Vitamin D status during pregnancy and in cord blood in a large prospective French cohort

Association between VDR genetic polymorphisms and risk of gestational diabetes mellitus in the Chinese population

BACKGROUND AND AIMS

Abnormal metabolism of vitamin D was the primary mechanism in many pregnancy diseases. Our study was the first to examine the hypothesis that VDR gene polymorphisms contribute to the risk of gestational diabetes mellitus (GDM) in the Chinese population at high altitudes.

MATERIALS AND METHODS

One hundred and eighteen women with GDM and 104 women with normal glucose tolerance (NGT) were included in this study using a case-control design. Four single nucleotide polymorphisms (g.47879112G > A, g.47846052C > T, g.47844974A > G, and g.47845054C > A) of mother and fetus were genotyped.

RESULTS

Maternal and fetal frequency of the A allele of g.47879112G > A was significantly increased in women with GDM than in those with NGT (p < .05). A correlation between the AA homozygous genotype of g.47879112G > A and GDM was noted. Compared with non-carriers, A allele carriers showed higher fasting plasma insulin and two-hour post-challenge plasma glucose (2h-PPG), and lower levels of vitamin D. Furthermore, both maternal and fetal 4-marker haplotype ACCG were found to be significantly associated with GDM (p < .05).

CONCLUSIONS

Association and haplotype analysis indicated that the A allele of g.47879112G > A could be a risk factor for GDM development in the Chinese population at high altitudes. Additionally, the VDR gene polymorphism of the fetus and mother may have a synergistic effect. The VDR polymorphism is associated with an increased risk of GDM and may be useful for predicting the development of the disease.

Is 25OH Vitamin D Excess before 36 Weeks Corrected Age an Independent Risk Factor for Bronchopulmonary Dysplasia or Death?

Low 25-Hydroxyvitamin D (25(OH)D) in preterm infants is a risk factor for bronchopulmonary dysplasia (BPD), but increased supplementation failed to demonstrate a beneficial effect on BPD. In neonatal animal models, deficiency and excessive vitamin D exposure have been associated with increased mortality and histological alterations in the lung evocative of BPD. Our hypothesis is that 25(OH)D levels ≥ 120 nmol/L are also a risk factor for BPD or death. This retrospective single-center cohort study included only infants born at <31 weeks gestational age without major malformations with at least a determination of 25(OH)D at <36 weeks corrected age and no determination <50 nmol/L. Routine 25(OH)D determination was performed at 1 month and monthly thereafter. A total of 175 infants were included. Infants with BPD or who died had a significantly lower term and weight, but a similar frequency of 25(OH)D ≥120 nmol/L (50.5% vs. 43.9%, p = 0.53). The logistic regression identified weight (OR 0.997, 95% CI [0.995-0.998]) and term (OR 0.737, 95% CI [0.551-0.975]) as significantly associated with BPD or death; the occurrence of excessive 25(OH)D was not significantly associated (OR 1.029, 95% CI [0.503-2.093]). The present study did not demonstrate any significant association between excessive 25(OH)D after one month of age and BPD or death.

Does antenatal cholecalciferol supplementation affect the mode or timing of delivery? Post hoc analyses of the MAVIDOS randomized controlled trial

BACKGROUND

Observational studies relating maternal 25-hydroxyvitamin D status to timing and mode of delivery have reported inconsistent results. We assessed the effect of antenatal cholecalciferol supplementation on the incidence of preterm birth, delivery mode and post-partum haemorrhage (PPH).

METHODS

MAVIDOS was a randomized, double-blind, placebo-controlled trial of 1000 IU/day cholecalciferol from 14 weeks' gestation until delivery. Gestational age, mode of delivery [categorized as spontaneous vaginal delivery (SVD), instrumental (including forceps and vacuum extraction) or Caesarean section] and PPH (>500 ml estimated blood loss) were determined from medical records.

RESULTS

A total of 965 women participated in the study until delivery. Gestation at birth and incidence of preterm birth (cholecalciferol 5.7%, placebo 4.5%, P = 0.43) were similar between the two treatment groups. SVD (versus instrumental or Caesarean delivery) was more likely in women randomized to cholecalciferol [Relative Risk (RR) 1.13, 95% confidence interval (CI) 1.02,1.25] due to lower instrumental (RR 0.68, 95%CI 0.51,0.91) but similar risk of Caesarean delivery (RR 0.94, 95%CI 0.74,1.19). PPH was less common in women randomized to cholecalciferol [32.1% compared with placebo (38.1%, P = 0.054) overall], but similar when stratified by delivery mode.

CONCLUSIONS

Antenatal cholecalciferol supplementation did not alter timing of birth or prevalence of preterm birth but demonstrated a possible effect on the likelihood of SVD.

