Clinical trial NCT01355159
Conditions: Pregnancy Complications Preeclampsia
Keywords: Pregnancy Folic Acid supplementation Preeclampsia
Sponsor: Ottawa Hospital Research Institute
Start date: 2011-04-01; Completion date: 2016-09-01
Enrollment: 2464 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
To determine the efficacy of high dose folic acid supplementation for prevention of preeclampsia in women with at least one risk factor: pre-existing hypertension, pre-pregnancy diabetes (type 1 or 2), twin pregnancy, preeclampsia in a previous pregnancy, or body mass index ≥35. It was hypothesized that high dose (4.0 mg per day) supplementation starting in early pregnancy and continued throughout the entire pregnancy will lower the incidence of preeclampsia in pregnant women at high risk of developing preeclampsia.

Detailed description:
Preeclampsia is a complication of pregnancy which affects at least 5% of all pregnancies worldwide and has serious health consequences to these women and their babies. Preeclampsia is hypertension (high blood pressure) in pregnancy with proteinuria. Proteinuria is when protein is found in the urine, and it is a sign that the kidneys are not functioning properly. The only effective treatment for preeclampsia is delivery of the baby. Because delivery may be required before the anticipated date of delivery; preeclampsia is also one of the leading causes of preterm delivery and accounts for 25% of very low birth weight infants. Recent research has also shown that women who have had preeclampsia during pregnancy are more likely to be at risk for future cardiovascular events later in life.

Recently some studies have shown that supplementation with multivitamins containing folic acid is associated with a reduced risk of developing preeclampsia. These findings also suggested that for the prevention of preeclampsia, a high dose of folic acid (much higher than the amount of folate received from food intake or what is usually taken during pregnancy) may be needed.

A randomized controlled trial was conducted in 70 obstetrical centres in 5 countries (Argentina, Australia, Canada, Jamaica, and the UK) to evaluate the effect of high dose folic acid started in early pregnancy on the risk of developing preeclampsia in high-risk women. A sample size of 2464 allowed for 80% power and a 10% loss to follow-up/study withdrawal. Participants received either placebo or four 1.0 mg oral tablets of folic acid.

Arms: arm 1: Folic Acid 1.0 mg x 4 tablets will be taken daily by oral administration. The majority of women in the study will routinely take 1.0 mg folic acid in a prenatal vitamin supplement, as recommended by their primary obstetrical provider; the study requirements do not require that participants change their practice. Therefore the actual total daily dose may be up to 5.1 mg of folic acid arm 2: Women will be randomised in a 1:1 ratio to folic acid 4.0 mg or placebo
Interventions: intervention 1: Folic Acid 4 mg intervention 2: Placebo
Intervention descriptions: intervention 1: Folic Acid 1.0 mg or placebo x 4 tablets will be taken daily by oral administration. The majority of women in the study will routinely take 1.0 mg folic acid in a prenatal vitamin supplement, as recommended by their primary obstetrical provider; the study requirements do not require that participants change their practice. Therefore the actual total daily dose may be up to 5.1 mg of folic acid intervention 2: Placebo x 4 tablets will be taken daily by oral administration.

Protocol documents: