SynthesisMaternal & child nutrition2019
Folate, vitamin B12, and homocysteine in smoking-exposed pregnant women: A systematic review.
Synthesis in Maternal & child nutrition, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
23 citing papers in PubMed, 1 synthesis or guideline pooled it, 36 citations in OpenAlex.
- Folate, vitamin B12, and homocysteine in smoking-exposed pregnant women: A systematic review.Maternal & child nutrition · 2019Pooled it
- Association between smoking status and vitamin B12 levels in Jordanian adults: A cross-sectional study of active, passive, and non-smokers.Journal of public health research · 2026Article
- Real-time nanomolar vitamin monitoring in sweat using an electrochemical skin-attached device.Nature communications · 2026Article
- Role of combined serum homocysteine and small dense LDL-C in predicting cardiovascular events in obesity: a retrospective clinical study.BMC cardiovascular disorders · 2026Article
- Dietary and other lifestyle correlates of serum folate levels among female students at An-Najah National University in Palestine: a cross-sectional study.BMC nutrition · 2026Article
- Cumulative childhood lead exposure estimation and school-age IQ in a prospective birth cohort.Environmental health : a global access science source · 2025Article
- Preconceptional and Periconceptional Folic Acid Supplementation in the Visegrad Group Countries for the Prevention of Neural Tube Defects.Nutrients · 2024Review
- Exploring the Impact of Cigarette Smoke Extracts on Vitamin BBiochemistry research international · 2024Article
- Combination effects of environmental tobacco smoke exposure and nutrients supplement during pregnancy on obesity in Chinese preschool children.Frontiers in pediatrics · 2024Article
- Maternal Smoking during Pregnancy and its effects on Neural Tube Defects.Iranian journal of child neurology · 2024Article
- Influence ofOpen life sciences · 2023Article
- Prenatal exposure to tobacco and adverse birth outcomes: effect modification by folate intake during pregnancy.Maternal health, neonatology and perinatology · 2022Article
- Folate and vitamin B12 status: temporal evaluation after mandatory fortification in Brazil.European journal of clinical nutrition · 2022Article
- Commonalities in Metabolic Reprogramming between Tobacco Use and Oral Cancer.International journal of environmental research and public health · 2022Article
- First Trimester Maternal Homocysteine and Embryonic and Fetal Growth: The Rotterdam Periconception Cohort.Nutrients · 2022Article
- Association of MTHFD1 gene polymorphisms and maternal smoking with risk of congenital heart disease: a hospital-based case-control study.BMC pregnancy and childbirth · 2022Article
- Maternal tobacco smoke exposure is associated with increased DNA methylation at human metastable epialleles in infant cord blood.Environmental epigenetics · 2022Article
- Maternal serum Vitamin B12 and offspring attention-deficit/hyperactivity disorder (ADHD).European child & adolescent psychiatry · 2021Article
- Article
- Exposure to Tobacco, Environmental Tobacco Smoke and Nicotine in Pregnancy: A Pragmatic Overview of Reviews of Maternal and Child Outcomes, Effectiveness of Interventions and Barriers and Facilitators to Quitting.International journal of environmental research and public health · 2020Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Smoking exposure is associated with pregnancy complications, as are levels of folate, vitamin B12, and homocysteine. In nonpregnant adults, smoking exposure is associated negatively with folate and vitamin B12 levels and positively with homocysteine levels. A complete overview of the literature on this topic in pregnant women is lacking. To evaluate evidence of associations of maternal smoking exposure during pregnancy and levels of folate, homocysteine, and vitamin B12 in pregnancy and in cord blood, we searched MEDLINE, Embase, CINAHL, Cochrane, Scopus, Web of Science, and reference lists of relevant studies until August 2017. We selected studies in pregnant women describing the association of passive or active smoking and levels of folate, homocysteine, and/or vitamin B12. Data were extracted by two independent reviewers. We included 32 studies of 2,015 identified references with a total of 37,822 participants and more than 6,000 smokers. Twenty-eight studies measured folate, 14 measured vitamin B12, and 13 measured homocysteine. Nineteen out of 28 studies assessing folate reported significantly lower levels in pregnant women exposed to smoking compared with those unexposed. Vitamin B12 levels were lower in smoking mothers in eight out of 14 studies. Homocysteine levels tended to be higher in mothers exposed to smoking. Smoking exposure during pregnancy is generally associated with lower folate and vitamin B12 levels and higher homocysteine levels. This may help raise further awareness about the consequences of smoking and the need to encourage stopping smoking in all, especially in pregnant women.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.