Association of Maternal Gestational Vitamin D Supplementation with Respiratory Health of Young Children

This study aimed to evaluate the association between maternal gestational Vitamin D3 supplementation and early respiratory health in offspring. This was a population-based record-linkage study which used data from the French National Health Database System. Maternal Vitamin D3 supplementation consisted of a single high oral dose of cholecalciferol, (100,000 IU) from the seventh month of pregnancy, according to national guidelines. In total, 125,756 term-born singleton children were included, of which 37% had respiratory illness defined as hospital admission due to respiratory causes or inhalation treatment up to 24 months of age. Infants prenatally exposed to maternal Vitamin D3 supplementation (n = 54,596) were more likely to have a longer gestational age (GA) at birth (GA 36-38 weeks, 22% vs. 20%, p < 0.001 in exposed vs. non-exposed infants, respectively). After adjusting for the main risk factors (maternal age, socioeconomic level, mode of delivery, obstetrical and neonatal pathology, birth weight appropriateness, sex, and birth season), the risk of RD was found to be 3% lower than their counterparts (aOR [IC 95%], 0.97 [0.95-0.99], p = 0.01). In conclusion, this study provides evidence for the association between maternal gestational Vitamin D3 supplementation and improved early respiratory outcomes in young children.

Maternal serum 25-hydroxyvitamin D levels and infant atopic dermatitis: A prospective cohort study

BACKGROUND

Maternal vitamin D status during pregnancy has been linked with the risk of atopic dermatitis (AD) in children, while the results were inconsistent. The objective of this study was to assess the potential association.

METHODS

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in pregnant women from the birth cohort MKFOAD. Infant AD was diagnosed according to Williams' criteria. Multivariate logistic regression model was used to examine the association of maternal serum 25(OH)D levels in the first, second, and third trimester of gestation with the risk of infant AD at first year of age.

RESULTS

In total, 121 (26.5%) of 456 infants developed AD prior to 1 year of age. In general, higher maternal serum 25(OH)D levels throughout pregnancy were associated with increased risks of AD in infants prior to 1 year of age in multivariate logistic regression models, with borderline statistical significance in the first (per ln unit increase: adjusted OR = 1.93, 95% CI: 0.96, 3.88) and second (per ln unit increase: adjusted OR = 1.72, 95% CI: 0.93, 3.19) trimester. Multivariate logistic regression models using categorical variables of maternal 25(OH)D levels by tertiles showed similar results: Infants born to mothers with serum 25(OH)D levels in the highest tertile had higher risk of AD than those with 25(OH)D in the lowest tertile.

CONCLUSIONS

The present study found some evidence supporting that higher maternal 25(OH)D levels during pregnancy increased the risk of infant AD. However, the clinical implication of the findings should be limited for those with blood levels over the recommendations.

Vitamin D deficiency during late pregnancy mediates placenta-associated complications

During pregnancy, maternal vitamin D insufficiency could increase the risk of preeclampsia. Aim of the study was to evaluate the relationship between vitamin D status and the occurrence of placenta-mediated complications (PMCs) in a population at high risk. A prospective multicenter cohort study of 200 pregnant patients was conducted. The vitamin D level of patients with placenta-mediated complications was lower at 32 weeks compared to uncomplicated pregnancies (P = 0.001). At 32 weeks, the risk of occurrence of PMCs was five times higher in patients with vitamin D deficiency (RR: 5.14 95% CI (1.50-17.55)) compared to patients with normal vitamin D levels. There was a strong, inverse relationship between serum 25(OH)D levels at 32 weeks and the subsequent risk of PMCs (P = 0.001). At 32 weeks, the vitamin D level of patients with late-onset PMCs was lower than the one of patients with early-onset PMCs and of patients without PMCs (P < 0.0001). These results suggest a role of vitamin D in the maintenance of placental performance and therefore in the prevention of the onset of late PMC.

Vitamin D status in women with dichorionic twin pregnancies and their neonates: a pilot study in China

Background

Vitamin D deficiency is a global public health issue in women and children and is associated with adverse impacts on child growth, such as rickets. However, prior studies have mainly focused on measuring vitamin D levels in singleton pregnant women and their offspring, and very limited studies have revealed the prevalence of vitamin D deficiency in twin pregnant women and their offspring. The aim of this study was to investigate vitamin D levels in twin-pregnant women and their neonates. We also explored the correlation of maternal vitamin D levels with neonatal outcomes and infant growth.

