Calcium and bone metabolism in pregnancy and lactation

Prevalence of pregnancy- and lactation-associated osteoporosis in the postpartum period: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to estimate the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. We searched MEDLINE via PubMed and Igaku Chuo Zasshi for articles published in English or Japanese from the inception of the database to September 2021. Two researchers independently screened and included observational studies reporting the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. Of the 3,425 screened records, 8 articles centered on postpartum women were included in the review. Seven studies used dual-energy X-ray absorptiometry for assessing bone mineral density, while one used a quantitative ultrasound method. In the seven studies that used dual-energy X-ray absorptiometry, the parameters used to define osteoporosis were the T-score (two studies), Z-score (three studies), both T- and Z-scores (one study), and young adult mean (one study). Evaluation timeframes included 1 week (three studies), 1-2 months postpartum (three studies), and 1 week to 12 months postpartum (one study). The estimated prevalence of pregnancy- and lactation-associated osteoporosis defined by dual-energy X-ray absorptiometry was as follows: lumbar spine (six studies), 5% (95% confidence interval [CI], 0-13; heterogeneity [I2] = 99%) and femoral neck (three studies), 12% (95% CI, 0-30; I2 = 99%). Pregnancy and lactation were found to elevate the fracture risk in women, underscoring the necessity for a standardized assessment in diagnosing pregnancy- and lactation-associated osteoporosis. This imperative step aims to enable early detection and treatment of bone mineral loss among postpartum women.

Deletion of FNDC5/irisin modifies murine osteocyte function in a sex-specific manner

Irisin, released from exercised muscle, has been shown to have beneficial effects on numerous tissues but its effects on bone are unclear. We found significant sex and genotype differences in bone from wildtype (WT) mice compared to mice lacking Fndc5 (knockout [KO]), with and without calcium deficiency. Despite their bone being indistinguishable from WT females, KO female mice were partially protected from osteocytic osteolysis and osteoclastic bone resorption when allowed to lactate or when placed on a low-calcium diet. Male KO mice have more but weaker bone compared to WT males, and when challenged with a low-calcium diet lost more bone than WT males. To begin to understand responsible molecular mechanisms, osteocyte transcriptomics was performed. Osteocytes from WT females had greater expression of genes associated with osteocytic osteolysis and osteoclastic bone resorption compared to WT males which had greater expression of genes associated with steroid and fatty acid metabolism. Few differences were observed between female KO and WT osteocytes, but with a low-calcium diet, the KO females had lower expression of genes responsible for osteocytic osteolysis and osteoclastic resorption than the WT females. Male KO osteocytes had lower expression of genes associated with steroid and fatty acid metabolism, but higher expression of genes associated with bone resorption compared to male WT. In conclusion, irisin plays a critical role in the development of the male but not the female skeleton and protects male but not female bone from calcium deficiency. We propose irisin ensures the survival of offspring by targeting the osteocyte to provide calcium in lactating females, a novel function for this myokine.

Longitudinal changes of the femoral bone mineral density from first to third trimester of pregnancy: bone health assessment by means of non-ionizing REMS technology

BACKGROUND

Throughout the pregnancy, there is a substantial transfer of calcium from the maternal skeleton to the fetus, which leads to a transient net reduction of the maternal bone mineral density.

AIMS

To assess longitudinally the changes in the bone mineral density at the femoral neck between the first and third trimester of pregnancy in a cohort of healthy participants using Radiofrequency Echographic Multi Spectrometry (REMS) technology.

METHODS

Prospective, cohort study conducted at the University hospital of Parma, Italy between July 2022 and February 2023. We recruited healthy participants with an uncomplicated singleton pregnancy before 14 completed weeks of gestation. All included participants were submitted to a sonographic examination of the femoral neck to assess the bone mineral density (and the corresponding Z-score values) using REMS at 11-13 and 36-38 weeks of pregnancy. The primary outcome was the change in the bone mineral density values at the maternal femoral neck between the first and third trimester of pregnancy.

RESULTS

Over a period of 7 months, a total of 65 participants underwent bone mineral density measurement at the femoral neck at first and third trimester of the pregnancy using REMS. A significant reduction of the bone mineral density at the femoral neck (0.723 ± 0.069 vs 0.709 ± 0.069 g/cm2; p < 0.001) was noted with a mean bone mineral density change of - 1.9 ± 0.6% between the first and third trimester of pregnancy. At multivariable linear regression analysis, none of the demographic or clinical variables of the study population proved to be independently associated with the maternal bone mineral density changes at the femoral neck.

CONCLUSIONS

Our study conducted on a cohort of healthy participants with uncomplicated pregnancy demonstrates that there is a significant reduction of bone mineral density at femoral neck from early to late gestation.

Bone Mineral Density During and After Lactation: A Comparison of African American and Caucasian Women

During lactation, changes in maternal calcium metabolism are necessary to provide adequate calcium for newborn skeletal development. The calcium in milk is derived from the maternal skeleton through a process thought to be mediated by the actions of parathyroid hormone-related protein (PTHrP) in combination with decreased circulating estrogen concentrations. After weaning, bone lost during lactation is rapidly regained. Most studies of bone metabolism in lactating women have been performed in Caucasian subjects. There are well-documented differences between African American (AA) and Caucasian (C) bone metabolism, including higher bone mineral density (BMD), lower risk of fracture, lower 25-hydroxyvitamin D (25(OH) D), and higher PTH in AA compared to C. In this prospective paired cohort study, BMD and markers of bone turnover were compared in self-identified AA and C mothers during lactation and after weaning. BMD decreased in both AA and C women during lactation, with similar decreases at the lumbar spine (LS) and greater bone loss in the C group at the femoral neck (FN) and total hip (TH), demonstrating that AA are not resistant to PTHrP during lactation. BMD recovery compared to the 2 week postpartum baseline was observed 6 months after weaning, though the C group did not have complete recovery at the FN. Increases in markers of bone formation and resorption during lactation were similar in AA and C. C-terminal telopeptide (CTX) decreased to 30% below post-pregnancy baseline in both groups 6 months after weaning, while procollagen type 1 N-terminal (P1NP) returned to baseline in the AA group and fell to below baseline in the C group. Further investigation is required to determine impacts on long term bone health for women who do not fully recover BMD before a subsequent pregnancy.

Crosstalk within a brain-breast-bone axis regulates mineral and skeletal metabolism during lactation

To support the increased calcium demands for milk production during lactation, a dramatic and reversible physiological response occurs to alter bone and mineral metabolism. This coordinated process involves a brain-breast-bone axis that integrates hormonal signals that allow for adequate calcium delivery to milk yet also protects the maternal skeletal from excessive bone loss or decreases in bone quality or function. Here, we review the current knowledge on the crosstalk between the hypothalamus, mammary gland, and skeleton during lactation. We discuss the rare entity of pregnancy and lactation associated osteoporosis and consider how the physiology of bone turnover in lactation may impact the pathophysiology of postmenopausal osteoporosis. Further understanding of the regulators of bone loss during lactation, particularly in humans, may provide insights into new therapies for osteoporosis and other diseases of excess bone loss.

Vitamin D and parathyroid hormone in the umbilical cord blood - Correlation with light and dark maternal skin color

During pregnancy, vitamin D deficiency is associated with negative health consequences for mother and child. Furthermore, dark skin color is associated with lower vitamin D levels. We investigated 25-hydroxy-vitamin D (25(OH)D) and parathyroid hormone (PTH) levels in mothers and in cord blood of their newborns depending on maternal skin color. We recruited 202 mother and child pairs at the University Hospital Zurich and measured 25(OH)D and PTH concentrations in maternal and postpartum umbilical cord blood. Skin type was self-reported based on the Fitzpatrick Scale (type I to V). Uni- and multivariate methods were used to compare the maternal and neonatal 25(OH)D and PTH levels by skin type (light: I-III vs. dark: IV-V). As many as 54.5% of all mothers and 41.1% of the neonates were 25(OH)D deficient. This was higher in the neonates of dark-skinned (55.9%) than in the neonates of light-skinned mothers (38.1%; p = .06). The correlation of 25(OH)D in the maternal with umbilical cord blood was high (light: r = 0.85, dark: r = 0.87), with higher concentrations of 25(OH) vitamin D in the umbilical cord than in maternal blood. Regression analysis revealed that country of origin and maternal 25(OH)D concentration were the only statistically significant determinants for umbilical cord blood 25(OH)D. We observed no correlation of maternal with umbilical cord PTH concentrations; median PTH concentrations in the umbilical cord (5.6 pg/ml) were significantly lower than in maternal blood (25.7 pg/ml). The recommendation of vitamin D supplementation in newborns in their first 3 years of life should be particularly emphasized to dark-skinned mothers.

Pr-AKI: Acute Kidney Injury in Pregnancy – Etiology, Diagnostic Workup, Management

Despite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.

Bone metabolism and osteoporosis during pregnancy and lactation

PURPOSE

Osteoporosis in pregnancy is an uncommon disease and there is little information regarding its pathogenesis and its effects on the skeleton. This review aims to describe changes in mineral metabolism during pregnancy and lactation as well as their clinical impact.

METHODS

We performed a narrative review of the literature using the PubMed and Google Scholar databases for articles published from 1955 to 2021.

