Changes in calcitropic hormones, bone markers and insulin-like growth factor I (IGF-I) during pregnancy and postpartum: a controlled cohort study

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.

Effective strategies for pregnancy and lactation-associated osteoporosis: teriparatide use in focus

INTRODUCTION

Pregnancy and lactation-associated osteoporosis (PLO) is a rare condition characterized by fragility fractures occurring during late pregnancy or lactation, primarily affecting the spine and causing significant morbidity and back pain. PLO can lead to mobility impairment and work incapacity, with recovery taking up to several years. Due to the lack of clinical trials, treatment strategies remain poorly defined, historically focusing on calcium supplements, vitamin D, and weaning from breastfeeding. However, recent attention has turned to teriparatide (TPD) as an option due to its anabolic properties and potential suitability for women of childbearing age.

METHODS

This review evaluates TPD's use in PLO treatment, using published systematic reviews and case studies. Over 300 cases with PLO were identified through PubMed, Google Scholar, and Cochrane searches until August 2023.

RESULTS

We identified 175 cases with PLO treated with TPD alone or followed by antiresorptive therapy. Most women (85.7%) were primiparas. The mean ± SD duration of TPD use was 15 ± 6 months. Among the study patients, 91.4% used TPD alone, while 8.6% (15/175) utilized sequential therapy. Approximately 93% of our cohort exhibited potential risk factors for PLO. Despite the increased risk of recurrent fractures in PLO, only 14.7% (20/175) of those treated with TPD sustained new fractures during a 9-month to 9 years' follow-up period. The mean ± SD percent increase in BMD at the LS was 21.14% ± 7.4%, and at the FN it was 12.1% ± 9.3%. The baseline Z-scores at the LS ranged from -3.3 (-3.7 to -2.7), while the baseline Z-scores at the FN ranged from -2.0 (-2.7 to -1.5).

CONCLUSION

This review emphasizes PLO severity, advocating for increased awareness and timely interventions. TPD emerges as a promising therapeutic option in certain cases.

Dual role of pregnancy in breast cancer risk

Reproductive history is one of the strongest risk factors for breast cancer in women. Pregnancy can promote short-term breast cancer risk, but also reduce a woman's lifetime risk of breast cancer. Changes in hormone levels before and after pregnancy are one of the key factors in breast cancer risk. This article summarizes the changes in hormone levels before and after pregnancy, and the roles of hormones in mammary gland development and breast cancer progression. Other factors, such as changes in breast morphology and mammary gland differentiation, changes in the proportion of mammary stem cells (MaSCs), changes in the immune and inflammatory environment, and changes in lactation before and after pregnancy, also play key roles in the occurrence and development of breast cancer. This review discusses the dual effects and the potential mechanisms of pregnancy on breast cancer risk from the above aspects, which is helpful to understand the complexity of female breast cancer occurrence.

Associations of free, bioavailable and total 25-hydroxyvitamin D with neonatal birth anthropometry and calcium homoeostasis in mother-child pairs in a sunny Mediterranean region

Sufficient vitamin D status is crucial for successful pregnancy and fetal development. The assessment of 25-hydroxyvitamin D (25(OH)D) concentrations is commonly used to evaluate vitamin D status. Our objective was to examine the interrelated biodynamics of maternal and neonatal total, free and bioavailable 25(OH)D in maternal-neonatal dyads at birth and their associations with homeostasis and neonatal birth anthropometry. We analysed a cohort of seventy full-term mother-child pairs. We found positive associations between all neonatal measures of vitamin D status. Maternal forms exhibited a similar pattern of association, except for the bioavailable maternal form. In multivariate analysis, both total and free maternal 25(OH)D concentrations were correlated with all neonatal forms (neonatal total 25(OH)D: 1·29 (95 % CI, 1·12, 1·46) for maternal total 25(OH)D, 10·89 (8·16, 13·63) for maternal free 25(OH)D), (neonatal free 25(OH)D: 0·15 for maternal total 25(OH)D, 1·28 (95 % CI, 0·89, 1·68) for maternal free 25(OH)D) and (0·13 (95 % CI, 0·10, 0·16), 1·06 (95 % CI, 0·68, 1·43) for maternal free 25(OH)D), respectively, with the exclusion of the bioavailable maternal form. We observed no significant interactions within or between groups regarding maternal and neonatal vitamin D parameters and maternal calcium and parathyroid hormone concentrations, and neonatal birth anthropometry. Our study indicates that bioavailable maternal and neonatal 25(OH)D have no significant effects on vitamin D equilibrium, Ca homeostasis and neonatal anthropometry at birth. However, we observed an interaction between maternal and neonatal total and free 25(OH)D concentrations at the maternal-neonatal interface, with no associations observed with other calciotropic or anthropometric outcomes.

Changes in Serum Concentrations of Bone Turnover Markers in Healthy Pregnant Women

Background

Changes in bone metabolism during pregnancy have not received sufficient attention because of the lack of effective screening tools. Bone turnover markers (BTMs) could reflect the changes of bone metabolism. Currently, reference intervals for bone metabolism during normal pregnancy are inconclusive. This study aimed to determine reference intervals for BTMs in pregnant women taking prenatal care and to facilitate clinical research on diseases affecting bone metabolism during pregnancy.

Methods

We surveyed 120 low-risk pregnant women attending routine antenatal care from January 2020 to March 2020. The serum levels of procollagen type I N-propeptide (PINP), N-terminal osteocalcin (N-MID), and C-terminal telopeptide of type I collagen (β-CTX) were measured in the first trimester (<13 weeks), second trimester (14-27 weeks), and third trimester (>28 weeks). Reference intervals for BTMs during pregnancy were analyzed. The Kruskal-Wallis test and paired t-test are used to analyze differences between groups. Spearman correlation coefficients expressed the measure of linear association.

Results

The bone resorption marker β-CTX in third trimester increases compared to the first trimester and the second trimester (P < 0.001, P < 0.001). The bone formation markers PINP and N-MID were decreased from the first trimester to the second trimester (P = 0.01, P < 0.001) and then raised from the second trimester to the third trimester (P < 0.001, P < 0.001). Two indices of bone turnover rate, β-CTX/PINP and β-CTX/N-MID, were increased from the first trimester to the second trimester (P < 0.001, P < 0.001) and then decreased from the second trimester to the third trimester (P = 0.02, P < 0.001).

Conclusion

This study established reference intervals for BTMs in pregnant women and observed the changes in BTMs during the different trimesters of pregnancy. The present findings can help in clinical monitoring of the effects of pregnancy diseases on the bone metabolism of pregnant women.

Bone turnover in lactating and nonlactating women

PURPOSE

During lactation, bone turnover increases, reflecting the mobilization of Calcium from maternal skeletal stores and resulting in bone loss. However, mechanisms are not yet fully understood, and previous studies have been comparatively small. We aim to assess bone metabolism during lactation by comparing bone-metabolism-related-parameters between large cohorts of lactating and nonlactating women.

METHODS

In a retrospective cohort study, we recruited 779 postpartum women and 742 healthy, nonpregnant, nonlactating controls. Postpartum women were examined 3 and 6 months after delivery and retrospectively assigned to either the exclusively breastfeeding (exc-bf) group if they had exclusively breastfed or the nonexclusively breastfeeding (nonexc-bf) group if they had not exclusively breastfed up to the respective visit. Serum levels of PTH, Estradiol, total Calcium, Phosphate, and bone turnover markers (ßCTX, P1NP, Osteocalcin) were compared between the groups.

RESULTS

Bone turnover markers were significantly increased in exc-bf and nonexc-bf women compared with the controls (all ps < .001). ßCTX was approximately twice as high in exc-bf women than in the controls. PTH levels were marginally higher in exc-bf (p < .001) and nonexc-bf women (p = .003) compared with the controls (6 months). Estradiol was suppressed in exc-bf women compared with the controls (p < .001, 3 months).

CONCLUSION

Exc-bf and even nonexc-bf states are characterized by an increase in bone formation and resorption markers. The PTH data distribution of exc-bf, nonexc-bf, and control groups in the underpart of the reference range suggest that lactational bone loss is relatively independent of PTH.

Abnormal Calcium Levels are Associated With Worse Maternal and Fetal Outcomes; Results From an Exploratory Study

CONTEXT

Precise estimates of the incidence of hyper- and hypocalcemia in pregnancy are unknown. Abnormal calcium levels have been associated with unfavorable pregnancy-related outcomes.

OBJECTIVE

Determine frequency of hypercalcemia and hypocalcemia in pregnancy when tested and their associations with maternal and fetal outcomes.

DESIGN

Exploratory retrospective cohort study.

SETTING

Single tertiary care maternity unit.

PATIENTS

Pregnant women with expected delivery date between 2017 and 2019 and a second additional cohort of pregnant women with hypercalcemia between 2014 and 2016 and 2020 and 2021.

INTERVENTIONS

Observational.

MAIN OUTCOMES MEASURED

(1) Incidence of hyper- and hypocalcemia when calcium tested; (2) maternal outcomes: incidence of preterm delivery, emergency cesarean section, and blood loss during delivery; and (3) fetal outcomes: fetal loss (miscarriage/stillbirth), neonatal intensive care unit admission, and fetal birth weight (for term deliveries).

RESULTS

Total number of gestations and livebirths recorded were 33 118 and 20 969, respectively, with median [interquartile range] age of 30.1 [25.6-34.3] years. A total of 15.7% (n = 5197) of all gestations had albumin-adjusted calcium tested, and incidence of hypercalcemia and hypocalcemia when tested was 0.8% (n = 42) and 9.5% (n = 495), respectively. Both hypercalcemia (including additional cohort n = 89) and hypocalcemia were associated with increased incidence of preterm delivery (P < .001), emergency cesarean section (P < .001 and .019), blood loss (P < .001), and neonatal intensive care unit admission (P < .001). A total of 27% in the hypercalcemic group had an established diagnosis of primary hyperparathyroidism.

