Effects of calcium supplementation during pregnancy on maternal, fetal and birth outcomes

Effects of calcium supplementation on the prevention of preeclampsia: an umbrella review of systematic reviews and meta-analyses

Background

Preeclampsia is the leading cause of maternal and fetal morbidity and mortality. Calcium supplementation has been considered a potential intervention to reduce the risk of preeclampsia. This umbrella review aims to summarize the effects of calcium supplementation in the prevention of preeclampsia based on existing systematic reviews and meta-analyses studies.

Methods

A systematic search of electronic databases, such as MEDLINE, Web of Science, SCOPUS, and the Cochrane Library, was conducted from inception to 30 December 2023. The methodological quality of the included studies was assessed using the revised version of the Assessing the Methodological Quality of Systematic Reviews (AMSTAR 2) tool. A random-effects model was used to estimate the effect of calcium supplementation on preeclampsia. Heterogeneity among included studies and publication bias were assessed using the I2 statistic and the Egger's test, respectively.

Results

Calcium supplementation reduced the risk of preeclampsia by 47% (RR: 0.53, 95% CI: 0.42, 0.68) with a considerable level of heterogeneity (I2 = 84.39%). Our subgroup analyses revealed that the risk of preeclampsia was significantly lower in high-risk pregnancies that received calcium supplementation (RR: 0.35, 95% CI: 0.26, 0.47), indicating a 65% risk reduction. In comparison, low-risk pregnant women who received calcium supplementation experienced a 33% risk reduction (RR: 0.67, 95% CI: 0.59, 0.77). Furthermore, the effects of calcium supplementation were more pronounced in women from developing countries compared to those from developed countries.

Conclusion

This umbrella review provides a summary of the evidence supporting the use of calcium supplementation to reduce preeclampsia. Incorporating calcium supplementation into antenatal care interventions may help to reduce the burden of preeclampsia and improve maternal and fetal outcomes. Further studies are needed to explore the impact of baseline calcium levels, optimal dosage, timing, and routes of supplementation to effectively decrease the incidence of preeclampsia.

Renal calcium and magnesium handling during pregnancy: modeling and analysis

Pregnancy is associated with elevated demand of most nutrients, with many trace elements and minerals critical for the development of fetus. In particular, calcium (Ca2+) and magnesium (Mg2+) are essential for cellular function, and their deficiency can lead to impaired fetal growth. A key contributor to the homeostasis of these ions is the kidney, which in a pregnant rat undergoes major changes in morphology, hemodynamics, and molecular structure. The goal of this study is to unravel the functional implications of these pregnancy-induced changes in renal handling of Ca2+ and Mg2+, two cations that are essential in a healthy pregnancy. To achieve that goal, we developed computational models of electrolyte and water transport along the nephrons of a rat in mid and late pregnancy. Model simulations reveal a substantial increase in the reabsorption of Mg2+ along the proximal tubules and thick ascending limbs. In contrast, the reabsorption of Ca2+ is increased in the proximal tubules but decreased in the thick ascending limbs, due to the lower transepithelial concentration gradient of Ca2+ along the latter. Despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of Ca2+ and Mg2+ in pregnancy. Furthermore, we conducted simulations of hypocalcemia and hypomagnesemia. We found that hypocalcemia lowers Ca2+ excretion substantially more than Mg2+ excretion, with this effect being more pronounced in virgin rats than in pregnant ones. Conversely, hypomagnesemia reduces the excretion of Mg2+ and Ca2+ to more similar degrees. These differences can be explained by the greater sensitivity of the calcium-sensing receptor (CaSR) to Ca2+ compared with Mg2+.NEW & NOTEWORTHY A growing fetus' demands of minerals, notably calcium and magnesium, necessitate adaptations in pregnancy. In particular, the kidney undergoes major changes in morphology, hemodynamics, and molecular structure. This computational modeling study provides insights into how these pregnancy-induced renal adaptation impact calcium and magnesium transport along different nephron segments. Model simulations indicate that, despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of calcium and magnesium in pregnancy.

Correlation between essential and toxic elements in maternal blood during early pregnancy and atrial septal defects/ventricular septal defects/patent ductus arteriosus in offspring

BACKGROUND

Congenital heart defects (CHDs) are the most common congenital malformation in the world. Recent studies have found that essential and toxic trace element levels may play a crucial role in the risk of neonatal malformation. However, the relationships between element levels in early pregnancy and CHD risk among humans remain unclear. This study investigates the association between maternal essential element (copper [Cu], zinc [Zn], calcium [Ca], manganese [Mg] and iron [Fe]) and toxic element (lead [Pb] and cadmium [Cd]) levels during early pregnancy and CHDs.

METHODS

A hospital-based case-control study was conducted, including 181 cases and 218 controls. Eligible participants underwent antenatal examination during gestational weeks 11-14 and trace element levels were detected by the atomic absorption method. Multi-variable logistic regression was used to examine the associations between the level of maternal trace elements and CHD risks.

RESULTS

Higher levels of Ca in early pregnancy were associated with lower risk of ASD/VSD risks. Moreover, higher Fe, Pb, and Cd levels in the first trimester were associated with higher risks of all CHD and the subtypes risks, and the tests for trend were significant (all p < .05). The restricted cubic spline analysis showed that there was a nonlinear inverted u-shaped dose-response relationship between levels of Zn, Pb, and Cd in the first trimester and risk of CHDs (non-linearity test p < .05).

CONCLUSIONS

A moderate increase in Zn and Ca levels and a decrease in Pb and Cd levels during early pregnancy are needed to reduce the incidence of CHDs in the Chinese population.

Calcium supplementation in pregnancy: An analysis of potential determinants in an under-resourced setting

INTRODUCTION

Despite the evidence that calcium supplementation in pregnancy improves maternofoetal outcomes, many women still do not take calcium supplements during pregnancy in Cameroon. This study identifies factors that influence calcium supplementation during pregnancy in a low resource setting.

METHODS

We conducted a cross-sectional hospital-based study (from November 2020 to September 2021) targeting 1074 healthy women in late pregnancy at the maternities of four major health facilities in the Nkongsamba Health District, Cameroon. Data were collected using an interview-administered semi-structured questionnaire and analysed using Epi Info version 7.2.4.0, and the statistical threshold for significance set at p-value = 0.05.

RESULTS

The mean age of the participants was 28.20±6.08 years, with a range of 15-47 years. The proportion of women who reported taking any calcium supplements in pregnancy was 72.62 [69.85-75.22]%. Only 12% of calcium-supplemented women took calcium supplements throughout pregnancy, while a majority (50%) took calcium supplements just for 4-5 months. Women believe that taking calcium supplements is more for foetal growth and development (37.12%) and prevention of cramps (38.86%), than for the prevention of hypertensive diseases in pregnancy (2.84%). About all pregnant women (97.65%) took iron and folic acid supplements during pregnancy, and 99.24% took these supplements at least once every two days. Upon control for multiple confounders, the onset of antenatal care before 4 months of pregnancy (AOR = 2.64 [1.84-3.78], p-value = 0.000), having had more than 3 antenatal care visits (AOR = 6.01 [3.84-9.34], p-value = 0.000) and support/reminder from a partner on the necessity to take supplements in pregnancy (AOR = 2.00 [1.34-2.99], p-value = 0.001) were significantly associated with higher odds of taking any calcium supplements in pregnancy.

CONCLUSION

Calcium supplementation practices in pregnancy remain poor in this population and far from WHO recommendations. Early initiation of antenatal care, a high number of antenatal visits and reminders or support from the partner on supplement intake significantly increase the odds of taking any calcium supplements in pregnancy. In line with WHO recommendations, women of childbearing age should be sensitised to initiate antenatal care earlier and attain as many visits as possible. Male involvement in prenatal care might also boost the likelihood of these women taking calcium supplements.

Scaling up prenatal nutrition could reduce the global burden of noncommunicable diseases in the next generation: a modeling analysis

BACKGROUND

Nutritional conditions during pregnancy may influence the epigenetic development of an individual and consequently their later-life risk of noncommunicable disease (NCD). Improving nutrition for pregnant females may therefore serve the dual purpose of directly improving pregnancy outcomes and preventing NCDs in the next generation.

OBJECTIVES

We estimated the impact of prenatal supplementation with iron and folic acid (IFA), multiple micronutrients (MMS), or calcium at 50%, 75%, or 90% coverage on future NCDs by age and sex in 2015.

METHODS

We used secondary data sources from 132 countries to quantify the cases of diabetes and hypertension and the deaths from selected NCDs that could be averted or delayed by scaling up prenatal micronutrient supplementation.

