Pre-Eclampsia
Conditions
Keywords
Folate, One Carbon Metabolism, Preeclampsia, Folic Acid, Pregnancy
Brief summary
The FACT Biomarker Subgroup Analysis is a pilot study of mothers who participated in the Folic Acid Clinical Trial (FACT, NCT01355159). This subgroup analysis aims to determine the effect of high-dose folic acid supplementation in pregnancy on maternal folate status and subsequent impact on risk for pre-eclampsia.
Detailed description
The Folic Acid Clinical Trial (FACT) was developed to conclusively determine the effect of high dose folic acid supplementation in pregnancy on the prevention of preeclampsia (PE) in a randomized controlled trial (RCT) design. The primary objective of the FACT Biomarker Subgroup Analysis is to determine the folate status and its impact on risk for PE in a subgroup of women participating in FACT. Our secondary objectives are to: i) To determine serum vitamin B6 and B12 status, modifiers of folate metabolism, and their impact on risk for PE in women participating in the FACT ii) To determine plasma homocysteine status, a folate-responsive biomarker for PE risk, and its relationship with risk for PE in women participating in the FACT iii) To determine the modifying effect of single nucleotide polymorphisms (SNPs) in key folate metabolic enzymes (MTHFR, MTHFD1, MTR) on PE risk in women participating in the FACT iv) To determine the effect of folic acid supplementation and folate status on biomarkers of PE (sFLT, sENG, PlGF) and their association with PE risk in women participating in the FACT Folate biomarker analyses will provide key information to identify modifiers of the response to folic acid treatment and elucidate the mechanism(s) underlying the relationship between folic acid treatment and PE risk. Folate status will vary in response to folic acid treatment depending on a number of factors including compliance in taking the study supplement, folate intake from the diet (natural folate and folic acid used for enrichment), vitamin B12 status, and genetic polymorphisms in enzymes involved in folate metabolism that have been shown to effect placental development/function. As such, variation in the response to folic acid treatment may account for differences in observed PE risk. Folic acid supplementation may also reduce homocysteine, its related endothelial dysfunction and consequently reduce PE risk. In addition, homocysteine metabolism is dependent on vitamins B12 and B6, the deficiency of which can result in hyperhomocysteinemia. Thus, homocysteine, B12 and B6 will each be evaluated. Lastly, it will be useful to assess biomarkers of placental health and PE risk (sFlt-1, sEng, PlGF) that are found in maternal circulation and determine their association with folate intake and status.
Interventions
OTHER4.0mg Folic Acid received through participation in FACT (NCT01355159)
Participants in this study received either daily high-dose folic acid supplementation during pregnancy OR placebo through their participation in FACT (NCT01355159). Details of the FACT Folic Acid intervention are provided below: 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
OTHERPlacebo received through participation in FACT
Participants in this study received either daily high-dose folic acid supplementation during pregnancy OR placebo through their participation in FACT (NCT01355159). Details of the FACT Folic Acid placebo are provided below: Placebo x 4 tablets will be taken daily by oral administration.
Sponsors
Ottawa Hospital Research Institute
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Individuals participating in FACT (NCT01355159) will be eligible to participate. FACT eligibility criteria are as follows: INCLUSION criteria 1. Capability of subject to comprehend and comply with study requirements 2. ≥ 18 years of age at time of consent 3. Subject is taking ≤1.1 mg of folic acid daily at the time of randomization 4. Live fetus (documented positive fetal heart prior to randomization) 5. Gestational age between 8+0 and 16+6 weeks of pregnancy (Gestational age (GA) of subjects will be calculated based on the first day of the last menstrual period (LMP) or ultrasound performed before 12+6. If early ultrasound and LMP dates differ by ≤ 7 days, base GA estimate on LMP date; if \> 7 days, use early \< 12+6 ultrasound) 6. Subject plans to give birth in a participating hospital site 7. Pregnant subjects must fulfill at least one of the following identified risk factors for pre-eclampsia (PE): * Pre-existing hypertension (documented evidence of diastolic blood pressure ≥ 90 mmHg on two separate occasions or at least 4 hours apart prior to randomization, or use of antihypertensive medication during this pregnancy specifically for the treatment of hypertension prior to randomization) * Pre-pregnancy diabetes (documented evidence of Type I or type II DM) * Twin pregnancy * Documented evidence of history of PE in a previous pregnancy * BMI \> 35 kg/m2 within 3 months prior to this pregnancy and up to randomization of this pregnancy (documented evidence of height and weight to calculate BMI is required)
