL-6) level (p: .02, r: -.243). In the second trimester, serum selenium level positively correlated with white blood cell (p: .002, r: .424), neutrophil (p: .006, r: .39), lymphocyte (p: .004, r: .410) count and hemoglobin (p: .02, r: .323), hematocrit (p: .008, r: .38) status. In the third trimester, it was found that maternal selenium level positively correlated with monocyte (p: .04, r: .353) and negatively correlated with C-reactive protein level (p: .03, r: -.384). Serum selenium level was gradually decreased during the pregnancy period, however, this natural decrease was enhanced together with COVID-19 infection. The reason might be increased selenium needs depended on the immune response against infection. The decrease in maternal selenium level was found to be related to IL-6 and D-dimer levels, which indicate selenium's role in disease progression.

Longitudinal Assessment of Vitamin D Status across Trimesters of Pregnancy.

BACKGROUND: The evolution of vitamin D status across pregnancy trimesters and its association with prepregnancy body mass index (ppBMI; in kg/m2) remain unclear. OBJECTIVES: We aimed to 1) assess trimester-specific serum total 25-hydroxyvitamin D [25(OH)D] concentrations, 2) compare those concentrations between ppBMI categories, and 3) examine associations between 25(OH)D concentrations, ppBMI, and vitamin D intake. METHODS: As part of a prospective cohort study, 79 pregnant women with a mean age of 32.1 y and ppBMI of 25.7 kg/m2 were recruited in their first trimester (average 9.3 weeks of gestation). Each trimester, vitamin D intake was assessed by 3 Web-based 24-h recalls and a Web questionnaire on supplement use. Serum total 25(OH)D was measured by LC-tandem MS. Repeated-measures ANOVA was performed to assess the evolution of 25(OH)D concentrations across trimesters of pregnancy and comparisons of 25(OH)D concentrations between ppBMI categories were assessed by 1-factor ANOVAs. Stepwise regression analyses were used to identify determinants of 25(OH)D concentrations in the third trimester. RESULTS: Mean ± SD serum total 25(OH)D concentrations increased across trimesters, even after adjustments for ppBMI, seasonal variation, and vitamin D intake from supplements (67.5 ± 20.4, 86.5 ± 30.9, and 88.3 ± 29.0 nmol/L at mean ± SD 12.6 ± 0.8, 22.5 ± 0.8, and 33.0 ± 0.6 weeks of gestation, respectively; P < 0.0001). In the first and third trimesters, women with a ppBMI ≥30 had lower serum total 25(OH)D concentrations than women with a ppBMI <25 (P < 0.05); however, most had concentrations >40nmol/L by the second trimester. Vitamin D intake from supplements was the strongest determinant of third-trimester serum total 25(OH)D concentrations (r2 = 0.246, ß = 0.51; P < 0.0001). CONCLUSIONS: There was an increase in serum total 25(OH)D concentrations across trimesters, independent of ppBMI, seasonal variation, and vitamin D intake from supplements. Almost all women had serum total 25(OH)D concentrations over the 40- and 50-nmol/L thresholds, thus our study supports the prenatal use of a multivitamin across pregnancy.

Complex patterns of circulating fatty acid levels in gestational diabetes mellitus subclasses across pregnancy.

