Trajectory of vitamin D status during pregnancy in relation to neonatal birth size and fetal survival: a prospective cohort study

Autophagy Proteins and clinical data reveal the prognosis of polycystic ovary syndrome

OBJECTIVE

We aimed to investigate the significance of autophagy proteins and their association with clinical data on pregnancy loss in polycystic ovary syndrome (PCOS), while also constructing predictive models.

METHODS

This study was a secondary analysis. we collected endometrial samples from 33 patients with polycystic ovary syndrome (PCOS) and 7 patients with successful pregnancy control women at the Reproductive Center of the Second Hospital of Lanzhou University between September 2019 and September 2020. Liquid chromatography tandem mass spectrometry was employed to identify expressed proteins in the endometrium of 40 patients. R was use to identify differential expression proteins(DEPs). Subsequently, Metascape was utilized for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Multivariate Cox analysis was performed to analyze autophagy proteins associated with reproductive outcomes, while logistic regression was used for analyzing clinical data. Linear correlation analysis was conducted to examine the relationship between autophagy proteins and clinical data. We established prognostic models and constructed the nomograms based on proteome data and clinical data respectively. The performance of the prognostic model was evaluated by the receiver operating characteristic curve (ROC) and decision curve analysis (DCA).

RESULTS

A total of 5331 proteins were identified, with 450 proteins exhibiting significant differential expression between the PCOS and control groups. A prognostic model for autophagy protein was developed based on three autophagy proteins (ARSA, ITGB1, and GABARAPL2). Additionally, another prognostic model for clinical data was established using insulin, TSH, TPOAB, and VD3. Our findings revealed a significant positive correlation between insulin and ARSA (R = 0.49), as well as ITGB1 (R = 0.3). Conversely, TSH exhibited a negative correlation with both ARSA (-0.33) and ITGB1 (R = -0.26).

CONCLUSION

Our research could effectively predict the occurrence of pregnancy loss in PCOS patients and provide a basis for subsequent research.

Vitamin D Intake and Serum Levels in Pregnant and Postpartum Women

Maternal vitamin D deficiency, which is highly prevalent in pregnant women in Europe, is linked to adverse health effects for both the mother and child. The objective was to assess vitamin D status in pregnant women by evaluating their dietary and supplemental vitamin D intake, serum vitamin D levels, parathyroid hormone levels, and lifestyle factors. This cross-sectional study, with a total of 735 participants (145 pregnant and 590 up to the seventh day postpartum), took place in Latvia. Blood samples, a food frequency questionnaire, and medical documentation were used for data collection. The median serum vitamin D concentration was 34.0 ng/mL, with pregnant women having higher levels (42.9 ng/mL) than postpartum women (31.8 ng/mL). There was no association between vitamin D serum concentration and dietary intake of vitamin D (p > 0.05), whereas there was a significant correlation with use of vitamin D supplements (r = 0.41; p < 0.001 in pregnant women and r = 0.35; p < 0.001 in postpartum women). This study demonstrated that a minority of pregnant women (21.9%) had optimal serum vitamin D concentration (>45 ng/mL), and diet had no significant impact on vitamin D levels. Thus, our proposed recommendation for vitamin D intake during pregnancy was 63 mcg (2500 IU) year-round for optimal levels in pregnant women in Northeastern Europe.

Is there a relation between stillbirth and low levels of vitamin D in the population? A bi-national follow-up study of vitamin D fortification

BACKGROUND

Stillbirth has been associated with low plasma vitamin D. Both Sweden and Finland have a high proportion of low plasma vitamin D levels (< 50 nmol/L). We aimed to assess the odds of stillbirth in relation to changes in national vitamin D fortification.

METHODS

We surveyed all pregnancies in Finland between 1994 and 2021 (n = 1,569,739) and Sweden (n = 2,800,730) with live or stillbirth registered in the Medical Birth Registries. The mean incidences before and after changes in the vitamin D food fortification programs in Finland (2003 and 2009) and Sweden (2018) were compared with cross-tabulation with 95% confidence intervals (CI).

RESULTS

In Finland, the stillbirth rate declined from ~ 4.1/1000 prior to 2003, to 3.4/1000 between 2004 and 2009 (odds ratio [OR] 0.87, 95% CI 0.81-0.93), and to 2.8/1000 after 2010 (OR 0.84, 95% CI 0.78-0.91). In Sweden, the stillbirth rate decreased from 3.9/1000 between 2008 and 2017 to 3.2/1000 after 2018 (OR 0.83, 95% CI 0.78-0.89). When the level of the dose-dependent difference in Finland in a large sample with correct temporal associations decreased, it remained steady in Sweden, and vice versa, indicating that the effect may be due to vitamin D. These are observational findings that may not be causal.

CONCLUSION

Each increment of vitamin D fortification was associated with a 15% drop in stillbirths on a national level. If true, and if fortification reaches the entire population, it may represent a milestone in preventing stillbirths and reducing health inequalities.