Exclusion criteria
1. Known history or presence of any clinically significant disease or condition which would be a contraindication to folic acid supplementation of up to 5 mg daily for the duration of pregnancy 2. Known major fetal anomaly or fetal demise 3. History of medical complications, including: renal disease with altered renal function, epilepsy, cancer, or use of folic acid antagonists such as valproic acid 4. Individual who is currently enrolled or has participated in another clinical trial or who received an investigational drug within 3 months of the date of randomization (unless approved by the Trial Coordinating Centre) 5. Known presence of: Alcohol abuse (≥ 2 drinks per day) or alcohol dependence, Illicit drug/substance use and/or dependence, Known hypersensitivity to folic acid, Multiple Pregnancy (triplets or more), Participation in this study in a previous pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Folate Status | From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation. | The primary outcome measure is maternal folate status. Folate status will be determined by: 1. Red blood cell (RBC) folate concentrations. 2. Total serum folate concentrations. 3. The relative contribution of folate vitamers to total serum folate concentrations (unmetabolized folic acid, tetrahydrofolic acid, 5,10-methenylTHF, 5-formylTHF, 5-methylTHF and MeFox). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Homocysteine Status | From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation. | Maternal homocysteine concentrations will be determined. |
| Status of Modifiers of Folate metabolism_vitamin B-12 | Taken at one time point between 24 and 26 completed weeks gestation. | Status of modifiers of folate metabolism will be determined by Vitamin B6 and B12 concentrations |
| Angiogenic Potential | From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation. | Angiogenic potential will be determined from measurement of maternal circulating s-FLT-1, s-ENG-1 and placental growth factor concentrations. |
| Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | Taken at one time point between 24 and 26 completed weeks gestation. | Status of modifiers of folate metabolism will be determined by frequency of single nucleotide polymorphisms (SNPs) in the key folate metabolic enzyme MTHFR |
| Status of Modifiers of Folate metabolism_ Vitamin B6 (Pyridoxal 5-phosphate) | Taken at one time point between 24 and 26 completed weeks gestation. | Status of modifiers of folate metabolism will be determined by Vitamin B6 and B12 concentrations |
Countries
Canada
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| FACT High-dose Folic Acid Treatment Group Consenting study participants who, through their participation in FACT (NCT01355159) are randomized to receive daily high-dose folic acid supplementation during pregnancy.
4.0mg Folic Acid received through participation in FACT (NCT01355159): Participants in this study received either daily high-dose folic acid supplementation during pregnancy OR placebo through their participation in FACT (NCT01355159). Details of the FACT Folic Acid intervention are provided below:
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 | 19 |
| FACT Placebo Treatment Group Consenting study participants who, through their participation in FACT (NCT01355159) are randomized to receive daily placebo supplementation during pregnancy.
Placebo received through participation in FACT: Participants in this study received either daily high-dose folic acid supplementation during pregnancy OR placebo through their participation in FACT (NCT01355159). Details of the FACT Folic Acid placebo are provided below:
Placebo x 4 tablets will be taken daily by oral administration. | 31 |
| Total | 50 |
Baseline characteristics
| Characteristic | FACT High-dose Folic Acid Treatment Group | FACT Placebo Treatment Group | Total |
|---|---|---|---|
| Age, Continuous | 32 years | 32 years | 32 years |
| Race/Ethnicity, Customized Caucasian race | 18 Participants | 28 Participants | 46 Participants |
| Race/Ethnicity, Customized Other race | 1 Participants | 3 Participants | 4 Participants |
| Region of Enrollment Canada | 19 participants | 31 participants | 50 participants |
| Sex: Female, Male Female | 19 Participants | 31 Participants | 50 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 19 | 0 / 31 |
| serious Total, serious adverse events | 0 / 19 | 0 / 31 |
Outcome results
Primary
Folate Status
The primary outcome measure is maternal folate status. Folate status will be determined by: 1. Red blood cell (RBC) folate concentrations. 2. Total serum folate concentrations. 3. The relative contribution of folate vitamers to total serum folate concentrations (unmetabolized folic acid, tetrahydrofolic acid, 5,10-methenylTHF, 5-formylTHF, 5-methylTHF and MeFox).