RESULTS

Globally, >51,000 NCD deaths, 6 million cases of hypertension, and 3 million cases of diabetes could be prevented per offspring birth cohort if mothers were prenatally supplemented with MMS at 90% coverage. For IFA these numbers would be roughly half. Calcium supplementation at 90% could delay 51,000 deaths per birth cohort. Our model suggests that substantial numbers of NCD deaths and cases of hypertension and diabetes could be prevented in future generations by scaling up micronutrient supplementation for mothers during pregnancy.

CONCLUSIONS

Highlighting the additional benefits of proven nutrition interventions is critical in ensuring adequate and sustained investments, and programmatic integration. As the double burden of disease continues to grow, population-wide efforts to scale up micronutrient supplementation to pregnant females could help prevent both undernutrition and chronic disease.

Adverse maternofoetal outcomes associated with ionised calcaemia, total calcaemia, albuminaemia, and calcium supplementation in pregnancy: Analysis from a resource-limited setting

INTRODUCTION

Disorders of total calcium (tCa) in pregnancy have been associated with adverse maternofoetal outcomes. However, studies evaluating this from the viewpoint of ionised calcaemia are practically inexistent. This study estimates the prevalence of some adverse maternal and foetal outcomes and the potential effect of ionised calcium (iCa), tCa, albumin and calcium supplementation on some maternofoetal outcomes.

METHODS

A cross-sectional study was conducted among 1074 pregnant women in late pregnancy from four health facilities in the Nkongsamba Health District. Data were collected by interview, analysis of maternal blood samples and measurement of maternal and foetal parameters. Total calcaemia and albuminaemia were measured by atomic absorption spectrophotometry, while iCa and pH were measured using ion-selective potentiometry. Associations were measured using the odds ratio in simple and multiple logistic regression.

RESULTS

The prevalence of low birth weight, macrosomia, and hypertension in pregnancy was 6.27 [4.97-7.89]%, 4.78 [3.65-7.89]%, 10.24 [8.57-12.20]%, respectively. Following multiple logistic regression, women with iCa levels ≤ 1.31mmol/L had significantly increased odds of hypertension in pregnancy (AOR = 2.47 [1.63-3.74], p-value = 0.000), having babies with low birth weight (AOR = 2.02[1.33-3.61], p-value = 0.002), low birth length (AOR = 2.00 [1.34-2.99], p-value = 0.001), low brachial circumference (AOR = 1.41[1.10-1.81], p-value = 0.007), first minute Apgar score < 7 (AOR = 3.08[1.70-5.59], p-value = 0.000) and fifth minute Apgar score < 7 (AOR = 2.86[1.32-6.16], p-value = 0.007). Ionised calcaemia had no significant association with maternal body mass index immediately after birth and the head circumference of the baby. Total calcaemia was found to have no significant association with any of the selected outcomes, while women with total albuminaemia ≤ 30mg/L had significantly higher odds of having babies with low birth weight (AOR = 3.40[1.96-5.91], p-value = 0.000), and Apgar scores < 7 at the first (AOR = 2.07[1.16-3.70], p-value = 0.013). Calcium supplementation showed no significant association with any of the selected outcomes except for the first (OR = 0.42[0.24-0.72], p-value = 0.002) and fifth minute Apgar score (OR = 0.25[0.12-0.50], p-value = 0.000).

CONCLUSION

The prevalence of low birth weight, macrosomia, and hypertension in pregnancy was 6.27 [4.97-7.89]%, 4.78 [3.65-7.89]%, 10.24 [8.57-12.20]%, respectively. Maternal iCa levels ≤ 1.31mmol/L significantly increase the odds of having babies with low birth weight, low birth length, low brachial circumference at birth, low Apgar scores at the first and fifth minutes and maternal hypertension in pregnancy. Low maternal albuminaemia is significantly associated with low birth weight, and Apgar score < 7 at the first minute. None f the selected maternofoetal outcomes directly depend on total calcaemia, given that none of the associations was statistically significant. Even though iCa levels remain relatively normal in normal pregnancies, it remains the strongest predictor of foetal outcomes. Calcium supplementation significantly improves the Apgar scores at the first and fifth minute. Routine pregnancy follow-up should include evaluating maternal calcaemic states, particularly the ionised fraction, to detect the low-normal concentrations likely to impact maternal and foetal outcomes. Normal iCa levels for pregnant women need revisiting.

Association of Dietary Calcium Intake with Dental, Skeletal and Non-Skeletal Fluorosis among Women in the Ethiopian Rift Valley

Fluorosis is a major public health problem in the Rift Valley of Ethiopia. Low calcium (Ca) intake may worsen fluorosis symptoms. We assessed the occurrence of fluorosis symptoms among women living in high-fluoride (F) communities in South Ethiopia and their associations with dietary Ca intake. Women (n = 270) from two villages provided clinical and questionnaire data. Dental fluorosis examination was done using Dean’s Index, and skeletal and non-skeletal fluorosis assessment was carried out using physical tests and clinical symptoms. Daily Ca intake was estimated by a food frequency questionnaire. Food, drinking water and beverage samples were analyzed for F level. Many subjects (56.3%) exhibited dental fluorosis. One-third of the women were unable to perform the physical exercises indicative of skeletal fluorosis; about half had ≥2 symptoms of skeletal/non-skeletal fluorosis. The average F level in drinking water sources was ~5 mg/L. The F content in staple food samples varied from 0.8–13.6 mg/kg. Average Ca intake was 406 ± 97 mg/day. Women having ≤400 mg/day Ca intake had ~3 times greater odds of developing skeletal rigidity with joint pains [AOR = 2.8, 95%CI: 1.6, 5.0] and muscular weakness [AOR = 2.9, 95%CI: 1.3, 6.3] compared to those with higher intakes. No association of calcium intake was seen with dental fluorosis. As low dietary Ca intake was associated with symptoms related to skeletal and non-skeletal fluorosis, this warrants nutritional intervention on calcium intakes in this setting.

Relationships between Dairy and Calcium Intake and Mental Health Measures of Higher Education Students in the United States: Outcomes from Moderation Analyses

Background: The prevalence of mental health concerns among university students in the United States (U.S.) continues to increase, while current treatments, including medication and counseling, present shortcomings. Higher dairy and calcium intakes are associated with protective effects on mental health; however, previous studies have focused on investigating singular relationships between dairy and calcium intakes and mental health measures. A more complex exploration of these relationships is warranted to better examine whether increasing dairy and calcium intakes could serve as an intervention to improve mental health. The present study sought to further characterize the relationships between dairy and calcium intake, perceived stress, and a variety of mental health measures using linear regression and moderation analyses. Methods: The present cross-sectional study involved students studying at three large U.S. universities, and data collection occurred from April to May 2020 when students were learning remotely due to the COVID-19 pandemic. An online survey comprising validated tools was distributed among students to assess dairy and calcium intake, perceived stress, anxiety, negative and positive moods, rumination, and resilience, sleep quality and duration, dietary risk, and physical activity. Results: A total of 1233 students completed the study. Higher dairy and calcium intake was coincident with lower perceived stress and higher positive mood scores, while higher calcium intake was also coincident with lower anxiety, rumination, and higher resilience scores. Additionally, as calcium intake increased, the relationship between perceived stress and anxiety and the relationship between perceived stress and negative mood weakened. Dairy intake did not have this effect. Conclusions: Based on the results, and considering that calcium is a shortfall nutrient, universities should consider initiating programs and public health campaigns to promote dairy and calcium intake among this population.

Impact of water fortification with calcium on calcium intake in different countries: a simulation study

OBJECTIVE

To simulate the impact - effectiveness and safety - of water fortification with different concentrations of Ca using the Intake Modelling, Assessment and Planning Program.

DESIGN

This is a secondary analysis of national or sub-national dietary intake databases.

SETTING AND PARTICIPANTS

Uganda, Lao People's Democratic Republic (PDR), Bangladesh, Zambia, Argentina, USA and Italy.

RESULTS

We found that for dietary databases assessed from low- and middle-income countries (LMIC), the strategy of fortifying water with 500 mg of Ca/l would decrease the prevalence of low Ca intake in all age groups. We also found that this strategy would be safe as no group would present a percentage of individuals exceeding the upper limit in >2 %, except women aged 19-31 years in Lao PDR, where 6·6 % of women in this group would exceed the upper limit of Ca intake. The same strategy would lead to some groups exceeding the upper limit in USA and Italy.

CONCLUSIONS

We found that for most LMIC countries, water fortified with Ca could decrease the prevalence of Ca intake inadequacy without exceeding the upper levels of Ca intake.

