Positive effect of low dose vitamin D supplementation on growth of fetal bones: A randomized prospective study

Parental conditions, modifiable lifestyle factors, and first trimester growth and development: a systematic review

INTRODUCTION

The embryonic period in human development is the foundation of lifelong and even transgenerational health. Although previously believed to be uniform, there is increasing evidence that embryonic growth is influenced by the conditions and modifiable lifestyle factors of parents in the periconception period. In ongoing pregnancies, a delay in growth in the first trimester has been associated with miscarriages, malformations, low birth weight, preterm birth, and small for gestational age at birth. This has stimulated research on factors associated with variations in human embryonic growth. However, there is still no consensus on which parental conditions and modifiable lifestyle factors affect first trimester growth and development and to what extent.

OBJECTIVE AND RATIONALE

A systematic review was undertaken according to PRISMA guidelines to provide an overview of literature on the associations between parental conditions and lifestyle factors in the periconception period and first trimester growth and development, with an aim to identify existing evidence gaps.

SEARCH METHODS

A systematic search of the literature concerning articles on embryonic growth and lifestyle factors published between 1900 and 2024 was performed in six electronic databases. Studies were eligible for inclusion if they reported on the association between periconception parental conditions and/or modifiable lifestyle factors and an in vivo measure of first trimester growth or development (i.e. crown-rump length, embryonic volume and/or Carnegie stage) between 6 + 0 and 13 + 6 weeks gestational age in singleton pregnancies. Parental conditions and modifiable lifestyle factors were defined as ex utero determinants divided into characteristics (age, ethnicity, BMI, blood pressure), lifestyle risk factors (caffeine intake, alcohol consumption, and smoking), nutrition (dietary patterns and food groups), vitamins (vitamin B9/B11, vitamin B12, vitamin D, and supplements), and the ambient environment (air pollution, noise exposure, and neighborhood deprivation). Risk of bias of the included studies was assessed using the Newcastle-Ottawa Scale. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach was used to assess the evidence level of the studies included in the review.

OUTCOMES

A total of 4708 unique records were identified, of which 34 studies were included in the systematic review. The majority of studies investigating smoking and BMI suggested an inverse association with embryonic growth and development, while maternal age, folic acid supplement use, and folate levels were positively associated with embryonic growth and development. Studies on blood pressure, ethnicity, vitamin B12, vitamin D, alcohol consumption, caffeine consumption, and ambient environment were too limited to conclude an association with embryonic growth and development. Reported effect estimates were heterogeneous for all determinants. Based on the GRADE criteria, the quality of evidence for the results of this review was considered low or very low.

WIDER IMPLICATIONS

Some periconceptional parental conditions and modifiable lifestyle factors are associated with first trimester growth and development and should be considered in clinical preconception care. To advance our understanding and establish strong, high-level evidence-based recommendations, future research should prioritize methodological quality and focus on lifestyle intervention studies.

REGISTRATION NUMBER

PROSPERO (ID: CRD42021240618).

Maternal vitamin D status, fetal growth patterns, and adverse pregnancy outcomes in a multisite prospective pregnancy cohort

BACKGROUND

Few studies have examined maternal vitamin D status and fetal growth patterns across gestation. Furthermore, time points in pregnancy at which maternal vitamin D status is most critical for optimal fetal growth and pregnancy outcomes are uncertain.

OBJECTIVES

Our objective was to examine whether first and second trimester maternal vitamin D status are associated with fetal growth patterns and pregnancy outcomes.

METHODS

We conducted a secondary analysis using data and samples from a multisite prospective cohort study of nulliparous pregnant females in the United States. We measured serum 25-hydroxyvitamin D (25(OH)D) for 351 participants at 6-13 and 16-21 weeks of gestation. Fetal growth was measured by ultrasound at 16-21 and 22-29 weeks of gestation, and neonatal anthropometric measures at birth. We constructed fetal growth curves using length, weight, and head circumference z-scores, and calculated risk of preterm birth (<37 wk) and small for gestational age (SGA). We examined outcomes across 25(OH)D concentrations assessed continuously, using Institute of Medicine (IOM) cutoffs (<50 compared with ≥50 nmol/L), and using exploratory cutoffs (<40, 40-59.9, 60-79.9, ≥80 nmol/L).