A Modern Look at the Development of Intrauterine Pneumonia in Premature Newborns: Literature Review

Infectious diseases such as malaria, pneumonia, diarrhea and preventable neonatal diseases are common causes of death in children. Globally, neonatal mortality is 44% (2.9 million) annually, with up to 50% of babies dying within the first day of life. Pneumonia kills between 750000 and 1.2 million infants in the neonatal period each year in developing countries. Premature birth, pneumonia, and labor complications are common causes of neonatal mortality. The objective of the study is to present the general characteristics of congenital pneumonia, vitamin D deficiency and micronutrient deficiencies in premature infants. To date, numerous studies confirm the relationship between the inadequate supply of the body with macro- and microelements and the development of diseases of varying severity, including metabolic disorders. Based on this, primary screening, aimed at identifying metabolic disorders of macro- and microelements and further drug correction, should become the main concept for the management of patients in modern times.

Relationship between Maternal Vitamin D Levels and Adverse Outcomes

Vitamin D (VD), a fat-soluble vitamin, has a variety of functions that are important for growth and development, including regulation of cell differentiation and apoptosis, immune system development, and brain development. As such, VD status during pregnancy is critical for maternal health, fetal skeletal growth, and optimal pregnancy outcomes. Studies have confirmed that adverse pregnancy outcomes, such as preeclampsia, low birth weight, neonatal hypocalcemia, poor postnatal growth, skeletal fragility, and increased incidence of autoimmune diseases, can be associated with low VD levels during pregnancy and infancy. Thus, there is growing interest in the role of VD during pregnancy. This review summarizes the potential adverse health outcomes of maternal VD status during pregnancy for both mother and offspring (gestational diabetes mellitus, hypertensive gestational hypertension, intrauterine growth restriction, miscarriage, stillbirth, and preterm birth) and discusses the underlying mechanisms (regulation of cytokine pathways, immune system processing, internal secretion, placental function, etc.) of VD in regulating each of the outcomes. This review aims to provide a basis for public health intervention strategies to reduce the incidence of adverse pregnancies.

Blood metals and vitamin D status in a pregnancy cohort: A bidirectional biomarker analysis

Low 25-hydroxyvitamin D (25OHD), a biomarker of vitamin D status, is associated with reduced immune function and adverse pregnancy outcomes, such as preterm birth. Observational studies indicate that long-term, high level exposure to metals such as cadmium (Cd) and lead (Pb) can impact a person's vitamin D status. However, the directionality of the association is uncertain, particularly for low-level exposures. We used three distinct longitudinal data analysis methods to investigate cross-sectional, longitudinal and bidirectional relationships of Cd and Pb biomarkers with 25-hydroxyvitamin D (25OHD) in a Canadian pregnancy cohort. Maternal whole blood Cd and Pb and plasma 25OHD concentrations were measured in the 1st (n = 1905) and 3rd (n = 1649) trimester and at delivery (25OHD only, n = 1542). Our multivariable linear regression analysis showed weak inverse associations between Cd and 25OHD concentrations cross-sectionally and longitudinally while the latent growth curve models showed weak associations with Pb on the 25OHD intercept. In the bidirectional analysis, using cross lagged panel models, we found no association between 1st trimester metals and 3rd trimester 25OHD. Instead, 1st trimester 25OHD was associated with 9% (-15%, -3%) lower 3rd trimester Cd and 3% (-7, 0.1%) lower Pb. These findings suggest the 25OHD may modify metal concentrations in pregnancy and demonstrates the value of controlling for contemporaneous effects and the persistence of a biomarker over time, in order to rule out reverse causation.

The Gestational Effects of Maternal Bone Marker Molecules on Fetal Growth, Metabolism and Long-Term Metabolic Health: A Systematic Review

Fetal exposure in adverse environmental factors during intrauterine life can lead to various biological adjustments, affecting not only in utero development of the conceptus, but also its later metabolic and endocrine wellbeing. During human gestation, maternal bone turnover increases, as reflected by molecules involved in bone metabolism, such as vitamin D, osteocalcin, sclerostin, sRANKL, and osteoprotegerin; however, recent studies support their emerging role in endocrine functions and glucose homeostasis regulation. Herein, we sought to systematically review current knowledge on the effects of aforementioned maternal bone biomarkers during pregnancy on fetal intrauterine growth and metabolism, neonatal anthropometric measures at birth, as well as on future endocrine and metabolic wellbeing of the offspring. A growing body of literature converges on the view that maternal bone turnover is likely implicated in fetal growth, and at least to some extent, in neonatal and childhood body composition and metabolic wellbeing. Maternal sclerostin and sRANKL are positively linked with fetal abdominal circumference and subcutaneous fat deposition, contributing to greater birthweights. Vitamin D deficiency correlates with lower birthweights, while research is still needed on intrauterine fetal metabolism, as well as on vitamin D dosing supplementation during pregnancy, to diminish the risks of low birthweight or SGA neonates in high-risk populations.