Genes and Pathways Affecting Sheep Productivity Traits: Genetic Parameters, Genome-Wide Association Mapping, and Pathway Enrichment Analysis

Ewe productivity is a composite and maternal trait that is considered the most important economic trait in sheep meat production. The objective of this study was the application of alternative genome-wide association study (GWAS) approaches followed by gene set enrichment analysis (GSEA) on the ewes’ genome to identify genes affecting pregnancy outcomes and lamb growth after parturition in Iranian Baluchi sheep. Three maternal composite traits at birth and weaning were considered. The traits were progeny birth weight, litter mean weight at birth, total litter weight at birth, progeny weaning weight, litter mean weight at weaning, and total litter weight at weaning. GWASs were performed on original phenotypes as well as on estimated breeding values. The significant SNPs associated with composite traits at birth were located within or near genes RDX, FDX1, ARHGAP20, ZC3H12C, THBS1, and EPG5. Identified genes and pathways have functions related to pregnancy, such as autophagy in the placenta, progesterone production by the placenta, placental formation, calcium ion transport, and maternal immune response. For composite traits at weaning, genes (NR2C1, VEZT, HSD17B4, RSU1, CUBN, VIM, PRLR, and FTH1) and pathways affecting feed intake and food conservation, development of mammary glands cytoskeleton structure, and production of milk components like fatty acids, proteins, and vitamin B-12, were identified. The results show that calcium ion transport during pregnancy and feeding lambs by milk after parturition can have the greatest impact on weight gain as compared to other effects of maternal origin.

No effect of calcium and vitamin D intake on maternal blood pressure in a healthy pregnant population

OBJECTIVES

Clinical studies have reported an inverse relationship between calcium and vitamin D intake and hypertensive disorders of pregnancy (HDP). The aim of this study was to investigate if there was an association between calcium/vitamin D intake, and vitamin D (25OHD) status, and maternal blood pressure (BP), during pregnancy and at 5-year follow-up.

STUDY DESIGN

This was an observational study of 415 women who participated in the ROLO (Randomised cOntrolled trial of LOw glycaemic index diet for the prevention of recurrence of macrosomia) study. Maternal BP measurements were taken during each trimester and at 5-year follow-up. Calcium and vitamin D intake were determined at each trimester and 25OHD was measured in early and late pregnancy.

RESULTS

Over two-thirds of the cohort were vitamin D sufficient (25OHD > 30 nmol/L) and had adequate calcium intake (>750 mg/day). There was no correlation between calcium intake or vitamin D intake and maternal BP in trimester 1 to 3 or at 5-year follow-up. Vitamin D status at 13 weeks' gestation negatively correlated with mean arterial pressure in trimester 1 (r = -0.152, p = 0.044). There was no correlation however between 25OHD at 28 weeks' gestation and BP at 28 or 34 weeks' gestation or 25OHD and BP at 5-year follow-up.

CONCLUSIONS

In a healthy population of women with adequate calcium and vitamin D intake, no clinically significant correlation existed between calcium and vitamin D and maternal BP.

Impact of flour fortification with calcium on calcium intake: a simulation study in seven countries

Calcium intake is low in many countries, especially in low-income countries. Our objective was to perform a simulation exercise on the impact, effectiveness, and safety of a flour fortification strategy using the Intake Modelling, Assessment, and Planning Program. Modeling of calcium fortification scenarios was performed with available dietary intake databases from Argentina, Bangladesh, Italy, the Lao People's Democratic Republic (Lao PDR), Uganda, Zambia, and the United States. This theoretical exercise showed that simulating a fortification with 156 mg of calcium per 100 g of flour would decrease the prevalence of low calcium intake, and less than 2% of the individuals would exceed the recommended calcium upper limit (UL) in Argentina, Italy, Uganda, and Zambia. Bangladesh and the Lao PDR showed little impact, as flour intake is uncommon. By contrast, in the United States, this strategy would lead to some population groups exceeding the UL. This exercise should be replicated and adapted to each country, taking into account the updated prevalence of calcium inadequacy, flour consumption, and technical compatibility between calcium and the flour-type candidate for fortification. A fortification plan should consider the impact on all age groups to avoid the risk of exceeding the upper levels of calcium intake.

Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence Map

The placenta is a vital, multi-functional organ that acts as an interface between maternal and fetal circulation during pregnancy. Nutritional deficiencies during pregnancy alter placental development and function, leading to adverse pregnancy outcomes, such as pre-eclampsia, infants with small for gestational age and low birthweight, preterm birth, stillbirths and maternal mortality. Maternal nutritional supplementation may help to mitigate the risks, but the evidence base is difficult to navigate. The primary purpose of this umbrella review is to map the evidence on the effects of maternal nutritional supplements and dietary interventions on pregnancy outcomes related to placental disorders and maternal mortality. A systematic search was performed on seven electronic databases, the PROSPERO register and references lists of identified papers. The results were screened in a three-stage process based on title, abstract and full-text by two independent reviewers. Randomized controlled trial meta-analyses on the efficacy of maternal nutritional supplements or dietary interventions were included. There were 91 meta-analyses included, covering 23 types of supplements and three types of dietary interventions. We found evidence that supports supplementary vitamin D and/or calcium, omega-3, multiple micronutrients, lipid-based nutrients, and balanced protein energy in reducing the risks of adverse maternal and fetal health outcomes. However, these findings are limited by poor quality of evidence. Nutrient combinations show promise and support a paradigm shift to maternal dietary balance, rather than single micronutrient deficiencies, to improve maternal and fetal health. The review is registered at PROSPERO (CRD42020160887).

A success story of reduction in childhood stunting and underweight in India: analysis of pooled data from three rounds of Indian Demographic and Health Surveys (1998-2016)

This study used a series of individual-level datasets from National Family Health Surveys conducted in 1998-99, 2005-06 and 2015-16 to assess the factors behind the reduction in childhood stunting and underweight in India between the years 1998-99 and 2015-16. A multivariable decomposition regression analysis was performed. Results showed that the prevalence of childhood stunting declined from 49.4% in 1998-99 to 34.9% in 2015-16. Over the same period, the prevalence of childhood underweight declined from 41.9% in 1998-99 to 33.1% in 2015-16. The reduction in the prevalence of stunting was found to be contributed largely by a reduction in the combined prevalence of stunting and underweight (60%), followed by stunted only (21%) and the combined prevalence of stunting, underweight and wasting (19%). Likewise, the reduction in the prevalence of underweight was contributed by a reduction in the combined prevalence of stunting and underweight and the combined prevalence of stunting, underweight and wasting. Results of the decomposition analysis showed that over the period 1998-99 to 2015-16, improvement in wealth status and maternal education led to 13% and 12% declines, respectively, in childhood stunting and to 31% and 19% declines, respectively, in childhood underweight. Furthermore, reductions in childhood stunting and underweight were due to an increased average number of antenatal care visits, lower average birth order, decreased share of children with below-average birth size, increased use of clean fuel for cooking and a reduction in the practice of open defecation. These findings suggest that further reduction in the prevalence of childhood stunting and underweight could be attained through more equitable household economic growth, investment in girl's education, greater access to improved toilet facilities, more widespread use of clean fuel for cooking, reduction in average birth order, increased antenatal care visits and greater consumption of IFA tablets by pregnant women. Policymakers need to prioritize these measures to further reduce malnutrition among Indian children.

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.

An observational study on Ca supplementation and dietary intake during pregnancy on low birth weight and small for gestational age

OBJECTIVE

To evaluate the effects of dietary Ca intake and Ca supplementation during pregnancy on low birth weight (LBW) and small for gestational age (SGA) infants.

DESIGN

A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity and Child Care Hospital in Lanzhou, China.

SETTING

A birth cohort study.

PARTICIPANTS

Totally, 9595 pregnant women who came to the hospital for delivery at 20 weeks of gestation or more, and who were 18 years of age or older.

RESULTS

Compared with non-users, Ca supplement users had a reduced risk of LBW infants (OR = 0·77, 95 % CI: 0·63, 0·95) and a reduced risk of nulliparous women giving birth to LBW infants (OR = 0·75, 95 % CI: 0·58, 0·98) (P < 0·05). More specifically, both the use of Ca supplement before conception and during pregnancy (OR = 0·44, 95 % CI: 0·19, 0·99) and during pregnancy only (OR = 0·80, 95 % CI: 0·65, 0·99) had the main effect of reducing risk of nulliparous women giving birth to LBW infants (P < 0·05). There was no association between Ca supplementation and SGA (OR = 0·87, 95 % CI: 0·75, 1·01) (P > 0·05). However, higher dietary Ca intake during pregnancy decreases the risk of both LBW (quartile 2: OR = 0·72, 95 % CI: 0·55, 0·94; quartile 3: OR = 0·68, 95 % CI: 0·50, 0·62) and SGA infants (quartile 2: OR = 0·77, 95 % CI: 0·63, 0·95; quartile 3: OR = 0·71, 95 % CI: 0·57, 0·88, quartile 4: OR = 0·71, 95 % CI: 0·57, 0·88) (P < 0·05).

CONCLUSIONS

Ca supplementation and adequate dietary intake of Ca during pregnancy are associated with a decreased risk of LBW infants born to nulliparous women.