RESULTS

Mineral metabolism in the mother must adapt to the demand created by the fetus and the placenta, which together absorb calcium and other minerals from the mother to mineralize the developing fetal skeleton; analyses of iliac bone biopsies at the beginning and end of pregnancy have shown that pregnancy significantly modifies maternal bone status. The greatest demand for calcium for the maternal skeleton occurs during lactation; women who breastfeed have an even greater loss of calcium to produce milk. However, it is controversial whether breastfeeding can increase the risk of osteoporotic fractures, and the possible mechanism is considerably complicated. Osteoporosis in pregnancy is an uncommon disease characterized by the occurrence of fragility fractures, most commonly in the vertebral column, in the third trimester of pregnancy, or early postpartum. The pathogenesis of PLO remains unclear owing to its rarity; DXA provides a sensitive and specific method for diagnosing osteoporosis by measuring BMD, one of the parameters that allow a better understanding of fracture risk. One limitation is the controversy in using radiation in pregnant women and the risk to the embryo/fetus; a safe alternative can be MRI.

CONCLUSION

Pregnancy and lactation alter the maternal bone status; without a balance in metabolism, this may cause an increased risk of fracture due to changes in BMD. There is little information on BMD during pregnancy; more clinical studies are required to elucidate if this represents a risk factor for osteoporosis.

Does parity and duration of lactation have any effect on the bone mineral density of the femur and lumbar spine in Indian women? A cross-sectional study from the Northeast region of India

Background:

The effects of multiple pregnancies and period of lactation on bone density have not been studied till date and there is very less data available, especially from developing countries like India. Lumbar spine and femoral neck were used to measure BMD and results were recorded.

Objective:

To find out the effect of parity and period of lactation on occurrence of osteoporosis in spine and femoral neck in women of the Northeast region of India.

Materials and Methods:

The cross-sectional study included 294 perimenopausal and postmenopausal women aged 30–65 year old. Age, body mass index (BMI), parity, total lactation period, menopausal status, duration of menopause socioeconomic status, and nutritional history were noted. The dual-energy X-ray absorptiometry system was used to measure the BMD of lumbar and femoral neck BMD. Multiple regression analysis was done for finding out the association of parity and lactation with BMD.

Results:

The parity was inversely related with BMD of lumbar spine (β = −0.138, P = 0.00423) and BMD of femoral neck (β = −0.142, P = 0.00487). This relation remained significant after adjusting for age, BMI, and duration of menopause. Period of lactation was also inversely correlated with BMD for lumbar spine (β = −0.0812, P = 0.0012) and BMD of femoral neck (β = −0.033, P = 0.0031).

Conclusion:

The number of parity and prolonged period of lactation have a negative effect on BMD in both regions especially in the lower socioeconomic strata with poor nutritional intake. Our data supports that parity and duration of lactation can be associated with future osteoporosis.

Health reference intervals and values for common bottlenose dolphins (Tursiops truncatus), Indo-Pacific bottlenose dolphins (Tursiops aduncus), Pacific white-sided dolphins (Lagenorhynchus obliquidens), and beluga whales (Delphinapterus leucas)

This study reports comprehensive clinical pathology data for hematology, serum, and plasma biochemistry reference intervals for 174 apparently healthy common bottlenose dolphins (Tursiops truncatus) and reference values for 27 Indo-Pacific bottlenose dolphins (Tursiops aduncus), 13 beluga whales (Delphinapterus leucas), and 6 Pacific white-sided dolphins (Lagenorhynchus obliquidens) in zoos and aquariums accredited by the Alliance for Marine Mammal Parks and Aquariums and the Association of Zoos & Aquariums. Blood samples were collected as part of a larger study titled "Towards understanding the welfare of cetaceans in zoos and aquariums" (colloquially called the Cetacean Welfare Study). Two blood samples were collected following a standardized protocol, and two veterinarian examinations were conducted approximately six months apart between July to November 2018 and January to April 2019. Least square means, standard deviations, and 95% confidence intervals were calculated for hematology, serum, and plasma biochemical variables. Comparisons by age, gender, and month revealed statistically significant differences (p < 0.01) for several variables. Reference intervals and values were generated for samples tested at two laboratories for up to 56 hematologic, serum, and plasma biochemical variables. To apply these data, ZooPhysioTrak, an iOS mobile software application, was developed to provide a new resource for cetacean management. ZooPhysioTrak provides species-specific reference intervals and values based on user inputs of individual demographic and sample information. These data provide a baseline from which to compare hematological, serum, and plasma biochemical values in cetaceans in zoos and aquariums.

The importance of maternal pregnancy vitamin D for offspring bone health: learnings from the MAVIDOS trial

Optimisation of skeletal mineralisation in childhood is important to reduce childhood fracture and the long-term risk of osteoporosis and fracture in later life. One approach to achieving this is antenatal vitamin D supplementation. The Maternal Vitamin D Osteoporosis Study is a randomised placebo-controlled trial, the aim of which was to assess the effect of antenatal vitamin D supplementation (1000 IU/day cholecalciferol) on offspring bone mass at birth. The study has since extended the follow up into childhood and diversified to assess demographic, lifestyle and genetic factors that determine the biochemical response to antenatal vitamin D supplementation, and to understand the mechanisms underpinning the effects of vitamin D supplementation on offspring bone development, including epigenetics. The demonstration of positive effects of maternal pregnancy vitamin D supplementation on offspring bone development and the delineation of underlying biological mechanisms inform clinical care and future public-health policies.

A case of pregnancy and lactation associated osteoporosis in the third pregnancy; robust response to teriparatide despite delayed administration

BACKGROUND

Pregnancy and lactation associated osteoporosis (PLO) is a rare condition that may present with fragility fractures occurring for the first time in pregnancy or postpartum period while breastfeeding. Here, we report a rare case of PLO in the 3rd pregnancy treated with teriparatide.

CASE REPORT

A 35-year-old woman who presented with back pain (visual analogue scale; VAS = 10/10) two months after her third delivery. PLO was diagnosed from multiple vertebral fragility fractures and low bone mineral density (BMD). She was treated with teriparatide and her pain significantly reduced in the second month. After 12 months of teriparatide treatment, her BMD increased 18.1% from the baseline.

CONCLUSION

PLO should be considered in patients who complain with back pain during late pregnancy and postpartum period. Weaning off breastfeeding and supplementation of calcium/vitamin D should be the first recommendation as conventional treatment after the diagnosis of PLO. Teriparatide may be an effective option to improve the recovery of BMD If there is not enough improvement with conventional treatment.

Hypocalcaemia and calcium intake in pregnancy: A research protocol for critical analysis of risk factors, maternofoetal outcomes and evaluation of diagnostic methods in a third-category health facility, Cameroon

INTRODUCTION

Hypocalcaemia in pregnancy remains a major health issue, particularly in the developing world where daily calcium intakes are suboptimal. This electrolyte imbalance can lead to severe maternofoetal and childhood consequences. Calcium supplementation, amongst others, contributes significantly to meeting calcium demands in pregnancy. With ionised calcaemia as the gold standard for diagnosis, total calcaemia and albumin-corrected calcaemia in other pathological states have been found to overestimate the burden of hypocalcaemia. The main objectives of this study are to describe the blood calcium level (total, albumin corrected, and ionised calcaemia) and associated maternofoetal outcomes while identifying determinants of calcium supplementation and ionised hypocalcaemia. This study will also evaluate the sensitivity and specificity of albumin corrected calcaemia as a diagnostic tool for hypocalcaemia (ionised calcaemia as the gold standard) among pregnant women in the Nkongsamba Regional Hospital, Cameroon.

METHODS

Our study will target a total of 1067 term pregnant women who shall be included consecutively into the study as they arrive the maternity of the Nkongsamba Regional Hospital for their last antenatal care visit. Data shall be collected using a semi-structured interview-administered questionnaire and blood samples collected for total plasma calcium, albumin and serum ionized calcium assays. Additional data will be collected at birth (maternal and foetal variables; foetal outcomes evaluated as secondary outcomes). Total calcaemia and albuminemia shall be measured by atomic absorption spectrophotometry, while ionised calcaemia will be measured by ion-selective electrode potentiometry(using MSLEA15-H electrolyte analyzer) per standard BIOLABO and MSLEA15 protocols, respectively. Data will be analysed using the statistical softwares epi-Info version 7.2.2.16 and STATA version 16.

EXPECTED RESEARCH OUTCOME

This study will present a more precise estimate of the burden of hypocalcaemia in late pregnancy as well as identify and analyse the different factors associated with calcium supplementation and ionised hypocalcaemia among term pregnant women in a developing world setting. Maternofoetal outcomes associated with hypocalcaemia will be determined as well as the sensitivity and specificity of total and albumin-corrected calcaemia in diagnosing hypocalcaemia. Our findings will contribute significantly to designing or strengthening interventions to control this electrolyte imbalance.