Methods

A prospective subcohort investigation was carried out among 72 dichorionic, diamniotic twin-pregnant mothers and their twin offspring from the Longitudinal Twin Study. Peripheral blood was collected from the mothers in the third trimester, and cord blood was collected from neonates at birth to identify 25[OH]D levels. Data on the characteristics of the mothers and neonates were collected. Infant growth data and food sensitivities were also collected.

Results

The average maternal 25[OH]D level was 31.78 ng/mL, with 19.4% being deficient and 20.8% insufficient, while the average neonatal 25[OH]D level was 15.37 ng/mL, with 99.3% being deficiency or insufficient. A positive correlation was found between maternal and neonatal 25[OH]D levels (beta-value: 0.43, 95% CI: 0.37, 0.49). Interestingly, the higher the maternal 25[OH]D level was, the smaller the cotwin birthweight discordance (beta-value: -2.67, 95% CI: − 5.11, − 0.23). In addition, the infants of mothers with vitamin D deficiency were more likely to be allergic to foods at 6 months than those of mothers with vitamin D sufficiency.

Conclusions

Twin neonates were at high risk of vitamin D deficiency, although their mothers’ vitamin D deficiency partially improved. Higher maternal vitamin D levels were associated with smaller discordance of cotwin birthweight.

Trial registration

Chinese Clinical Trial Registry ChiCTR-OOC-16008203, 1st April 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03707-7.

Associations between maternal vitamin D status during three trimesters and cord blood 25(OH)D concentrations in newborns: a prospective Shanghai birth cohort study

PURPOSE

Prenatal vitamin D (VitD) deficiency influences children's health in later life. We aimed to test the associations between maternal VitD status in each of the three trimesters of pregnancy and cord blood 25(OH)D concentrations in newborns.

METHODS

Participants were pregnant women recruited from the Shanghai Birth Cohort (SBC) (n = 1100). Of all the participants, 946 completed the collection of venous blood at early (< 16 weeks, T1), mid- (24-28 weeks, T2), and late (32-34 weeks, T3) pregnancy as well as the corresponding cord blood in the newborns. Maternal serum 25(OH)D concentrations were measured by LC-MS/MS, and the information on confounding factors was obtained through a standardized questionnaire.

RESULTS

The mean 25(OH)D concentrations at time points T1, T2, T3 in maternal blood and cord blood of the newborns were 26.31 ng/mL, 31.92 ng/mL, 35.62 ng/mL, and 19.77 ng/mL, respectively. Neonatal 25(OH)D level in cord blood was positively correlated with maternal serum 25(OH)D levels at each trimester, and the strongest correlation was found at time point T3.

CONCLUSION

Maternal 25(OH)D concentrations at each trimester were positively associated with neonatal VitD status in cord blood, and the strongest correlation was found in the late stage of pregnancy, which could be considered as a sensitive time window. Attention should be paid to the nutritional status of VitD during pregnancy to better prevent the VitD deficiency in neonates.

Prevalence and risk factors of hypovitaminosis D in pregnant Spanish women

The hypovitaminosis D epidemic is a global health problem. Our aim was to assess the prevalence and potential risk factors of hypovitaminosis D among pregnant women on the eastern Mediterranean coast. Cross-sectional analysis involved 793 healthy pregnant women (35.3 ± 5.0 years) participating in ECLIPSES, a multicenter randomized trial. Socio-demographic, obstetric, anthropometric, lifestyle, dietary variables and blood draw was collected in the first trimester. Vitamin D deficiency was identified in 50.2% and insufficiency in 30.3% of pregnant women. The mean vitamin D level in the overall sample was 33.9 nmol/L (SD, 17.0). Multivariable logistic regression analysis applying AIC-based backward selection identified excess weight during the 1st trimester (BMI ≥ 25 kg/m²) (OR = 1.950, 95% CI = 1.409, 2.699), Arab ethnic group/dark skin colour (OR = 4.005, 95% CI = 2.488, 6.447), winter/spring (OR = 4.319, 95% CI = 3.112, 5.994), and consumption of milk (OR = 0.754, 95% CI = 0.572, 0.993) and yogurt (OR = 0.635, 95% CI = 0.436, 0.922) as independent risk factors for vitamin D deficiency. All of these factors (except yogurt consumption) and physical activity were independently associated with vitamin D deficiency/insufficiency risk in the final multivariable model (all p < 0.05). All these factors and social class were the most important determinants of circulating 25(OH)D concentrations. Our results confirm a high prevalence of vitamin D deficiency and insufficiency among pregnant women from the eastern Mediterranean coast.

