Background and objective: Plasma cobalamins decrease during pregnancy but it is not fully elucidated how this is reflected in the total and cobalamin saturated transport proteins, transcobalamin (total TC, holoTC) and haptocorrin (total HC, holoHC). TC transports cobalamin into the cells. The function of HC is unknown, but in contrast to TC it binds both cobalamins and cobalamin analogues. Design...
Date First Received: April 27, 2007
Last Updated: April 27, 2007
Verified by: University of Aarhus, April 2007
Clinical Trial Phase: N/A | Start Date: January 1995
Overall Status: Completed
Estimated Enrollment: 150
Brief Summary
Official Title: “Holotranscobalamin Remains Unchanged During Pregnancy. Longitudinal Changes of Cobalamins and Its Binding Proteins During Pregnancy and Postpartum”
Condition Keyword(s):
Background and objective: Plasma cobalamins decrease during pregnancy but it is not fully elucidated how this is reflected in the total and cobalamin saturated transport proteins, transcobalamin (total TC, holoTC) and haptocorrin (total HC, holoHC). TC transports cobalamin into the cells. The function of HC is unknown, but in contrast to TC it binds both cobalamins and cobalamin analogues.
Design and methods: Healthy pregnant women (N=141) had blood samples drawn at 18th, 32nd, 39th gestation week and 8 weeks postpartum. The protein moiety of TC and HC (total and holo) was measured by in-house ELISA methods.
Results: During pregnancy, cobalamins and HC (total and holo) decreased, holoTC remained unchanged, while total TC increased. The medians in pmol/L at 18th, (39th) gestation week and [8 weeks postpartum] were: cobalamins 230(170)[310], holoHC 310(260)[380], totalHC 510(450)[450], holoTC 79(79)[93] and total TC 850(950)[810]. The sum of holoTC and holoHC exceeded cobalamins by 150(170)[150] supporting that HC carries both analogues and cobalamins.
Interpretation and conclusions: While cobalamins decrease during pregnancy the active part of the cobalamins, holoTC, remains unchanged. The decrease in cobalamins can be explained by a decrease in holoHC suggesting that holoTC is more useful than cobalamins as a marker of vitamin B12 deficiency during pregnancy.
Study Type: Observational
Study Design: Natural History, Longitudinal, Defined Population, Prospective Study
Detailed Clinical Trial Description
Background and objective: Plasma cobalamins decrease during pregnancy but it is not fully elucidated how this is reflected in the total and cobalamin saturated transport proteins, transcobalamin (total TC, holoTC) and haptocorrin (total HC, holoHC). TC transports cobalamin into the cells. The function of HC is unknown, but in contrast to TC it binds both cobalamins and cobalamin analogues.
Design and methods: Healthy pregnant women (N=141) had blood samples drawn at 18th, 32nd, 39th gestation week and 8 weeks postpartum. The protein moiety of TC and HC (total and holo) was measured by in-house ELISA methods.
Results: During pregnancy, cobalamins and HC (total and holo) decreased, holoTC remained unchanged, while total TC increased. The medians in pmol/L at 18th, (39th) gestation week and [8 weeks postpartum] were: cobalamins 230(170)[310], holoHC 310(260)[380], totalHC 510(450)[450], holoTC 79(79)[93] and total TC 850(950)[810]. The sum of holoTC and holoHC exceeded cobalamins by 150(170)[150] supporting that HC carries both analogues and cobalamins.
Interpretation and conclusions: While cobalamins decrease during pregnancy the active part of the cobalamins, holoTC, remains unchanged. The decrease in cobalamins can be explained by a decrease in holoHC suggesting that holoTC is more useful than cobalamins as a marker of vitamin B12 deficiency during pregnancy.
Criteria for Participation in this Clinical Trial
Inclusion Criteria:
- Danish healthy Caucasian women >18 years of age with previous uncomplicated pregnancies and deliveries and presently with a normal pregnancy.
Exclusion Criteria:
- >4 cigarettes smoked per day,
- Treatment with vitamin B12, folic acid or acetyl salicylic acid,
- Impaired renal function and clinically significant vaginal haemorrhage before first visit as well as blood haemoglobin <6.4 mmol/L at first visit.
Gender Eligibility for this Clinical Trial: Female
Minimum Age for this Clinical Trial: 18 Years
Maximum Age for this Clinical Trial: 45 Years
Are Healthy Volunteers Accepted for this Clinical Trial?: Accepts Healthy Volunteers
Clinical Trial Sponsor Information
Lead Sponsor: University of Aarhus
Overall Clinical Trial Officials and Contacts
Nils Milman, MD Principal Investigator University of Copenhagen
Additional Information
Information obtained from ClinicalTrials.gov on October 10, 2008
Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00467623
Study ID Number: KA-93140
ClinicalTrials.gov Identifier: NCT00467623
Health Authority: Denmark: Ethics Committee
Clinical Trials Authorship and Review
Clinical Trials content is provided directly by the U.S. National Institutes of Health via ClinicalTrials.gov and is not reviewed separately by ClinicalTrialsFeeds.org. Every page of specific clinical trials information contains a unique identifier which can be used to find further details directly from the National Institutes of Health.