Pre-eclampsia

Low dietary calcium intake prior to and during pregnancy is a risk factor for pre-eclampsia, and calcium supplementation in women in areas of low dietary calcium intake is considered to reduce the risk of pre-eclampsia and its complications. However, clinical trials conducted to date have demonstrated conflicting results on calcium supplementation strategies for preventing pre-eclampsia. ​

There is an urgent need to determine how calcium supplementation can be used most effectively to prevent and reduce pre-eclampsia to reduce maternal and perinatal morbidity and mortality. Optimising the use of calcium to prevent pre-eclampsia is a priority area for WHO, and the 2018 Guideline Development Group (GDG) identified that further research on the minimal dose and optimal commencement schedule for calcium supplementation was a high research priority. Prevention of pre-eclampsia and its complications is crucial to achieving the health-related Sustainable Development Goals (SDGs), and the WHO Thirteenth General Programme of Work for universal health coverage. ​

The International Calcium in Pregnancy (i-CIP) Collaborative Network plans to fill these gaps in evidence by investigating which calcium supplementation regimen is most clinically effective, acceptable, scalable, and cost-effective in preventing pre-eclampsia and improving maternal and perinatal outcomes in LMIC. To reach its aims, i-CIP Collaborative Network is divided in four work packages (WP), as follow: individual participant data (IPD) meta-analysis (WP 1); stakeholder views on uptake, implementation, and scalability of calcium supplementation strategies (WP 2); health economic and decision-analytic modelling (WP3); and research capacity strengthening and sustainability (WP4)​

ICIP Network website

What is the problem?​

When pre-eclampsia occurs early in pregnancy, before 34 weeks of gestation, it is more severe than late onset disease and contributes disproportionately to adverse maternal and fetal outcomes. In women with early onset pre-eclampsia, mothers are often delivered early to improve their condition, contributing to prematurity associated complications including death, and long-term neurological disability in the children. This leads to significant costs to the NHS in caring for the preterm baby and societal costs for their long-term care.​

What is needed?​

Accurate and early identification of women at high risk of pre-eclampsia will allow clinicians to commence preventative interventions such as aspirin, and frequent monitoring in pregnancy.​

Where are the gaps in research?​

Although over 100 tools (models) have been reported worldwide to predict pre-eclampsia, to-date their performance in women managed in the National Health Service in UK is not known.​

What are the aims of the IPPIC network?​

To comprehensively identify all published models to predict pre-eclampsia and assess if they accurately predict the risk in UK population by accessing the data of individual women for analysis. If existing models did not perform satisfactorily, IPPIC aims to develop new models to predict early, late and any onset pre-eclampsia.​

What did the IPPIC Network find?​

The IPPIC (International Prediction of Pregnancy Complications) network provided data from the largest number of studies (78 studies, 25 countries, 125 researchers). Of the 131 models published on prediction of pre-eclampsia, we were able to assess the performance of 24 in 11 UK datasets. The models did not accurately predict the risk of pre-eclampsia across all UK datasets, with varied performance within individual datasets. We developed 12 IPPIC models that showed promising performance on average across all datasets. But their ability to correctly identify women who develop pre-eclampsia varied between populations. The models showed net benefit over and above a strategy of treating all women when applied to first time mothers pregnant with one child in the UK.