Effect of micronutrient supplements on low-risk pregnancies in high-income countries: a systematic quantitative literature review

OBJECTIVE

To assess the quantity and focus of recent empirical research regarding the effect of micronutrient supplementation on live birth outcomes in low-risk pregnancies from high-income countries.

DESIGN

A systematic quantitative literature review.

SETTING

Low-risk pregnancies in World Bank-classified high-income countries, 2019.

RESULTS

Using carefully selected search criteria, a total of 2475 publications were identified, of which seventeen papers met the inclusion criteria for this review. Data contributing to nine of the studies were sourced from four cohorts; research originated from ten countries. These cohorts exhibited a large number of participants, stable data and a low probability of bias. The most recent empirical data offered by these studies was 2011; the most historical was 1980. In total, fifty-five categorical outcome/supplement combinations were examined; 67·3 % reported no evidence of micronutrient supplementation influencing selected outcomes.

CONCLUSIONS

A coordinated, cohesive and uniform empirical approach to future studies is required to determine what constitutes appropriate, effective and safe micronutrient supplementation in contemporary cohorts from high-income countries, and how this might influence pregnancy outcomes.

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.

Calcium Intake and Health

There are striking inequities in calcium intake between rich and poor populations. Appropriate calcium intake has shown many health benefits, such as reduction of hypertensive disorders of pregnancy, lower blood pressure particularly among young people, prevention of osteoporosis and colorectal adenomas, lower cholesterol values, and lower blood pressure in the progeny of mothers taking sufficient calcium during pregnancy. Studies have refuted some calcium supplementation side effects like damage to the iron status, formation of renal stones and myocardial infarction in older people. Attention should be given to bone resorption in post-partum women after calcium supplementation withdrawal. Mechanisms linking low calcium intake and blood pressure are mediated by parathyroid hormone raise that increases intracellular calcium in vascular smooth muscle cells leading to vasoconstriction. At the population level, an increase of around 400-500 mg/day could reduce the differences in calcium intake between high- and middle-low-income countries. The fortification of food and water seems a possible strategy to reach this goal.

Applying international guidelines for calcium supplementation to prevent pre-eclampsia: simulation of recommended dosages suggests risk of excess intake in Ethiopia

OBJECTIVE

To simulate impact of Ca supplementation on estimated total Ca intakes among women in a population with low dietary Ca intakes, using WHO recommendations: 1·5-2·0 g elemental Ca/d during pregnancy to prevent pre-eclampsia.

DESIGN

Single cross-sectional 24 h dietary recall data were adjusted using IMAPP software to simulate proportions of women who would meet or exceed the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) assuming full or partial adherence to WHO guidelines.

SETTING

Nationally and regionally representative data, Ethiopia's 'lean' season 2011.

SUBJECTS

Women 15-45 years (n 7908, of whom 492 pregnant).

RESULTS

National mean usual Ca intake was 501 (sd 244) mg/d. Approximately 89, 91 and 96 % of all women, pregnant women and 15-18 years, respectively, had dietary Ca intakes below the EAR. Simulating 100 % adherence to 1·0, 1·5 and 2·0 g/d estimated nearly all women (>99 %) would meet the EAR, regardless of dosage. Nationally, supplementation with 1·5 and 2·0 g/d would result in intake exceeding the UL in 3·7 and 43·2 % of women, respectively, while at 1·0 g/d those exceeding the UL would be <1 % (0·74 %) except in one region (4·95 %).

CONCLUSIONS

Most Ethiopian women consume insufficient Ca, increasing risk of pre-eclampsia. Providing Ca supplements of 1·5-2·0 g/d could result in high proportions of women exceeding the UL, while universal consumption of 1·0 g/d would meet requirements with minimal risk of excess. Appropriately tested screening tools could identify and reduce risk to high Ca consumers. Research on minimum effective Ca supplementation to prevent pre-eclampsia is also needed to determine whether lower doses could be recommended.

Elemental Metabolomics and Pregnancy Outcomes

Trace elements are important for human health and development. The body requires specific micronutrients to function, with aberrant changes associated with a variety of negative health outcomes. Despite this evidence, the status and function of micronutrients during pregnancy are relatively unknown and more information is required to ensure that women receive optimal intakes for foetal development. Changes in trace element status have been associated with pregnancy complications such as gestational diabetes mellitus (GDM), pre-eclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth. Measuring micronutrients with methodologies such as elemental metabolomics, which involves the simultaneous quantification and characterisation of multiple elements, could provide insight into gestational disorders. Identifying unique and subtle micronutrient changes may highlight associated proteins that are affected underpinning the pathophysiology of these complications, leading to new means of disease diagnosis. This review will provide a comprehensive summary of micronutrient status during pregnancy, and their associations with gestational disorders. Furthermore, it will also comment on the potential use of elemental metabolomics as a technique for disease characterisation and prediction.

The association between daily 500 mg calcium supplementation and lower pregnancy-induced hypertension risk in Bangladesh

BACKGROUND

Evidence suggests that daily supplementation of 1500 to 2000 mg of calcium during pregnancy reduces pregnancy-induced hypertension (PIH). However, the evidence on the efficacy of low-dose calcium supplementation on PIH is limited. This paper assesses the longitudinal correlation between low-dose calcium intake (500 mg daily) and change in blood pressure during pregnancy among a homogeneous population in terms of hypertension and pre-eclampsia.

METHODS

The study followed a retrospective cohort study design, and was carried out among 11,387 pregnant women from 10 rural upazilas (sub-districts) of Bangladesh where maternal nutrition initiative (MNI), implemented by Building Resources Across Communities (BRAC), was ongoing. The modified Poisson regression model was used to estimate the association (risk ratio) between consumption of calcium tablets and PIH.

RESULTS

The present research found that women who consumed 500 mg/d calcium tablets for more than 6 months during their pregnancy had a 45% lower risk of developing hypertension compared to those who consumed less calcium (RR = 0.55, 95% CI = 0.33-0.93).

CONCLUSIONS

Daily supplementation of 500 mg oral calcium during pregnancy for at least 180 tablets is associated with a considerably reduced risk of PIH, but this study is unable to confirm whether this association is causal. The causal relationship needs to be confirmed through a large scale randomized controlled trial.

Who is the Woman in Women's Nutrition? A Narrative Review of Evidence and Actions to Support Women's Nutrition throughout Life

Nutrition interventions that target mothers alone inadequately address women's needs across their lives: during adolescence, preconception, and in later years of life. They also fail to capture nulliparous women. The extent to which nutrition interventions effectively reach women throughout the life course is not well documented. In this comprehensive narrative review, we summarized the impact and delivery platforms of nutrition-specific and nutrition-sensitive interventions targeting adolescent girls, women of reproductive age (nonpregnant, nonlactating), pregnant and lactating women, women with young children <5 y, and older women, with a focus on nutrition interventions delivered in low- and middle-income countries. We found that although there were many effective interventions that targeted women's nutrition, they largely targeted women who were pregnant and lactating or with young children. There were major gaps in the targeting of interventions to older women. For the delivery platforms, community-based settings, compared with facility-based settings, more equitably reached women across the life course, including adolescents, women of reproductive age, and older women. Nutrition-sensitive approaches were more often delivered in community-based settings; however, the evidence of their impact on women's nutritional outcomes was less clear. We also found major research and programming gaps relative to targeting overweight, obesity, and noncommunicable disease. We conclude that focused efforts on women during pregnancy and in the first couple of years postpartum fail to address the interrelation and compounding nature of nutritional disadvantages that are perpetuated across many women's lives. In order for policies and interventions to more effectively address inequities faced by women, and not only women as mothers, it is essential that they reflect on how, when, and where to engage with women across the life course.

Systematic review to identify proxy indicators to quantify the impact of eHealth tools on maternal and neonatal health outcomes in low-income and middle-income countries including Delphi consensus

OBJECTIVE

To identify interventions that could serve as reliable proxy indicators to measure eHealth impact on maternal and neonatal outcomes.

DESIGN

Systematic review and Delphi study.

METHODS

We searched PubMed, Embase and Cochrane from January 1990 to May 2016 for studies and reviews that evaluated interventions aimed at improving maternal/neonatal health and reducing mortality. Interventions that are not low-income and middle-income context appropriate and that cannot currently be diagnosed, managed or impacted by eHealth (eg, via telemedicine distance diagnostic or e-learning) were excluded. We used the Cochrane risk of bias, Risk Of Bias In Non- randomised Studies - of Interventions and ROBIS tool to assess the risk of bias. A three-step modified Delphi method was added to identify additional proxy indicators and prioritise the results, involving a panel of 13 experts from different regions, representing obstetricians and neonatologists.