CONCLUSIONS

Abnormal calcium levels during pregnancy are common and associated with worse pregnancy-related outcomes, which raises the possible need for routine calcium testing. Prospective studies to confirm the incidence, etiology, and effects of abnormal calcium in pregnancy are recommended.

Expert consensus on multidisciplinary approach to the diagnosis and treatment of primary hyperparathyroidism in pregnancy in China

Primary hyperparathyroidism in pregnancy is a rare disease that can have detrimental effects on both maternal and fetal/neonatal outcomes. The physiological changes that occur during pregnancy can complicate the diagnosis, imaging examinations, and treatment of this disorder. To enhance our understanding and management of primary hyperparathyroidism in pregnancy, experts from various fields, including endocrinology, obstetrics, surgery, ultrasonography, nuclear medicine, pediatrics, nephrology, and general practice in China, collaborated to develop a consensus addressing the critical aspects of the diagnosis and treatment of primary hyperparathyroidism in pregnancy with a multidisciplinary team approach. This consensus provides valuable guidance for healthcare professionals in managing this condition, ultimately improving outcomes for both mothers and their babies.

Management of Hypoparathyroidism

Hypoparathyroidism (HypoPT) is a rare disorder characterized by hypocalcemia in the presence of a low or inappropriately normal parathyroid hormone level. HypoPT is most commonly seen after neck surgery, which accounts for approximately 75% of cases, whereas approximately 25% have HypoPT due to nonsurgical causes. In both groups of patients, conventional therapy includes calcium and active vitamin D analogue therapy aiming to maintain serum calcium concentration in the low normal or just below the normal reference range and normalize serum phosphorus, magnesium concentrations, and urine calcium levels. The limitations of conventional therapy include wide fluctuations in serum calcium, high pill burden, poor quality of life, and renal complications. Parathyroid hormone (PTH) replacement therapy may improve the biochemical profile in those in whom conventional therapy proves unsatisfactory. Based on a systematic review and meta-analysis of the literature, the panel made a graded recommendation suggesting conventional therapy as first line therapy rather than administration of PTH (weak recommendation, low quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers use of PTH. Because pregnancy and lactation are associated with changes in calcium homeostasis, close monitoring is required during these periods with appropriate adjustment of calcium and active vitamin D analogue therapy to ensure that serum calcium remains in the mid to low normal reference range in order to avoid maternal and fetal complications. Emerging therapies include molecules with prolonged PTH action as well as different mechanisms of action that may significantly enhance drug efficacy and safety. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Reference intervals for clinical biochemistry and haematology tests during normal pregnancy

BACKGROUND

Pregnancy induces physiological changes which affect biochemical and haematological parameters. As the significance of laboratory test results change throughout pregnancy, the reference interval (RI) or key result interpretive guide should be specific to pregnancy. This study sought to establish trimester-specific-RIs for routine biochemical and haematological tests in healthy white European women with singleton pregnancies with comparison to RIs for non-pregnant European adults.

METHODS

A retrospective analysis of a prospective longitudinal single-centre study of healthy pregnant women conducted between November 2018 and December 2020 in a tertiary academic hospital with approximately 3000 births annually. Inclusion criteria: signed informed consent, age ≥18 years, white European, body mass index (BMI) <25 kg/m2, blood pressure <140/90mmHg, non-smoker, no previous pathology or gestational diabetes. Trimester defined as T1: up to 13 weeks + 6 days, T2: 14-27 weeks + 6 days and T3: ≥28-41 weeks + 6 days. Baseline demographics, anthropometric and laboratory measurements were recorded. In total, 31 biochemical and 10 haematological ISO15189:2012 accredited tests were measured using Roche Cobas® and Sysmex XN-9100™ analysers, respectively. RIs were established according to the International Federation of Clinical Chemistry (IFCC) recommended method.

RESULTS

Apparently healthy pregnant women (n = 124) with bio-banked serum samples in each trimester were recruited. At the booking visit, 49.2% (n = 61) of participants were nulliparous, with median age of 34.4 (IQR: 31.3-37.3) years, gestational age of 89 (IQR: 84-93) days, BMI of 22.5 (IQR: 21.0-23.7) kg/m² and systolic and diastolic blood pressure of 116 (110-125) mmHg and 67 (61-75) mmHg, respectively.

CONCLUSIONS

Normative trimester-specific biological intervals for routinely requested biochemical and haematological medical laboratory tests were established. These RIs will be invaluable to result interpretation and the management of pregnant women.

Individualized high dairy protein + walking program supports bone health in pregnancy: a randomized controlled trial

BACKGROUND

Pregnancy induces bone mineral mobilization, which may be further compromised if diet and physical activity are suboptimal.

OBJECTIVES

We aimed to determine the effects of a Nutrition + Exercise intervention during pregnancy on maternal calciotropic and bone biomarker profiles throughout pregnancy and the postpartum.

METHODS

In the Be Healthy in Pregnancy (BHIP) randomized controlled trial, 203 of 225 participants who consented to the bone health substudy were, randomly assigned at 12-17 weeks gestation to receive either usual care (control) or a structured and monitored Nutrition + Exercise plan (intervention) providing an individualized high dairy protein diet and a walking program throughout pregnancy. Maternal serum total procollagen type 1 N-terminal propeptide (P1NP; bone formation), C-terminal telopeptide of type I collagen (CTX; bone resorption), and insulin-like growth factor-1 (IGF-1) were measured by ELISA, and vitamin D metabolites by ultra-performance LC tandem MS at early and late pregnancy, 6 mo postpartum, and in cord blood.

RESULTS

In 187 participants completing all measures, significantly higher intakes were observed in the intervention than in the control group for total protein (P < 0.0001), protein intake from dairy foods (P < 0.0001), and calcium (P < 0.0001), whereas vitamin D intake was similar between treatment groups in both the second and third trimesters. The intervention group had significantly lower serum CTX at end of pregnancy (mean ± SD: 0.78 ± 0.31 ng/mL; n = 91 compared with 0.89 ± 0.33 ng/mL; n = 96, P = 0.034) and in cord serum (0.58 ± 0.13 ng/mL; n = 31 compared with 0.69 ± 0.18 ng/mL; n = 22, P < 0.025). Serum concentrations of P1NP rose significantly (P < 0.02) from early pregnancy to 6 mo postpartum for the intervention group only. Serum 25-hydroxyvitamin D status was >50 nmol/L for 97% of all participants.

CONCLUSIONS

Higher maternal dietary protein and calcium intakes than usual care in concert with normal vitamin D status minimized bone resorption and maintained bone formation and may protect bone health during pregnancy.This trial was registered at clinicaltrials.gov as NCT01689961.

The concordance of signals based on irregular incremental lines in the human tooth cementum with documented pregnancies: Results from a systematic approach

Background and objective

There is evidence from previous studies that pregnancies and diseases are recorded in the tooth cementum. This study aims to assess the degree of concordance between signals based on irregular incremental lines (ILs) and reported pregnancies.

Material and methods

23 recent and 24 archaeological human teeth with known birth history were included in this investigation. 129 histological sections of tooth roots were assessed for irregularities in appearance and width using a standardized protocol. Similarity of observed irregularities at the section level allowed us to define signals at the tooth level. The sensitivity of signals to detect pregnancies was determined and related to the signal prevalence.

Results

Pregnancy signals were frequently visually observed. However, applying a standardized process we could only reach signal sensitivities to identify pregnancies up to 20 percentage points above chance level.

Conclusions

Based on a standardized and reproducible method it could be confirmed that some pregnancies leave visible signals in the tooth cementum. The results show the potential of the tooth cementum to support reconstruction of life courses in paleopathology. However, it seems that not all pregnancies affect the cementogenesis in such a way that irregular ILs are identifiable. Further research is needed to better understand which type of pregnancies and other conditions are recorded in the tooth cementum.

Physiological Changes in Serum Calcium, Phosphate, Vitamin D, Parathyroid Hormone and Calcitonin During Pregnancy and Lactation in Randomised Population of Zaria Women

Pregnancy and lactation are usual but stressful physiological conditions accompanied by changes in calcium and phosphate metabolism and their regulatory hormones which may lead to calcium-related disorders in pregnant women. This study aimed to evaluate the changes in serum levels of calcium, phosphate, vitamin D and their regulatory hormones in pregnant and lactating women in Zaria, Nigeria. A cross‑sectional descriptive study was conducted at Ahmadu Bello University Teaching Hospital, Zaria for three (3) months. Blood samples were collected, anthropometric measurements (weight, height and body mass index) of 179 women were taken. Serum calcium, phosphate, vitamin D, parathyroid hormone and calcitonin were determined using standard methods. Data were presented as mean ± SD, analysis was performed using one-way ANOVA and Pearson's correlation analysis. Values were considered significant at p ≤ 0.05. There was a significant decrease in serum calcium concentration (p < 0.01) during the third trimester of pregnancy and lactation. An increase in serum concentration of vitamin D, parathyroid hormone, and calcitonin in the 2nd trimester and a decrease during the third trimester and lactation although not statistically significant when compared with the control. There was a negative correlation between serum calcium concentration and gestational age (r = 0.255) while no correlation between gestational age and serum phosphate concentration. Changes in serum calcium, vitamin D, parathyroid hormone and calcitonin during pregnancy and lactation has been demonstrated suggesting a relationship between calcium metabolism and these hormones at some stages of pregnancy.

Hypercalcemia in Pregnancy

Hypercalcemic disorders are rare in pregnant women and are usually due to primary hyperparathyroidism. Clinical manifestations of hypercalcemia are nonspecific and can be masked by the physiologic changes of pregnancy. Furthermore, routine antenatal screening does not include serum calcium measurement and a hypercalcemia diagnosis may therefore be delayed until term or even after delivery. Timely recognition and appropriate interventions are essential to decrease maternal and fetal complications. Conservative measures are appropriate in the presence of mild hypercalcemia. Parathyroidectomy remains the mainstay of treatment for primary hyperparathyroidism with significant hypercalcemia not responding to conservative measures.