RESULTS

Vitamin D insufficiency (25(OH)D <50 nmol/L) was prevalent in 20% of participants in the first trimester. Each 10 nmol/L increase in first trimester 25(OH)D was associated with a 0.05 [95% confidence interval (CI): 0.01, 0.10] increase in length-for-age z-score but was not associated with weight or head circumference. There were no differences in risk of preterm birth or SGA using IOM cutoffs; participants with first trimester 25(OH)D <40 compared with ≥80 nmol/L had 4.35 (95% CI: 1.14, 16.55) times risk of preterm birth. Second trimester 25(OH)D was not associated with fetal growth patterns or with pregnancy outcomes.

CONCLUSIONS

First trimester 25(OH)D is positively associated with linear growth. Low first trimester 25(OH)D (<40 nmol/L) is associated with a higher risk of preterm birth. Second trimester 25(OH)D is not associated with fetal growth or pregnancy outcomes assessed.

Vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D supplementation during pregnancy may help improve maternal and neonatal health outcomes (such as fewer preterm birth and low birthweight babies) and reduce the risk of adverse pregnancy outcomes (such as severe postpartum haemorrhage).

OBJECTIVES

To examine whether vitamin D supplementation alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve certain maternal and neonatal outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Trials Register (which includes results of comprehensive searches of CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, and relevant conference proceedings) (3 December 2022). We also searched the reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy in comparison to placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently i) assessed the eligibility of studies against the inclusion criteria, ii) assessed trustworthiness based on pre-defined criteria of scientific integrity, iii) extracted data from included studies, and iv) assessed the risk of bias of the included studies. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

The previous version of this review included 30 studies; in this update, we have removed 20 of these studies to 'awaiting classification' following assessments of trustworthiness, one study has been excluded, and one new study included. This current review has a total of 10 included studies, 117 excluded studies, 34 studies in awaiting assessment, and seven ongoing studies. We used the GRADE approach to assess the certainty of the evidence. This removal of the studies resulted in evidence that was downgraded to low-certainty or very low-certainty due to study design limitations, inconsistency between studies, and imprecision. Supplementation with vitamin D compared to no intervention or a placebo A total of eight studies involving 2313 pregnant women were included in this comparison. We assessed four studies as having a low risk of bias for most domains and four studies as having high risk or unclear risk of bias for most domains. The evidence is very uncertain about the effect of supplementation with vitamin D during pregnancy compared to placebo or no intervention on pre-eclampsia (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.21 to 1.33; 1 study, 165 women), gestational diabetes (RR 0.53, 95% CI 0.03 to 8.28; 1 study, 165 women), preterm birth (< 37 weeks) (RR 0.76, 95% CI 0.25 to 2.33; 3 studies, 1368 women), nephritic syndrome (RR 0.17, 95% CI 0.01 to 4.06; 1 study, 135 women), or hypercalcaemia (1 study; no cases reported). Supplementation with vitamin D during pregnancy may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome (RR 0.68, 95% CI 0.51 to 0.91; 1 study, 1134 women; low-certainty evidence) and may reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out (RR 0.69, 95% CI 0.44 to 1.08; 3 studies, 371 infants; low-certainty evidence). Supplementation with vitamin D + calcium compared to no intervention or a placebo One study involving 84 pregnant women was included in this comparison. Overall, this study was at moderate to high risk of bias. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported. The evidence is very uncertain about the effect of supplementation with vitamin D and calcium on preterm birth (RR not estimable; very low-certainty evidence) or for low birthweight (RR 1.45, 95% CI 0.14 to 14.94; very low-certainty evidence) compared to women who received placebo or no intervention. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) One study involving 1298 pregnant women was included in this comparison. We assessed this study as having a low risk of bias in all domains. Pre-eclampsia was not reported. The evidence is very uncertain about the effect of supplementation with vitamin D, calcium, and other vitamins and minerals during pregnancy compared to no vitamin D on gestational diabetes (RR 0.42, 95% CI 0.10 to 1.73; very low-certainty evidence), maternal adverse events (hypercalcaemia no events and hypercalciuria RR 0.25, 95% CI 0.02 to 3.97; very low-certainty evidence), preterm birth (RR 1.04, 95% CI 0.68 to 1.59; low-certainty evidence), or low birthweight (RR 1.12, 95% CI 0.82 to 1.51; low-certainty evidence).