Comparative Study of the Effects of Two Dietary Sources of Vitamin D on the Bone Metabolism, Welfare and Birth Progress of Sows Fed Protein- and Phosphorus-Reduced Diets

To investigate the influence of two dietary sources of vitamin D on the vitamin D status, bone metabolism, welfare and birth progress of gestating and lactating sows, forty-nine multiparous sows were randomly assigned to one of two diets: “CON” (n = 25; 50 μg vitamin D3/kg feed) and “HYD” (n = 24; 50 μg 25-hydroxycholecalciferol/kg feed). The basal diets were protein- and phosphorus-reduced. The trial started on day 3 ante insemination of the sows and ended with weaning of the piglets on day 28 postpartum. Dietary supplementation of 25-hydroxycholecalciferol resulted in improved maternal vitamin D status (p < 0.001), fewer gait changes (p < 0.01) and longer standing time after feeding (day 5 ante partum; p < 0.05) compared to vitamin D3. However, the bone markers CrossLaps and osteocalcin were not affected. Overall, the present results suggest that sows fed 25-hydroxycholecalciferol instead of vitamin D3 showed improved locomotion and stance strength. However, this outcome is probably not related to altered bone metabolism. The underlying mechanisms must be investigated in further studies.

Effect of maternal vitamin D status on risk of adverse birth outcomes: a systematic review and dose-response meta-analysis of observational studies

PURPOSE

Accumulating evidence suggests that vitamin D deficiency increases the risk of adverse perinatal outcomes. However, the dose-response relationship between maternal vitamin D status and adverse birth outcomes remains unclear. Focusing on prospective observational studies, we aimed to explore the dose-response relationship of vitamin D status with the risk of low birth weight (LBW), macrosomia (MA), preterm birth (PTB), small for gestational age (SGA), and intrauterine growth restriction (IUGR).

METHODS

Databases including PubMed, Embase, Scopus, and Web of Science were used up to 19 January 2021 to search for observational studies that fulfilled criteria as follows: cohort studies, case-cohort studies, or nested case-control studies. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs) in the observational studies.

RESULTS

A total of 72 publications were included in this systematic review and 71 in the meta-analysis. Maternal 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with the risk of LBW (RR: 0.65; 95% CI 0.48-0.86), PTB (RR: 0.67; 95% CI 0.57-0.79), and SGA (RR: 0.61; 95% CI 0.49-0.76) in the highest versus lowest meta-analysis, but not associated with MA and IUGR. Linear dose-response analysis showed that each 25 nmol/L increase in 25(OH)D was associated with a 6% and 10% reduction in the risk of PTB (RR: 0.94; 95% CI 0.90-0.98) and SGA (RR: 0.90; 95% CI 0.84-0.97), respectively.

CONCLUSION

Our study suggests that a sufficient vitamin D status during pregnancy is protective against the risk of LBW, PTB, and SGA.

Interactive Effects of Maternal Vitamin D Status and Socio-Economic Status on the Risk of Spontaneous Abortion: Evidence from Henan Province, China

Background: Maternal vitamin D deficiency might generate adverse reproductive outcomes, and socio-economic inequalities in micronutrient-related diseases have often been found. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Methods: A population-based case–control study was conducted including 293 women with spontaneous abortion and 498 control women in December 2009 and January, 2010 in Henan Province, China. Information on pregnancy outcomes, maternal demographic, lifestyle and exposure factors and blood samples were collected at the same time. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. SES index was constructed with principal component analysis by aggregating women’s and their husbands’ education level and occupation, and household income and expenditure. Interactive effects were assessed on a multiplicative scale with ratio of the odds ratio (ROR). Results: Compared to those with high SES and vitamin D sufficiency, women with vitamin D deficiency and low SES index had an increased risk of spontaneous abortion (aOR: 1.99; 95% CI: 1.23–3.23). The ROR was 2.06 (95% CI: 1.04–4.10), indicating a significant positive multiplicative interaction. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population.

Maternal and Neonatal 3-epi-25-hydroxyvitamin D Concentration and Factors Influencing Their Concentrations

BACKGROUND

Little is known about the presence of 3-epi-25 hydroxyvitamin D in maternal and neonatal circulation, the extent of its contribution to total 25 hydroxyvitamin D, or factors influencing its levels.

METHODS

A total of 1502 and 1321 archived maternal and umbilical cord serum samples from the Hyperglycemia and Adverse Pregnancy Outcome Study cohort from Hong Kong were assayed for 25(OH)D2, 25(OH)D3, and isomeric form of 25(OH)D3 (3-epi-25(OH)D3) by a liquid chromatography-tandem mass spectrometry method.

RESULTS

Vitamin D deficiency (total serum 25(OH)D level < 50 nmol/L) and severe vitamin D deficiency (total serum 25(OH)D level < 25 nmol/L) occurred in 590 (39.3%) and 25 (1.7%) mothers, respectively. 3-epi-25(OH)D3 could be detected in 94.5% of maternal and 92.1% of neonatal umbilical sera, with the highest 3-epi-25(OH)D3 levels contributing to 19.9% and 15.3% of the maternal and umbilical cord sera 25(OH)D3 levels, respectively. Pregnancy with a male fetus, ambient solar radiation, and maternal glycemia and 25(OH)D3 levels were independent factors associated with maternal 3-epi-25(OH)D3 level. Advanced maternal age, multiparity, maternal gestational weight gain below the Institute of Medicine recommendation, maternal glycemic status, and earlier gestational age at delivery were significantly associated with higher umbilical cord serum 3-epi-25(OH)D3.

CONCLUSIONS

3-epi-25(OH)D3 accounted for a significant portion of total 25(OH)D in maternal and neonatal circulations. Further study is needed to determine the possible mechanism underlying this observation.