Changes in Serum Calcium and Treatment of Hypoparathyroidism During Pregnancy and Lactation: A Single-center Case Series

BACKGROUND

Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited.

DESIGN AND SETTING

This was a retrospective study on a relatively large case series in a single center from mainland China.

METHODS

A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected.

RESULTS

During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery.

CONCLUSIONS

Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia.

Bone turnover in pregnancy, measured by urinary CTX, is influenced by vitamin D supplementation and is associated with maternal bone health: findings from the Maternal Vitamin D Osteoporosis Study (MAVIDOS) trial

BACKGROUND

The pattern of change in maternal bone turnover throughout pregnancy is poorly characterized.

OBJECTIVES

We investigated changes across pregnancy in a marker of maternal bone resorption, urinary C-terminal telopeptide of type I collagen (CTX), the influence of gestational vitamin D supplementation, and associations between CTX and maternal postnatal bone indices.

METHODS

MAVIDOS (the Maternal Vitamin D Osteoporosis Study) is a randomized, double-blind, placebo-controlled trial of 1000 IU cholecalciferol/d compared with placebo from 14 weeks of gestation to birth. Maternal second-void urinary α- and β-CTX were measured (ELISA) at 14 and 34 weeks of gestation; DXA was performed within 2 wk postpartum. The Mann-Whitney Rank Sum test, Spearman's rank correlation, and linear regression were used to compare median CTX values within and between groups from early to late pregnancy, and associations with maternal bone outcomes.

RESULTS

In total, 372 women had CTX and 25-hydroxyvitamin D [25(OH)D] measured in early and late pregnancy. CTX at 14 and 34 weeks of gestation were correlated in both placebo (r = 0.31) and cholecalciferol (r = 0.45) groups (P < 0.0001). Median CTX increased from 14 to 34 weeks of gestation in both groups (n = 372 total) [placebo (n = 188): from 223.6 to 449.7 μg/mmol creatinine; cholecalciferol (n = 184): from 222.3 to 419.3 μg/mmol creatinine; P = 0.03 for placebo compared with cholecalciferol difference in CTX at 34 weeks of gestation]. The conditional mean ± SD increase in CTX [z-score (SD)] from early to late pregnancy was greater in the placebo group (n = 188) than in the cholecalciferol group (n = 184) (placebo: 0.16 ± 0.92; cholecalciferol: -0.16 ± 1.06; P-difference < 0.01). Higher CTX at 34 weeks of gestation was associated, similarly in both groups, with lower maternal total hip and lumbar spine bone mineral content and bone mineral density (BMD) (e.g., lumbar spine BMD: β = -0.02 g · cm-2 · SD-1 increase in CTX; 95% CI: -0.027, -0.002 g · cm-2 · SD-1; P = 0.02, n = 283).

CONCLUSIONS

Maternal urinary CTX, a bone resorption marker, rises through pregnancy, although to a lesser degree with gestational cholecalciferol supplementation, and is inversely associated with maternal bone mass postpartum.This trial was registered at www.isrctn.com as ISRCTN 82927713 and eudract.ema.europa.eu as EudraCT 2007-001716-23.

Maternal and infant outcomes during the COVID-19 pandemic: a retrospective study in Guangzhou, China

In late December 2019, the COVID-19 pandemic caused a great threat to people's lives worldwide. As a special category of the population, pregnant women are vulnerable during emergencies. This study was designed to explore whether or not the COVID-19 pandemic has influenced maternal and infant outcomes. We collected maternal characteristics, laboratory results, condition in the third trimester, maternal outcome, fetal or neonatal outcomes, and characteristics of amniotic fluid, umbilical cord and placenta from pregnant women and fetals or newborns in the first affiliated hospital of Jinan university from 24 January to 31 March 2020 (peak period), chose the same types of data at the hospital during the same period in 2019 and 1 January-23 January 2020 (prior to the outbreak of COVID-19 in 2020) as a control. Our study focused on uncomplicated singleton pregnancies among women not infected by COVID-19. The results demonstrated that there was not an increase in adverse outcomes of pregnant women and newborns during the COVID-19 pandemic; This might be associated with the updated design of major epidemic prevention and control systems in Guangzhou, and the extension of pregnant women's rest time during the third trimester of pregnancy. Nevertheless, the survey showed an increased incidence rate of 25-hydroxyvitamin D and zinc deficiency in newborns during the epidemic, implying that pregnant women should participate in appropriate physical exercise, increase their exposure to outdoor sunlight and improve nutrition intake to ensure healthy newborns during the quarantine period. Our study has provided some guidance for maternal management during the COVID-19 pandemic.

High prevalence of vitamin D deficiency in Shenzhen pregnant women

BACKGROUND

Vitamin D deficiency is a public health problem worldwide. Vitamin D deficiency in pregnant women often leads to negative clinical consequence and has been distributed differently in certain latitudes. Here, we aimed to determine the prevalence of vitamin D deficiency in pregnant women in Shenzhen City and investigate the influencing factors.

METHODS

A total of 27,166 healthy pregnant women, undergoing prenatal examinations in our hospital between July 2014 and December 2018, were enrolled in our study. Maternal characteristics, including the duration of pregnancy, age and enrollment time, were recorded. The concentrations of serum 25(OH)D in the blood samples were detected by immunochemistry assays.

RESULTS

For the total study population, the median serum 25(OH)D concentration was 23.36 [17.98-29.51] ng/mL, and 34.3% and 42.4% of the participants exhibited vitamin D deficiency (serum 25(OH) D < 20 ng/mL) and insufficiency (serum 25(OH)D 21-29 ng/mL), respectively. Vitamin D deficiency decreased with gestation (37.83%, 33.8%, and 29.3% for the first trimester, second trimester and third trimester, respectively, p < .001) and decreased by age (36.03%, 35.20%, 31.86% and 29.83%, for the age groups 18-24, 25-29, 30-34 and 35-46 years, respectively, p < .001). This prevalence had conspicuous seasonality (winter vs. autumn, OR 3.69, 95% CI: 3.42-3.99, p < .001). Temperature was positively associated with women's serum 25(OH)D level (r = 0.48, p < .001).

CONCLUSIONS

Overall, we demonstrated that vitamin D deficiency in pregnant women in Shenzhen was common and was affected by gestation, age and season/temperature.

Maternal and fetal vitamin D and their roles in mineral homeostasis and fetal bone development

During pregnancy, female physiology adapts to meet the additional mineral demands of the developing fetus. Meanwhile, the fetus actively transports minerals across the placenta and maintains high circulating levels to mineralize the rapidly developing skeleton. Most of this mineral is accreted during the last trimester, including 30 g of calcium, 20 g of phosphate and 0.8 g of magnesium. Given the dependence of calcium homeostasis on vitamin D and calcitriol in the adult and child, it may be expected that vitamin D sufficiency would be even more critical during pregnancy and fetal development. However, the pregnant mother and fetus appear to meet their mineral needs independent of vitamin D. Adaptations in maternal mineral and bone metabolism during pregnancy appear to be invoked independent of maternal vitamin D, while fetal mineral metabolism and skeletal development appear to be protected from vitamin D deficiency and genetic disorders of vitamin D physiology. This review discusses key data from both animal models and human studies to address our current knowledge on the role of vitamin D and calcitriol during pregnancy and fetal development.

Hypoparathyroidism in Pregnancy and Lactation: Current Approach to Diagnosis and Management

Background: Hypoparathyroidism is an uncommon endocrine disorder. During pregnancy, multiple changes occur in the calcium-regulating hormones, which may affect the requirements of calcium and active vitamin D during pregnancy in patients with hypoparathyroidism. Close monitoring of serum calcium during pregnancy and lactation is ideal in order to optimize maternal and fetal outcomes. In this review, we describe calcium homeostasis during pregnancy in euparathyroid individuals and also review the diagnosis and management of hypoparathyroidism during pregnancy and lactation. Methods: We searched the MEDLINE, CINAHL, EMBASE, and Google scholar databases from 1 January 1990 to 31 December 2020. Case reports, case series, book chapters, and clinical guidelines were included in this review. Conclusions: During pregnancy, rises in 1,25-dihydroxyvitamin D (1,25-(OH)2-D3) and PTH-related peptide result in suppression of PTH and enhanced calcium absorption from the bowel. In individuals with hypoparathyroidism, the requirements for calcium and active vitamin D may decrease. Close monitoring of serum calcium is advised in women with hypoparathyroidism with adjustment of the doses of calcium and active vitamin D to ensure that serum calcium is maintained in the low-normal to mid-normal reference range. Hyper- and hypocalcemia should be avoided in order to reduce the maternal and fetal complications of hypoparathyroidism during pregnancy and lactation. Standard of care therapy consisting of elemental calcium, active vitamin D, and vitamin D is safe during pregnancy.

Vitamin D and the risk of dystocia: A case-control study

BACKGROUND

Dystocia is one of the most common causes of cesarean section in nulliparous women. Studies have described the presence of vitamin D receptors in the myometrium, but it is still unclear whether vitamin D affects the contractility of the smooth muscles. We therefore aimed to determine the association between the vitamin D serum level at labor and the risk of dystocia.

METHOD

We conducted a case-control study between January 2012 and June 2017. Cases were primiparous women, with spontaneous onset of labor, who gave birth by cesarean section due to dystocia. Controls were primiparous women with a spontaneous vaginal delivery. We included 60 women (30 cases and 30 controls) in the analysis. The differences between cases and controls were assessed using chi-squared test for categorical variables and two-sample t-test or unequal t-test for continuous variables, as appropriate, after evaluation of whether they followed the normal distributions.