AUTHORS' CONCLUSIONS

This updated review using the trustworthy assessment tool removed 21 studies from the previous update and added one new study for a total of 10 included studies. In this setting, supplementation with vitamin D alone compared to no intervention or a placebo resulted in very uncertain evidence on pre-eclampsia, gestational diabetes, preterm birth, or nephritic syndrome. It may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome. It may also reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out. Supplementation with vitamin D and calcium versus placebo or no intervention resulted in very uncertain evidence on preterm birth and low birthweight. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported in the only study included in this comparison. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) resulted in very uncertain evidence on gestational diabetes and maternal adverse events (hypercalciuria) and uncertain evidence on preterm birth and low birthweight. Pre-eclampsia was not reported in the only study included in this comparison. All findings warrant further research. Additional rigorous, high-quality, and larger randomised trials are required to evaluate the effects of vitamin D supplementation in pregnancy, particularly in relation to the risk of maternal adverse events.

Are Maternal Vitamin D (25(OH)D) Levels a Predisposing Risk Factor for Neonatal Growth? A Cross-Sectional Study

BACKGROUND

Neonatal bone mass may potentially be influenced by existing maternal vitamin D (25(OH)D) levels. Few studies evaluated maternal vitamin D deficiency (VDD) with neonatal anthropometrics such as weight, height and head circumference (HC), especially in Greece, which is a Mediterranean country with plenty of sunshine and consequently benefits the synthesis of 25(OH)D. We investigated this potential association in Greece, taking into account the administration or not of prenatal vitamin D supplements. The purpose of our study is to ascertain if there is a possible association between maternal VDD and neonatal specific anthropometric characteristics (weight, height and HC) at birth. If this is confirmed by future clinical studies, it would be of interest to develop a prenatal pregnancy selection program that would detect VDD early or during pregnancy in order to improve fetal-neonatal development in a Mediterranean country like ours.

METHODS

We performed a cross-sectional study on 248 early early term infants (after 37 + 0 to 38 + 6 weeks of gestation) but also on full-term infants (after 39 to 40 weeks of gestation) and their Greek mothers from September 2019 to January 2022. Blood samples of 25(OH)D were taken from the mother at the beginning of labor and cord blood was taken from the newborn. Pregnant women were divided into two groups: those who received or did not receive a normal dose of calcium (500 mg/day) and vitamin D supplements (400-800 IU/day) as instructed by their treating physicians.

RESULTS

Our findings revealed a positive association between maternal VDD and low neonate birth weight (LBW) in women receiving vitamin D during pregnancy and no association between maternal VDD and neonatal height or head circumference (HC) at birth.

CONCLUSIONS

Overall, this study highlighted the association between maternal VDD at the end of gestation and LBW neonates born to mothers who received vitamin D supplementation. We did not find any correlation in two of the three somatometric characteristics studied, height and HC. In any case, more clinical studies are needed to further corroborate any potential association of maternal VDD with other neonatal somatometric characteristics.

Effects of vitamin D supplementation during pregnancy on bone health and offspring growth: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Whether vitamin D supplementation during pregnancy is beneficial to bone health and offspring growth remains controversial. Moreover, there is no universal agreement regarding the appropriate dose and the time of commencement of vitamin D supplementation during pregnancy.

OBJECTIVE

We aimed to systematically review the effects of vitamin D supplementation during pregnancy on bone development and offspring growth.

METHODS

A literature search for randomized controlled trials (RCTs) was performed in 7 electronic databases to identify relevant studies about the effects of vitamin D supplementation during pregnancy on bone development and offspring growth from inception to May 22, 2022. A Cochrane Risk Assessment Tool was used for quality assessment. Vitamin D supplementation was compared with placebo or standard supplements. The effects are presented as the mean differences (MDs) with 95% CIs. The outcomes include bone mineral content (BMC), bone mineral density (BMD), bone area (BA), femur length (FL) and humeral length (HL); measurement indicators of growth, including length, weight and head circumference; and secondary outcome measures, including biochemical indicators of bone health, such as the serum 25(OH)D concentration. Additionally, subgroup analyses were carried out to evaluate the impact of different doses and different initiation times of supplementation with vitamin D.

