Background
Pre-eclampsia and eclampsia are common causes of serious morbidity and death. Calcium supplementation may reduce the risk of pre-eclampsia, and may help to prevent preterm birth.

Objectives
To assess the effects of calcium supplementation during pregnancy on hypertensive disorders of pregnancy and related maternal and child outcomes.

Search methods
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 March 2013) and contacted study authors for more data where possible. We updated the search in May 2014 and added the results to the 'Awaiting Classification' section of the review.

Selection criteria
Randomised controlled trials (RCTs) comparing high-dose (at least 1 g daily of calcium) or low-dose calcium supplementation during pregnancy with placebo or no calcium.

Data collection and analysis
We assessed eligibility and trial quality, extracted and double-entered data.

Main results
High-dose calcium supplementation (≥1 g/day)

We included 14 studies in the review, however one study contributed no data. We included 13 high-quality studies in our meta-analyses (15,730 women). The average risk of high blood pressure (BP) was reduced with calcium supplementation compared with placebo (12 trials, 15,470 women: risk ratio (RR) 0.65, 95% confidence interval (CI) 0.53 to 0.81; I² = 74%). There was also a significant reduction in the risk of pre-eclampsia associated with calcium supplementation (13 trials, 15,730 women: RR 0.45, 95% CI 0.31 to 0.65; I² = 70%). The effect was greatest for women with low calcium diets (eight trials, 10,678 women: average RR 0.36, 95% CI 0.20 to 0.65; I² = 76%) and women at high risk of pre-eclampsia (five trials, 587 women: average RR 0.22, 95% CI 0.12 to 0.42; I² = 0%). These data should be interpreted with caution because of the possibility of small-study effect or publication bias.

The composite outcome maternal death or serious morbidity was reduced (four trials, 9732 women; RR 0.80, 95% CI 0.65 to 0.97; I² = 0%). Maternal deaths were not significantly different (one trial of 8312 women: calcium group one death versus placebo group six deaths). There was an anomalous increase in the risk of HELLP (haemolysis, elevated liver enzymes and low platelets) syndrome (two trials, 12,901 women: RR 2.67, 95% CI 1.05 to 6.82; I² = 0%) in the calcium group, however, the absolute number of events was low (16 versus six).

The average risk of preterm birth was reduced in the calcium group (11 trials, 15,275 women: RR 0.76, 95% CI 0.60 to 0.97; I² = 60%) and amongst women at high risk of developing pre-eclampsia (four trials, 568 women: average RR 0.45, 95% CI 0.24 to 0.83; I² = 60%), but no significant reduction in neonatal high care admission. There was no overall effect on the risk of stillbirth or infant death before discharge from hospital (11 trials 15,665 babies: RR 0.90, 95% CI 0.74 to 1.09; I² = 0%).

One study showed a reduction in childhood systolic BP greater than 95th percentile among children exposed to calcium supplementation in utero (514 children: RR 0.59, 95% CI 0.39 to 0.91). In a subset of these children, dental caries at 12 years old was also reduced (195 children, RR 0.73, 95% CI 0.62 to 0.87).

Low-dose calcium supplementation (< 1 g/day)

We included 10 trials (2234 women) that evaluated low-dose supplementation with calcium alone (4) or in association with vitamin D (3), linoleic acid (2), or antioxidants (1). Most studies recruited women at high risk for pre-eclampsia, and were at high risk of bias, thus the results should be interpreted with caution. Supplementation with low doses of calcium significantly reduced the risk of pre-eclampsia (RR 0.38, 95% CI 0.28 to 0.52; I² = 0%). There was also a reduction in hypertension, low birthweight and neonatal intensive care unit admission.

Authors' conclusions
Calcium supplementation (≥ 1 g/day) is associated with a significant reduction in the risk of pre-eclampsia, particularly for women with low calcium diets. The treatment effect may be overestimated due to small-study effects or publication bias. It also reduces preterm birth and the occurrence of the composite outcome 'maternal death or serious morbidity'. We considered these benefits to outweigh the increased risk of HELLP syndrome, which was small in absolute numbers. The World Health Organization recommends calcium 1.5 g to 2 g daily for pregnant women with low dietary calcium intake.