Utility of umbilical cord blood 25-hydroxyvitamin D levels for predicting bronchopulmonary dysplasia in preterm infants with very low and extremely low birth weight

BACKGROUND AND OBJECTIVE

There remains controversy regarding vitamin D deficiency and bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) and extremely low birth weight (ELBW) preterm infants. This study aimed to determine the prevalence of vitamin D deficiency assessed by umbilical cord blood 25-hydroxyvitamin D [25(OH)D] in preterm infants in northeast China and to evaluate the ability and optimal threshold of 25(OH)D for predicting BPD.

METHODS

The clinical data of VLBW and ELBW preterm infants with known cord-blood 25(OH)D levels were analyzed retrospectively. Infants were divided into groups based on their cord-blood 25(OH)D levels and BPD diagnosis. Logistic regression was performed to assess the risk factors for BPD and a nomogram was established. Receiver operating characteristic (ROC) curve analysis was used to evaluate the optimal threshold of cord-blood 25(OH)D concentration for predicting BPD.

RESULTS

A total of 267 preterm infants were included, of which 225 (84.3%) exhibited vitamin D deficiency and 134 (50.2%) were diagnosed with BPD. The incidence of BPD was lower in the group with a 25(OH)D level of >20 ng/ml than in the other groups (P = 0.024). Infants with BPD had lower cord-blood 25(OH)D levels than those without BPD (11.6 vs. 13.6 ng/ml, P = 0.016). The multivariate logistic regression model revealed that 25(OH)D levels (odds ratio [OR] = 0.933, 95% confidence interval [95% CI]: 0.891-0.977), gestational age (OR = 0.561, 95% CI: 0.425-0.740), respiratory distress syndrome (OR = 2.989, 95% CI: 1.455-6.142), and pneumonia (OR = 2.546, 95% CI: 1.398-4.639) were independent risk factors for BPD. A predictive nomogram containing these four risk factors was established, which had a C-index of 0.814. ROC curve analysis revealed that the optimal cutoff value of 25(OH)D for predicting BPD was 15.7 ng/ml (area under the curve = 0.585, 95% CI: 0.523-0.645, P = 0.016), with a sensitivity of 75.4% and a specificity of 42.9%.

CONCLUSIONS

A cord-blood 25(OH)D level of <15.7 ng/ml was predictively valuable for the development of BPD. The nomogram established in this study can help pediatricians predict the risk of BPD more effectively and easily.

Vitamin D supplementation during pregnancy: an overview

PURPOSE OF REVIEW

Examine recent evidence of randomized controlled trials and meta-analyses regarding the effect of maternal vitamin D status and supplementation over obstetrical and offspring outcomes.

RECENT FINDINGS

Maternal serum 25-hydroxyvitamin [25(OH)D] progressively declines during pregnancy because of fetal physiological demands and adjustments. Vitamin D supplementation during pregnancy in women with low vitamin D status may improve fetal growth and reduce the risks for small-for-gestational-age, preeclampsia, preterm birth, and gestational diabetes. Mothers with sufficient vitamin D levels have offsprings with less enamel defects and less attention deficit and hyperactive disorders and autism. All pregnant women should be supplemented with 600 IU/day of vitamin D3. We discuss evidence indicating that higher vitamin D doses (1000-4000 IU/day) may be convenient to achieve better maternal and infant outcomes. Low maternal vitamin D status during pregnancy may be associated in infants with a higher risk for lower bone mineral content, enamel defects and attention deficit hyperactive disorder.

SUMMARY

Recent evidence from vitamin D intervention studies and meta-analyses of a large number of studies support vitamin D supplementation during pregnancy to improve maternal, fetal and, immediate and later offspring health.

Large retrospective cohort study of the association between maternal 25-hydroxyvitamin D status and birth weight of neonate

BACKGROUND

The effect of maternal vitamin D levels on the birth weight of the offspring remains controversial, as the results are inconsistent between different populations. This large retrospective cohort study aimed to assess the relationship between maternal vitamin D levels and birth weight of neonates in southern China.

METHODS

Serum samples were collected from 10,586 Chinese women at 13-27 weeks of pregnancy, and the 25-hydroxyvitamin D (25(OH)D) level of the participants was assessed. Using the INTERGROWTH-21st standards, the offspring were classified into three groups based on their gestational age and birth weight, which were small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). The differences in vitamin D levels among the different groups were compared, and their correlation with newborn birth weight was analyzed.

RESULTS

The average maternal vitamin D concentration was 61.1 nmol/L. The 25(OH)D concentrations were 50-75 nmol/L, 25-50 nmol/L and below 25 nmol/L in 45.5%, 29.5%, and 1.6% of the participants, respectively. No significant differences were observed in the vitamin D levels between the three groups. With the increase in 25(OH)D levels, the risk of SGA and LGA tended to increase and decrease, respectively. AGA was not affected by the 25(OH)D levels. The results of the curve fitting and threshold effect analyses did not support the correlation between vitamin D levels and SGA or LGA. Based on the univariate prediction model and the model adjusted for risk factors, the area under the curve was extremely small. Thus, 25(OH)D levels are not an effective predictor of SGA and LGA.

CONCLUSIONS

Low maternal vitamin D levels were not associated with SGA or LGA.