RESULTS

The mean serum 25-hydroxyvitamin D concentrations were 53.1nmol/l (95%CI; 45.2 to 60.9) among cases and 69.9nmol/l (95%CI; 57.5 to 82.4) among controls (P = 0.02). The mean plasma parathyroid hormone levels were 2.25 pmol/l and 2.38, respectively (P = 0.57). Even though 78% of all women reported taking a minimum of 10μg/day of vitamin D throughout pregnancy, 43% had vitamin D insufficiency, defined as serum 25-hydroxyvitamin D levels below 50nmol/l.

CONCLUSIONS

In a Danish group of women having a cesarean section due to dystocia, we found decreased vitamin D levels.

Pregnancy-Related Bone Mineral and Microarchitecture Changes in Women Aged 30 to 45 Years

At birth, the neonatal skeleton contains 20 to 30 g calcium (Ca). It is hypothesized maternal bone mineral may be mobilized to support fetal skeletal development, although evidence of pregnancy-induced mineral mobilization is limited. We recruited healthy pregnant (n = 53) and non-pregnant non-lactating (NPNL; n = 37) women aged 30 to 45 years (mean age 35.4 ± 3.8 years) and obtained peripheral quantitative computed tomography (pQCT) and high-resolution pQCT (HR-pQCT) scans from the tibia and radius at 14 to 16 and 34 to 36 weeks of pregnancy, with a similar scan interval for NPNL. Multiple linear regression models were used to assess group differences in change between baseline and follow-up; differences are expressed as standard deviation scores (SDS) ± SEM. Decreases in volumetric bone mineral density (vBMD) outcomes were found in both groups; however, pregnancy-related decreases for pQCT total and trabecular vBMD were -0.65 ± 0.22 SDS and -0.50 ± 0.23 SDS greater (p < .05). HR-pQCT total and cortical vBMD decreased compared with NPNL by -0.49 ± 0.24 SDS and -0.67 ± 0.23 SDS, respectively; trabecular vBMD decreased in both groups to a similar magnitude. Pregnancy-related changes in bone microarchitecture significantly exceeded NPNL change for trabecular number (0.47 ± 0.23 SDS), trabecular separation (-0.54 ± 0.24 SDS), cortical thickness (-1.01 ± 0.21 SDS), and cortical perimeter (0.78 ± 0.23 SDS). At the proximal radius, cortical vBMD and endosteal circumference increased by 0.50 ± 0.23 SDS and 0.46 ± 0.23 SDS, respectively, compared with NPNL, whereas cortical thickness decreased -0.50 ± 0.22 SDS. Pregnancy-related decreases in total and compartment-specific vBMD exceed age-related change at the distal tibia. Changes at the radius were only evident with pQCT at the cortical-rich proximal site and suggest endosteal resorption. Although the magnitude of these pregnancy-related changes in the appendicular skeleton are small, if they reflect global changes across the skeleton at large, they may contribute substantially to the Ca requirements of the fetus. © 2020 Crown copyright. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

Vitamin D Deficiency and Autism Spectrum Disorder

Vitamin D is a neurosteroid hormone crucially involved in neurodevelopment. Neural cell proliferation, neurotransmission, oxidative stress and immune function represent the main mechanisms mediated by vitamin D in the Central Nervous System. Therefore, its deficiency during pregnancy and early childhood may significantly impact on a developing brain, leading to possible adverse neuropsychological outcomes including Autism Spectrum Disorder (ASD). Significant vitamin D deficiency is described within children affected by ASD and in pregnant mothers whose offspring will later develop ASD, suggesting a possible role of the hormone as a contributing risk factor in the etiopathogenesis of ASD. We reviewed the actual literature on the potential contributing role of prenatal and early postnatal vitamin D deficiency in ASD etiopathogenesis, at both genetic and environmental levels, and the possible effect of vitamin D supplementation in autistic children. Conflicting but promising results emerged on the topic. Further Randomized Controlled Trials studies carried out during pregnancy and early infancy are necessary for better understanding the possible contribution of vitamin D deficiency in the etiopathogenesis of autism and the potential efficacy of the hormone supplementation in the improvement of ASD core symptoms.

Summer Season and Recommended Vitamin D Intake Support Adequate Vitamin D Status throughout Pregnancy in Healthy Canadian Women and Their Newborns

BACKGROUND

Vitamin D deficiency in pregnancy is reported as a prevalent public health problem.

OBJECTIVES

We aimed to evaluate, in pregnant Canadian women, 1) vitamin D intake, 2) maternal and cord serum 25-hydroxycholecalciferol [25(OH)D] and maternal 1,25-dihydroxycholecalciferol [1,25(OH)2D], and 3) factors associated with maternal serum 25(OH)D.

METHODS

Women (n = 187; mean prepregnancy BMI 24.4 kg/m2, mean age 31 y) recruited to the Be Healthy in Pregnancy study provided fasting blood samples and nutrient intake at 12-17 (early) and 36-38 (late) weeks of gestation, and cord blood. Vitamin D intakes (Nutritionist Pro™) and serum 25(OH)D and 1,25(OH)2D concentrations (LC-tandem MS) were measured.

RESULTS

Vitamin D intake was comparable in early and late pregnancy [median (IQR) = 586 (459, 859) compared with 689 (544, 974) IU/d; P = 0.83], with 71% consumed as supplements. Serum 25(OH)D was significantly higher in late pregnancy (mean ± SD: 103.1 ± 29.3 nmol/L) than in early pregnancy (82.5 ± 22.5 nmol/L; P < 0.001) and no vitamin D deficiency (<30 nmol/L) occurred. Serum 1,25(OH)2D concentrations were significantly higher in late pregnancy (101.1 ± 26.9 pmol/L) than in early pregnancy (82.2 ± 19.2 pmol/L, P < 0.001, n = 84). Cord serum 25(OH)D concentrations averaged 55% of maternal concentrations. In adjusted multivariate analyses, maternal vitamin D status in early pregnancy was positively associated with summer season (est.β: 13.07; 95% CI: 5.46, 20.69; P < 0.001) and supplement intake (est.β: 0.01; 95% CI: 0.00, 0.01; P < 0.001); and in late pregnancy with summer season (est.β: 24.4; 95% CI: 15.6, 33.2; P < 0.001), nonmilk dairy intake (est.β: 0.17; 95% CI: 0.02, 0.32; P = 0.029), and supplement intake (est.β: 0.01; 95% CI: 0.00, 0.01; P = 0.04).

CONCLUSIONS

Summer season and recommended vitamin D intakes supported adequate vitamin D status throughout pregnancy and in cord blood at >50 nmol/L in healthy Canadian pregnant women. This trial was registered at clinicaltrials.gov as NCT01693510.

Measuring incremental line width and appearance in the tooth cementum of recent and archaeological human teeth to identify irregularities: First insights using a standardized protocol

OBJECTIVE

Irregular incremental lines (ILs) in the tooth cementum were previously associated with pregnancy and certain diseases. This study aims to identify irregular ILs and assess their patterns and reproducibility.

MATERIALS

24 recent and 32 archaeological teeth from the nineteenth century with known birth history.

METHODS

Histological sections of tooth roots were microscopically assessed. The width and appearance of 16,605 ILs were measured according to a standardized protocol.

RESULTS

Irregular appearing ILs were present in earlier deposited ILs, which correspond to younger years in life. Irregular appearances decreased as the IL number increased, whereas irregular width was spread evenly across all ILs. Within-section reproducibility was relatively high for irregular appearance (intra class correlation close to 0.70 in recent and archaeological teeth) and irregular width (intra class correlation: recent: 0.49; archaeological: 0.58), whereas the across-section reproducibility was moderate.

CONCLUSIONS

Irregular width and appearance in ILs were identified successfully with within-section reproducibility. The moderate reproducibility across sections needs to be addressed in further studies by more systematic sampling of sections.

SIGNIFICANCE

The proposed protocol identifies irregularities in a reproducible manner and may suggest that irregular ILs could be used in paleopathology to identify pregnancies and diseases.

LIMITATIONS

The correlation between the identified irregular ILs and known pregnancies has not been assessed as part of this study.

SUGGESTIONS FOR FURTHER RESEARCH

The identified irregular ILs need to be validated by correlating them with known life history data.

Regimens of vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D deficiency during pregnancy increases the risk of pre-eclampsia, gestational diabetes, preterm birth, and low birthweight. In a previous Cochrane Review we found that supplementing pregnant women with vitamin D alone compared to no vitamin D supplementation may reduce the risk of pre-eclampsia, gestational diabetes, and low birthweight and may increase the risk of preterm births if it is combined with calcium. However the effects of different vitamin D regimens are not yet clear.

OBJECTIVES

To assess the effects and safety of different regimens of vitamin D supplementation alone or in combination with calcium or other vitamins, minerals or nutrients during pregnancy, specifically doses of 601 international units per day (IU/d) or more versus 600 IU/d or less; and 4000 IU/d or more versus 3999 IU/d or less.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (12 July 2018), and the reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials evaluating the effect of different vitamin D regimens (dose, frequency, duration, and time of commencement of supplementation during pregnancy), alone or in combination with other nutrients on pregnancy and neonatal health outcomes. We only included trials that compared 601 IU/d or more versus 600 IU/d or less and 4000 IU/d or more versus 3999 IU/d or less. We did not include in the analysis groups that received no vitamin D, as that comparison is assessed in another Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently: i) assessed the eligibility of studies against the inclusion criteria; ii) extracted data from included studies, and iii) assessed the risk of bias of the included studies. Our primary maternal outcomes were: pre-eclampsia, gestational diabetes, and any adverse effects; our primary infant outcomes were preterm birth and low birthweight. Data were checked for accuracy. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