The limited evidence on low-dose calcium supplementation suggests a reduction in pre-eclampsia, but needs to be confirmed by larger, high-quality trials. Pending such results, in settings of low dietary calcium where high-dose supplementation is not feasible, the option of lower-dose supplements (500 to 600 mg/day) might be considered in preference to no supplementation.

Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems

Neonatal and perinatal mortality: country, regional and global estimates.

Background
Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, low-dose aspirin in particular, might prevent or delay development of pre-eclampsia.

Objectives
To assess the effectiveness and safety of antiplatelet agents for women at risk of developing pre-eclampsia.

Search methods
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (July 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 1), EMBASE (1994 to November 2005) and handsearched congress proceedings of the International and European Societies for the Study of Hypertension in Pregnancy.

We updated the search of the Cochrane Pregnancy and Childbirth Group's Trials Register on 31 May 2010 and added the results to the awaiting classification section

Selection criteria
All randomised trials comparing antiplatelet agents with either placebo or no antiplatelet agent were included. Quasi-random studies were excluded. Participants were pregnant women at risk of developing pre-eclampsia. Interventions were any comparisons of an antiplatelet agent (such as low-dose aspirin or dipyridamole) with either placebo or no antiplatelet.

Data collection and analysis
Two authors assessed trials for inclusion and extracted data independently.

Main results
Fifty-nine trials (37,560 women) are included. There is a 17% reduction in the risk of pre-eclampsia associated with the use of antiplatelet agents ((46 trials, 32,891 women, relative risk (RR) 0.83, 95% confidence interval (CI) 0.77 to 0.89), number needed to treat (NNT) 72 (52, 119)). Although there is no statistical difference in RR based on maternal risk, there is a significant increase in the absolute risk reduction of pre-eclampsia for high risk (risk difference (RD) -5.2% (-7.5, -2.9), NNT 19 (13, 34)) compared with moderate risk women (RD -0.84 (-1.37, -0.3), NNT 119 (73, 333)).

Antiplatelets were associated with an 8% reduction in the relative risk of preterm birth (29 trials, 31,151 women, RR 0.92, 95% CI 0.88 to 0.97); NNT 72 (52, 119)), a 14% reduction in fetal or neonatal deaths (40 trials, 33,098 women, RR 0.86, 95% CI 0.76 to 0.98); NNT 243 (131, 1,666) and a 10% reduction in small-for-gestational age babies (36 trials, 23,638 women, RR 0.90, 95% CI0.83 to 0.98). There were no statistically significant differences between treatment and control groups for any other outcomes.

Authors' conclusions
Antiplatelet agents, largely low-dose aspirin, have moderate benefits when used for prevention of pre-eclampsia and its consequences. Further information is required to assess which women are most likely to benefit, when treatment is best started, and at what dose.

[Note: The 16 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]

/pdf/antiplatelet-agents-for-preventing-pre-eclampsia-and-its-5axiz9hgcj.pdf

Antiplatelet agents for preventing pre‐eclampsia and its complications

Objective To determine the relation between overweight and obesity in mothers and preterm birth and low birth weight in singleton pregnancies in developed and developing countries. Design Systematic review and meta-analyses. Data sources Medline and Embase from their inceptions, and reference lists of identified articles. Study selection Studies including a reference group of women with normal body mass index that assessed the effect of overweight and obesity on two primary outcomes: preterm birth (before 37 weeks) and low birth weight ( Data extraction Two assessors independently reviewed titles, abstracts, and full articles, extracted data using a piloted data collection form, and assessed quality. Data synthesis 84 studies (64 cohort and 20 case-control) were included, totalling 1 095 834 women. Although the overall risk of preterm birth was similar in overweight and obese women and women of normal weight, the risk of induced preterm birth was increased in overweight and obese women (relative risk 1.30, 95% confidence interval 1.23 to 1.37). Although overall the risk of having an infant of low birth weight was decreased in overweight and obese women (0.84, 0.75 to 0.95), the decrease was greater in developing countries than in developed countries (0.58, 0.47 to 0.71 v 0.90, 0.79 to 1.01). After accounting for publication bias, the apparent protective effect of overweight and obesity on low birth weight disappeared with the addition of imputed “missing” studies (0.95, 0.85 to 1.07), whereas the risk of preterm birth appeared significantly higher in overweight and obese women (1.24, 1.13 to 1.37). Conclusions Overweight and obese women have increased risks of preterm birth and induced preterm birth and, after accounting for publication bias, appeared to have increased risks of preterm birth overall. The beneficial effects of maternal overweight and obesity on low birth weight were greater in developing countries and disappeared after accounting for publication bias.