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.

Late Pregnancy Vitamin D Deficiency is Associated with Doubled Odds of Birth Asphyxia and Emergency Caesarean Section: A Prospective Cohort Study

Objectives

The aim of this prospective cohort study was to investigate the associations between maternal vitamin D status in late pregnancy and emergency caesarean section (EMCS) and birth asphyxia, in a population based sample of women in Sweden.

Methods

Pregnant women were recruited at the antenatal care in Sweden and 1832 women were included after exclusion of miscarriages, terminated pregnancies and missing data on vitamin D status. Mode of delivery was retrieved from medical records. EMCS was defined as caesarean section after onset of labour. Birth asphyxia was defined as either 5 min Apgar score < 7 or arterial umbilical cord pH < 7.1. Serum was sampled in the third trimester of pregnancy (T3) and 25-hydroxyvitamin D (25OHD) was analysed by liquid chromatography tandem mass spectrometry. Vitamin D deficiency was defined as 25OHD < 30 nmol/L, and associations were studied using logistic regression analysis and expressed as adjusted odds ratios (AOR).

Results

In total, 141 (7.7%) women had an EMCS and 58 (3.2%) children were born with birth asphyxia. Vitamin D deficiency was only associated with higher odds of EMCS in women without epidural anaesthesia (AOR = 2.01, p = 0.044). Vitamin D deficiency was also associated with higher odds of birth asphyxia (AOR = 2.22, p = 0.044).

Conclusions for Practice

In this Swedish prospective population-based cohort study, vitamin D deficiency in late pregnancy was associated with doubled odds of birth asphyxia and with EMCS in deliveries not aided by epidural anaesthesia. Prevention of vitamin D deficiency among pregnant women may reduce the incidence of EMCS and birth asphyxia. The mechanism behind the findings require further investigation.

Development of a pregnancy-specific reference material for thyroid biomarkers, vitamin D, and nutritional trace elements in serum

OBJECTIVES

Matrix differences among serum samples from non-pregnant and pregnant patients could bias measurements. Standard Reference Material 1949, Frozen Human Prenatal Serum, was developed to provide a quality assurance material for the measurement of hormones and nutritional elements throughout pregnancy.

METHODS

Serum from non-pregnant women and women in each trimester were bottled into four levels based on pregnancy status and trimester. Liquid chromatography tandem mass spectrometry (LC-MS/MS) methods were developed and applied to the measurement of thyroid hormones, vitamin D metabolites, and vitamin D-binding protein (VDBP). Copper, selenium, and zinc measurements were conducted by inductively coupled plasma dynamic reaction cell MS. Thyroid stimulating hormone (TSH), thyroglobulin (Tg), and thyroglobulin antibody concentrations were analyzed using immunoassays and LC-MS/MS (Tg only).

RESULTS

Certified values for thyroxine and triiodothyronine, reference values for vitamin D metabolites, VDBP, selenium, copper, and zinc, and information values for reverse triiodothyronine, TSH, Tg, and Tg antibodies were assigned. Significant differences in serum concentrations were evident for all analytes across the four levels (p≤0.003). TSH measurements were significantly different (p<0.0001) among research-only immunoassays. Tg concentrations were elevated in research-only immunoassays vs. Federal Drug Administration-approved automated immunoassay and LC-MS/MS. Presence of Tg antibodies increased differences between automated immunoassay and LC-MS/MS.

CONCLUSIONS

The analyte concentrations' changes consistent with the literature and the demonstration of matrix interferences in immunoassay Tg measurements indicate the functionality of this material by providing a relevant matrix-matched reference material for the different stages of pregnancy.

First trimester maternal vitamin D, ferritin, hemoglobin level and their associations with neonatal birthweight: Result from cohort study on vitamin D status and its impact during pregnancy and childhood in Indonesia

INTRODUCTION

Vitamin D deficiency and anemia are examples of nutritional problems of global health significance. When these health issues effect pregnant women, they may become a threat to the fetus' potention for intrauterine growth. It has been known that the first trimester is the golden period of fetal programming which influences the fetuses and their life after birth. This study was aiming to analyze the association between first trimester maternal vitamin D, serum ferritin, hemoglobin level and neonatal birth weight.

METHODS

From July 2016 a prospective cohort of pregnant women had been observed in four cities in West Java, Indonesia. Two hundred ninety four pregnant women were recuited in the first trimester and 203 of them had complete follow up until delivery. Collected data included maternal demography, blood analysis for ferritin, 25(OH) vitamin D in the first trimester of pregnancy and the birth weight of neonates. Associations were analyzed with multiple regression models.

RESULTS

Vitamin D deficiency was highly prevalent among pregnant women in this study (approximately 75%) while anemia was found in 7.5 %, a little above the target of 5 %. However, no significant association was found between maternal serum vitamin D, serum ferritin, hemoglobin level in the first trimester and birth weight of the neonates, before and after adjustment for maternal age, pre-pregnancy body mass index, and parity.

CONCLUSION

There were no associations found between vitamin D, ferritin, and hemoglobin level in the first trimester and neonatal birth weight. The negative results in this study should not diminish the benefit of nutritional supplementation during pregnancy. The possibility of other explanatory variables that influence these associations warrants further studies.