Skeletal changes during lactation and after weaning in osteocyte-specific sclerostin overexpressed mice

INTRODUCTION

Lactation inevitably leads to a state of rapid bone loss; however, maternal bone undergoes rapid remineralization after weaning. Sclerostin, encoded by the gene SOST, is exclusively secreted from osteocytes and plays important roles in bone remodeling. However, there are few studies about the effect of sclerostin during lactation and weaning on bone microstructures. Therefore, we conducted the study to demonstrate any possible association of sclerostin with bone metabolism and skeletal changes during lactation and after weaning.

MATERIALS AND METHODS

We analyzed bone mineral density (BMD) by dual-energy X-ray absorptiometry at the spine and femur, bone microstructure by micro-computed tomography (μCT) at the distal and mid-shaft of the femur and biochemical markers such as sclerostin and bone turnover markers at 1 week and 3 weeks of lactation and 2 weeks post-weaning in osteocyte-specific sclerostin-overexpressed transgenic mice, and compared them with wild type.

RESULTS

Lactation significantly resulted in decreased spine and femur BMD at day 7 and day 21 of breastfeeding; specifically, cortical microstructure (cross-sectional thickness and cross-sectional area) at the mid-shaft of the femur had significantly deteriorated. At day 14 after weaning, femur BMD and cortical microstructure at the mid-shaft of the femur in both the wild and DMP-SOST mice had incompletely recovered; however, spine BMD and trabecular microstructures at the distal femur recovered in wild type mice.

CONCLUSIONS

Sclerostin, secreted by osteocytes, played a role in bone loss during lactation and also in the recovery of trabecular bone compartment by activating bone formation after weaning.

Intertrochanteric fracture in pregnancy- and lactation-associated osteoporosis

Pregnancy- and lactation-associated osteoporosis (PLO) is a special form of osteoporosis, which is the result of multiple factors affecting bone metabolism. The manifestations of PLO include severe low back or hip pain in the third trimester of pregnancy and postpartum period, and some patients present with a decrease in height and even fragility fractures. We report here a 33-year-old patient who presented with a left intertrochanteric fracture after falling from standing height at 10 months postpartum. She was diagnosed with PLO because of a considerable decrease in bone mineral density. Our findings are discussed in relation to the literature. Early diagnosis and timely and appropriate therapy are particularly important for PLO. PLO should be considered in patients who complain of low back or transient hip pain during pregnancy and lactation. Discontinuing breastfeeding and supplementing calcium/vitamin D should be recommended after diagnosis of PLO is established.

Vitamin D, and Maternal and Child Health

Vitamin D has important roles in calcium metabolism and in the prevention of rickets and osteomalacia; low levels of 25-hydroxyvitamin D are common in the general population and amongst pregnant women. Whilst there is a wealth of observational evidence linking vitamin D deficiency to a wide range of disease outcomes, there are currently few high-quality randomised controlled trials to confirm any causal associations, although many are currently in progress. Furthermore, currently, the vast majority of published guidelines recommend standard supplemental vitamin D doses for children and pregnant women, yet there is increasing recognition that individual characteristics and genetic factors may influence the response to supplementation. As such, future research needs to concentrate on documenting definite beneficial clinical outcomes of vitamin D supplementation, and establishing personalised dosing schedules and demonstrating effective approaches to optimising initiation and adherence.

Developmental Vitamin D Deficiency in the Rat Impairs Recognition Memory, but Has No Effect on Social Approach or Hedonia

Developmental vitamin D (DVD) deficiency is a risk factor for schizophrenia. In rodents we show that DVD-deficiency alters brain development and produces behavioral phenotypes in the offspring of relevance to the positive symptoms of schizophrenia. The aims of this study are to examine behavioral phenotypes specific to the cognitive and negative symptoms of schizophrenia in this model, and to vary the duration of vitamin D deficiency during gestation and beyond birth. We hypothesize that a longer duration of DVD-deficiency would result in greater behavioral impairments. Female vitamin D-deficient Sprague Dawley dams were mated at 10 weeks of age. Dietary vitamin D was reintroduced to dams and/or pups at different developmental time-points: Conception, Birth, Post-natal day (PND) 6 and PND21. Adult male and female offspring were assessed on a battery of behavioral tests, including sucrose preference, open field, novel object recognition (NOR), social approach and social novelty. We find that all windows of DVD-deficiency impaired NOR a cognitive measure that requires intact recognition memory. Sucrose consumption, social approach and social memory negative symptom-like phenotypes were unaffected by any maternal dietary manipulation. In addition, contrary to our hypothesis, we find that rats in the Conception group, that is the shortest duration of vitamin D deficiency, demonstrate increased locomotor activity, and decreased interaction time with novel objects. These findings have implications for the increasing number of studies examining the preclinical consequences of maternal vitamin D deficiency, and continue to suggest that adequate levels of maternal vitamin D are required for normal brain development.

Prevalence and correlates of low serum calcium in late pregnancy: A cross sectional study in the Nkongsamba Regional Hospital; Littoral Region of Cameroon

INTRODUCTION

Women from low and middle income countries are generally more likely to have sub-optimal calcium intake. The objective of this study was to assess serum calcium disorders and correlates in late pregnancy.

METHODS

We conducted from December 2018 to April 2019, a cross-sectional hospital-based study targeting pregnant women in late pregnancy in the Nkongsamba Regional Hospital. Data were collected by measurement of parameters (weight, height, blood pressure and foetal birthweight), administration of a semi-structured questionnaire and analysis of blood samples collected from each participant. Absorption spectrophotometry was used to measure serum calcium and albumin concentrations and corrected serum calcium calculated from the Payne's equation. With a statistical significant threshold set at p-value = 0.05, the odds ratio was used as a measure of the strength of association between hypocalcaemia and maternofoetal variables.

RESULTS

We enrolled a total of 354 consenting participants with a mean age of 27.41±5.84 years. The prevalence of hypocalcaemia in late pregnancy was 58.76 [53.42-63.90]%. The rate of calcium supplementation in pregnancy was 57.63[52.28-62.80]% with a mean duration of supplementation of 3.69±1.47 months. When controlled for marital status, age, level of education, and gestational age at delivery, pregnant women with systolic blood pressures below 130 mmHg were significantly less likely to have hypocalcaemia than their counterparts with higher systolic blood pressures (Adjusted Odds Ratio = 0.41[0.18-0.89], p-value = 0.020). No statistically significant associations were found between diastolic blood pressure, body mass index, foetal birth weight and hypocalcaemia.

CONCLUSION

Hypocalcaemia in late pregnancy is highly prevalent (59%) among women accessing reproductive services at the Nkongsamba Regional Hospital. There is also a wide gap in calcium supplementation compared to World Health Organization recommendations. Hypocalcaemia is significantly associated to higher systolic blood pressure in pregnancy. Systematic calcium supplementation and consumption of high calcium containing locally available meals should be encouraged.

Machine learning classification models for fetal skeletal development performance prediction using maternal bone metabolic proteins in goats

Background

In developing countries, maternal undernutrition is the major intrauterine environmental factor contributing to fetal development and adverse pregnancy outcomes. Maternal nutrition restriction (MNR) in gestation has proven to impact overall growth, bone development, and proliferation and metabolism of mesenchymal stem cells in offspring. However, the efficient method for elucidation of fetal bone development performance through maternal bone metabolic biochemical markers remains elusive.

Methods

We adapted goats to elucidate fetal bone development state with maternal serum bone metabolic proteins under malnutrition conditions in mid- and late-gestation stages. We used the experimental data to create 72 datasets by mixing different input features such as one-hot encoding of experimental conditions, metabolic original data, experimental-centered features and experimental condition probabilities. Seven Machine Learning methods have been used to predict six fetal bone parameters (weight, length, and diameter of femur/humerus).

Results

The results indicated that MNR influences fetal bone development (femur and humerus) and fetal bone metabolic protein levels (C-terminal telopeptides of collagen I, CTx, in middle-gestation and N-terminal telopeptides of collagen I, NTx, in late-gestation), and maternal bone metabolites (low bone alkaline phosphatase, BALP, in middle-gestation and high BALP in late-gestation). The results show the importance of experimental conditions (ECs) encoding by mixing the information with the serum metabolic data. The best classification models obtained for femur weight (Fw) and length (FI), and humerus weight (Hw) are Support Vector Machines classifiers with the leave-one-out cross-validation accuracy of 1. The rest of the accuracies are 0.98, 0.946 and 0.696 for the diameter of femur (Fd), diameter and length of humerus (Hd, Hl), respectively. With the feature importance analysis, the moving averages mixed ECs are generally more important for the majority of the models. The moving average of parathyroid hormone (PTH) within nutritional conditions (MA-PTH-experim) is important for Fd, Hd and Hl prediction models but its removal for enhancing the Fw, Fl and Hw model performance. Further, using one feature models, it is possible to obtain even more accurate models compared with the feature importance analysis models. In conclusion, the machine learning is an efficient method to confirm the important role of PTH and BALP mixed with nutritional conditions for fetal bone growth performance of goats. All the Python scripts including results and comments are available into an open repository at https://gitlab.com/muntisa/goat-bones-machine-learning.

Effects of Parity and Breast Feeding Duration on the Risk of Osteoporosis in Postmenopausal Korean Women: A Systematic Review and Meta-Analysis

OBJECTIVES

To summarize the evidence regarding the association of parity and breast feeding duration with the risk of osteoporosis in postmenopausal Korean women. This was because studies have been inconsistent regarding the effect of parity and breast feeding duration on the risk of osteoporosis.