Time frame: From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Folate Status | RBC folate | 2701 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | THF | 3 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | Serum total folate by LC-MS/MS | 148.4 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | 5-formylTHF | 1.3 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | Serum total folate by protein binding assay | 105 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | 5,10-MethenylTHF | 0.9 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | 5-MethylTHF | 126.6 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | MeFox | 6.9 nmol/L |
| FACT High-dose Folic Acid Treatment Group | Folate Status | unmetabolized folic acid | 4.6 nmol/L |
| FACT Placebo Treatment Group | Folate Status | MeFox | 5.0 nmol/L |
| FACT Placebo Treatment Group | Folate Status | RBC folate | 2686 nmol/L |
| FACT Placebo Treatment Group | Folate Status | Serum total folate by protein binding assay | 67.1 nmol/L |
| FACT Placebo Treatment Group | Folate Status | Serum total folate by LC-MS/MS | 122.8 nmol/L |
| FACT Placebo Treatment Group | Folate Status | unmetabolized folic acid | 1.9 nmol/L |
| FACT Placebo Treatment Group | Folate Status | THF | 2.4 nmol/L |
| FACT Placebo Treatment Group | Folate Status | 5-formylTHF | 1.4 nmol/L |
| FACT Placebo Treatment Group | Folate Status | 5,10-MethenylTHF | 0.8 nmol/L |
| FACT Placebo Treatment Group | Folate Status | 5-MethylTHF | 108.6 nmol/L |
Secondary
Angiogenic Potential
Angiogenic potential will be determined from measurement of maternal circulating s-FLT-1, s-ENG-1 and placental growth factor concentrations.
Time frame: From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Angiogenic Potential | Placenta growth factor (PlGF) | 421.4 pg/mL |
| FACT High-dose Folic Acid Treatment Group | Angiogenic Potential | soluble fms-like tyrosin kinase 1 (sFlt-1) | 862.9 pg/mL |
| FACT High-dose Folic Acid Treatment Group | Angiogenic Potential | soluble endoglin (sEng-1) | 961.5 pg/mL |
| FACT Placebo Treatment Group | Angiogenic Potential | Placenta growth factor (PlGF) | 331.2 pg/mL |
| FACT Placebo Treatment Group | Angiogenic Potential | soluble fms-like tyrosin kinase 1 (sFlt-1) | 812 pg/mL |
| FACT Placebo Treatment Group | Angiogenic Potential | soluble endoglin (sEng-1) | 1061.0 pg/mL |
Secondary
Homocysteine Status
Maternal homocysteine concentrations will be determined.
Time frame: From FACT randomization at 8-16 weeks gestation to date of sample collection taken at one time point between 24 and 26 completed weeks gestation.
Population: Two participants in the High-dose Folic Acid Treatment Group and one participant in the Placebo Treatment Group had missing data for this outcome.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Homocysteine Status | 6 nmol/L |
| FACT Placebo Treatment Group | Homocysteine Status | 6.4 nmol/L |
Secondary
Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T)
Status of modifiers of folate metabolism will be determined by frequency of single nucleotide polymorphisms (SNPs) in the key folate metabolic enzyme MTHFR
Time frame: Taken at one time point between 24 and 26 completed weeks gestation.
Population: The baseline distribution of MTHFR (C677T) genotype frequencies, ie, CC, TT, and CT are describe in each row.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | CC | 7 Participants |
| FACT High-dose Folic Acid Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | CT | 9 Participants |
| FACT High-dose Folic Acid Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | TT | 3 Participants |
| FACT Placebo Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | CC | 12 Participants |
| FACT Placebo Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | CT | 15 Participants |
| FACT Placebo Treatment Group | Status of Modifiers of Folate metabolism_MTHFR Genotype (C677T) | TT | 4 Participants |
Secondary
Status of Modifiers of Folate metabolism_vitamin B-12
Status of modifiers of folate metabolism will be determined by Vitamin B6 and B12 concentrations
Time frame: Taken at one time point between 24 and 26 completed weeks gestation.
Population: For Vitamin B-12 measurement, sample data are not available for one participant in the high-dose folic acid treatment group, and one participant in the placebo treatment group.~Missing data are due to insufficient sample volume or compromised sample quality.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Status of Modifiers of Folate metabolism_vitamin B-12 | 217.5 pmol/L |
| FACT Placebo Treatment Group | Status of Modifiers of Folate metabolism_vitamin B-12 | 208.5 pmol/L |
Secondary
Status of Modifiers of Folate metabolism_ Vitamin B6 (Pyridoxal 5-phosphate)
Status of modifiers of folate metabolism will be determined by Vitamin B6 and B12 concentrations
Time frame: Taken at one time point between 24 and 26 completed weeks gestation.
Population: For Vitamin B-6 (pyridoxal 5-phosphate), sample data are not available for one participant in the high-dose folic acid treatment group.~Missing data are due to insufficient sample volume or compromised sample quality.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| FACT High-dose Folic Acid Treatment Group | Status of Modifiers of Folate metabolism_ Vitamin B6 (Pyridoxal 5-phosphate) | 44.3 nmol/L |
| FACT Placebo Treatment Group | Status of Modifiers of Folate metabolism_ Vitamin B6 (Pyridoxal 5-phosphate) | 40.0 nmol/L |