In this review, we included data from 30 trials involving 7289 women. We excluded 11 trials, identified 16 ongoing/unpublished trials and two trials are awaiting classification. Overall risk of bias for the trials was mixed.Comparison 1. 601 IU/d or more versus 600 IU/d or less of vitamin D alone or with any other nutrient (19 trials; 5214 participants)Supplementation with 601 IU/d or more of vitamin D during pregnancy may make little or no difference to the risk of pre-eclampsia (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.65 to 1.42); 5 trials; 1553 participants,low-certainty evidence), may reduce the risk of gestational diabetes (RR 0.54, 95% CI 0.34 to 0.86; 5 trials; 1846 participants; moderate-certainty evidence), may make little or no difference to the risk of preterm birth (RR 1.25, 95% CI 0.92 to 1.69; 4 trials; 2294 participants; low-certainty evidence); and may make little or no difference to the risk of low birthweight (RR 0.90, 95% CI 0.66 to 1.24; 4 trials; 1550 participants; very low-certainty evidence) compared to women receiving 600 IU/d or less.Comparison 2. 4000 IU or more versus 3999 IU or less of vitamin D alone (15 trials; 4763 participants)Supplementation with 4000 IU/d or more of vitamin D during pregnancy may make little or no difference to the risk of: pre-eclampsia (RR 0.87, 95% CI 0.62 to 1.22; 4 trials, 1903 participants, low-certainty evidence); gestational diabetes (RR 0.89, 95% CI 0.56 to 1.42; 5 trials, 2276 participants; low-certainty evidence); preterm birth (RR 0.85, 95% CI 0.64 to 1.12; 6 trials, 2948 participants, low-certainty evidence); and low birthweight (RR 0.92, 95% CI 0.49 to 1.70; 2 trials; 1099 participants; low-certainty evidence) compared to women receiving 3999 IU/d or less.Adverse events (such as hypercalcaemia, hypocalcaemia, hypercalciuria, and hypovitaminosis D) were reported differently in most trials; however, in general, there was little to no side effects reported or similar cases between groups.

AUTHORS' CONCLUSIONS

Supplementing pregnant women with more than the current vitamin D recommendation may reduce the risk of gestational diabetes; however, it may make little or no difference to the risk of pre-eclampsia, preterm birth and low birthweight. Supplementing pregnant women with more than the current upper limit for vitamin D seems not to increase the risk of the outcomes evaluated. In general, the GRADE was considered low certainty for most of the primary outcomes due to serious risk of bias and imprecision of results. With respect to safety, it appears that vitamin D supplementation is a safe intervention during pregnancy, although the parameters used to determine this were either not reported or not consistent between trials. Future trials should be consistent in their reports of adverse events. There are 16 ongoing trials that when published, will increase the body of knowledge.

Vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D supplementation during pregnancy may be needed to protect against adverse pregnancy outcomes. This is an update of a review that was first published in 2012 and then in 2016.

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 maternal and neonatal outcomes.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register (12 July 2018), contacted relevant organisations (15 May 2018), reference lists of retrieved trials and registries at clinicaltrials.gov and WHO International Clinical Trials Registry Platform (12 July 2018). Abstracts were included if they had enough information to extract the data.

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 trials against the inclusion criteria, ii) extracted data from included trials, and iii) assessed the risk of bias of the included trials. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 30 trials (7033 women), excluded 60 trials, identified six as ongoing/unpublished trials and two trials are awaiting assessments.Supplementation with vitamin D alone versus placebo/no interventionA total of 22 trials involving 3725 pregnant women were included in this comparison; 19 trials were assessed as having low-to-moderate risk of bias for most domains and three trials were assessed as having high risk of bias for most domains. Supplementation with vitamin D alone during pregnancy probably reduces the risk of pre-eclampsia (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.30 to 0.79; 4 trials, 499 women, moderate-certainty evidence) and gestational diabetes (RR 0.51, 95% CI 0.27 to 0.97; 4 trials, 446 women, moderate-certainty evidence); and probably reduces the risk of having a baby with low birthweight (less than 2500 g) (RR 0.55, 95% CI 0.35 to 0.87; 5 trials, 697 women, moderate-certainty evidence) compared to women who received placebo or no intervention. Vitamin D supplementation may make little or no difference in the risk of having a preterm birth < 37 weeks compared to no intervention or placebo (RR 0.66, 95% CI 0.34 to 1.30; 7 trials, 1640 women, low-certainty evidence). In terms of maternal adverse events, vitamin D supplementation may reduce the risk of severe postpartum haemorrhage (RR 0.68, 95% CI 0.51 to 0.91; 1 trial, 1134 women, low-certainty evidence). There were no cases of hypercalcaemia (1 trial, 1134 women, low-certainty evidence), and we are very uncertain as to whether vitamin D increases or decreases the risk of nephritic syndrome (RR 0.17, 95% CI 0.01 to 4.06; 1 trial, 135 women, very low-certainty evidence). However, given the scarcity of data in general for maternal adverse events, no firm conclusions can be drawn.Supplementation with vitamin D and calcium versus placebo/no interventionNine trials involving 1916 pregnant women were included in this comparison; three trials were assessed as having low risk of bias for allocation and blinding, four trials were assessed as having high risk of bias and two had some components having a low risk, high risk, or unclear risk. Supplementation with vitamin D and calcium during pregnancy probably reduces the risk of pre-eclampsia (RR 0.50, 95% CI 0.32 to 0.78; 4 trials, 1174 women, moderate-certainty evidence). The effect of the intervention is uncertain on gestational diabetes (RR 0.33,% CI 0.01 to 7.84; 1 trial, 54 women, very low-certainty evidence); and low birthweight (less than 2500 g) (RR 0.68, 95% CI 0.10 to 4.55; 2 trials, 110 women, very low-certainty evidence) compared to women who received placebo or no intervention. Supplementation with vitamin D and calcium during pregnancy may increase the risk of preterm birth < 37 weeks in comparison to women who received placebo or no intervention (RR 1.52, 95% CI 1.01 to 2.28; 5 trials, 942 women, low-certainty evidence). No trial in this comparison reported on maternal adverse events.Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D)One trial in 1300 participants was included in this comparison; it was assessed as having low risk of bias. Pre-eclampsia was not assessed. Supplementation with vitamin D + other nutrients may make little or no difference in the risk of preterm birth < 37 weeks (RR 1.04, 95% CI 0.68 to 1.59; 1 trial, 1298 women, low-certainty evidence); or low birthweight (less than 2500 g) (RR 1.12, 95% CI 0.82 to 1.51; 1 trial, 1298 women, low-certainty evidence). It is unclear whether it makes any difference to the risk of gestational diabetes (RR 0.42, 95% CI 0.10 to 1.73) or maternal adverse events (hypercalcaemia no events; hypercalciuria RR 0.25, 95% CI 0.02 to 3.97; 1 trial, 1298 women,) because the certainty of the evidence for both outcomes was found to be very low.

AUTHORS' CONCLUSIONS

We included 30 trials (7033 women) across three separate comparisons. Our GRADE assessments ranged from moderate to very low, with downgrading decisions based on limitations in study design, imprecision and indirectness.Supplementing pregnant women with vitamin D alone probably reduces the risk of pre-eclampsia, gestational diabetes, low birthweight and may reduce the risk of severe postpartum haemorrhage. It may make little or no difference in the risk of having a preterm birth < 37 weeks' gestation. Supplementing pregnant women with vitamin D and calcium probably reduces the risk of pre-eclampsia but may increase the risk of preterm births < 37 weeks (these findings warrant further research). Supplementing pregnant women with vitamin D and other nutrients may make little or no difference in the risk of preterm birth < 37 weeks' gestation or low birthweight (less than 2500 g). 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.

Standards of care for hypoparathyroidism in adults: a Canadian and International Consensus

PURPOSE

To provide practice recommendations for the diagnosis and management of hypoparathyroidism in adults.

METHODS

Key questions pertaining to the diagnosis and management of hypoparathyroidism were addressed following a literature review. We searched PubMed, MEDLINE, EMBASE and Cochrane databases from January 2000 to March 2018 using keywords 'hypoparathyroidism, diagnosis, treatment, calcium, PTH, calcidiol, calcitriol, hydrochlorothiazide and pregnancy'. Only English language papers involving humans were included. We excluded letters, reviews and editorials. The quality of evidence was evaluated based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. These standards of care for hypoparathyroidism have been endorsed by the Canadian Society of Endocrinology and Metabolism.

RESULTS

Hypoparathyroidism is a rare disease characterized by hypocalcemia, hyperphosphatemia and a low or inappropriately normal serum parathyroid hormone level (PTH). The majority of cases are post-surgical (75%) with nonsurgical causes accounting for the remaining 25% of cases. A careful review is required to determine the etiology of the hypoparathyroidism in individuals with nonsurgical disease. Hypoparathyroidism is associated with significant morbidity and poor quality of life. Treatment requires close monitoring as well as patient education. Conventional therapy with calcium supplements and active vitamin D analogs is effective in improving serum calcium as well as in controlling the symptoms of hypocalcemia. PTH replacement is of value in lowering the doses of calcium and active vitamin D analogs required and may be of value in lowering long-term complications of hypoparathyroidism. This manuscript addresses acute and chronic management of hypoparathyroidism in adults.

MAIN CONCLUSIONS

Hypoparathyroidism requires careful evaluation and pharmacologic intervention in order to improve serum calcium and control the symptoms of hypocalcemia. Frequent laboratory monitoring of the biochemical profile and patient education is essential to achieving optimal control of serum calcium.

Disparities in the timing and measurement methods to assess vitamin D status during pregnancy: A Narrative Review

Studies that examined associations between low circulating 25-hydroxyvitamin D (25(OH)D) and adverse pregnancy outcomes used various designs, assay methods and time points for measurement of 25(OH)D concentrations, which creates some confusion in the current literature. We aimed to investigate the variability in the timing and measurement methods used to evaluate vitamin D status during pregnancy. Analysis of 198 studies published between 1976 and 2017 showed an important variability in the choice of 1) threshold values for 25(OH)D insufficiency or deficiency, 2) 25(OH)D measurement methods, and 3) trimester in which 25(OH)D concentrations were measured. Blood samples were taken once during pregnancy in a large majority of studies, which may not be representative of vitamin D status throughout pregnancy. Most studies reported adjustment for confounding factors including season of blood sampling, but very few studies used the 25(OH)D gold standard assay, the LC-MS/MS. Prospective studies assessing maternal 25(OH)D concentrations 1) by standardized and validated methods, 2) at various time points during pregnancy, and 3) after considering potential confounding factors, are needed.