METHODS

A systematic literature search of relevant studies published by December 26, 2018 was conducted in PubMed, EMBASE, the Cochrane Library, CINAHL, RISS, KISS, KMbase, and KoreaMed. Outcome estimates of odds ratio (OR) or standardized mean difference were pooled with fixed or random-effect model. In case of heterogeneity, subgroup analysis was conducted.

RESULTS

Seven cross-sectional studies (with 3,813 subjects) were included in the analysis. OR for osteoporosis was 1.43 (95% confidence interval [CI] = 1.09-1.88, P = 0.010) in postmenopausal women with higher parity compared to those with less parity. Moreover, OR for osteoporosis was 1.93 (95% CI = 1.28-2.93, P = 0.002) in postmenopausal women with longer durations of breast feeding than in those with shorter durations of breast feeding.

CONCLUSIONS

This study revealed that duration of breast feeding increased the risk of osteoporosis in postmenopausal Korean women. More cohort studies with high quality research designs are needed to confirm our results.

Expression of prolactin receptors in the duodenum, kidneys and skeletal system during physiological and sulpiride-induced hyperprolactinaemia

INTRODUCTION AND AIM

Hyperprolactinaemia in pregnancy leads to mild and reversible changes in the maternal skeletal system, and medicamentous hyperprolactinemia causes more detrimental effects. We conducted an experimental study to evaluate differences between Prlr gene expression in the duodenum, vertebrae and kidneys during physiological and medicamentous hyperprolactinaemia, which could influence calcium homeostasis.

METHODS

Experimental animals (18 weeks old, Wistar female rats) were divided as follows: group P (nine rats that were 3 weeks pregnant), group M (ten rats that were intramuscularly administrated sulpiride (10 mg/kg) twice daily for 3 weeks), and the control group (C, ten age-matched nulliparous rats, 18-week-old). Laboratory investigations included measurements of serum ionized calcium, phosphorus, urinary calcium and phosphorus excretion, osteocalcin (OC), serum procollagen type 1 N-terminal propeptide (P1NP), vitamin D, parathyroid hormone (PTH) and prolactin (PRL). Relative quantification of gene expression for prolactin receptors in the duodenum, vertebrae and kidneys was determined using real-time PCR.

RESULTS

Expression of the Prlr gene was significantly higher in the duodenum (p < 0.001) and lower in vertebrae (p < 0.001) and kidneys (p < 0.01) in rats with physiological hyperprolactinaemia (PHP) than in the control group. Significantly lower Prlr expression in the duodenum was verified (p < 0.001), along with increased Prlr gene expression in vertebrae (p < 0.001) and kidneys (p < 0.01), in rats with medicamentous hyperprolactinaemia (MHP) than in the C group.

CONCLUSIONS

Downregulation of Prlr gene expression in the duodenum may explain the diminished intestinal calcium absorption in medicamentous hyperprolactinaemia. Prolactin takes calcium from the skeletal system following increased Prlr gene expression in the vertebrae to maintain calcium homeostasis, which increases the harmful effect on bone metabolism compared to that of physiological hyperprolactinaemia.

Serum Calcium and Magnesium Levels in Normal Ghanaian Pregnant Women: A Comparative Cross-Sectional Study

BACKGROUND:

Pregnancy is described as a normal physiologic state associated with various biochemical changes. Magnesium and calcium are essential macronutrients required for foetal growth. Complications associated with their deficiency during normal pregnancy include; low neonatal birth weight, pre-eclampsia, eclampsia and preterm labour. Changes in serum levels of magnesium and calcium in normal pregnancy have not been extensively studied among Ghanaian women.

AIM:

To determine the variation in serum magnesium and calcium levels with gestational age in normal pregnancy in Ghanaian women.

METHODS:

A hospital-based comparative cross-sectional study was conducted among 32 normal non-pregnant women (Group A) and 100 normal pregnant women (Group B) attending the clinic at the Korle-Bu Teaching hospital. The group B pregnant women were further divided into Group B1 (n = 33), Group B2 (n = 37) and Group B3 (n = 30) based on their pregnancy gestation as first, second and third trimester respectively. Blood samples were obtained from the antecubital vein of subjects and total serum calcium, magnesium, protein and albumin were estimated. Data obtained were analysed using SPSS for windows version 20. Analysis of variance (ANOVA) was employed to determine the statistical differences between the groups. A p-value of ≤ 0.05 was considered significant.

RESULTS:

Mean serum total calcium and magnesium in first, second and third trimester normal pregnant women were 2.14 ± 0.16, 2.13 ± 0.44, 2.13 ± 0.35 mmol/L and 0.77 ± 0.11, 0.77 ± 0.16 and 0.76 ± 0.14 mmol/L respectively. Mean serum total calcium and magnesium levels in non-pregnant women were 2.20 ± 0.16 and 0.80 ± 0.10 mmol/L respectively. There was a statistically non-significant difference in serum total calcium and magnesium between non-pregnant and normal pregnant women, with p-values of 0.779 and 0.566 respectively. Mean total serum protein and albumin in first, second and third-trimester normal pregnant women were 68.42 ± 10.37, 70.46 ± 6.84, 66.70 ± 7.83 g/L and 39.92 ± 3.22, 40.75 ± 8.06, 38.26 ± 3.02 g/L respectively. Mean total serum protein and albumin in non-pregnant women were 73.13 ± 7.02 and 42.94 ± 3.03 g/L respectively. Mean total serum protein and albumin levels were lower in pregnant women as compared to non-pregnant women with the difference being significant in the third trimester (p-values of 0.012 and 0.002).

CONCLUSION:

Total serum calcium and magnesium levels in normal pregnancy were non-significantly lower compared to non-pregnant women in Ghana. There was a reduction in total serum protein, and albumin levels during pregnancy with a significant reduction noticed during the third trimester compared to the non-pregnant state.

Hypocalcemia in Pregnancy: A Clinical Review Update

Though hypocalcemia in pregnancy is not often reported in the literature, it occurs in cases of hypoparathyroidism and in mothers with severe dietary inadequacy. Hypocalcemia during pregnancy can pose numerous problems to the mother and fetus. It is associated with hypertensive disorders and can increase the risk of numerous problems such as preeclampsia and fetal growth disorders. In this review, we summarize the challenges physicians face diagnosing and managing hypocalcemia during pregnancy. A multidisciplinary team including endocrinologists and obstetricians is warranted to ensure appropriate treatment and optimal outcomes.

Serotonin induces parathyroid hormone-related protein in goat mammary gland

During lactation, large amounts of calcium are exported from the mammary gland into milk to ensure skeletal growth of the offspring. Recent studies revealed that serotonin (5-HT) is essential to stimulate skeletal calcium resorption for milk synthesis. Our objective was to explore the correlation between circulating 5-HT and serum calcium and parathyroid hormone-related protein (PTHrP) concentrations around parturition in dairy goats. We also investigated the effect of 5-HT on PTHrP expression in cultured primary goat mammary epithelial cells (GMEC). Blood samples of multiparous Guanzhong dairy goats were collected on day -5 to 3 postpartum for analysis of serum concentrations of calcium, 5-HT, and PTHrP. Results revealed that from day -3 to 0 postpartum serum calcium and 5-HT concentrations decreased progressively, but serum PTHrP concentration only had a sharp drop in the postpartum period sampled. Correlation analysis of circulating 5-HT and serum calcium and PTHrP concentrations on day 1 and 2 postpartum revealed that low serum 5-HT concentration was positively correlated with serum total calcium or PTHrP concentration. By knocking down tryptophan hydroxylase-1 (TPH1) or adding 5-hydroxytryptophan (5-HTP) to decrease or increase the levels of 5-HT in GMEC, we observed that 5-HTP increased PTHrP expression in a dose-dependent manner and siTPH1 decreased PTHrP protein expression. Furthermore, 5-HT increased mRNA abundance of calcium-sensing receptor (CaSR) in a dose-dependent manner and decreased the expression of plasma membrane Ca2+ ATPase-1 (PMCA1). Taken together, 5-HT seems to induce PTHrP expression in goat mammary cells during and after parturition. These findings suggest that increasing 5-HT biosynthesis could be a potential therapeutic target for prevention of hypocalcemia in dairy goats.

Maternal vitamin D supplementation during pregnancy

Introduction

Maternal vitamin D status in pregnancy has been linked to many health outcomes in mother and offspring. A wealth of observational studies have reported on both obstetric outcomes and complications, including pre-eclampsia, gestational diabetes, mode and timing of delivery. Many foetal and childhood outcomes are also linked to vitamin D status, including measures of foetal size, body composition and skeletal mineralization, in addition to later childhood outcomes, such as asthma.

Sources of data

Synthesis of systematic and narrative reviews.

Areas of agreement and controversy

The findings are generally inconsistent in most areas, and, at present, there is a lack of data from high-quality intervention studies to confirm a causal role for vitamin D in these outcomes. In most areas, the evidence tends towards maternal vitamin D being of overall benefit, but often does not reach statistical significance in meta-analyses.