BACKGROUND & AIMS: To investigate the relationship between maternal serum fatty acid levels and gestational diabetes mellitus (GDM) subtypes across pregnancy. METHODS: A total of 680 singleton mothers enrolled in the Complex Lipids in Mothers and Babies (CLIMB) study in Chongqing, China were included. Clinical information and serum samples were collected at gestational weeks (GWs) 11-14, 22-28, and 32-34. 75 g Oral Glucose Tolerance Test (OGTT) was conducted at GW 24-28 and GDM subtypes divided into three groups using International Association of Diabetes and Pregnancy Study Group (IADPSG) guidelines criteria: elevated fasting plasma glucose (FPG group; n = 59); 1-h and/or 2-h post-load glucose (1h/2h-PG group; n = 94); combined group (FPG&1h/2h-PG group; n = 42). Non-GDM pregnancies were included (n = 485) as controls. Twenty fatty acids were quantified in serum using gas chromatography-mass spectrometry (GC-MS) analysis. RESULTS: Overall, most serum fatty acid concentrations increased rapidly from the first to second trimester, followed by a plateauing or reduction in the third trimester (p < 0.001). In cross sectional analysis, fatty acid concentrations were significantly higher in the FPG group at GW 11-14 and decreased in the 1h/2h-PG group at GW 32-34, relative to controls. Moreover, higher α-linolenic acid (ALA; the second tertile: adjusted odds ratio [aOR] = 2.53, 95% CI: 1.17 to 5.47; the third tertile: aOR = 2.60, 95% CI: 1.20 to 5.65) and docosahexaenoic acid (DHA; the second tertile: aOR = 2.34, 95% CI: 1.10 to 4.97; the third tertile: aOR = 2.16, 95% CI: 1.00 to 4.63) were significantly associated with a higher risk of GDM in women with elevated fasting plasma glucose at GW 11-14 (first tertile as reference). CONCLUSIONS: Our findings highlight the importance of considering GDM subtypes for the individualised management of GDM in pregnancy. ALA and DHA in early pregnancy are associated with a higher risk of FPG-GDM subtype. This has widespread implications when recommending n-3 PUFAs supplementation for women with GDM.

Long-Chain Polyunsaturated Fatty Acid Concentrations and Association with Weight Gain in Pregnancy.

Lower concentrations of omega-3 (ω-3) and higher concentrations of omega-6 (ω-6) have been associated with excess weight in adults; however, the information on this relationship in pregnancy remains in its infancy. This study aimed to investigate the association between plasma levels of ω-3 and ω-6 long-chain polyunsaturated fatty acids (PUFAs) and weight gain during the gestational period. This is a prospective cohort study involving 185 pregnant women registered with the prenatal services of a municipality in the northeast of Brazil. The dosage of the serum concentration of fatty acids and the anthropometric measurements were carried out at the baseline, and the women's weight information in the first, second, and third trimesters was collected from their pregnancy cards. Serum fatty acids were determined with the help of gas chromatography. The response variable of this study is the latent variable weight gain in pregnancy, derived from three variables: gestational weight in the first, second, and third trimesters. The main exposure was the plasma concentrations of PUFAs. Structural equation modeling was used for the data analysis. The mean age of the pregnant women was 26.74 years old (SD: 5.96 years). Most of the women had not completed high school (84%) and had a low income (70.86%). It was observed that the ω-3 PUFAs, represented by ALA plasm (alpha-linolenic acid), DHA (docosahexaenoic acid), and the EPA/ALA ratio (eicosapentaenoic acid to alpha-linolenic acid ratio), were negatively associated with the weight gain during pregnancy construct (-0.20, -0.12, and -0.14, respectively). Meanwhile, the PUFAs represented by the ratio between the ω-6 category acids ARA and LA (arachidonic acid and linoleic acid) had a direct and positive association (0.22) with that construct. Excess maternal weight gain was associated with ω-3 and ω-6 plasma levels. The women with the greatest gestational weight gain were the ones that presented the highest ARA/LA ratio (ω-6) and the lowest plasma concentrations of ALA, DHA, and EPA/ALA ratio (ω-3).

Effects of iodine supplementation during pregnancy on pregnant women and their offspring: a systematic review and meta-analysis of trials over the past 3 decades.

