Calcium supplementation for Prevention of Pre-Eclampsia in high-risk women (CaPE)
Prevention of pre-eclampsia in women at increased risk
Pregnant women who meet the eligibility criteria of the trial will be randomised using a minimisation algorithm to ensure balance in treatment allocation (central randomisation, 1:1 ratio, with minimisation). Participants will be allocated to receive either calcium carbonate tablets 2 g/day (1 g tablet twice daily) commenced from 12 to 22 weeks’ gestation, taken until delivery, plus usual care (including aspirin), or to placebo tablets plus usual care.
1. Over 16 years of age 2. Able to provide informed consent to participate 3. After a dating scan has confirmed viability (usually between 10 and 14 weeks gestation) 4. 22 weeks’ 0 days gestation or less 5. Women deemed eligible for aspirin therapy based on NICE guideline criteria below where a woman has either: 5.1. One high-risk factor: 5.1.1. Hypertensive disease during a previous pregnancy 5.1.2. Chronic renal disease 5.1.3. Autoimmune disease such as SLE or antiphospholipid syndrome 5.1.4. Type 1 or 2 diabetes 5.1.5. Chronic hypertension 5.2. Or two or more moderate risk factors: 5.2.1. First pregnancy 5.2.2. Age more than 40 years 5.2.3. BMI ≥35 at first visit 5.2.4. Family history of pre-eclampsia 5.2.5. Multiple pregnancy 5.2.6. Pregnancy interval of 10 years or more 5.3. Or the Fetal Medicine Foundation (FMF) algorithm for pre-eclampsia risk assessment, as used locally 5.4. Or any other national pre-eclampsia screening criteria guidelines that may be used in the future The study will also include women identified to be at high risk of pre-eclampsia based on any other national screening criteria guidelines that may be used in the future.
1. Any known contraindications to regular calcium intake (history of renal stones, known renal impairment with pre-pregnancy eGFR <30 ml/min/1.73m² or serum creatinine >150 (μmol/l), known history of hypercalcaemia or hypercalcaemia-causing diseases (e.g. parathyroid disease, sarcoidosis, malignancy), current severe persistent vomiting leading to dehydration or requiring hospitalisation (if persisting vomiting resolves, the patient may be re-assessed for inclusion in the trial, providing all other inclusion and exclusion criteria are met) 2. Use of drugs with potential for severe interactions with calcium: digoxin or other cardiac glycosides; antiretroviral drugs for HIV treatment, anti-neoplastic drugs, and diuretics (thiazide, thiazide-like or xipamide). 3. Use of any additional calcium supplement either on its own or as part of other multivitamin or Vitamin D preparations, and unwilling to stop them or change to other multivitamins, as this could lead to higher doses of calcium supplementation in the calcium group and contamination in the placebo group 4. Women who are taking vitamin D regularly in high doses >1000 IU/day, as supplements or for conditions such as malabsorption syndromes. Note: a short course of high dose Vitamin D (e.g., 20,000 IU weekly for 6 weeks) to treat Vitamin D deficiency during pregnancy is NOT an exclusion criteria 5. Known contraindications to excipient Isomalt (e.g. hereditary fructose intolerance)