RESULTS

We included 44 studies and reviews, identifying 40 potential proxy indicators with a positive impact on maternal/neonatal outcomes. The Delphi experts completed and prioritised these, resulting in a list of 77 potential proxy indicators.

CONCLUSIONS

The proxy indicators propose relevant outcome measures to evaluate if eHealth tools directly affect maternal/neonatal outcomes. Some proxy indicators require mapping to the local context, practices and available resources. The local mapping facilitates the utilisation of the proxy indicators in various contexts while allowing the systematic collection of data from different projects and programmes. Based on the mapping, the same proxy indicator can be used for different contexts, allowing it to measure what is locally and temporally relevant, making the proxy indicator sustainable.

PROSPERO REGISTRATION NUMBER

CRD42015027351.

Stones in pregnancy and pediatrics

Urinary stone disease is a highly prevalent condition affecting approximately 10% of the population, and has increased in incidence significantly over the past 20 years. Along with this, the rate of stone disease among women and children is also on the rise. The management of stone disease in specific populations, such as in children and during pregnancy can present unique challenges to the urologist. In both populations, a multi-disciplinary approach is strongly recommended given the complexities of the patients. Prompt and accurate diagnosis requires a high degree of suspicion and judicious use of diagnostic imaging given the higher risks of radiation exposure. In general, management proceeds from conservative to more invasive approaches and must be individualized to the patient with careful consideration of the potential adverse effects. However, innovations in endourologic equipment and techniques have allowed for the wider application of surgical stone treatment in these patients, and significant advancement in the field. This review covers the history and current advances in the diagnosis and management of stone disease in pregnant and pediatric populations. It is paramount for the urologist to understand the complexities of properly managing stones in these patients in order to maximize treatment efficacy, while minimizing complications and morbidity.

Antenatal care services and its implications for vital and health outcomes of children: evidence from 193 surveys in 69 low-income and middle-income countries

OBJECTIVES

Antenatal care (ANC) is an essential part of primary healthcare and its provision has expanded worldwide. There is limited evidence of large-scale cross-country studies on the impact of ANC offered to pregnant women on child health outcomes. We investigate the association of ANC in low-income and middle-income countries with short- and long-term mortality and nutritional child outcomes.

SETTING

We used nationally representative health and welfare data from 193 Demographic and Health Surveys conducted between 1990 and 2013 from 69 low-income and middle-income countries for women of reproductive age (15-49 years), their children and their respective household.

PARTICIPANTS

The analytical sample consisted of 752 635 observations for neonatal mortality, 574 675 observations for infant mortality, 400 426 observations for low birth weight, 501 484 observations for stunting and 512 424 observations for underweight.

MAIN OUTCOMES AND MEASURES

Outcome variables are neonatal and infant mortality, low birth weight, stunting and underweight.

RESULTS

At least one ANC visit was associated with a 1.04% points reduced probability of neonatal mortality and a 1.07% points lower probability of infant mortality. Having at least four ANC visits and having at least once seen a skilled provider reduced the probability by an additional 0.56% and 0.42% points, respectively. At least one ANC visit is associated with a 3.82% points reduced probability of giving birth to a low birth weight baby and a 4.11 and 3.26% points reduced stunting and underweight probability. Having at least four ANC visits and at least once seen a skilled provider reduced the probability by an additional 2.83%, 1.41% and 1.90% points, respectively.

CONCLUSIONS

The currently existing and accessed ANC services in low-income and middle-income countries are directly associated with improved birth outcomes and longer-term reductions of child mortality and malnourishment.

Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis

Vitamin D supplementation effects with or without calcium in pregnancy for reducing risk of preeclampsia and gestational or pregnancy induced hypertension are controversial. Literature was systematically searched in Medline, Scopus and Cochrane databases from inception to July 2017. Only randomized controlled trials (RCTs) in English were selected if they had any pair of interventions (calcium, vitamin D, both, or placebo). Systematic review with two-step network-meta-analysis was used to indirectly estimate supplementary effects. Twenty-seven RCTs with 28,000 women were eligible. A direct meta-analysis suggested that calcium, vitamin D, and calcium plus vitamin D could lower risk of preeclampsia when compared to placebo with the pooled risk ratios (RRs) of 0.54 (0.41, 0.70), 0.47 (0.24, 0.89) and 0.50 (0.32, 0.78), respectively. Results of network meta-analysis were similar with the corresponding RRs of 0.49 (0.35, 0.69), 0.43 (0.17, 1.11), and 0.57 (0.30, 1.10), respectively. None of the controls were significant. Efficacy of supplementation, which was ranked by surface under cumulative ranking probabilities, were: vitamin D (47.4%), calcium (31.6%) and calcium plus vitamin D (19.6%), respectively. Calcium supplementation may be used for prevention for preeclampsia. Vitamin D might also worked well but further large scale RCTs are warranted to confirm our findings.

A Simplified Regimen Compared with WHO Guidelines Decreases Antenatal Calcium Supplement Intake for Prevention of Preeclampsia in a Cluster-Randomized Noninferiority Trial in Rural Kenya

Background: To prevent preeclampsia, the WHO recommends antenatal calcium supplementation in populations with inadequate habitual intake. The WHO recommends 1500-2000 mg Ca/d with iron-folic acid (IFA) taken separately, a complex pill-taking regimen. Objective: The objective of this study was to test the hypothesis that simpler regimens with lower daily dosages would lead to higher adherence and similar supplement intake.Methods: In the Micronutrient Initiative Calcium Supplementation study, we compared the mean daily supplement intake associated with 2 dosing regimens with the use of a parallel, cluster-randomized noninferiority trial implemented in 16 primary health care facilities in rural Kenya. The standard regimen was 3 × 500 mg Ca/d in 3 pill-taking events, and the low-dose regimen was 2 × 500 mg Ca/d in 2 pill-taking events; both regimens included a 200 IU cholecalciferol and calcium pill and a separate IFA pill. We enrolled 990 pregnant women between 16 and 30 wk of gestation. The primary outcome was supplemental calcium intake measured by pill counts 4 and 8 wk after recruitment. We carried out intention-to-treat analyses with the use of mixed-effect models, with regimen as the fixed effect and health care facilities as a random effect, by using a noninferiority margin of 125 mg Ca/d.Results: Women in facilities assigned to the standard regimen consumed a mean of 1198 mg Ca/d, whereas those assigned to the low-dose regimen consumed 810 mg Ca/d. The difference in intake was 388 mg Ca/d (95% CI = 341, 434 mg Ca/d), exceeding the prespecified margin of 125 mg Ca/d. The overall adherence rate was 80% and did not differ between study arms.Conclusions: Contrary to our expectation, a simpler, lower-dose regimen led to significantly lower supplement intake than the regimen recommended by the WHO. Further studies are needed to precisely characterize the dose-response relation of calcium supplementation and preeclampsia risk and to examine cost effectiveness of lower and simpler regimens in program settings. This trial was registered at clinicaltrials.gov as NCT02238704.

Assessing and Improving Childhood Nutrition and Growth Globally

Improving maternal and child nutrition is central to global development goals and reducing the noncommunicable disease burden. Although the process of becoming malnourished starts in utero, the consequences of poor nutrition extend across the life cycle and into future generations. The global nutrition targets for 2025 include reducing infant and young child growth faltering, halting the increase of overweight children, improving breastfeeding practices, and reducing maternal anemia. In this review, we address nutritional assessment, discuss nonnutritive factors that affect growth, and endorse the evidence-based interventions that should be scaled up to improve maternal and child nutrition.

Systematic review on evidence-based adolescent nutrition interventions

Adolescence is a critical stage in the life cycle, and adequate nutrition is necessary for the proper growth and development of individuals and their offspring. Here, we comprehensively review all published systematic reviews (through October 2016) on adolescents (10-19 years) and women of reproductive age, including pregnant women, which targeted interventions related to nutrition. For interventions where there was no existing systematic review on adolescents, we reviewed primary studies/trials. We included interventions on micronutrient supplementation (iron, folic acid, iron-folic acid (IFA), calcium, vitamin D, vitamin A, zinc, iodine, and multiple micronutrients), food/protein energy supplementation, nutrition education for pregnant adolescents, obesity prevention and management, and management of gestational diabetes. We identified a total of 35 systematic reviews, of which only five were conducted on adolescents, and 107 primary studies on adolescents. Our review suggests that iron alone, IFA, zinc, and multiple micronutrient supplementation in adolescents can significantly improve serum hemoglobin concentration. While zinc supplementation in pregnant adolescents showed improvements in preterm birth and low birth weight, we found a paucity of trials on calcium, vitamin D, vitamin A, and iodine supplementation. We found limited evidence on food/protein energy supplementation in adolescents. Interventions to prevent and manage obesity showed a nonsignificant impact on reducing body mass index. This review underscores the importance of adolescent nutrition interventions. It is imperative that countries design nutritional interventions, particularly for adolescents.