OBJECTIVE: The current systematic review aimed to provide comprehensive data on the effects of iodine supplementation in pregnancy and investigate its potential benefits on infant growth parameters and neurocognitive development using meta-analysis. METHODS: A systematic review was conducted on trials published from January 1989 to December 2019 by searching MEDLINE, Web of Science, the Cochrane Library, Scopus, and Google Scholar. For most maternal and neonatal outcomes, a narrative synthesis of the data was performed. For birth anthropometric measurements and infant neurocognitive outcomes, the pooled standardized mean differences (SMDs) with 95% CIs were estimated using fixed/random effect models. RESULTS: Fourteen trials were eligible for inclusion in the systematic review, of which five trials were included in the meta-analysis. Although the findings of different thyroid parameters are inconclusive, more consistent evidence showed that iodine supplementation could prevent the increase in thyroglobulin concentration during pregnancy. In the meta-analysis, no differences were found in weight (-0.11 (95% CI: -0.23 to 0.01)), length (-0.06 (95% CI: -0.21 to 0.09)), and head circumference (0.26 (95% CI: -0.35 to 0.88)) at birth, or in cognitive (0.07 (95% CI: -0.07 to 0.20)), language (0.06 (95% CI: -0.22 to 0.35)), and motor (0.07 (95% CI: -0.06 to 0.21)) development during the first 2 years of life in infants between the iodine-supplemented and control groups. CONCLUSION: Iodine supplementation during pregnancy can improve the iodine status in pregnant women and their offspring; however, according to our meta-analysis, there was no evidence of improved growth or neurodevelopmental outcomes in infants of iodine-supplemented mothers.

Prevalence of inadequate and excessive iodine intake in a US pregnancy cohort.

BACKGROUND: US iodine intake, estimated from the median urinary iodine concentration of population representative data, has declined by half since the 1970s, which is problematic because maternal iodine intake is critical for fetal neurodevelopment. Relying on median urinary concentrations to assess iodine intake of populations is standard practice but does not describe the number of individuals with insufficient intake. Prevalence estimates of inadequate and excessive intake are better for informing public health applications but require multiple urine samples per person; such estimates have been generated in pediatric populations but not yet among pregnant women. OBJECTIVE: Our aims were as follows: (1) to assess median urinary iodine concentrations across pregnancy for comparison with national data and (2) to estimate the prevalence of inadequate and excessive iodine intake among pregnant women in mid-Michigan. STUDY DESIGN: Data were collected from 2008 to 2015 as part of a prospective pregnancy cohort in which women were enrolled at their first prenatal clinic visit. Few exclusion criteria (<18 years or non-English speaking) resulted in a sample of women generally representative of the local community, unselected for any specific health conditions. Urine specimens were obtained as close as practicable to at least 1 specimen per trimester during routine prenatal care throughout pregnancy (n=1-6 specimens per woman) and stored at -80°C until urinary iodine was measured to estimate the iodine intake (n=1014 specimens from 464 women). We assessed urinary iodine across pregnancy by each gestational week of pregnancy and by trimester. We used multiple urine specimens per woman, accounted for within-person variability, performed data transformation to approximate normality, and estimated the prevalence of inadequate and excessive iodine intake using a method commonly employed for assessment of nutrient status. RESULTS: Maternal characteristics reflected the local population in racial and ethnic diversity and socioeconomic status as follows: 53% non-Hispanic white, 22% non-Hispanic black, and 16% Hispanic; 48% had less than or equal to high school education and 71% had an annual income of <$25,000. Median urinary iodine concentrations in the first, second, and third trimester-including some women contributing more than 1 specimen per trimester-were 171 µg/L (n=305 specimens), 181 µg/L (n=366 specimens), and 179 µg/L (n=343 specimens), respectively, with no significant difference by trimester (P=.50, Kruskal-Wallis test for equality of medians). The estimated prevalence of inadequate and excessive iodine intake was 23% and <1%, respectively. CONCLUSION: Median urinary iodine concentrations in each trimester were above the World Health Organization cutoff of 150 µg/L, indicating iodine sufficiency at the group level across pregnancy. However, the estimated prevalence of inadequate iodine intake was substantial at 23%, whereas prevalence of excessive intake was <1%, indicating a need for at least some women to increase consumption of iodine during pregnancy. The American Thyroid Association, the Endocrine Society, and the American Academy of Pediatrics recommend that all pregnant and lactating women receive a daily multivitamin or mineral supplement that contains 150 µg of iodine. The data presented here should encourage the collection of similar data from additional US population samples for the purpose of informing the American College of Obstetricians and Gynecologists' own potential recommendations for prenatal iodine supplementation.