Growing points and areas timely for developing research

The most conclusive evidence is in the role of maternal vitamin D supplementation in the prevention of neonatal hypocalcaemia; as a consequence the UK department of health recommends that pregnant women take 400 IU vitamin D daily. High-quality randomized placebo-controlled trials, such as the UK-based MAVIDOS trial, will inform the potential efficacy and safety of vitamin D supplementation in pregnancy across a variety of outcomes.

Fetal Skeletal Size and Growth are Relevant Biometric Markers in Vitamin D Deficient Mothers: A North East India Prospective Cohort Study

CONTEXT

The neonatal skeletal outcomes due to maternal Vitamin D deficiency.

AIMS

The aim of this study is to assess the serum 25 hydroxy Vitamin D (25[OH]D) status in pregnant women and correlate with cord blood 25(OH)D levels, femur length at 34 weeks gestation, and neonatal anthropometry (birth weight, birth length, and head circumference).

SETTINGS AND DESIGN

This was prospective cohort study.

SUBJECTS AND METHODS

This study was carried out in 250 healthy primigravida between 18 and 40 years of age in the third trimester of gestation attending the Obstetrics and Gynaecology Department of Gauhati Medical College, Guwahati from December 2012 to December 2015. Dietary assessment of calcium and Vitamin D intake, sunlight exposure among the pregnant mothers and fetal femur length measurements were done. The neonates were followed up at birth for biometric assessment and the estimation of cord 25(OH)D.

STATISTICAL ANALYSIS USED

Chi-square test and Pearson correlation were carried out to see the association and correlation between different variables. Statistical significance was set at the 0.05 level.

RESULTS

We found low Vitamin D levels (60%) in the majority of pregnant mothers and newborns (62.4%). The mean Vitamin D levels were 17.51 ± 2.24 ng/ml and 14.51 ± 1.8 ng/ml among the low Vitamin D maternal subjects and their new born, respectively. There was a significant association of maternal Vitamin D levels with sun exposure, dietary intake of Vitamin D, serum calcium, serum alkaline phosphatase levels, and serum parathyroid hormone in subjects with low Vitamin D. Fetal femur length and birth length were significantly shorter in mothers with low Vitamin D (P < 0.01).

CONCLUSIONS

Maternal hypovitaminosis D was associated with adverse skeletal outcome in neonates.

Subsequent fracture risk of women with pregnancy and lactation-associated osteoporosis after a median of 6 years of follow-up

Almost a quarter of patients with PAO will sustain a subsequent fracture; patients need to be informed about potential risks before deciding for further pregnancies.

INTRODUCTION

Pregnancy and lactation-associated osteoporosis (PAO) is a severe type of premenopausal osteoporosis which predominantly occurs in the last trimester of pregnancy or immediately postpartum. Long-term follow-up data including subsequent fracture risk have yet to be reported.

METHODS

This single-center prospective cohort study investigated the subsequent fracture risk of all 107 patients with PAO who were referred to our institution.

RESULTS

Overall, 107 presented with at least one fracture. Each patient sustained on average four fractures most commonly at the thoracolumbar spine. During a median of 6 years of follow-up, 26 (24.3%) of patients who had a fracture at baseline reported a subsequent fracture. Overall, 30 PAO patients (28%) reported a further pregnancy. In subsequent pregnancies, 6 (20%) of patients reported a subsequent fracture. Patients with up to 1 vs. > 1 fracture at time of diagnosis showed a 3 (10%) and 25 (27%) subsequent fracture rate, respectively (p = 0.047). There was a significant correlation between the number of fractures at time of diagnosis and subsequent fracture risk (N = 26,p= 0.56, p = 0.003).

CONCLUSIONS

Almost a quarter of patients with PAO will sustain a subsequent fracture, and this fracture risk correlates with the number of fractures at time of diagnosis. Patients with PAO need to be informed about their potential subsequent fracture risk before deciding for further pregnancies.

Hematologic and biochemical differences between two free ranging Yangtze finless porpoise populations: The implications of habitat

The goals of this study were to compare the serum chemistry and hematology values of wild and semi-natural free-ranging Yangtze Finless Porpoises (Neophocaena asiaeorientalis ssp. asiaeorientalis) populations and to ascertain how these values change with the different environmental condition. For this study, samples were collected from 81 YFPs, 35 living in the wild and 46 living in a semi-natural reserve. Each population was divided into 8 life history categories; Male Calf, Female Calf, Juvenile Male, Juvenile Female, Adult Male, Pregnant, Lactating and Pregnant plus Lactating. Statistically significant differences in the various parameters were observed in the same life history categories for both populations. Generally, Lipid Profile, Hepatic Enzymes, Creatine Kinase, Red Blood Cells, Hemoglobin, Hematocrit and Neutrophils were significantly higher in the Tian-E-Zhou Oxbow population while, Creatinine, Phosphate, Lactate Dehydrogenase, Bilirubin and Lymphocytes were significantly higher in the Poyang Lake YFPs. Across the groups in the Tian-E-Zhou Oxbow population, a significant decrease in serum Albumin, Alkaline Phosphatase and Calcium, while a significant increase in the Neutrophils and Platelets was observed. Similarly, in the Poyang Lake, Alkaline Phosphatase levels in the Female Calves group, High Density Lipoprotein Cholesterol in Lactating group, basophil counts in Pregnant plus Lactating group, lymphocytes counts in Juvenile Females group and Globulin and Total Protein levels in Pregnant group were significantly higher. This study in health assessments can help us to understand the effect of sex, age, reproductive status and environmental conditions on the well-being of Yangtze Finless Porpoises.

Maternal Obesity, 25-Hydroxy Vitamin D Concentration, and Bone Density in Breastfeeding Dyads

OBJECTIVE

To examine the association between maternal body mass index (BMI) and serum 25-hydroxy vitamin D [25(OH)D] concentration and bone density in mother-infant pairs.

STUDY DESIGN

The study was a secondary analysis of 234 exclusively breastfeeding dyads who were recruited in the first postpartum month for a randomized controlled trial of maternal vs infant vitamin D supplementation. Mean 25(OH)D concentrations and bone mineral density (BMD) were compared by BMI group. The adjusted association between maternal BMI and 25(OH)D and bone density was examined at 1, 4, and 7 months postpartum.

RESULTS

Obese breastfeeding women had lower 25(OH)D concentrations and higher BMD than lean women at all 3 time points (P  <  .01). Higher maternal BMI was associated with lower maternal serum levels of 25(OH)D at 1, 4, and 7 months postpartum (adjusted β = -0.45 ng/ml per kg/m², 95% CI -.076, -0.14, at 1 month) and higher BMD at the same time points (β = 0.006 BMD z score; 95% CI 0.003, 0.01 at 1 month). Seventy-six percent of infants were vitamin D deficient at 1 month of age. Infants born to overweight and obese mothers had lower 25(OH)D concentrations than infants of lean mothers (P < .01). For infants in the maternal supplementation group, higher maternal BMI was associated with lower 25(OH)D concentrations at 4 months (β = -0.68; 95% CI -1.17, -0.20) and lower bone density at 7 months (β = -0.001; 95% CI -0.002, -0.0001).

CONCLUSIONS

In exclusively breastfeeding dyads, maternal obesity is associated with lower maternal and infant serum 25(OH)D concentrations, which may impact infant bone density.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00412074.

Associations of Parity, Breastfeeding, and Fractures in the Women's Health Observational Study

OBJECTIVE

To examine associations of several aspects of parity and history of lactation with incident hip fractures and clinical fractures and, in a subset of women, with bone mineral density.

METHODS

In this observational study, we analyzed data from 93,676 postmenopausal women participating in the Women's Health Initiative Observational Study and all bone density data from the subset of participants who underwent bone density testing at three clinical centers. At baseline, participants were aged 50-79 years. Using Cox proportional hazards regression analysis, we examined associations of fracture incidence and bone density with several aspects of parity (number of pregnancies, age at first pregnancy lasting 6 months or greater, and number of pregnancies lasting 6 months or greater) and breastfeeding (number of episodes of breastfeeding for at least 1 month, number of children breastfed, age when first breastfed, age when last breastfed, total number of months breastfed).

RESULTS

The mean baseline age (standard deviation) of participants was 64 (±7.4) years (mean follow-up 7.9 years). During follow-up, the incident rate of hip fracture was 1.27%. Ten percent of participants were nulligravid. In fully adjusted models, number of pregnancies, parity, age at first birth, number of children breastfed, age at first breastfeeding, age at last breastfeeding, and total duration of breastfeeding were not statistically significantly associated with hip fracture incidence. There were no consistent associations of parity or lactation characteristics with overall clinical fracture risk or bone density. However, compared with never breastfeeding, a history of breastfeeding for at least 1 month was associated with a decreased risk of hip fracture (yes compared with no, hazard ratio 0.84, 95% confidence interval 0.73-0.98).

CONCLUSION

Patterns of parity and history of lactation were largely unrelated to fracture risk or bone density.

Nutrition of Black Women During Pregnancy

OBJECTIVE

To examine the consistency and adequacy of nutritional intake in a population of Black women in the second and third trimesters of pregnancy.

DESIGN

This was a longitudinal descriptive study. Data were collected from women with low-risk pregnancies at 22- to 24-week prenatal visits and two subsequent visits.