The role of vitamin D in perinatology. An up-to-date review

The role of vitamin D in perinatology is a subject of major interest in current medicine. There is growing evidence about the role of maternal vitamin D levels in pregnancy outcomes. The aim of this review is to summarize the current literature about the role of vitamin D in perinatology. Evidence from this review suggests associations between low levels of maternal vitamin D and higher risk of certain obstetrical complications. Vitamin D has been found to be related to preeclampsia, gestational diabetes mellitus, low birth weight, and preterm birth. The current literature supports vitamin D supplementation in pregnant women, but more high-quality data are necessary. The problem that remains is how to achieve an optimal 25-hydroxyvitamin D level. To determine the real benefits of vitamin D supplementation in pregnancy, we need high-quality trials in larger groups.

Structured diet and exercise guidance in pregnancy to improve health in women and their offspring: study protocol for the Be Healthy in Pregnancy (BHIP) randomized controlled trial

BACKGROUND

Evidence from epidemiological and animal studies support the concept of programming fetal, neonatal, and adult health in response to in utero exposures such as maternal obesity and lifestyle variables. Excess gestational weight gain (GWG), maternal physical activity, and sub-optimal and excess nutrition during pregnancy may program the offspring's risk of obesity. Maternal intake of dairy foods rich in high-quality proteins, calcium, and vitamin D may influence later bone health status. Current clinical practice guidelines for managing GWG are not founded on randomized trials and lack specific "active intervention ingredients." The Be Healthy in Pregnancy (BHIP) study is a randomized controlled trial (RCT) designed to test the effectiveness of a novel structured and monitored Nutrition + Exercise intervention in pregnant women of all pre-pregnancy weight categories (except extreme obesity), delivered through prenatal care in community settings (rather than in hospital settings), on the likelihood of women achieving recommended GWG and a benefit to bone status of offspring and mother at birth and six months postpartum.

METHODS

The BHIP study is a two-site RCT that will recruit up to 242 participants aged > 18 years at 12-17 weeks of gestation. After baseline measures, participants are randomized to either a structured and monitored Nutrition + Exercise (intervention) or usual care (control) program for the duration of their pregnancy. The primary outcome of the study is the percent of women who achieve GWG within the Institute of Medicine (IOM) guidelines. The secondary outcomes include: (1) maternal bone status via blood bone biomarkers during pregnancy; (2) infant bone status in cord blood; (3) mother and infant bone status measured by dual-energy absorptiometry scanning (DXA scan) at six months postpartum; (4) other measures including maternal blood pressure, blood glucose and lipid profiles, % body fat, and postpartum weight retention; and (5) infant weight z-scores and fat mass at six months of age.

DISCUSSION

If effective, this RCT will generate high-quality evidence to refine the nutrition guidelines during pregnancy to improve the likelihood of women achieving recommended GWG. It will also demonstrate the importance of early nutrition on bone health in the offspring.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01689961 Registered on 21 September 2012.

High maternal osteocalcin levels during pregnancy is associated with low birth weight infants: A nested case-control study in China

BACKGROUND

Low birth weight infants (LBW) are at risk of chronic diseases in later life due to the disorder of energy metabolism during pregnancy. Osteocalcin (OC) has been identified as a hormone that regulate energy metabolism. However, few studies have researched on the associations between maternal serum OC levels and low birth weight infants.

OBJECTIONS

To examine the associations between maternal serum OC concentrations and LBW.

METHODS

This was a nested case-control study involving a total of 230 pregnant women delivering LBW and 382 control pregnant women (matched for infant gender, gestational age at blood draw, region of Maternity and Child Healthcare Hospital and maternal age in 1: (1-2) ratio). One serum sample was collected from each pregnant woman at 5-35 weeks' gestation. Pregnant women were divided into 3 groups (1st, 2nd and 3rd trimester group). There were 60 and 142 and 28 pregnant women delivering LBW in the first, second and third trimester, respectively. Similarly, there were 101 and 233 and 48 controls in the first, second and third trimester, respectively. Maternal serum OC and 25(OH)D concentrations were categorized into low and high levels, the low level used as reference in analyses. Binary logistic regression model was used to compute odd radio (ORs) for LBW according to levels of maternal serum OC and 25(OH)D.

RESULTS

Compared with the subjects in low level in first trimester, LBW was two times as likely to occur among pregnancy women with high serum OC concentrations (OR = 2.04, 95%CI:1.05-3.96). After adjusted for confounding factors, a significant positive relationship still existed (adjusted ORs = 2.29, 95%CI: 1.11-4.72). In second trimester, women in high level of serum OC had nearly 1.6 times the risk of delivering LBW infants as those in the low level (OR = 1.55, 95%CI: 1.01-2.37). After adjusted for confounding factors, the ORs increased (ORs = 1.59, 95%CI:1.03-2.45). No significant associations were found between maternal serum OC levels and LBW in third trimester. In addition, there were no associations between maternal 25(OH)D concentrations and LBW during pregnancy.

CONCLUSION

High maternal serum OC levels in the first or the second trimester during pregnancy may be associated with the risk of LBW.

Vitamin D: effects on pregnancy, maternal, fetal and postnatal outcomes

A high prevalence of vitamin D deficiency and its negative consequences for health is identified as area of primary concern for scientists and clinicians worldwide. Vitamin D deficiency affects not only bone health but many socially significant acute and chronic diseases. Observational studies support that pregnant and lactating women, children and teenagers represent the high risk groups for developing vitamin D deficiency. Current evidence highlights a crucial role of vitamin D in providing the fetal life-support system and fetus development, including implantation, placental formation, intra - and postpartum periods. Hypovitaminosis D during pregnancy is associated with a higher incidence of placental insufficiency, spontaneous abortions and preterm birth, preeclampsia, gestational diabetes, impaired fetal and childhood growth, increased risk of autoimmune diseases for offsprings. Potential mechanisms for the observed associations contain metabolic, immunomodulatory and antiinflammatory effects of vitamin D. Epigenetic modifications in vitamin D-associated genes and fetal programming are of particular interest. The concept of preventing vitamin D deficiency is actively discussed, including supplementation in different ethnic groups, required doses, time of initiation and therapy duration, influence on gestation and childbirth. An adequate supply of vitamin D during pregnancy improves the maternal and fetal outcomes, short and long term health of the offspring. Still current data on relationship between maternal vitamin D status and pregnancy outcomes remains controversial. The large observational and interventional randomized control trials are required to create evidence-based guidelines for the supplementation of vitamin D in pregnant and lactating women.

The Role of Vitamin D in Fertility and during Pregnancy and Lactation: A Review of Clinical Data

Vitamin D deficiency is common and there exists a huge gap between recommended dietary vitamin D intakes and the poor vitamin D supply in the general population. While vitamin D is important for musculoskeletal health, there are accumulating data suggesting that vitamin D may also be important for fertility, pregnancy outcomes and lactation. Significant changes in vitamin D metabolism during pregnancy such as increased production of the “active vitamin D hormone” calcitriol support the important role of vitamin D in this setting. Observational studies show that vitamin D deficiency is a risk marker for reduced fertility and various adverse pregnancy outcomes and is associated with a low vitamin D content of breast milk. Meta-analyses of randomized controlled trials (RCTs) document that physiological vitamin D supplementation during pregnancy is safe and improves vitamin D and calcium status, thereby protecting skeletal health. Although certain RCTs and/or meta-analyses reported some other beneficial effects, it is still not clear whether vitamin D supplementation improves fertility or decreases the risk of adverse pregnancy outcomes such as low birth weight, pre-eclampsia and neonatal mortality, or reduces wheeze/asthma in the infants. Nevertheless, vitamin D supplementation in pregnant women is frequently required to achieve a sufficient vitamin D status as recommended by nutritional vitamin D guidelines. In this review, we provide an overview of systematic reviews, meta-analyses and large trials reporting clinical data on the role of vitamin D for fertility, pregnancy and lactation.

Exploring the concept of functional vitamin D deficiency in pregnancy: impact of the interaction between 25-hydroxyvitamin D and parathyroid hormone on perinatal outcomes

Background

Associations of vitamin D with perinatal outcomes are inconsistent and few studies have considered the wider calcium metabolic system.

Objectives

We aimed to explore functional vitamin D deficiency in pregnancy by investigating associations between vitamin D status, parathyroid hormone (PTH), and perinatal outcomes.

Design

SCOPE (Screening for Pregnancy Endpoints) Ireland is a prospective cohort study of low-risk, nulliparous pregnant women. We measured serum 25-hydroxyvitamin D [25(OH)D] and PTH at 15 wk of gestation in 1754 participants.

Results

Mean ± SD 25(OH)D was 56.6 ± 25.8 nmol/L (22.7 ± 10.3 ng/mL) and geometric mean (95% CI) PTH was 7.84 pg/mL (7.7, 8.0 pg/mL) [0.86 pmol/L (0.85, 0.88 pmol/L)]. PTH was elevated in 34.3% of women who had 25(OH)D <30 nmol/L and in 13.9% of those with 25(OH)D ≥75 nmol/L. Whereas 17% had 25(OH)D <30 nmol/L, 5.5% had functional vitamin D deficiency, defined as 25(OH)D <30 nmol/L with elevated PTH. Elevated mean arterial pressure (MAP), gestational hypertension, pre-eclampsia, and small-for-gestational-age (SGA) birth were confirmed in 9.2%, 11.9%, 3.8%, and 10.6% of participants, respectively. In fully adjusted regression models, neither low 25(OH)D nor elevated PTH alone increased the risk of any individual outcome. The prevalence of elevated MAP (19.1% compared with 9.7%) and SGA (16.0% compared with 6.7%) were highest (P < 0.05) in those with functional vitamin D deficiency compared with the reference group [25(OH)D ≥75 nmol/L and normal PTH]. The adjusted prevalence ratio (PR) and RR (95% CIs) for elevated MAP and SGA were 1.83 (1.02, 3.27) and 1.53 (0.80, 2.93), respectively. There was no effect of functional vitamin D deficiency on the risk of gestational hypertension (adjusted RR: 1.00; 95% CI: 0.60, 1.67) or pre-eclampsia (adjusted RR: 1.17; 95% CI: 0.32, 4.20).