Effect of early and late prenatal vitamin D and maternal asthma status on offspring asthma or recurrent wheeze.

BACKGROUND: Childhood asthma developmental programming is complex. Maternal asthma is a strong risk factor for childhood asthma, whereas vitamin D (VD) has emerged as a modifiable prenatal exposure. OBJECTIVE: Our aim was to examine the combined effect of early and late prenatal VD status in during pregnancies in women with and without asthma on childhood asthma or recurrent wheeze development. METHODS: We conducted a cohort study using prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial, a randomized, double-blinded, placebo-controlled VD supplementation trial in pregnant women at high risk of offspring asthma (N = 806 mother-offspring pairs). 25-Hydroxyvitamin-D (25(OH)D) level was measured in early and late pregnancy. Our main exposure was an ordered variable representing early and late prenatal VD sufficiency (25(OH)D level ≥ 30 ng/mL) status during pregnancy in women with and without asthma. The primary outcome was offspring with asthma or recurrent wheeze by age 3 years. We also examined the effect of prenatal VD level on early life asthma or recurrent wheeze progression to active asthma at age 6 years. RESULTS: Among mothers with asthma versus among mothers with early and late prenatal VD insufficiency, those with early or late VD sufficiency (adjusted odds ratio = 0.56; 95% CI = 0.31-1.00) or early and late VD sufficiency (adjusted odds ratio = 0.36; 95% CI = 0.15-0.81) had a lower risk of offspring with asthma or recurrent wheeze by age 3 years (Pfor trend = .008). This protective trend was reiterated in asthma or recurrent wheeze progression to active asthma from age 3 to 6 years (Pfor trend = .04). CONCLUSION: This study implies a protective role for VD sufficiency throughout pregnancy, particularly in attenuating the risk conferred by maternal asthma on childhood asthma or recurrent wheeze development.

Weight loss prior to pregnancy and subsequent gestational weight gain: Prepare, a randomized clinical trial.

BACKGROUND: Women with elevated body mass index are encouraged to lose weight before pregnancy, but no trials have tested the effects of prepregnancy weight loss on health outcomes. OBJECTIVE: This study aimed to determine whether prepregnancy weight loss reduces gestational weight gain and improves pregnancy outcomes. STUDY DESIGN: Pragmatic randomized clinical trial was conducted between May 2015 and October 2019 at Kaiser Permanente Northwest, an integrated health system. Data collection was blind to condition assignment. Eligible participants were women aged 18 to 40 years with a body mass index of ≥27 kg/m2 who were planning pregnancy within 2 years. Recruitment contacts were sent to 27,665 health system members who met age and body mass index criteria; 329 women attended screening visits, and 326 were randomized. They were randomized to either a behavioral weight loss intervention or usual care control. The intervention consisted of health coaching phone sessions weekly for 6 months and then monthly for 18 months or until end of pregnancy. We used logistic regression to examine the a priori primary hypothesis that participants in the intervention would be less likely to exceed National Academy of Medicine guidelines for gestational weight gain during each trimester and overall. Secondary and exploratory outcomes included absolute weight gain before and during pregnancy and perinatal and newborn outcomes. RESULTS: Of the 326 participants, 169 had singleton pregnancies lasting ≥14 weeks (analytical cohort: intervention, 89; control, 80). At baseline, mean age was 31.3±3.5 years, and body mass index was 34.8±5.8 kg/m2. Participants in the intervention group lost more weight before pregnancy than those in the control group (-0.25±0.51 vs -0.03±0.21 kg/wk; P<.001). However, participants in the intervention group gained more weight than those in the control group in the second trimester (0.42±0.26 vs 0.33±0.28 kg/wk; P=.04) and third trimester (0.56±0.37 vs 0.43±0.33 kg/wk; P=.02) and overall (13.2±8.20 vs 10.3±7.41 kg; P=.03). Nevertheless, arms did not differ in rates of exceeding gestational weight gain guidelines at any time point. Spontaneous pregnancy loss was less common in the intervention arm than in the control arm (8 [4.9%] vs 19 [11.8%]; odds ratio, 0.39 [0.16-0.92]), but we found no other differences in the secondary or exploratory outcomes. CONCLUSION: Participation in the prepregnancy weight loss intervention had no effect on women's likelihood of exceeding gestational weight gain guidelines. Although the intervention group successfully lost weight before conception, the intervention group was associated with greater weight gain in late pregnancy. To effectively reduce weight throughout pregnancy and improve maternal and child outcomes, prepregnancy weight loss interventions may need to be combined with intensive weight management that continues throughout delivery.