Effective nutrition education and communication for sustainable maternal and child health

Maternal and child health (MCH) consists of an interdependent reproductive system that collectively determines the survival of the mother during childbirth, and determines the health and survival of the child. This interdependency underscores the importance of appropriate and timely interventions during pregnancy through the first 1000 d at the minimum. The Millennium Development Goals (MDG) recommended the use of the continuum of care for the development of interventions by addressing all the stages of MCH. The purpose of the present paper is to review the factors that contributed to the attainment of the MDG 4 and MDG 5 by analysing the interventions conducted by the countries that achieved at least 5·0 and 5·5 %, respectively, and determine the level of their intervention based on the MCH conceptual framework. Out of the eighteen selected countries discussed, fifteen countries achieved their target for either MDG 4 or MDG 5 or both, while three countries did not achieve their target. The countries that were more likely to achieve their targets addressed the societal, underlying and direct causes, and implemented country wide policies. In contrast, the countries that did not succeed were more likely to address the direct causes with poor policy implementation. Understanding the motivation and limitations of the target population, including nutrition education and targeting behaviour change has the potential to result in sustainable MCH. This information has the potential to enlighten the policymakers as we progress to the sustainable development goals, specifically goals 2 and 3.

Risk of gestational diabetes mellitus in relation to maternal dietary calcium intake

OBJECTIVE

The present study sought to examine the association between dietary Ca intake and risk of gestational diabetes mellitus (GDM).

DESIGN

We assessed periconceptional (i.e. before conception and early pregnancy) Ca intake and consumption of foods rich in Ca using an FFQ among 3414 participants in a prospective cohort study. Diagnoses of GDM were abstracted from medical records. We used multivariable generalized linear regression models to derive estimates of relative risk (RR) for GDM and 95 % confidence intervals.

SETTING

A prospective cohort of women in Seattle and Tacoma, WA, USA.

SUBJECTS

Women (n 3414).

RESULTS

A total of 169 GDM incident cases were identified in the cohort (4·96 %). Higher dietary Ca intake was inversely, although not statistically significantly, associated with GDM risk. After adjusting for confounders, the RR (95 % CI) for GDM according to successive increasing quartile of Ca intake was 1·00, 0·63 (0·41, 0·98), 0·66 (0·39, 1·11) and 0·57 (0·27, 1·21), respectively, with the lowest quartile as the reference (P trend=0·131). Compared with women in the first quartile for Ca intake, women in the higher three quartiles (≥795 v. <795 mg/d) had a 42 % (RR=0·58; 95 % CI 0·38, 0·90; P=0·015) lower GDM risk. GDM risk was inversely associated with low-fat dairy (P trend=0·032) and whole grains (P trend=0·019) consumption.

CONCLUSIONS

These findings suggest that higher levels of periconceptional Ca intake, particularly intake of Ca-rich low-fat dairy products and whole grains, are associated with lower GDM risk.

Calcium Deficiency in Bangladesh: Burden and Proposed Solutions for the First 1000 Days

BACKGROUND

Bangladesh incurs among the highest prevalence of stunting and micronutrient deficiencies in the world, despite efforts against diarrheal disease, respiratory infections, and protein-energy malnutrition which have led to substantial and continuous reductions in child mortality over the past 35 years. Although programs have generally paid more attention to other micronutrients, the local importance of calcium to health has been less recognized.

OBJECTIVE

To synthesize available information on calcium deficiency in Bangladesh in order to inform the design of an effective national calcium program.

METHODS

We searched 3 online databases and a multitude of survey reports to conduct a narrative review of calcium epidemiology in Bangladesh, including population intake, determinants and consequences of deficiency, and tested interventions, with particular reference to young children and women of childbearing age. This was supplemented with secondary analysis of a national household survey in order to map the relative extent of calcium adequacy among different demographics.

RESULTS

Intake of calcium is low in the general population of Bangladesh, with potentially serious and persistent effects on public health. These effects are especially pertinent to young children and reproductive-age women, by virtue of increased physiologic needs, disproportionately poor access to dietary calcium sources, and a confluence of other local determinants of calcium status in these groups.

CONCLUSION

A tablet supplementation program for pregnant women is an appealing approach for the reduction in preeclampsia and preterm birth. Further research is warranted to address the comparative benefit of different promising approaches in children for the prevention of rickets.

Maternal vitamin D concentrations during pregnancy, fetal growth patterns, and risks of adverse birth outcomes

BACKGROUND

Maternal vitamin D deficiency during pregnancy may affect fetal outcomes.

OBJECTIVE

The objective of this study was to examine whether maternal 25-hydroxyvitamin D [25(OH)D] concentrations in pregnancy affect fetal growth patterns and birth outcomes.

DESIGN

This was a population-based prospective cohort in Rotterdam, Netherlands in 7098 mothers and their offspring. We measured 25(OH)D concentrations at a median gestational age of 20.3 wk (range: 18.5-23.3 wk). Vitamin D concentrations were analyzed continuously and in quartiles. Fetal head circumference and body length and weight were estimated by repeated ultrasounds, and preterm birth (gestational age <37 wk) and small size for gestational age (less than the fifth percentile) were determined.

RESULTS

Adjusted multivariate regression analyses showed that, compared with mothers with second-trimester 25(OH)D concentrations in the highest quartile, those with 25(OH)D concentrations in the lower quartiles had offspring with third-trimester fetal growth restriction, leading to a smaller head circumference, shorter body length, and lower body weight at birth (all P < 0.05). Mothers who had 25(OH)D concentrations in the lowest quartile had an increased risk of preterm delivery (OR: 1.72; 95% CI: 1.14, 2.60) and children who were small for gestational age (OR: 2.07; 95% CI: 1.33, 3.22). The estimated population attributable risk of 25(OH)D concentrations <50 nmol/L for preterm birth or small size for gestational age were 17.3% and 22.6%, respectively. The observed associations were not based on extreme 25(OH)D deficiency, but presented within the common ranges.

CONCLUSIONS

Low maternal 25(OH)D concentrations are associated with proportional fetal growth restriction and with an increased risk of preterm birth and small size for gestational age at birth. Further studies are needed to investigate the causality of these associations and the potential for public health interventions.

Maternal Dietary Supplementation with Oligofructose-Enriched Inulin in Gestating/Lactating Rats Preserves Maternal Bone and Improves Bone Microarchitecture in Their Offspring

Nutrition during pregnancy and lactation could exert a key role not only on maternal bone, but also could influence the skeletal development of the offspring. This study was performed in rats to assess the relationship between maternal dietary intake of prebiotic oligofructose-enriched inulin and its role in bone turnover during gestation and lactation, as well as its effect on offspring peak bone mass/architecture during early adulthood. Rat dams were fed either with standard rodent diet (CC group), calcium-fortified diet (Ca group), or prebiotic oligofructose-enriched inulin supplemented diet (Pre group), during the second half of gestation and lactation. Bone mineral density (BMD) and content (BMC), as well as micro-structure of dams and offspring at different stages were analysed. Dams in the Pre group had significantly higher trabecular thickness (Tb.Th), trabecular bone volume fraction (BV/TV) and smaller specific bone surface (BS/BV) of the tibia in comparison with CC dams. The Pre group offspring during early adulthood had an increase of the lumbar vertebra BMD when compared with offspring of CC and Ca groups. The Pre group offspring also showed significant increase versus CC in cancellous and cortical structural parameters of the lumbar vertebra 4 such as Tb.Th, cortical BMD and decreased BS/BV. The results indicate that oligofructose-enriched inulin supplementation can be considered as a plausible nutritional option for protecting against maternal bone loss during gestation and lactation preventing bone fragility and for optimizing peak bone mass and architecture of the offspring in order to increase bone strength.

Calcium-Vitamin D Co-supplementation Affects Metabolic Profiles, but not Pregnancy Outcomes, in Healthy Pregnant Women

BACKGROUND

Pregnancy is associated with unfavorable metabolic profile, which might in turn result in adverse pregnancy outcomes. The current study was designed to evaluate the effects of calcium plus Vitamin D administration on metabolic status and pregnancy outcomes in healthy pregnant women.

METHODS

This randomized double-blind placebo-controlled clinical trial was performed among 42 pregnant women aged 18-40 years who were at week 25 of gestation. Subjects were randomly allocated to consume either 500 mg calcium-200 IU cholecalciferol supplements (n = 21) or placebo (n = 21) for 9 weeks. Blood samples were obtained at the onset of the study and after 9-week trial to determine related markers. Post-delivery, the newborn's weight, length, and head circumference were measured during the first 24 h after birth.