https://www.bmj.com/content/bmj/341/bmj.c3428.full.pdf

Overweight and obesity in mothers and risk of preterm birth and low birth weight infants: systematic review and meta-analyses

Objective Fewer than 3% of 4 million annual neonatal deaths occur in countries with reliable vital registration (VR) data. Global estimates for asphyxia-related neonatal deaths vary from 0.7 to 1.2 million. Estimates for intrapartum stillbirths are not available. We aimed to estimate the numbers of intrapartum-related neonatal deaths and intrapartum stillbirths in the year 2000. Methods Sources of data on neonatal death included: vital registration (VR) data on neonatal death from countries with full (> 90%) VR coverage (48 countries, n = 97 297); studies identified through literature searches (> 4000 abstracts) and meeting inclusion criteria (46 populations, 30 countries, n = 12 355). A regression model was fitted to cause-specific proportionate mortality data from VR and the literature. Predicted cause-specific proportions were applied to the number of neonatal deaths by country, and summed to a global total. Intrapartum stillbirths were estimated using median cause-specific mortality rate by country (73 populations, 52 countries, n = 46 779) or the subregional median in the absence of country data. Findings Intrapartum-related neonatal deaths were estimated at 0.904 million (uncertainty 0.65–1.17), equivalent to 23% of the global total of 4 million neonatal deaths. Country-level model predictions compared well with population-based data sets not included in the input data. An estimated 1.02 million intrapartum stillbirths (0.66–1.48 million) occur annually, comprising 26% of global stillbirths. Conclusion Intrapartum-related neonatal deaths account for almost 10% of deaths in children aged under 5 years. Intrapartum stillbirths are a huge and invisible problem, but are potentially preventable. Programmatic attention and improved information are required.

/pdf/no-cry-at-birth-global-estimates-of-intrapartum-stillbirths-19mecsy16q.pdf

No cry at birth: global estimates of intrapartum stillbirths and intrapartum-related neonatal deaths.

A prospective randomised clinical trial comprising 510 pregnant patients was performed to determine whether supplementation with calcium, low-dose aspirin or a combination of calcium and low-dose aspirin can lower the incidence of hypertension in pregnancy. Greatest benefits were obtained with calcium. Perinatal mortality was lowest in the aspirin group.

Prevention of hypertensive disorders of pregnancy.

Amniotic fluid creatinine in normal and abnormal pregnancies

A postmortem study of the degree of displacement of the tracheal tube was performed on 13 neonates of varying birthweights. There was significant movement of the tube on flexion and extension of the neck, and on opening the infant's mouth. Our findings lend support to certain techniques of tracheal tube placement; the ultimate aim is to position it accurately.

Instability of the tracheal tube in neonates. A postmortem study.

A survey of the records of 103 consecutive patients who underwent abdominal myomectomy revealed that menorrhagia and infertility were the commonest presenting complaints. The overall successful pregnancy rate was only 28.2%, but the procedure was corrective in two-thirds of patients with leiomyomata-related infertility. Intra-operative blood loss, post-operative adhesion formation and recurrence of tumour remain major drawbacks of myomectomy.

The results of abdominal myomectomy

Amniotic fluid urea and creatinine in normal pregnancy and in pre-eclampsia.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

S. Roopnarinesingh

Author Tools

Chat about Author