SETTING

Participants were recruited from urban prenatal clinics in one city in the Northeastern United States.

PARTICIPANTS

Pregnant women who self-identified as Black (N = 195).

METHODS

A 24-hour diet recall was obtained at each of the three study time points. Food models and measuring cups were used to improve the accuracy of portion size reporting. Data from diet recalls were manually entered in Food Processor software to compute nutritional content.

RESULTS

A linear mixed-effects model was used to examine dietary intake. Dietary patterns were stable from the second to the third trimesters, and caloric intake was inadequate. Women met minimal daily requirements for carbohydrate and protein intake, but the overall percentages of fat, protein, and carbohydrates indicated that additional calories needed to come from protein. Although more than 80% of women regularly took prenatal vitamins, micronutrient and fiber intake were consistently inadequate.

CONCLUSION

Prenatal care to help women identify foods that are rich in fiber, protein, and micronutrients is important for the health of women and newborns. Knowing that nutritional intake is consistently inadequate, nurses can counsel pregnant women whenever they have contact with them to attempt to improve nutritional intake and make women aware of inexpensive nutrient sources.

Calcium intake in winter pregnancy attenuates impact of vitamin D inadequacy on urine NTX, a marker of bone resorption

PURPOSE

Pregnancy is characterised by increased bone turnover, but high bone turnover with resorption exceeding formation may lead to negative maternal bone remodelling. Recent studies are conflicting regarding the effect of calcium on skeletal health in pregnancy. The aim of this study was to examine the seasonal effect of serum 25-hydroxyvitamin D (25OHD) and dietary calcium on a marker of bone resorption.

METHODS

This was prospective study of 205 pregnant women [two cohorts; early pregnancy at 13 weeks (n = 96), and late pregnancy at 28 weeks (n = 109)]. Serum 25OHD and urine cross-linked N-telopeptides of type I collagen (uNTX) were measured at both time points. Intakes of vitamin D and calcium were recorded using 3-day food diaries at each trimester.

RESULTS

Compared to summer pregnancies, winter pregnancies had significantly lower 25OHD and significantly higher uNTX. Higher calcium intakes were negatively correlated with uNTX in winter, but not summer. In late pregnancy, compared to those reporting calcium intakes ≥1000 mg/day, intakes of <1000 mg/day were associated with a greater increase in uNTX in winter pregnancies than in summer (41.8 vs. 0.9%). Increasing calcium intake in winter by 200 mg/day predicted a 13.3% reduction in late pregnancy uNTX.

CONCLUSIONS

In late pregnancy, during winter months when 25OHD is inadequate, intakes of dietary calcium <1000 mg/day were associated with significantly increased bone resorption (uNTX). Additional dietary calcium is associated with reduced bone resorption in late pregnancy, with greater effect observed in winter. Further research regarding optimal dietary calcium and 25OHD in pregnancy is required, particularly for women gestating through winter.

A study of bone turnover markers in gestational diabetes mellitus

INTRODUCTION

Gestational diabetes is defined as carbohydrate intolerance resulting in hyperglycemia of variable severity with the first recognition during pregnancy. Established risk factors for gestational diabetes mellitus (GDM) are maternal age, obesity, family history of diabetes, etc. Vitamin D, parathyroid hormone (PTH), and various other hormones are known for their function in maintaining calcium and phosphorous homeostatic. Furthermore, Vitamin D, PTH serum ionized calcium, and alkaline phosphatase (ALP) have been reported to be altered with glucose homeostasis. The present study compares the bone markers in pregnant women with and without gestational diabetes.

MATERIALS AND METHODS

This cross-sectional study was conducted at outpatient antenatal check-up clinic and outpatient diabetic clinics at J. N. Medical College and Hospital, Aligarh. One hundred pregnant females, of which fifty with GDM and fifty without GDM, were included in the study from January 2014 to November 2015. Detailed history, physical examination, and anthropometric measurement were done. Bone turnover markers in the form of Vitamin D, parathyroid hormone, serum ionized calcium, and serum ALP were measured in pregnant women who had gestational diabetes which was compared with normal pregnant women.

RESULTS

In our study, the mean age of participate of GDM group was 28.2 ± 3 years, while the mean age group in non-GDM group was 25.44 ± 2.78 years. Ionized calcium in GDM was found to be 4.606 ± 0.354 mEq/L, while in non-GDM, it was 4.548 ± 0.384 mEq/L, P = 0.430. Vitamin D came out to be 21.80 ± 9.48 ng/ml, while it was 32.346 ± 8.37 ng/ml in non-GDM group. Serum PTH in GDM group was 71.436 ± 36.189 pg/ml and 37.168 ± 8.128 pg/ml in nondiabetic gestational group. Serum ALP in GDM group was 9.1 ± 4.56 KA U/dl and 6.98 ± 2.2 KA U/dl in nondiabetic gestational group, P - 0.0038. In GDM group, there was a significant negative linear correlation between PTH and 25-hydroxyvitamin D with research correlation coefficient r = -0.9073, P = 0; there was a significant positive linear correlation coefficient between PTH and ALP with Persian correlation coefficient r = 0.6597, P = 0; there was no statistically significant correlation between PTH and ionized calcium r = 0.1416, P = 0.3267.

CONCLUSION

All GDM subjects should ideally be screened for serum calcium, vitamin D, PTH, ALP. If found impaired should immediately be corrected in order to prevent its adverse effects on maternal and fetal outcome. Vitamin D supplementation should ideally be initiated in all GDM females even if the above parameters are not investigated in Indian setup.

Effect of Multiparity and Prolonged Lactation on Bone Mineral Density

OBJECTIVES

This study was done to determine the effect of multiparity and prolonged lactation on bone mineral density (BMD).

METHODS

This cross-sectional study included 196 perimenopausal and postmenopausal women aged 40 to 60 years old. Age, body mass index (BMI), menopausal status, duration of menopause, parity and total duration of lactation, nutritional history were recorded. Lumbar spine (LS; L2-L4) and femur neck (FN) BMD were measured using dual energy X-ray absorptiometry. Correlation of parity and lactation with BMD were investigated using multiple regression analysis.

RESULTS

Parity was inversely correlated to BMD for LS (β = -0.266, P = 0.001) and FN (β = -0.380, P = 0.000). This relation remained significant even after adjusting for age, BMI and duration of menopause. Duration of lactation was inversely correlated with BMD for LS (β = -0.271, P = 0.001) but no for FN (β = -0.124, P = 0.130).

CONCLUSIONS

Multiparity and prolonged lactation have negative impact on BMD especially with in a socioeconomic group whose nutritional intake is borderline. Our data support that parity and duration of lactation can be associated with future osteoporosis.

Vitamin D Deficiency in Pregnant Women and Their Neonates

BACKGROUND & OBJECTIVE

Vitamin D deficiency during pregnancy is a worldwide problem. Studies have reported prevalence ranged 18-84% in pregnant women. Receiving adequate calcium and vitamin D during pregnancy period is necessary for calcium homeostasis, fetal growth and bone mineralization. This study was aimed to determine the prevalence of vitamin D deficiency in pregnant women and their neonates in Shahroud city in the northeast Iran.

METHODS

In this cross-sectional study, 284 pregnant women and their neonates referred to Fatemiyeh Hospital of Shahroud were included. Blood samples of mothers and umbilical cords were collected during the delivery and were sent to laboratory in order to measure calcium and 25-hydroxy vitamin D.

FINDINGS

Amounts of Vitamin D insufficiency (20-30 ng/mL) and deficiency (<20 ng/mL) in (mothers, neonates) were found to be (60.2%, 48.9%) and (1.1%, 2.5%) respectively. Calcium deficiency (<8.5 mg/dL) was present in 33.5% of mothers and 25% of neonates. There was a weak correlation between maternal serum and cord blood 25-hydroxy vitamin D (r=0.12, p=0.053).

CONCLUSION

More than half of the mothers and their neonates had some degrees of vitamin D deficiency. It is recommended to evaluate the nutritional status of vitamin D in pregnant women along with public health interventions to be carried out.

Vitamin D receptor polymorphisms and growth until adulthood after very premature birth

The accretion of bone mass is often impaired in preterm infants, which may contribute to postnatal growth failure. We tested the effects of the vitamin D receptor single-nucleotide polymorphisms (SNPs) c1521g, Fok1, Bsm1, and Taq1 on linear growth up until adulthood in 341 subjects born very prematurely (i.e., <32 weeks of gestation) from the Dutch Project On Preterm and Small-for-gestational-age infants cohort. The GG genotype of the c1521g SNP was associated with a 0.36 [95 % confidence interval (CI), 0.02-0.69] SD taller adult stature and the ff genotype of the Fok1 SNP with a 0.38 SD (95 % CI, 0.02-0.75) taller adult stature. Interaction between these genotypes on stature was observed from the age of 1 year onward (albeit nonsignificantly before the age of 5 years), with adult height being 1.54 (95 % CI, 0.44-2.63) SD taller in subjects carrying both genotypes. The Bsm1 and Taq1 variants were both associated with faster catch-up growth until 2 years of age. Statistical correction for potential confounders did not change our results. We conclude that homozygosity for the minor alleles of both c1521g and Fok1 is associated with a taller adult stature in subjects born very prematurely. The minor alleles of Bsm1 and Taq1 are associated with faster catch-up growth in infancy.