RESULTS

Consumption of calcium-Vitamin D co-supplements resulted in a significant reduction of serum high-sensitivity C-reactive protein levels compared with placebo (-1856.8 ± 2657.7 vs. 707.1 ± 3139.4 μg/mL, P = 0.006). We also found a significant elevation of plasma total antioxidant capacity (89.3 ± 118.0 vs. -9.4 ± 164.9 mmol/L, P = 0.03), serum 25-hydroxyvitamin D (2.5 ± 3.5 vs. -1.7 ± 1.7 ng/mL, P < 0.0001), and calcium levels (0.6 ± 0.6 vs. -0.1 ± 0.4 mg/dL, P < 0.0001). The supplementation led to a significant decrease in diastolic blood pressure (-1.9 ± 8.3 vs. 3.1 ± 5.2 mmHg, P = 0.02) compared with placebo. No significant effect of calcium-Vitamin D co-supplements was seen on other metabolic profiles. We saw no significant change of the co-supplementation on pregnancy outcomes as well.

CONCLUSIONS

Although calcium-Vitamin D co-supplementation for 9 weeks in pregnant women resulted in improved metabolic profiles, it did not affect pregnancy outcomes.

Calcium Plus Vitamin D Supplementation During the Third Trimester of Pregnancy in Adolescents Accustomed to Low Calcium Diets Does Not Affect Infant Bone Mass at Early Lactation in a Randomized Controlled Trial

BACKGROUND

Pregnancy and lactation in adolescents with low calcium intake may impair fetal growth and infant bone mass.

OBJECTIVE

We investigated the effects of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers consuming low calcium diets (∼600 mg/d) on fetal biometry and infant bone mass, and the relation between infant and maternal bone mass during early lactation.

METHODS

Infants of mothers who received calcium (600 mg/d) plus cholecalciferol (200 IU/d) supplementation (n = 30) or placebo (n = 26) from 26 wk of gestation until parturition were studied. Fetal biometric measurements at 23 and 36 wk of gestation were obtained from medical records. Infant anthropometric and total body bone measurements [bone mineral content (BMC), bone area (BA), and bone mineral density (BMD)] at 5 wk postpartum were assessed by dual-energy X-ray absorptiometry. Maternal BMD z scores for total body, lumbar spine, total hip, and femoral neck at 5 wk postpartum were obtained. Group comparisons were adjusted for significant covariates.

RESULTS

Maternal mean serum 25-hydroxyvitamin D was 59 nmol/L at baseline in both groups. No differences in fetal measurements at 36 wk of gestation were observed between the groups, except for body weight and its increment from 23 to 36 wk, which were higher in the supplemented group (6.8%, P = 0.014 and 10.5%, P = 0.07, respectively). Infant BMC (61.1 ± 21.7 g), BA (167 ± 79 cm(2)), and BMD (0.385 ± 0.069 g/cm(2)) did not significantly differ between the groups. In the placebo group, infant BMC and BA were negatively correlated with maternal BMD z scores for total body (r = -0.40 and r = -0.47; P < 0.05) and hip (r = -0.41 and r = -0.46; P < 0.05). In contrast, no correlations were observed in the supplemented group.

CONCLUSIONS

Calcium and vitamin D supplementation of the adolescents studied resulted in higher fetal body weight at 36 wk of gestation and had no effect on infant bone mass at 5 wk postpartum. Because correlations between maternal and infant bone mass were evident only in the placebo group, infant bone mass appeared to be more dependent on maternal skeletal mass when calcium intake was low. This trial was registered at clinicaltrials.gov as NCT01732328.

Micronutrients in pregnancy in low- and middle-income countries

Pregnancy is one of the more important periods in life when increased micronutrients, and macronutrients are most needed by the body; both for the health and well-being of the mother and for the growing foetus and newborn child. This brief review aims to identify the micronutrients (vitamins and minerals) likely to be deficient in women of reproductive age in Low- and Middle-Income Countries (LMIC), especially during pregnancy, and the impact of such deficiencies. A global prevalence of some two billion people at risk of micronutrient deficiencies, and multiple micronutrient deficiencies of many pregnant women in LMIC underline the urgency to establishing the optimal recommendations, including for delivery. It has long been recognized that adequate iron is important for best reproductive outcomes, including gestational cognitive development. Similarly, iodine and calcium have been recognized for their roles in development of the foetus/neonate. Less clear effects of deficiencies of zinc, copper, magnesium and selenium have been reported. Folate sufficiency periconceptionally is recognized both by the practice of providing folic acid in antenatal iron/folic acid supplementation and by increasing numbers of countries fortifying flours with folic acid. Other vitamins likely to be important include vitamins B12, D and A with the water-soluble vitamins generally less likely to be a problem. Epigenetic influences and the likely influence of micronutrient deficiencies on foetal origins of adult chronic diseases are currently being clarified. Micronutrients may have other more subtle, unrecognized effects. The necessity for improved diets and health and sanitation are consistently recommended, although these are not always available to many of the world's pregnant women. Consequently, supplementation programmes, fortification of staples and condiments, and nutrition and health support need to be scaled-up, supported by social and cultural measures. Because of the life-long influences on reproductive outcomes, including inter-generational ones, both clinical and public health measures need to ensure adequate micronutrient intakes during pregnancy, but also during adolescence, the first few years of life, and during lactation. Many antenatal programmes are not currently achieving this. We aim to address the need for micronutrients during pregnancy, the importance of micronutrient deficiencies during gestation and before, and propose the scaling-up of clinical and public health approaches that achieve healthier pregnancies and improved pregnancy outcomes.

Could molecular assessment of calcium metabolism be a useful tool to early screen patients at risk for pre-eclampsia complicated pregnancy? Proposal and rationale

One of the most frequent causes of maternal and perinatal morbidity is represented by hypertensive disorders during pregnancy. Women at high risk must be subjected to a more intensive antenatal surveillance and prophylactic treatments. Many genetic risk factors, clinical features and biomarkers have been proposed but none of these seems able to prevent pre-eclampsia onset. English literature review of manuscripts focused on calcium intake and hypertensive disorders during pregnancy was performed. We performed a critical analysis of evidences about maternal calcium metabolism pattern in pregnancy analyzing all possible bias affecting studies. Calcium supplementation seems to give beneficial effects on women with low calcium intake. Some evidence reported that calcium supplementation may drastically reduce the percentage of pre-eclampsia onset consequently improving the neonatal outcome. Starting from this evidence, it is intuitive that investigations on maternal calcium metabolism pattern in first trimester of pregnancy could represent a low cost, large scale tool to screen pregnant women and to identify those at increased risk of pre-eclampsia onset. We propose a biochemical screening of maternal calcium metabolism pattern in first trimester of pregnancy to discriminate patients who potentially may benefit from calcium supplementation. In a second step we propose to randomly allocate the sub-cohort of patients with calcium metabolism disorders in a treatment group (calcium supplementation) or in a control group (placebo) to define if calcium supplementation may represent a dietary mean to reduce pre-eclampsia onset and to improve pregnancy outcome.

Multiple micronutrient supplementation during pregnancy and lactation in low-to-middle-income developing country settings: impact on pregnancy outcomes

BACKGROUND

Malnutrition, including micronutrient deficiencies, remains one of the major public health challenges, particularly in low-to-middle-income countries. Micronutrient deficiencies affect people of all ages, but its effects appear more devastating in pregnant women and children. Poor maternal nutrition contributes to at least 20% of maternal deaths and increases the probability of poor pregnancy outcomes including intrauterine growth restriction, resulting in low birth weight, stunting, wasting and mortality. Key Messages: Several strategies have been employed to provide pregnant women with micronutrients. These strategies include education, dietary modification, food provision, agricultural interventions, supplementation and fortification either alone or in combination. Micronutrient supplementation is the most widely practiced intervention to prevent and manage single or multiple micronutrient deficiencies. Micronutrient supplementation either alone or in combination has shown to be effective in improving maternal, birth and child outcomes.

CONCLUSIONS

There is a need to focus on maternal micronutrient status as a continuum from the periconceptional period throughout pregnancy to lactation. Given the wide prevalence of multiple micronutrient deficiencies in low-to-middle-income countries, the challenge is to implement intervention strategies that combine appropriate maternal and child health interventions with micronutrient interventions.

Can available interventions end preventable deaths in mothers, newborn babies, and stillbirths, and at what cost?