Effects of vitamin D supplementation on circulating concentrations of growth factors and immune-mediators in healthy women during pregnancy.

BACKGROUND: For the second aim of the Kellogg Foundation grant, this double-blind RCT investigated the impact of plasma vitamin D metabolite 25-hydroxyvitamin D (25(OH)D) on plasma immune-mediators during pregnancy. We hypothesized that higher 25(OH)D concentrations would associate with reduced pro-inflammatory and increased tolerogenic immune-mediator concentrations. METHODS: Pregnant women enrolled at 10-14 weeks gestation were randomized to 400 or 4400 IU vitamin D3/day. Data on health, safety, circulating 25(OH)D, and 9 immune-mediators were collected at each trimester. Associations between immune-mediators and 25(OH)D at baseline and at second and third trimesters were examined. RESULTS: Baseline TGF-ß and second and third trimesters IFN-γ and IL-2 were associated with baseline 25(OH)D. Baseline immune-mediators were associated with immune-mediators at second and third trimesters for all immune-mediators except IL-5 and IL-10. Race was associated with baseline TGF-ß, VEGF and IL-10 and with IL-10 at second and third trimesters. CONCLUSIONS: Both treatment groups had increased 25(OH)D at second and third trimesters, greatest in the 4400 IU group. Though associations between baseline 25(OH)D and baseline TGF-ß and second and third trimester IFN-γ and IL-2 were noted, vitamin D supplementation throughout pregnancy did not impact immune-mediators at later trimesters. Supplementing with vitamin D before conception conceivably influences immune-mediator responses during pregnancy. IMPACT: In this vitamin D supplementation clinical trial, baseline (first trimester) but not increasing plasma 25(OH)D concentration impacted select plasma immune-mediator profiles in pregnant women. Baseline 25(OH)D was associated with baseline TGF-ß and with IFN-γ and IL-2 at second and third trimesters. Baseline IFN-γ, CRP, TGF-ß, TNF-α, VEGF, IL-2, and IL-4 were associated with concentrations at second and third trimesters for respective immune-mediators; however, 25(OH)D concentration at second and third trimesters were not. Some racial differences existed in immune-mediator concentrations at baseline and at second and third trimesters. This study assesses the impact of vitamin D supplementation on multiple immune-mediators in pregnant women of different racial/ethnic groups using longitudinal data from a relatively large randomized controlled trial. This study found that race was associated with baseline TGF-ß, VEGF, and IL-10 and with IL-10 at second and third trimesters, a novel finding that sheds light where relationships were less well defined. The results of this study suggest that vitamin D supplementation before conception or early in pregnancy, rather than during pregnancy, may be necessary to significantly impact immune-mediator response. This study sets premise for future clinical trials to evaluate the effect of vitamin D supplementation before conception or prior to pregnancy.