Conclusion

The concept of functional vitamin D deficiency, reflecting calcium metabolic stress, should be considered in studies of vitamin D in pregnancy. The SCOPE pregnancy cohort is registered at http://www.anzctr.org.au as ACTRN12607000551493.

Interactions between Vitamin D Status, Calcium Intake and Parathyroid Hormone Concentrations in Healthy White-Skinned Pregnant Women at Northern Latitude

Adverse effects of low vitamin D status and calcium intakes in pregnancy may be mediated through functional effects on the calcium metabolic system. Little explored in pregnancy, we aimed to examine the relative importance of serum 25-hydroxyvitamin D (25(OH)D) and calcium intake on parathyroid hormone (PTH) concentrations in healthy white-skinned pregnant women. This cross-sectional analysis included 142 participants (14 ± 2 weeks' gestation) at baseline of a vitamin D intervention trial at 51.9 °N. Serum 25(OH)D, PTH, and albumin-corrected calcium were quantified biochemically. Total vitamin D and calcium intakes (diet and supplements) were estimated using a validated food frequency questionnaire. The mean ± SD vitamin D intake was 10.7 ± 5.2 μg/day. With a mean ± SD serum 25(OH)D of 54.9 ± 22.6 nmol/L, 44% of women were <50 nmol/L and 13% <30 nmol/L. Calcium intakes (mean ± SD) were 1182 ± 488 mg/day and 23% of participants consumed <800 mg/day. The mean ± SD serum albumin-adjusted calcium was 2.2 ± 0.1 mmol/L and geometric mean (95% CI) PTH was 9.2 (8.4, 10.2) pg/mL. PTH was inversely correlated with serum 25(OH)D (r = -0.311, p < 0.001), but not with calcium intake or serum calcium (r = -0.087 and 0.057, respectively, both p > 0.05). Analysis of variance showed that while serum 25(OH)D (dichotomised at 50 nmol/L) had a significant effect on PTH (p = 0.025), calcium intake (<800, 800⁻1000, ≥1000 mg/day) had no effect (p = 0.822). There was no 25(OH)D-calcium intake interaction effect on PTH (p = 0.941). In this group of white-skinned women with largely sufficient calcium intakes, serum 25(OH)D was important for maintaining normal PTH concentration.

Impact of vitamin D on pregnancy-related disorders and on offspring outcome

Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for preeclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.

Mal de Debarquement Syndrome: A Retrospective Online Questionnaire on the Influences of Gonadal Hormones in Relation to Onset and Symptom Fluctuation

Introduction

Mal de Debarquement Syndrome (MdDS) is a condition characterized by a persistent perception of self-motion, in most cases triggered from exposure to passive motion (e.g., boat travel, a car ride, flights). Patients whose onset was triggered in this way are categorized as Motion-Triggered (MT) subtype or onset group. However, the same syndrome can occur spontaneously or after non-motion events, such as childbirth, high stress, surgery, etc. Patients who were triggered in this way are categorized as being of the Spontaneous/Other (SO) subtype or onset group. The underlying pathophysiology of MdDS is unknown and there has been some speculation that the two onset groups are separate entities. However, despite the differences in onset between the subtypes, symptoms are parallel and a significant female predominance has been shown. To date, the role of gonadal hormones in MdDS pathophysiology has not been investigated. This study aimed to evaluate the hormonal profile of MdDS patients, the presence of hormonal conditions, the influence of hormones on symptomatology and to assess possible hormonal differences between onset groups. In addition, the prevalence of migraine and motion sickness and their relation to MdDS were assessed.

Method

Retrospective online surveys were performed in 370 MdDS patients from both onset groups. Data were analyzed using Fisher’s exact test or Fisher-Freeman-Hanlon exact test. When possible, data were compared with normative statistical data from the wider literature.

Results

From the data collected, it was evident that naturally cycling female respondents from the MT group were significantly more likely to report an aggravation of MdDS symptoms during menses and mid-cycle (p < 0.001). A few preliminary differences between the onset groups were highlighted such as in regular menstrual cycling (p = 0.028), reporting menses during onset (p < 0.016), and migraine susceptibility after onset (p = 0.044).

Conclusion

These results demonstrate a potential relation between hormone fluctuations and symptom aggravation in the MT group. This study is an important first step to suggest a hormonal involvement in the pathophysiology of MdDS and provides a base for further hormonal investigation. Future prospective studies should expand upon these results and explore the implications for treatment.

Osteoporosis in premenopausal women

PURPOSE OF REVIEW

The scope of this review was to review the newest developments in the context of the existing knowledge on premenopausal bone fragility. Fragility fractures are common in postmenopausal women and men and diagnostic criteria for osteoporosis have been agreed and multiple pharmacological treatments have been developed over the last 25 years. In premenopausal women, fragility fractures and very low bone mass are uncommon and osteoporosis in premenopausal women has therefore attracted much less interest.

RECENT FINDINGS

Recent studies have highlighted that lifestyle and dietary habits affect premenopausal bone mass. Bone mass may be improved by sufficient intake of calcium and vitamin D together with increased physical activity in premenopausal women with idiopathic osteoporosis. If pharmacological treatment is needed, teriparatide has been demonstrated to efficiently increase bone mass; however, no fracture studies and no comparative studies against antiresorptive therapies have been conducted. Pregnancy affects bone turnover and mass significantly, but pregnancy-associated osteoporosis is a rare and heterogeneous condition.

SUMMARY

The diagnosis of osteoporosis should only be considered in premenopausal women with existing fragility fractures, diseases or treatments known to cause bone loss or fractures. Secondary causes of osteoporosis should be corrected or treated if possible. The women should be recommended sufficient intake of calcium and vitamin and physical activity. In women with recurrent fractures or secondary causes that cannot be eliminated, for example glucocorticoid or cancer treatment, pharmacological intervention with bisphosphonates or teriparatide (not in the case of cancer) may be considered.

Strategies Developed to Induce, Direct, and Potentiate Bone Healing

Bone exhibits a great ability for endogenous self-healing. Nevertheless, impaired bone regeneration and healing is on the rise due to population aging, increasing incidence of bone trauma and the clinical need for the development of alternative options to autologous bone grafts. Current strategies, including several biomolecules, cellular therapies, biomaterials, and different permutations of these, are now developed to facilitate the vascularization and the engraftment of the constructs, to recreate ultimately a bone tissue with the same properties and characteristics of the native bone. In this review, we browse the existing strategies that are currently developed, using biomolecules, cells and biomaterials, to induce, direct and potentiate bone healing after injury and further discuss the biological processes associated with this repair.

Pregnancy-related fractures: a retrospective study of a French cohort of 52 patients and review of the literature

A retrospective, multicentre study involving 52 patients was carried out to define the causes and characteristics of pregnancy-related osteoporosis. The mean number of vertebral fractures occurring during the last trimester of pregnancy or at the time of delivery was 3.8. This is often promoted by risk factors before or during pregnancy.

INTRODUCTION

In order to define the causes or predisposing factors of pregnancy-related osteoporosis and its clinical, radiological and bone density characteristics, laboratory findings, course and outcome, we carried out a retrospective multicentre study.

METHODS

The records of 52 women hospitalised over the last 10 years in the rheumatology departments of six French university hospitals and with a diagnosis of pregnancy-related osteoporosis were examined.

RESULTS

The patients' mean age at time of fracture was 32.1 years. In 10 patients, the fractures had occurred during the last trimester of pregnancy, and in 36 at the time of delivery or during the first 2 months post-partum. The mean number of vertebral fractures was 3.8 ± 2.0. Thirty three of the 52 patients had a risk factor of low bone mass before pregnancy. Twelve had disorders or treatments (heparin) that might promote osteoporosis during pregnancy, while 14 had no trigger factors before or during pregnancy. Overall, phosphate and calcium levels were normal, except for hyperphosphoraemia in lactating women (90%). On DXA scan, osteoporosis predominated in the trabecular bone (spinal T-score - 3.4, hip T-score - 2). Only 10 patients had a repeat fracture, and the increase in bone mineral density during follow-up was considerable, and improved by bisphosphonates (annual gain + 10% in the spine) or teriparatide (+ 15%).

CONCLUSIONS

Pregnancy-related osteoporosis gives rise to multiple vertebral fractures. It is often promoted by risk factors before or during pregnancy. Its mechanism is still unknown. Treatment with bisphosphonates or teriparatide appears to improve the recovery of bone mineral density.

Vitamin D in pregnancy: current perspectives and future directions

As neonatal vitamin D status is determined by circulating maternal 25-hydroxyvitamin D [25(OH)D] concentrations, prevention of maternal vitamin D deficiency during pregnancy is essential for the avoidance of neonatal deficiency. However, a high prevalence of vitamin D deficiency has been extensively reported among gravidae and neonates from ethnic minorities and white populations resident at high latitude. Currently, regulatory authorities recommend vitamin D intakes for pregnant women that are similar to non-pregnant adults of the same age, at 10-15 µg/day (400-600 IU), to meet 25(OH)D thresholds of 25-50 nmol/liter. The lack of pregnancy-specific dietary recommendations is due to inadequate data indicating whether nutritional requirements for vitamin D during pregnancy differ from the non-pregnant state. In addition, there are few dose-response studies to determine the maternal 25(OH)D response to vitamin D intake throughout pregnancy at high latitude. These data are also required to determine vitamin D requirements during pregnancy for prevention of neonatal deficiency, an outcome which is likely to require a higher maternal 25(OH)D concentration than prevention of maternal deficiency only. With regard to the impact of vitamin D on perinatal health outcomes, which could guide pregnancy-specific 25(OH)D thresholds, dietary intervention studies to date have been inconsistent and recent systematic reviews have highlighted issues of low quality and a high risk of bias as drawbacks in the trial evidence to date. Many observational studies have been hampered by a reliance on retrospective data, unclear reporting, suboptimal clinical phenotyping and incomplete subject characterization. Current investigations of vitamin D metabolism during pregnancy have potentially exciting implications for clinical research. This paper provides an update of current dietary recommendations for vitamin D in pregnant women and a synopsis of the evidence relating vitamin D status with maternal and infant health.