Vitamin D insufficiency among Danish pregnant women-Prevalence and association with adverse obstetric outcomes and placental vitamin D metabolism

INTRODUCTION

In pregnancy, vitamin D deficiency is associated with increased risk of fetal growth restriction and preeclampsia. The underlying mechanisms are not known, but placental dysfunction is believed to play a role. In a Danish population, where health authorities recommend a 10 µg/day vitamin D supplement during pregnancy, we explored current use of vitamin D supplements and vitamin D status. In term placentas, alterations in vitamin D metabolism and placental growth, evaluated by the key placental growth factor pregnancy-associated plasma protein-A (PAPP-A), and their relation to vitamin D insufficiency were investigated.

MATERIAL AND METHODS

We included 225 randomly selected pregnant women attending a nuchal translucency scan at gestational weeks 11-14. Information on use of vitamin D supplements and body mass index (BMI) at inclusion was obtained using self-reported questionnaires. Plasma 25-hydroxyvitamin D was measured at inclusion and correlated with pregnancy outcomes and placental biology, as judged by expression of PAPP-A and enzymes involved in vitamin D metabolism (CYP24A1, CYP27B1) in term placentas.

RESULTS

Vitamin D supplements were used by 92% of the women, but 42% were vitamin D insufficient (plasma 25-hydroxyvitamin D <75 nmol/L). Eleven women with singleton pregnancies developed fetal growth restriction or preeclampsia. In this small subset, first-trimester mean plasma 25-hydroxyvitamin D was lower in women who developed fetal growth restriction (43 ± 33nmol/L; n = 3; P = .006) and there was a tendency towards lower plasma 25-hydroxyvitamin D among women who developed preeclampsia (65 ± 19 nmol/L; n = 8; P = .08) in third trimester compared with uncomplicated pregnancies (79 ± 22 nmol/L; n = 187). In term placentas, PAPP-A expression was lower among participants with first-trimester vitamin D insufficiency (P = .009; n = 30) but no correlation was found between plasma 25-hydroxyvitamin D and mRNA expression of CYP24A1 (P = .67) and CYP27B1 (P = .34). BMI was negatively correlated with plasma 25-hydroxyvitamin D (P = .03) and positively correlated with placental mRNA expression of CYP24A1 (P = .003; n = 30).

CONCLUSIONS

Despite high compliance with official guidelines regarding vitamin D supplements, vitamin D insufficiency was frequent and the findings indicate that vitamin D insufficiency may affect placental growth. High BMI was associated with vitamin D insufficiency and increased placental vitamin D turnover, but further investigations are needed.

Influence of vitamin D binding protein polymorphism, demographics and lifestyle factors on vitamin D status of healthy Malaysian pregnant women

BACKGROUND

Vitamin D deficiency (VDD) has been related to vitamin D binding protein (GC) gene polymorphism, demographics and lifestyle factors in different populations. However, previous studies only focused on demographic and lifestyle factors or genetic factors alone. Therefore, this cross-sectional study aimed to assess the association between GC gene polymorphism, demographics and lifestyle factors with VDD among Malaysian pregnant women.

METHOD

Information on demographic characteristics, dietary vitamin D intake from supplement and food, time spent outdoors, skin type and clothing were collected using a questionnaire. Plasma total 25-hydroxyvitamin D (25OHD) levels were measured using an Ultra-High-Performance Liquid Chromatography (UHPLC). Maternal GC single nucleotide polymorphisms (SNPs) (rs4588 and rs7041) were determined using restriction fragment length polymorphism (RFLP) technique.

RESULTS

Results showed that 50.2% of pregnant women were vitamin D deficient (25OHD < 30 nmol/L). VDD (25OHD < 30 nmol/L) was significantly associated with age, veiled clothing, maternal vitamin D intakes from both food and supplements, and GC rs7041(and GC diplotypes). In contrast to previous studies that reported for non-pregnant population, a significant positive association was found between CC genotype for SNP GC rs7041, GC 1s-1s and GC If-2 with risk of VDD (25OHD < 30 nmol/L).

CONCLUSIONS

The high prevalence of maternal VDD found in this study suggests the need for urgent development and implementation of vitamin D supplementation or fortification strategies to reduce VDD among pregnant women. The discrepancy in the association between GC rs7041 gene polymorphism and VDD reflects the variation in the factors associated with VDD in pregnancy compared to non-pregnant state.

Gestational vitamin D deficiency causes placental insufficiency and fetal intrauterine growth restriction partially through inducing placental inflammation

Several epidemiological studies suggest an association between vitamin D deficiency (VDD) and fetal intrauterine growth restriction (IUGR). Here, we explored the mechanism through which VDD induced fetal IUGR. Pregnant mice were fed with VDD diet to establish VDD model. Cyp27b1^+/- mice were generated to develop a model of active vitamin D3 deficiency. Cyp27b1^+/- mice were injected with either 1α,25(OH)₂D₃ or vehicle once a day throughout pregnancy. As expected, fetal weight and crown-rump length were reduced in VDD diet-fed mice. Correspondingly, fetal weight and crown-rump length were lower in cyp27b1^+/- mice. 1α,25(OH)₂D₃ elevated fetal weight and crown-rump length, and protected cyp27b1^+/- mice from fetal IUGR. Further analysis found that placental proliferation was inhibited and placental weight was decreased in VDD diet-fed mice. Several growth factors and nutrient transfer pumps were downregulated in the placentas of VDD diet-fed mice. Mechanistically, several inflammatory cytokines were upregulated and placental NF-κB was activated not only in VDD diet-fed mice but also in VDD pregnant women. Interestingly, 1α,25(OH)₂D₃ inhibited the downregulated of placental nutrient transfer pumps and the upregulated of placental inflammatory cytokines in Cyp27b1+/- mice. These results provide experimental evidence that gestational VDD causes placental insufficiency and fetal IUGR may be through inducing placental inflammation.