Progress in newborn survival has been slow, and even more so for reductions in stillbirths. To meet Every Newborn targets of ten or fewer neonatal deaths and ten or fewer stillbirths per 1000 births in every country by 2035 will necessitate accelerated scale-up of the most effective care targeting major causes of newborn deaths. We have systematically reviewed interventions across the continuum of care and various delivery platforms, and then modelled the effect and cost of scale-up in the 75 high-burden Countdown countries. Closure of the quality gap through the provision of effective care for all women and newborn babies delivering in facilities could prevent an estimated 113,000 maternal deaths, 531,000 stillbirths, and 1·325 million neonatal deaths annually by 2020 at an estimated running cost of US$4·5 billion per year (US$0·9 per person). Increased coverage and quality of preconception, antenatal, intrapartum, and postnatal interventions by 2025 could avert 71% of neonatal deaths (1·9 million [range 1·6-2·1 million]), 33% of stillbirths (0·82 million [0·60-0·93 million]), and 54% of maternal deaths (0·16 million [0·14-0·17 million]) per year. These reductions can be achieved at an annual incremental running cost of US$5·65 billion (US$1·15 per person), which amounts to US$1928 for each life saved, including stillbirths, neonatal, and maternal deaths. Most (82%) of this effect is attributable to facility-based care which, although more expensive than community-based strategies, improves the likelihood of survival. Most of the running costs are also for facility-based care (US$3·66 billion or 64%), even without the cost of new hospitals and country-specific capital inputs being factored in. The maximum effect on neonatal deaths is through interventions delivered during labour and birth, including for obstetric complications (41%), followed by care of small and ill newborn babies (30%). To meet the unmet need for family planning with modern contraceptives would be synergistic, and would contribute to around a halving of births and therefore deaths. Our analysis also indicates that available interventions can reduce the three most common cause of neonatal mortality--preterm, intrapartum, and infection-related deaths--by 58%, 79%, and 84%, respectively.

Effects of dietary interventions on pregnancy outcomes: a systematic review and meta-analysis

Dietary intake during pregnancy influences maternal health. Poor dietary practices during pregnancy have been linked to maternal complications. The objective was to determine the effect of dietary intervention before or during pregnancy on pregnancy outcomes. A systematic review was conducted without date restrictions. Randomised controlled trials (RCTs) evaluating whole diet or dietary components and pregnancy outcomes were included. Two authors independently identified papers for inclusion and assessed methodological quality. Meta-analysis was conducted separately for each outcome using random effects models. Results were reported by type of dietary intervention: (1) counselling; (2) food and fortified food products; or (3) combination (counseling + food); and collectively for all dietary interventions. Results were further grouped by trimester when the intervention commenced, nutrient of interest, country income and body mass index. Of 2326 screened abstracts, a total of 28 RCTs were included in this review. Dietary counselling during pregnancy was effective in reducing systolic [standardised mean difference (SMD) -0.26, 95% confidence interval (CI) -0.45 to -0.07; P < 0.001] and diastolic blood pressure (SMD -0.57, 95% CI -0.75 to -0.38; P < 0.001). Macronutrient dietary interventions were effective in reducing the incidence of preterm delivery (SMD -0.19, 95% CI -0.34 to -0.04; P = 0.01). No effects were seen for other outcomes. Dietary interventions showed some small, but significant differences in pregnancy outcomes including a reduction in the incidence of preterm birth. Further high-quality RCTs, investigating micronutrient provision from food, and combination dietary intervention, are required to identify maternal diet intakes that optimise pregnancy outcomes.

Design and Development of a Combined Calcium—Iron—Folic Acid Prenatal Supplement to Support Implementation of the New World Health Organization Recommendations for Calcium Supplementation during Pregnancy

Background

Hypertensive diseases of pregnancy are important causes of maternal and perinatal mortality. Based on meta-analyses of efficacy trials of prenatal cal- cium supplementation to reduce the risk of hypertensive diseases of pregnancy, the World Health Organization recommends 1.5 to 2.0 g of elemental calcium per day for pregnant women with low dietary calcium intakes (as well as 60 mg of iron and 400 μg of folic acid). However, implementation of this recommendation is challenged by the size and number of calcium tablets required and the need to avoid concurrent ingestion of calcium and iron due to intraintestinal interactions.

Objective

We developed a novel micronutrient powder containing microencapsulated pH-sensitive calcium in addition to iron and folic acid, designed to facilitate early intestinal iron release and delayed calcium release.

Methods

Two pharmaceutical companies were con- tracted to develop a prototype, one of which was chosen for clinical testing. Calcium carbonate granules were coated with a trilayer pH-sensitive enteric coating using a fluid-bed spray coater. Iron and folic acid granules were encapsulated with a time-release coating. Iron and cal- cium dissolution profiles were assessed during exposure to acidic (pH 1.2) and/or basic (pH 5.8) media using a modified USP apparatus 1 (basket) method.

Results

At pH 1.2, calcium and iron release was ≤ 10% and > 90% after 120 minutes, respectively. At pH 5.8, > 80% of total calcium was released after 90 minutes.

Conclusions

Based on in vitro criteria, the sup- plement may be a promising approach for delivering calcium, iron, and folic acid as a single daily dose to preg- nant women in settings of low dietary intake of calcium.

The stunting syndrome in developing countries

Linear growth failure is the most common form of undernutrition globally. With an estimated 165 million children below 5 years of age affected, stunting has been identified as a major public health priority, and there are ambitious targets to reduce the prevalence of stunting by 40% between 2010 and 2025. We view this condition as a 'stunting syndrome' in which multiple pathological changes marked by linear growth retardation in early life are associated with increased morbidity and mortality, reduced physical, neurodevelopmental and economic capacity and an elevated risk of metabolic disease into adulthood. Stunting is a cyclical process because women who were themselves stunted in childhood tend to have stunted offspring, creating an intergenerational cycle of poverty and reduced human capital that is difficult to break. In this review, the mechanisms underlying linear growth failure at different ages are described, the short-, medium- and long-term consequences of stunting are discussed, and the evidence for windows of opportunity during the life cycle to target interventions at the stunting syndrome are evaluated.

Evidence-based interventions for improvement of maternal and child nutrition: what can be done and at what cost?

Maternal undernutrition contributes to 800,000 neonatal deaths annually through small for gestational age births; stunting, wasting, and micronutrient deficiencies are estimated to underlie nearly 3·1 million child deaths annually. Progress has been made with many interventions implemented at scale and the evidence for effectiveness of nutrition interventions and delivery strategies has grown since The Lancet Series on Maternal and Child Undernutrition in 2008. We did a comprehensive update of interventions to address undernutrition and micronutrient deficiencies in women and children and used standard methods to assess emerging new evidence for delivery platforms. We modelled the effect on lives saved and cost of these interventions in the 34 countries that have 90% of the world's children with stunted growth. We also examined the effect of various delivery platforms and delivery options using community health workers to engage poor populations and promote behaviour change, access and uptake of interventions. Our analysis suggests the current total of deaths in children younger than 5 years can be reduced by 15% if populations can access ten evidence-based nutrition interventions at 90% coverage. Additionally, access to and uptake of iodised salt can alleviate iodine deficiency and improve health outcomes. Accelerated gains are possible and about a fifth of the existing burden of stunting can be averted using these approaches, if access is improved in this way. The estimated total additional annual cost involved for scaling up access to these ten direct nutrition interventions in the 34 focus countries is Int$9·6 billion per year. Continued investments in nutrition-specific interventions to avert maternal and child undernutrition and micronutrient deficiencies through community engagement and delivery strategies that can reach poor segments of the population at greatest risk can make a great difference. If this improved access is linked to nutrition-sensitive approaches--ie, women's empowerment, agriculture, food systems, education, employment, social protection, and safety nets--they can greatly accelerate progress in countries with the highest burden of maternal and child undernutrition and mortality.

Maternal and child undernutrition and overweight in low-income and middle-income countries

Maternal and child malnutrition in low-income and middle-income countries encompasses both undernutrition and a growing problem with overweight and obesity. Low body-mass index, indicative of maternal undernutrition, has declined somewhat in the past two decades but continues to be prevalent in Asia and Africa. Prevalence of maternal overweight has had a steady increase since 1980 and exceeds that of underweight in all regions. Prevalence of stunting of linear growth of children younger than 5 years has decreased during the past two decades, but is higher in south Asia and sub-Saharan Africa than elsewhere and globally affected at least 165 million children in 2011; wasting affected at least 52 million children. Deficiencies of vitamin A and zinc result in deaths; deficiencies of iodine and iron, together with stunting, can contribute to children not reaching their developmental potential. Maternal undernutrition contributes to fetal growth restriction, which increases the risk of neonatal deaths and, for survivors, of stunting by 2 years of age. Suboptimum breastfeeding results in an increased risk for mortality in the first 2 years of life. We estimate that undernutrition in the aggregate--including fetal growth restriction, stunting, wasting, and deficiencies of vitamin A and zinc along with suboptimum breastfeeding--is a cause of 3·1 million child deaths annually or 45% of all child deaths in 2011. Maternal overweight and obesity result in increased maternal morbidity and infant mortality. Childhood overweight is becoming an increasingly important contributor to adult obesity, diabetes, and non-communicable diseases. The high present and future disease burden caused by malnutrition in women of reproductive age, pregnancy, and children in the first 2 years of life should lead to interventions focused on these groups.