Maternal vitamin D levels during pregnancy and neonatal health: evidence to date and clinical implications

Low maternal vitamin D levels during pregnancy have been associated with a plethora of adverse neonatal outcomes, including small for gestational age and preterm births, detrimental effect on offspring bone and teeth development, and risk of infectious diseases. Although most observational studies indicate a significant linear relationship between maternal 25-hydroxyvitamin D and the above outcomes, some randomized controlled trials to date are inconclusive, mostly due to differences in study design and supplementation regimen. The currently available results indicate that vitamin D supplementation during pregnancy reduces the risk of preterm birth, low birth weight, dental caries of infancy, and neonatal infectious diseases such as respiratory infections and sepsis. This narrative review aims to summarize available trial results regarding the effect of low maternal vitamin D levels during pregnancy, in conjunction with neonatal outcomes on the field, with a discourse on the appropriate clinical approach of this important issue.

A systematic review of behavioural interventions to increase maternal calcium intake

Pregnancy and lactation are a time when adequate calcium consumption is essential for the development of the fetus and to ensure the health of the mother. Over 50% of Canadian women of childbearing and rearing age fail to meet the recommended daily intake of calcium. Identification of effective behavioural intervention strategies for increasing calcium intake is needed within this specific population. This paper brings together all published behavioural interventions designed to increase calcium consumption in pregnant, lactating or post-partum mothers in a systematic review. Relevant studies were obtained through searches of MEDLINE, EMBASE, PsycINFO, CINAHL and the Cochrane Library with no date restrictions. Studies were evaluated using previously published criteria for evaluating calcium behaviour change interventions. This systematic literature review identified five behavioural calcium interventions conducted within this population. Three interventions aimed to improve overall dietary behaviours, the fourth aimed to promote breastfeeding (including increasing calcium consumption) and the fifth aimed to increase daily servings of yoghurt. Only one of the five interventions yielded large effect sizes, with a mean change of 954 mg of calcium per day post-intervention. The number of behavioural change techniques did not appear to be related to intervention efficacy. Only one study used a theoretical framework to guide the intervention. This review highlights the lack of research examining behaviour change interventions aimed at increasing calcium consumption in pregnant, lactating and post-partum women and provides practical suggestions for researchers wishing to intervene with this population in the future.

Current concepts in perinatal mineral metabolism

The serum levels of calcium (Ca) and phosphate are maintained higher in the fetus than in the pregnant mother, especially in late gestation, to meet the demands of fetal bone development. In order to maintain this fetal stage-specific mineral homeostasis, the placenta plays a critical role through active transcellular mineral transport. Although the molecular mechanism of transplacental Ca transport has been well studied, little is known about the transport mechanism of phosphate and magnesium. Maternal mineral homeostasis is also altered during pregnancy to supply minerals to the fetus. In the lactating mother, osteocytic osteolysis is suggested to be involved in the supply of minerals to the baby. The levels of some calcitropic and phosphotropic (Ca- and phosphate-regulating, respectively) hormones in the fetus are also different from those in the adult. The PTH level in the fetus is lower than that in the mother and nonpregnant adult. It is suggested, however, that low fetal PTH plays an important role in fetal mineral metabolism. The concentration of PTHrP in the fetus is much higher than that of PTH and plays a critical role in perinatal Ca homeostasis. Uncovering the molecular mechanisms for fetal stage-specific mineral metabolism will lead to better management of perinatal patients with mineral abnormalities.

Knowledge and Attitude of Medical Nurses toward Oral Health and Oral Health Care of Pregnant Women

BACKGROUND

This study assessed the knowledge and attitudes of medical nurses regarding oral health and oral health care of pregnant women.

METHODS

This cross sectional study of 133 nurses in the district of Tumpat, Kelantan (Malaysia) used self-administered questionnaires.

RESULTS

Most nurses knew that dental plaque is associated with periodontal disease (97.7%). However, most nurses erroneously believed that tooth decay (86.5%) and excessive sugar consumption (87.2%) led to periodontal disease. About half of the nurses knew about the relationship between periodontal disease of pregnant women and low birth weight (43.6%) and preterm birth (48.9%). Many nurses had the misconception that the developing foetus draws calcium from the mothers' teeth (78.2%). Most nurses had good attitudes toward improving their oral health knowledge (97.0%) and agreed they should help to deliver oral health education to pregnant women (94.0%). Age, length of service as a nurse, and length of service in antenatal care had no effect on the scores for the nurses' knowledge and attitude regarding oral health and oral health care of pregnant women.

CONCLUSION

Medical nurses had limited knowledge about oral health of pregnant women and had some misunderstandings about oral health, although they had good attitudes. Age, length of service as a nurse, and length service in antenatal care had no effect on the knowledge and attitude scores of the nurses.

Parity and osteoporotic fracture risk in postmenopausal women: a dose-response meta-analysis of prospective studies

The present dose-response meta-analysis shows linearly decreased hip fracture (HF) risk and nonlinearly decreased osteoporotic fracture (OF) risk associated with increasing number of parity of up to five live births among postmenopausal women.

INTRODUCTION

Epidemiological reports suggest that parity is associated with reduced OF risk among women. However, these findings are controversial. Here, we present a meta-analysis of prospective studies of parity in relation to OF risk.

METHODS

We performed systematic searches using Medline and Embase from January 1, 1966, to December 31, 2014, with limits of language in English and prospective study design. Relative risks (RRs) and confidence intervals (CIs) were derived mainly using random-effects models. Categorical, dose-response, heterogeneity, publication bias, and subgroup analyses were conducted.

RESULTS

We analyzed 10 articles of 19 independent reports from 1966 to 2014, comprising a total of 217,295 participants and 26,525 cases of OF. Compared to nulliparous women, the OF and HF risks of parous women with at least one live birth were reduced by 11 % (95 % confidence interval (CI) 3-19 %; I (2) = 77.1 %, p < 0.001) and 26 % (95 % CI 17-35 %; I (2) = 19.5 %, p = 0.287), respectively. Representative nonlinearly and linearly inverse dose-response associations were found between parity (range of 0-6) and OF risk (p nonlinearity = 0.0163; I (2) = 79.7 %, p < 0.001), and between parity (range of 0-5) and HF risk (p nonlinearity = 0.054; I (2) = 76.5 %, p < 0.001), respectively. The lowest risk reduction for OF of 25 % (95 % CI 16-33 %) was observed for five live births. And, the summary risk reduction for HF was 12 % (95 % CI 9-15 %) for each one increased live birth.

CONCLUSIONS

We found that increasing number of parity is associated with linearly reduced HF risks among women. The association between parity of six or more live births and HF risks should be studied further in future.

Reproductive state and rank influence patterns of meat consumption in wild female chimpanzees (Pan troglodytes schweinfurthii)

An increase in faunivory is a consistent component of human evolutionary models. Animal matter is energy- and nutrient-dense and can provide macronutrients, minerals, and vitamins that are limited or absent in plant foods. For female humans and other omnivorous primates, faunivory may be of particular importance during the costly periods of pregnancy and early lactation. Yet, because animal prey is often monopolizable, access to fauna among group-living primates may be mediated by social factors such as rank. Wild chimpanzees (Pan troglodytes) across Africa habitually consume insects and/or vertebrates. However, no published studies have examined patterns of female chimpanzee faunivory during pregnancy and early lactation relative to non-reproductive periods, or by females of different rank. In this study, we assessed the influence of reproductive state and dominance rank on the consumption of fauna (meat and insects) by female chimpanzees of Gombe National Park, Tanzania. Using observational data collected over 38 years, we tested (a) whether faunivory varied by reproductive state, and (b) if high-ranking females spent more time consuming fauna than lower-ranking females. In single-factor models, pregnant females consumed more meat than lactating and baseline (meaning not pregnant and not in early lactation) females, and high-ranking females consumed more meat than lower-ranking females. A two-factor analysis of a subset of well-sampled females identified an interaction between rank and reproductive state: lower-ranking females consumed more meat during pregnancy than lower-ranking lactating and baseline females did. High-ranking females did not significantly differ in meat consumption between reproductive states. We found no relationships between rank or reproductive state with insectivory. We conclude that, unlike insectivory, meat consumption by female chimpanzees is mediated by both reproductive state and social rank. We outline possible mechanisms for these patterns, relate our findings to meat-eating patterns in women from well-studied hunter-gatherer societies, and discuss potential avenues for future research.

Life-course approach to nutrition

This narrative review summarizes the role that nutrition plays in the development and maintenance of a healthy skeleton throughout the life-course. Nutrition has a significant influence on bone health throughout the life cycle. This narrative review summarizes current knowledge and guidance pertaining to the development and maintenance of a healthy skeleton. The primary objectives proposed for good bone health at the various stages of life are the following: Children and adolescents: achieve genetic potential for peak bone mass Adults: avoid premature bone loss and maintain a healthy skeleton Seniors: prevention and treatment of osteoporosis Findings from cohort studies, randomized controlled trials, systematic reviews and meta-analyses, in addition to current dietary guidelines, are summarized with the intention of providing clear nutritional guidance for these populations and pregnant women.