Serum 25 hydroxyvitamin D levels and affecting factors among preconception fertile women

Background

Recent study found that vitamin D before conception was considered as a potential additional determinant for achieving pregnancy and live births. The study aimed to evaluate the serum 25 hydroxyvitamin D (25(OH)D) levels and its affecting factors among preconception fertile women.

Methods

This cross-sectional study enrolled 410 women aged 22–44 years who attended a preconception genetic counseling clinic from January 2018 to May 2019. Sociodemographic characteristics and reproductive history of women were collected, and height and weight were measured. Serum 25(OH)D concentration was assayed with chemiluminescence immunoassay. Descriptive statistics were used to examine serum 25(OH)D concentration, and socio-demographic characteristics and reproductive history among preconception women. Determinants of vitamin D deficiency and its affecting factors were assessed using χ2 test and logistic regression.

Results

Findings showed 84.4% of women had serum 25(OH)D concentration below 20 ng/mL. Women working indoors as well as without a history of childbirth had significantly lower 25(OH)D levels compared with those non-working individuals and having delivered a previous child (both P < 0.05). The 25(OH)D levels were the lowest in winter among that in spring, summer, and autumn (all P < 0.001). Women in winter have significantly elevated OR of 5.00 (95%CI 1.75–14.25) to develop vitamin D deficiency. Seasonal variation in serum 25(OH)D levels was not present in non-working individuals and women aged 31–44 years.

Conclusions

Vitamin D deficiency is common among preconception women especially nulliparous women and working women, which propose to screen serum 25(OH)D on preconception evaluation and emphasize need vitamin D supplements and get sunshine exposure.

Gestational hypercalcemia: Prevalence and biochemical profile

Gestational hypercalcemia is associated with an increased risk of maternal, fetal and neonatal morbidity and mortality. Hypercalcemia may develop during pregnancy in individuals who were previously asymptomatic. The increased sensitivity during pregnancy may be related to physiological, gestational alterations in vitamin D and calcium metabolism and may be influenced by gene variants. The prevalence is unknown. We investigated the prevalence of hypercalcemia in trimester 3 (T3) in a population representative prospective cohort study (n = 1832) in South-West Sweden. Women with serum albumin (Alb) adjusted calcium (Ca_Alb) ≥ 2.65 mmol/L in T3 (n = 30) were matched to normo-calcemic controls, and markers of calcium and vitamin D metabolism were investigated in trimester 1 (T1) and T3. Serum concentrations of Ca, phosphate (P), Magnesium (Mg), Alb and creatinine (Cr), parathyroid hormone (PTH; T3 only), vitamin D metabolites (total 25(OH)D, 1,25(OH)₂D, 24,25(OH)₂D, and free 25(OH)D) were analysed in T1 and T3. Ca_Alb (Payne; inter-laboratory difference: UEA = 0.15 + 0.9*UGOT; UEA 2.54 = UGOT 2.65) and estimated glomerular filtration rate (eGFR; modified 4-variable MDRD) and vitamin D metabolites ratios (VMR) were calculated. Normally and non-normally distributed data were presented as mean (SD) or median (95 %CI). Group differences in relationships between vitamin D metabolites and with PTH were investigated with multiple regression analyses. Hypercalcemia in T3 was found in 1.7 % of women. PTH concentrations suggestive of primary hyperparathyroidism was found in 1 woman and none had 25(OH)D or 24,25(OH)₂D concentrations in the toxicity range or suggestive of mutations in the CYP24A1 gene. Ca_Alb was significantly higher in hypercalcemic cases compared to controls in T1 (2.44 (2.30-2.80) vs 2.37 (2.25-2.49) mmol/L) and T3 (2.63 (2.52-2.78) vs 2.46 (2.31-2.58) mmol/L). Serum P was higher among cases than controls in T3 (1.12 (0.16) vs 1.07 (0.18) mmol/L) but not in T1 (1.12 (0.18) and 1.12 (0.16) mmol/L). PTH in T3 was lower in cases (1.6 (1.6-2.8) vs 2.3 (2.1-2.8) pmol/L) but 1,25(OH)₂D concentrations were similar. There were no significant group differences in serum 25(OH)D, free 25(OH)D, 24,25(OH)₂D, Mg, Alb, Cr and eGFR. Regression analyses did not show significant differences between cases and controls in relationships between vitamin D metabolites and with PTH, except for the free 25(OH)D-PTH relationship and a higher free:total 25(OH)D ratio in cases at T1. In conclusion, most common causes of hypercalcemia were excluded in the majority of women. Hypercalcemic women had a relatively high serum 1,25(OH)₂D concentration despite an appropriately suppressed PTH, suggestive of abnormal gestational adaptions.