RESULTS

Twenty-three studies with 5390 participants met our inclusion criteria. Vitamin D supplementation during pregnancy was associated with increased humeral length (HL) (MD 0.13, 95% CI 0.06, 0.21, I2 = 0, P = 0.0007) during the fetal period (third trimester). Vitamin D supplementation during pregnancy was associated with a significantly increased length at birth (MD 0.14, 95% CI 0.04, 0.24, I2 = 24%, P = 0.005) and was associated with a higher cord blood 25(OH)D concentration (MD 48.74, 95% CI 8.47, 89.01, I2 = 100%, P = 0.02). Additionally, subgroup analysis revealed that birth length was significantly higher in the vitamin D intervention groups of ≤1000 IU/day and ≥4001 IU/day compared with the control group. Prenatal (third trimester) vitamin D supplementation was associated with a significant increase in birth length, while prenatal (second trimester) vitamin D supplementation was associated with a significant increase in birth weight.

CONCLUSION

Vitamin D supplementation during pregnancy may be associated with increased humeral length (HL) in the uterus, increased body length at birth and higher cord blood 25(OH)D concentration. Evidence of its effect on long-term growth in children is lacking. Additional rigorous high-quality, long-term and larger randomized trials are required to more fully investigate the effects of vitamin D supplementation during pregnancy.

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.

Umbilical cord N-terminal procollagen of type l collagen (P1NP) and beta C-terminal telopeptide (βCTX) levels in term pregnancies with vitamin D deficiency

AIMS

The aim of the present study was to evaluate umbilical cord N-terminal procollagen of type l collagen (P1NP) and beta C-terminal telopeptide (βCTX) levels in term pregnancies with vitamin D deficiency.

MATERIALS AND METHODS

Ninety-two pregnant women between 19 and 35-years-old who delivered at term gestational age were included in the study and divided into deficient (n = 32), insufficient (n = 30), and normal (control) vitamin D levels (n = 30).

RESULTS

Maternal demographic characteristics and biochemical parameters were similar among groups. The mean umbilical cord P1NP level was 221.4 (211.7-231.0, 95%CI) pg/mL in the vitamin D deficiency group, 282.5 (271.2-293.8, 95%CI) pg/mL in the vitamin D insufficiency group, and 280.9 (270.9-290.8, 95%CI) pg/mL in the control group and significantly lower in vitamin D deficiency group than others (p < .001). Umbilical cord P1NP level was similar in the vitamin D insufficiency group and control group (p = .971). The mean umbilical cord βCTX level was 5530, 9 (5511.5-5550.3, 95%CI) pg/mL in the vitamin D deficiency group, 5516.3 (5498.4-5534.2, 95%CI) pg/mL in the vitamin D insufficiency group, and 5510 (5491.4-5528.5, 95%CI) pg/mL in the control group, which was statistically similar among the groups (p = .251).

CONCLUSION

Our results indicated that vitamin D deficiency during pregnancy affects fetal bone osteoblast activity.

Antenatal Antidepressant Prescription Associated With Reduced Fetal Femur Length but Not Estimated Fetal Weight: A Retrospective Ultrasonographic Study

PURPOSE/BACKGROUND

Antidepressants are among the most frequently prescribed medications during pregnancy and may affect fetal weight. Associations between antenatal antidepressant use and ultrasonographic measures of fetal development have rarely been examined. We hypothesized that the prescription of an antenatal antidepressant would be associated with lower estimated fetal weight (EFW).

METHODS/PROCEDURES

A retrospective analysis of routine ultrasonographic data extracted from electronic medical records was performed on a cohort of pregnant women with psychiatric diagnoses and grouped according to the presence of an antenatal antidepressant prescription (n = 32 antidepressant-prescribed and n = 44 antidepressant prescription-free). After stratifying for gestational age, comparisons included 13 ultrasonographic parameters, frequency of oligohydramnios and polyhydramnios and growth deceleration, and maternal serum protein markers assessed per routine care, including α-fetoprotein, free β-human chorionic gonadotropin, and unconjugated estriol levels, using t tests, nonparametric and Fisher tests, and effect sizes (ESs) were computed.

FINDINGS/RESULTS

No statistically significant EFW differences between groups at any time point were detected (P > 0.05). Antenatal antidepressant prescription was associated with lower femur length at weeks 33 to 40 (P = 0.046, ES = 0.75) and greater left ventricular diameter at weeks 25 to 32 (P = 0.04, ES = 1.18). No differences for frequency of oligohydramnios or polyhydramnios or growth deceleration were observed (P > 0.05). We did not detect group differences for maternal proteins (P > 0.05).

IMPLICATIONS/CONCLUSIONS

Our evidence suggested a lack of association between antenatal antidepressant prescription and lower EFW but indicated an association with lower femur length and greater left ventricular diameter in mid-late gestation. Future research should examine the clinical implications of these findings.