Folic acid supplementation, dietary folate intake during pregnancy and risk for spontaneous preterm delivery: a prospective observational cohort study
Artikel i vetenskaplig tidskrift, 2014

Background: Health authorities in numerous countries recommend periconceptional folic acid supplementation to prevent neural tube defects. The objective of this study was to examine the association of dietary folate intake and folic acid supplementation during different periods of pregnancy with the risk of spontaneous preterm delivery (PTD).MethodsThe Norwegian Mother and Child Cohort Study is a population-based prospective cohort study. A total of 66,014 women with singleton pregnancies resulting in live births in 2002¿2009 were included. Folic acid supplementation was self-reported from 26 weeks before pregnancy until pregnancy week 24. At gestational week 22, the women completed a food frequency questionnaire, which allowed the calculation of their average total folate intake from foods and supplements for the first 4¿5 months of pregnancy. Spontaneous PTD was defined as the spontaneous onset of delivery between weeks 22+0 and 36+6 (n = 1,755).ResultsThe median total folate intake was 313 ¿g/d (interquartile range IQR 167¿558) in the overall population and 530 ¿g/d (IQR 355¿636) in the supplement users. Eighty-five percent reported any folic acid supplementation from <8 weeks before to 24 weeks after conception while only 44% initiated folic acid supplementation before pregnancy. Cox regression analysis showed that the amount of dietary folate intake (hazard ratio HR 1.00; confidence interval 95% CI 0.61-1.65) and supplemental folate intake (HR 1.00; CI 1.00-1.00) was not significantly associated with the risk of PTD. The initiation of folic acid supplementation more than 8 weeks before conception was associated with an increased risk for spontaneous PTD (HR 1.18; CI 1.05-1.32) compared to no folic acid supplementation preconception. There was no significant association with PTD when supplementation was initiated within 8 weeks preconception (HR 0.99; CI 0.87-1.13). All analyses were adjusted for maternal characteristics and socioeconomic, health and dietary variables.ConclusionsOur findings do not support a protective effect of dietary folate intake or folic acid supplementation on spontaneous PTD. Preconceptional folic acid supplementation starting more than 8 weeks before conception was associated with an increased risk of spontaneous PTD. These results require further investigation before discussing an expansion of folic acid supplementation guidelines.

Gestational length

Pregnancy

Preterm birth

Preterm delivery

Folic acid supplementation

Folate

Författare

Verena Sengpiel

Göteborgs universitet

Jonas Bacelis

Göteborgs universitet

Ronny Myhre

Norwegian Institute of Public Health

Solveig Myking

Norwegian Institute of Public Health

Aase Devold Pay

Oslo universitetssykehus

Margaretha Haugen

Norwegian Institute of Public Health

Anne-Lise Brantsaeter

Norwegian Institute of Public Health

Helle M Meltzer

Norwegian Institute of Public Health

Roy Miodini Nilsen

Universitetet i Bergen

Per Magnus

Norwegian Institute of Public Health

Stein Vollset

Universitetet i Bergen

Staffan Nilsson

Chalmers, Matematiska vetenskaper, Matematisk statistik

Göteborgs universitet

Bo Jacobsson

Göteborgs universitet

BMC Pregnancy and Childbirth

1471-2393 (ISSN)

Vol. 14 1 375

Ämneskategorier

Reproduktionsmedicin och gynekologi

DOI

10.1186/s12884-014-0375-1

PubMed

25361626

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Senast uppdaterat

2022-03-10