Vitamin D Status in Pregnant Women in Southern China and Risk of Preterm Birth: A Large-Scale Retrospective Cohort Study

Background

The influence of maternal vitamin D on pregnancy outcomes, including preterm birth (PTB), is unclear due to different experimental designs and study populations (patient race and sample size) of previous studies. We aimed to investigate the relationship between 25-hydroxyvitamin D (25[OH] D) levels and PTB among pregnant women in southern China.

Material/Methods

A total of 11 641 pregnant women were retrospectively enrolled between January 2016 and April 2019. Vitamin D concentrations were evaluated by electrochemiluminescence immunoassay. Logistic regression analysis was used to analyze the association between vitamin D and PTB.

Results

The average 25(OH) D concentration was 59.3±21.5 nmol/L; 34.8% of patients were vitamin D deficient, 43.0% were vitamin D insufficient (25[OH] D <50 nmol/L and 50–74.9 nmol/L, respectively). In total, 3.6% of newborns were born prematurely. Comparing the pre-term and full-term groups, 45.7% versus 42.9% and 29.8% versus 35% were vitamin D deficient and insufficient, respectively These differences were not significant (P>0.05). However, the mean vitamin D status was significantly different between the pre-term and full-term groups (61.3±21.3 and 59.1±21.5 nmol/L, respectively). No association was found between vitamin D deficiency/insufficiency and PTB in unadjusted or adjusted models, compared with vitamin D sufficiency (adjusted odds ratio, 1.016; 95% confidence interval, 0.794–1.301 and 0.842; 0.641–1.106, respectively).

Conclusions

Low maternal 25(OH) D levels are common in southern China. However, low vitamin D status in pregnant women appears to be unrelated to PTB. Measuring vitamin D level alone is therefore not sufficient to predict PTB.

Vitamin D status during pregnancy and offspring outcomes: a systematic review and meta-analysis of observational studies

BACKGROUND/OBJECTIVES

Vitamin D deficiency during pregnancy may influence adverse outcomes in offspring. The aim of this systematic review and meta-analysis of observational studies was to assess the association between low prenatal concentrations of 25(OH)D (by using three different cut-off levels), preterm birth (PTB) and anthropometric and neurodevelopmental outcomes in offspring.

SUBJECTS/METHODS

Studies reporting data on the association between maternal vitamin D concentrations and offspring outcomes identified through a systematic review of scientific literature published in PubMed/MEDLINE, Scopus and the Cochrane Library databases up to April 2017.

RESULTS

We included 54 eligible studies. Vitamin D-deficient mothers (<30 nmol/L) had offspring with lower birthweight (MD -87.82 g; 95% CI -119.73, -55.91 g), head circumference (MD -0.19 cm; 95% CI -0.32, -0.06 cm) and a higher risk of small for gestational age (SGA) infants and PTB (OR 1.59; 95% CI 1.24, 2.03) compared to mothers with concentrations ≥30 nmol/L. Vitamin D insufficiency (<50 nmol/L) was associated with a higher risk of SGA and PTB (OR 1.43; 95% CI 1.08, 1.91 and OR 1.28; 95% CI 1.08, 1.52, respectively). Concentrations of 25(OH)D ≥75 nmol/L were not found to be associated with birthweight, SGA or PTB. Offspring of vitamin D-insufficient mothers had lower scores in mental (MD -1.12 points; 95% CI -1.82, -0.42 cm) and language developmental tests (MD -0.35 points; 95% CI -1.00, 0.31 cm).

CONCLUSION

Maternal vitamin D deficiency is associated with offspring adverse anthropometric outcomes and PTB; insufficiency with a higher risk of SGA, PTB and adverse neurodevelopmental outcomes.

Racial difference in preterm birth and low birthweight: Towards a new hypothesis involving the interaction of 25-hydroxyvitamin D with maternal fat mass

Preterm birth (PB) and low birthweight (LBW) remain a leading cause of infant mortality worldwide. Persistent racial disparities in prevalence rates have been reported, with the highest values observed in Subsaharan Africa and South Asia. In United States, non-Hispanic Black women are more likely to have a premature or low-birth-weight baby. Beyond the speculative debate on factors explaining such racial disparity, the key-question remains about the path from race to birth outcomes. Several hypotheses emerged from the published literature to explain the racial difference in likelihood for PB and LBW. However, the 'Hispanic paradox' remains unexplained. We relied here on published data to hypothesize that the racial disparity in PB/LBW is a consequence to the joint influence of 25-hydroxyvitamin D and fat mass. Beyond its role as a source of 1,25-dihydroxyvitamin D, the 25-hydroxyvitamin D is directly implicated in the fetal growth and the normal completion of pregnancy. Because of its lipophilic property, a large part of 25-hydroxyvitamin D is swiftly trapped into fat mass and the circulating fraction impact the body development during fetal period. We postulate that the positive effect of vitamin D to prevent PB/LBW is less beneficial for women with high fat mass, independent of race. The core problem may be related to bioavailable 25-hydroxyvitamin D, not directly to race.