Vitamin D and pregnancy outcomes: Overall results of the FEPED study

Vitamin D insufficiency is highly prevalent in children and adults including pregnant women. During pregnancy, maternal vitamin D insufficiency could increase risks of several pregnancy complications and adverse birth outcomes. The FEPED study was designed to assess the effects of maternal vitamin D status in the first trimester during pregnancy on risks of preeclampsia, gestational diabetes mellitus (GDM), preterm birth and small-for-gestational age (SGA) at birth. This observational prospective cohort included 3129 women with a singleton pregnancy between April 2012 and July 2014 in six maternity units in France and Belgium. The aim of this review is to summarize the results of the FEPED study. At the first trimester the mean 25(OH)D concentration was 21.9 ± 10.4 ng/mL and 25(OH)D concentration was <20 ng/mL in 46.5 % of patients. After matching 83 cases of preeclampsia with 319 controls, a significant decrease in the risk of preeclampsia was associated with maternal vitamin D levels ≥ 30 ng/mL in the third trimesters (OR = 0.34; 95 % CI: 0.13-0.86. P = 0.023). In the first trimester, the risk for preeclampsia was decreased in these patients, but did not achieve statistical significance (OR = 0.57 95 % CI, 0.30-1.01; p = 0.09). For the 250 cases with GDM matched with 941 controls, no linear relationship was found between GDM and 25OHD levels in the first trimester of pregnancy. Finally, 2813 pregnant women were included in analyses of risks of preterm and SGA birth. No association was found between low maternal vitamin D levels in the first trimester and the risks of preterm birth (aOR = 1.53; 95 % CI: 0.97-2.43) or SGA (aOR = 1.07; 95 % CI: 0.75-1.54). Further investigation is needed to understand the mechanisms behind the association between vitamin D and birth outcomes.

Relationship between vitamin D status in the first trimester of pregnancy and gestational diabetes mellitus - A nested case-control study

BACKGROUND & AIMS

Gestational diabetes mellitus (GDM) is one of the most frequent medical complications during pregnancy. It has been associated with many adverse pregnancy, fetal and neonatal outcomes, as well as with an increased risk for mothers and children in the long term. There is a growing interest in vitamin D and its potential role in the development of metabolic disorders. However, the medical literature is not consensual. The aim of this study was to assess the risk of GDM according to vitamin D status during the first trimester.

METHODS

This study is a nested case-control study performed from a multicenter prospective observational cohort of pregnant women assessed for 25-hydroxyvitamin D levels (25OHD). Three hundred ninety-three patients were included in the initial cohort. After applying exclusion criteria, a total of 1191 pregnant women were included. Two hundred fifty women with GDM (cases) were matched to 941 women without GDM (controls) for parity, age, body mass index before pregnancy, the season of conception, and phototype. This study was funded by a grant from the "Programme Hospitalier de Recherche Publique 2010".

RESULTS

The GDM risk was significantly greater for patients with 25OHD levels <20 ng/mL (OR = 1∙42, 95% CI 1∙06-1∙91; p = 0∙021). However, there was no significant relationship with other thresholds. The study of 25OHD levels with the more precise cutting of 5 units intervals showed a variable relationship with GDM risk, as the risk was low for very low 25OHD levels, increased for moderated levels, decreased for normal levels, and finally increased for higher levels.

CONCLUSION

According to our study, there seems to be no linear relationship between GDM and 25OHD levels in the first trimester of pregnancy since GDM risk does not continuously decrease as 25OHD concentrations increase. Our results most probably highlight the absence of an association between 25OHD levels and GDM risk.

First Trimester Maternal Vitamin D Status and Risks of Preterm Birth and Small-For-Gestational Age

Maternal 25-hydroxyvitamin D (25-OHD) deficiency during pregnancy may increase the risk of preterm and small-for-gestational age (SGA) birth, but studies report conflicting results. We used a multicenter prospective cohort of 2813 pregnant women assessed for 25-OHD levels in the first trimester of pregnancy to investigate the association between maternal 25-OHD concentrations and risks of preterm birth (<37 weeks) and SGA (birthweight <10th percentile). Odds ratios were adjusted (aOR) for potential cofounders overall and among women with light and dark skin separately, based on the Fitzpatrick scale. 25-OHD concentrations were <20 ng/mL for 45.1% of the cohort. A total of 6.7% of women had a preterm birth. The aOR for preterm birth associated with the 1st quartile of 25-OHD concentrations compared to the 4th quartile was 1.53 (95% confidence interval (CI): 0.97–2.43). In stratified analyses, an association was observed for women with darker skin (aOR = 2.89 (95% CI: 1.02–8.18)), and no association with lighter skin. A total of 11.9% of births were SGA and there was no association overall or by skin color. Our results do not provide support for an association between maternal first trimester 25-OHD deficiency and risk of preterm or SGA birth overall; the association with preterm birth risk among women with darker skin requires further investigation.