Department of Medicine Solna, Centre for Pharmacoepidemiology, Karolinska Institutet, Stockholm, Sweden.
Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
PLoS One. 2022 Aug 11;17(8):e0272046. doi: 10.1371/journal.pone.0272046. eCollection 2022.
Inconsistent results have been reported on the association between folic acid use in pregnancy and risk of GDM. The aim of this study was to estimate the association between folic acid use and GDM in two population-based Nordic cohorts.
Two cohort studies were conducted using data from the national population registers in Norway (2005-2018, n = 791,709) and Sweden (2006-2016, n = 1,112,817). Logistic regression was used to estimate the associations between GDM and self-reported folic acid use and prescribed folic acid use, compared to non-users, adjusting for covariates. To quantify how potential unmeasured confounders may affect the estimates, E-values were reported. An exposure misclassification bias analysis was also performed.
In Norwegian and Swedish cohorts, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for maternal self-reported folic acid use were 1.10 (1.06-1.14) and 0.89 (0.85-0.93), with E-values of 1.43 (1.31) and 1.50 (1.36), respectively. For prescribed folic acid use, ORs were 1.33 (1.15-1.53) and 1.56 (1.41-1.74), with E-values of 1.99 (1.57) and 2.49 (2.17), in Norway and Sweden respectively.
The slightly higher or lower odds for GDM in self-reported users of folic acid in Norway and Sweden respectively, are likely not of clinical relevance and recommendations for folic acid use in pregnancy should remain unchanged. The two Nordic cohorts showed different directions of the association between self-reported folic acid use and GDM, but based on bias analysis, exposure misclassification is an unlikely explanation since there may still be differences in prevalence of use and residual confounding. Prescribed folic acid is used by women with specific comorbidities and co-medications, which likely underlies the higher odds for GDM.
关于妊娠期间叶酸的使用与 GDM 风险之间的关联，研究结果并不一致。本研究旨在通过两项基于人群的北欧队列研究来评估叶酸的使用与 GDM 之间的关联。
本研究使用了来自挪威（2005-2018 年，n=791709）和瑞典（2006-2016 年，n=1112817）国家人口登记处的数据，开展了两项队列研究。采用 logistic 回归，在调整协变量后，比较了 GDM 与自我报告的叶酸使用和处方叶酸使用与非使用者之间的关联。为了量化潜在的未测量混杂因素可能如何影响估计值，报告了 E 值。还进行了暴露错分类偏倚分析。
在挪威和瑞典队列中，母亲自我报告的叶酸使用的调整后比值比（OR）和 95%置信区间（CI）分别为 1.10（1.06-1.14）和 0.89（0.85-0.93），E 值分别为 1.43（1.31）和 1.50（1.36）。对于处方叶酸的使用，OR 分别为 1.33（1.15-1.53）和 1.56（1.41-1.74），E 值分别为 1.99（1.57）和 2.49（2.17）。
在挪威和瑞典，自我报告的叶酸使用者发生 GDM 的几率略有升高或降低，这可能没有临床意义，妊娠期间叶酸的使用建议应保持不变。两个北欧队列显示了自我报告的叶酸使用与 GDM 之间关联的不同方向，但基于偏倚分析，暴露错分类不太可能是原因，因为使用的流行率和残余混杂因素仍可能存在差异。处方叶酸用于患有特定合并症和合并用药的女性，这可能是 GDM 风险较高的原因。