Maternal vitamin D biomarkers are associated with maternal and fetal bone turnover among pregnant women consuming controlled amounts of vitamin D, calcium, and phosphorus

Vitamin D plays a central role in calcium homeostasis; however, its relationship with bone turnover during pregnancy remains unclear due to a lack of studies that have rigorously controlled for vitamin D and other nutrients known to influence bone metabolism. Similarly, prior investigations of the effect of pregnancy on bone turnover relative to the nonpregnant state may have been confounded by varying intakes of these nutrients. Nested within a controlled intake study, the present investigation sought to quantify associations between maternal vitamin D biomarkers and biochemical markers of bone turnover among pregnant (versus nonpregnant) women and their fetuses under conditions of equivalent and adequate intakes of vitamin D and related nutrients. Changes in markers of bone turnover across the third trimester were also examined. Healthy pregnant (26-29 wk gestation; n=26) and nonpregnant (n=21) women consumed 511IU vitamin D/d, 1.6g calcium/d, and 1.9g phosphorus/d for 10weeks while participating in a controlled feeding study featuring two choline doses. Based on linear mixed models adjusted for influential covariates (e.g., BMI, ethnicity, and season), pregnant women had 50-150% higher (P<0.001) concentrations of bone resorption markers than nonpregnant women. Among pregnant women, increases in maternal 25(OH)D across the study period were associated (P<0.020) with lower osteocalcin and deoxypyridinoline at study-end, and higher fetal osteocalcin. In addition, maternal free 25(OH)D, 1,25(OH)₂D and 24,25(OH)₂D tended to be negatively associated (P≤0.063) with maternal NTx at study-end, and maternal free 25(OH)D and 24,25(OH)₂D were positively associated (P≤0.021) with fetal CTx. Similarly, maternal 3-epi-25(OH)D₃ was negatively related (P≤0.037) to maternal NTx and deoxypyridinoline at study-end. These declines in bone resorption markers resulting from higher vitamin D biomarker concentrations among pregnant women coincided with increases in their albumin-corrected serum calcium concentrations, indicating that calcium transfer to the fetus was uncompromised. Notably, none of these associations achieved statistical significance among nonpregnant women. Overall, our study findings suggest that achieving higher maternal concentrations of vitamin D biomarkers might attenuate third-trimester bone resorption while ensuring sufficient calcium delivery to the fetus.

Maternal serum vitamin D and parathormone concentrations during gestation and in umbilical cord blood - pilot study

OBJECTIVE

We wanted to define levels of vitamin D (25(OH)D), parathormone (PTH), calcium (Ca), phosphorus (P) and the correlations between them during gestation as well as in umbilical cord blood.

METHODS

The study included 37 healthy singleton pregnant women in the course of gestation with no medical history concerning systemic diseases, nor with negative obstetrics and gynecological history. Biochemical parameters were determined using commercially available kits.

RESULTS

In the studied group, there were no significant differences in serum vitamin D, PTH, Ca and P concentrations in each trimester and during delivery. The negative significant association between serum 25(OH)D and PTH level was observed (r=-0.25; p< 0.05). Vitamin D levels during the summer season were significantly higher than observed in winter time in I (p< 0.01) and II trimester (p< 0.05), but not in III trimester. There was positive correlation between maternal serum and cord blood 25(OH)D (r= 0.74; p < 0.01). It was noted that 38-48% mothers had severe deficiency of vitamin D.

CONCLUSION

The study showed that regardless of the supplementation only 11-21% of studied pregnant women had optimal levels of vitamin D. The association between maternal and cord blood 25(OH)D suggested that inadequate vitamin D stores- during pregnancy may lead to a deficiency of this vitamin in newborns.

Vitamin D supplementation during pregnancy: Updated meta-analysis on maternal outcomes

BACKGROUND

Vitamin D deficiency is highly prevalent during pregnancy. It has been suggested that vitamin D supplementation during pregnancy may reduce the risk of adverse gestational outcomes.

OBJECTIVES

To update a previous meta-analysis on the effects of oral vitamin D supplementation (alone or in combination with other vitamins and minerals) during pregnancy on maternal 25(OH)D levels and risk of developing pre-eclampsia, gestational diabetes, preterm birth, impaired glucose tolerance, caesarean section, gestational hypertension and other adverse conditions.

METHODS

We searched for randomized and quasi-randomized trials through the Cochrane Pregnancy and Childbirth Group's Trials Register, the International Clinical Trials Registry Platform, the Networked Digital Library of Theses and Dissertations, and direct communications with relevant organizations. Assessments of inclusion criteria, extraction of data from included studies, and risk of bias' assessments of the included studies were done independently by two review authors.

RESULTS

We included 15 trials, excluded 27 trials and 23 trials are still ongoing/unpublished. Data from seven trials with 868 women suggest that pregnant women supplemented with vitamin D had significantly higher 25(OH)D levels compared to controls (mean difference: 54.7nmol/L; 95% CI 36.6, 72.9). Two trials found a lower risk of preeclampsia (8.9% versus 15.5%; average risk ratio 0.52; 95% CI 0.25, 1.05) and two other trials found no difference in the risk of gestational diabetes with vitamin D supplementation. Also, three trials found that supplementation with vitamin D plus calcium reduced the risk of pre-eclampsia (5% versus 9%; average risk ratio 0.51; 95% CI 0.32, 0.80).

CONCLUSION

Supplementing pregnant women with vitamin D led to significantly higher levels of 25(OH)D at term compared to placebo/control but results were inconsistent. Vitamin D supplementation, with or without calcium, may be related to lower risk of preeclampsia but more studies are needed to confirm this.

Serum IGFBP4 concentration decreased in dairy heifers towards day 18 of pregnancy

This study was conducted to determine if the main components of the somatotropic axis change during the early phase of pregnancy in the maternal blood system and whether differences exist on day 18 after pregnancy recognition by the maternal organism. Blood samples of pregnant heifers (Holstein Friesian; n = 10 after embryo transfer) were obtained on the day of ovulation (day 0), as well as on days 7, 14, 16 and 18 and during pregnant, non-pregnant and negative control cycles. The oncentrations of progesterone (P₄), oestrogen, growth hormone (GH), insulin-like growth factor-1 and -2 (IGF1, -2) and IGF-binding protein-2, -3 and -4 (IGFBP2, -3, -4) were measured. The mRNA expressions of growth hormone receptor 1A, IGF1, IGF2, IGFBP2, IGFBP3 and IGFBP4 were detected using RT-qPCR in liver biopsy specimens (day 18). In all groups, total serum IGF1 decreased from day 0 to 16. Notably, IGFBP4 maternal blood concentrations were lower during pregnancy than during non-pregnant cycles and synchronized control cycles. It can be speculated that the lower IGFBP4 in maternal blood may result in an increase of free IGF1 for local action. Further studies regarding IGFBP4 concentration and healthy early pregnancy are warranted.

Bone remodeling during pregnancy and post-partum assessed by metal lead levels and isotopic concentrations

Bone remodeling is normally evaluated using bone turnover markers/indices as indicators of bone resorption and formation. However, during pregnancy and post-partum, there have been inconsistent results between and within biomarkers for bone formation and resorption. These differences may relate to pregnancy-related changes in metabolism and/or hemodilution altering measured marker levels. An alternative approach to evaluating bone remodeling is to use the metal lead (Pb) concentrations and Pb isotopic compositions in blood. These measurements can also provide information on the amount of Pb that is mobilized from the maternal skeleton. Despite some similarities with accepted bone turnover markers, the Pb data demonstrate increased bone resorption throughout pregnancy that further continues post-partum independent of length of breast-feeding, dietary intake and resumption of menses. Furthermore the isotopic measurements are not affected by hemodilution. These data confirm calcium balance studies that indicate increased bone resorption throughout pregnancy and lactation. They also indicate potentially major public health implications of the transfer of maternal Pb burden to the fetus and new born.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

During pregnancy and lactation, female physiology adapts to meet the added nutritional demands of fetuses and neonates. An average full-term fetus contains ∼30 g calcium, 20 g phosphorus, and 0.8 g magnesium. About 80% of mineral is accreted during the third trimester; calcium transfers at 300-350 mg/day during the final 6 wk. The neonate requires 200 mg calcium daily from milk during the first 6 mo, and 120 mg calcium from milk during the second 6 mo (additional calcium comes from solid foods). Calcium transfers can be more than double and triple these values, respectively, in women who nurse twins and triplets. About 25% of dietary calcium is normally absorbed in healthy adults. Average maternal calcium intakes in American and Canadian women are insufficient to meet the fetal and neonatal calcium requirements if normal efficiency of intestinal calcium absorption is relied upon. However, several adaptations are invoked to meet the fetal and neonatal demands for mineral without requiring increased intakes by the mother. During pregnancy the efficiency of intestinal calcium absorption doubles, whereas during lactation the maternal skeleton is resorbed to provide calcium for milk. This review addresses our current knowledge regarding maternal adaptations in mineral and skeletal homeostasis that occur during pregnancy, lactation, and post-weaning recovery. Also considered are the impacts that these adaptations have on biochemical and hormonal parameters of mineral homeostasis, the consequences for long-term skeletal health, and the presentation and management of disorders of mineral and bone metabolism.