Breast Feeding Is Associated with Postmenopausal Bone Loss: Findings from the Korea National Health and Nutrition Examination Survey

BACKGROUND

Postmenopausal osteoporosis is a common disease which can cause various morbidity and economic burden. Lactation is known to cause a decline in bone mineral density (BMD), but there are controversies on whether decreased BMD is fully recovered after lactation and whether lactation duration has an influence on postmenopausal BMD. This study was conducted to see whether breastfeeding is associated with postmenopausal bone loss using a highly representative sample of Korean population.

METHODS

Retrospective cross sectional study was done using data collected from Korea National Health and Nutrition Examination Survey V. The study outcome was BMD measured with dual-energy X-ray absorptiometry and divided into 2 groups: normal or low BMD (T score<-1), and breastfeeding duration was categorized into 4 groups (never, 1st, 2nd, and 3rd tertile). Logistic regression analysis was done to examine the association between lactation duration and BMD.

RESULTS

Among 1,694 postmenopausal women (mean age, 63.5±9.1), 85.71% were in low BMD group. Compared to never breastfeeding group, postmenopausal women with longer than 79 months of breastfeeding duration are more likely to have low BMD (adjusted risk ratio [ARR]=1.24; 95% confidence interval, 1.17 to 1.32). As the duration of breastfeeding increases, ARR and risk difference for low BMD also increases (P for trend=0.008).

CONCLUSION

The study results showed that total breastfeeding duration was associated with postmenopausal low BMD. All women planning on breastfeeding should be aware of its risks and should take adequate dietary calcium and vitamin D before, during, and after breastfeeding.

ENDOCRINOLOGY IN PREGNANCY: Influence of maternal vitamin D status on obstetric outcomes and the fetal skeleton

Vitamin D status has been increasingly associated with wide-ranging clinical outcomes. There is now a wealth of observational studies reporting on its associations with obstetric complications, including pre-eclampsia, gestational diabetes and the mode and timing of delivery. The findings are inconsistent, and currently there is a lack of data from high-quality intervention studies to confirm a causal role for vitamin D in these outcomes. This is similarly true with regards to fetal development, including measures of fetal size and skeletal mineralisation. Overall, there is an indication of possible benefits of vitamin D supplementation during pregnancy for offspring birthweight, calcium concentrations and bone mass as well as for reduced maternal pre-eclampsia. However, for none of these outcomes is the current evidence base conclusive, and the available data justify the instatement of high-quality randomised placebo controlled trials in a range of populations and health care settings to establish the potential efficacy and safety of vitamin D supplementation to improve particular outcomes.

Multi-generational drinking of bottled low mineral water impairs bone quality in female rats

BACKGROUND

Because of reproductions and hormone changes, females are more sensitive to bone mineral loss during their lifetime. Bottled water has become more popular in recent years, and a large number of products are low mineral water. However, research on the effects of drinking bottled low mineral water on bone health is sparse.

OBJECTIVE

To elucidate the skeletal effects of multi-generational bottled water drinking in female rats.

METHODS

Rats continuously drank tap water (TW), bottled natural water (bNW), bottled mineralized water (bMW), or bottled purified water (bPW) for three generations.

RESULTS

The maximum deflection, elastic deflection, and ultimate strain of the femoral diaphysis in the bNW, bMW, and bPW groups and the fracture strain in the bNW and bMW groups were significantly decreased. The tibiae calcium levels in both the bNW and bPW groups were significantly lower than that in the TW group. The tibiae and teeth magnesium levels in both the bNW and bPW groups were significantly lower than those in the TW group. The collagen turnover markers PICP (in both bNW and bPW groups) were significantly lower than that in the TW group. In all three low mineral water groups, the 1,25-dihydroxy-vitamin D levels were significantly lower than those in the TW group.

CONCLUSION

Long-term drinking of low mineral water may disturb bone metabolism and biochemical properties and therefore weaken biomechanical bone properties in females. Drinking tap water, which contains adequate minerals, was found to be better for bone health. To our knowledge, this is the first report on drinking bottled low mineral water and female bone quality on three generation model.

Mineral Metabolism in Singleton and Twin-pregnant Dairy Goats

During pregnancy, the maternal body undergoes significant physiological changes. The present study assessed the changes on calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) metabolism in singleton and twin-pregnant dairy goats. The 42 goats used (49.5 kg±7.6 body weight [BW]) were assigned at random to treatments that were factorially arranged to account for 2 breeds (Oberhasli and Saanen), 2 pregnancy types (singleton and twin) and 3 gestation periods (80, 110, and 140 days). Digestibility trials were performed at 80, 110, and 140 days of gestation. Mineral retention during pregnancy was determined in the maternal body, femur, uterus, mammary gland, fetus and fetal fluid. Blood samples were taken during pregnancy before and after a meal, and Ca, P, Mg, Na, K ions and alkaline phosphatase activity determined in serum. Bone mineral density was determined in the right femur. Statistical analyses were performed using the SAS MIXED procedure. Dry matter intake decreased linearly up to 140 days of gestation. Maternal BW gain, and Ca, P, and Mg retention (g/kg) decreased linearly with the advance of gestation days. Macromineral retention in maternal body (g/kg) was greater in Oberhasli than Saanen goats, and their fetuses had higher Ca, P, and Mg deposition (mg/g). Mineral retention (mg/g) increased in fetuses according to pregnancy development, with no differences between singleton and twin pregnancy. In the mammary gland, the retention of all minerals (g) increased with the days of pregnancy. In conclusion, related to Ca, P, and Mg metabolism can be divided into two stages. Up to 80 days of gestation, was characterized by the preparation of the maternal body reserves for future mineral demands. From 80 days of gestation onward, was characterized by the transfer of maternal body reserves for fetal development and colostrum production. Na and K supply was provided by adjustments in endogenous excretion and an increase in intestinal absorption. Finally, mineral metabolism was specific to each genotype and, except for Na, was not affected by the number of fetuses.

The "love hormone" oxytocin regulates the loss and gain of the fat-bone relationship

The involvement of oxytocin (OT) in bone metabolism is an interesting area of research that recently achieved remarkable results. Moreover, several lines of evidence have largely demonstrated that OT also participates in the regulation of energy metabolism. Hence, it has recently been determined that the posterior pituitary hormone OT directly regulates bone mass: mice lacking OT or OT receptor display severe osteopenia, caused by impaired bone formation. OT administration normalizes ovariectomy-induced osteopenia, bone marrow adiposity, body weight, and intra-abdominal fat depots in mice. This effect is mediated through inhibition of adipocyte precursor differentiation and reduction of adipocyte size. The exquisite role of OT in regulating the bone-fat connection adds another milestone to the biological evidence supporting the existence of a tight relationship between the adipose tissue and the skeleton.

Effect of calcium supplementation on bone resorption in pregnancy and the early postpartum: a randomized controlled trial in Mexican women

Background

Calcium needs are physiologically upregulated during pregnancy and lactation to meet demands of the developing fetus and breastfeeding infant. Maternal calcium homeostasis is maintained by hormonal adaptive mechanisms, thus, the role of dietary calcium supplementation in altering maternal responses to fetal-infant demand for calcium is thought to be limited. However, increased calcium absorption is directly related to maternal calcium intake and dietary supplementation has been suggested to prevent transient bone loss associated with childbearing.

Methods

In a double-blind, randomized placebo-controlled trial, we randomly assigned 670 women in their first trimester of pregnancy to 1,200 mg/day calcium (N = 334) or placebo (N = 336). Subjects were followed through 1-month postpartum and the effect on urinary cross-linked N-telopeptides (NTx) of type I collagen, a specific marker of bone resorption, was evaluated using an intent-to-treat analysis. Women with a baseline and at least one follow-up measurement (N = 563; 84%) were included. Subsequent analyses were conducted stratifying subjects by compliance assessed using pill counts. In random subsets of participants, bone-specific alkaline phosphatase (BAP) (N = 100) and quantitative ultrasound (QUS) (N = 290) were also measured.

Results

Calcium was associated with an overall reduction of 15.8% in urinary NTx relative to placebo (p < 0.001). Among those who consumed ≥50%, ≥67%, and ≥75% of pills, respectively, the effect was associated with 17.3%, 21.3%, and 22.1% reductions in bone resorption (all p < 0.001). There was no significant effect of calcium on bone formation measured by BAP. However, by 1-month postpartum, those in the calcium group had significantly lower NTx/BAP ratios than those in the placebo group (p = 0.04) indicating a net reduction in bone loss in the supplement group by the end of follow-up. Among subjects who consumed ≥50% and ≥75% of pills, respectively, calcium was also associated with an increase of 26.3 m/s (p = 0.03) and 59.0 m/s (p = 0.009) in radial SOS relative to placebo by 1-month postpartum.

Conclusions

Calcium administered during pregnancy and the early postpartum period, to women with intakes around adequacy, was associated with reduced bone resorption and, thus, may constitute a practical intervention to prevent transient skeletal loss associated with childbearing.

Trial registration

ClinicalTrials.gov Identifier NCT00558623