ArticleThe Journal of nutrition2019
Iron Consumption Is Not Consistently Associated with Fecundability among North American and Danish Pregnancy Planners.
Article in The Journal of nutrition, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
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
9 citing papers in PubMed, 15 citations in OpenAlex.
- Article
- Association between iron deficiency and fertility.Acta obstetricia et gynecologica Scandinavica · 2025Observational
- Iron intake in relation to ovarian reserve among women seeking infertility treatment.Human reproduction (Oxford, England) · 2023Observational
- The Role of Dietary Nutrients in Male Infertility: A Review.Life (Basel, Switzerland) · 2023Review
- Iron status in women with infertility and controls: a case-control study.Frontiers in endocrinology · 2023Article
- Dietary Supplement Intake and Fecundability in a Singapore Preconception Cohort Study.Nutrients · 2022Article
- Prepregnancy adherence to plant-based diet indices and exploratory dietary patterns in relation to fecundability.The American journal of clinical nutrition · 2022Article
- Female Fertility and the Nutritional Approach: The Most Essential Aspects.Advances in nutrition (Bethesda, Md.) · 2021Article
- Can Nutrition Help in the Treatment of Infertility?Preventive nutrition and food science · 2021Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 4 institutions in 3 countries.
Funding
Abstract
backgroundInfertility is an important public health problem with few known modifiable risk factors. Dietary factors including folic acid have been associated with improved fertility, but the association between iron and fertility is understudied. One study among US nurses found a 40% lower risk of ovulatory infertility with higher intake of nonheme iron and iron supplements.
objectivesThe aim of this study was to determine the extent to which iron intake from diet and supplements reported on structured questionnaires is associated with fecundability.
methodsWe conducted parallel analyses that used data from 2 prospective cohort studies of pregnancy planners from Denmark (Snart Foraeldre; n = 1693) and North America (PRESTO; n = 2969) during 2013-2018. Follow-up comprised menstrual cycles at risk until pregnancy or censoring for fertility treatment, stopped trying to conceive, withdrawal, loss to follow-up, or 12 cycles of attempt. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs, adjusting for confounders.
resultsWe found little association between dietary heme iron intake and fecundability in either cohort. The FR for nonheme iron intake (≥11 mg/d compared with <9 mg/day) was 1.11 for Snart Foraeldre participants (95% CI: 0.92, 1.34) and 1.01 for PRESTO participants (95% CI: 0.89, 1.14). The FR for iron-containing supplements was 1.01 in Snart Foraeldre (95% CI: 0.90, 1.13) and 1.19 in PRESTO (95% CI: 1.03, 1.38). In PRESTO, but not Snart Foraeldre, stronger positive associations were found for nonheme iron intake and iron supplement use among women with heavy menses or short menstrual cycles.
conclusionsOverall, dietary intake of iron was not consistently associated with fecundability, although there was some evidence for a positive association among women with risk factors for iron deficiency. We also found a small positive association between supplemental iron intake and fecundability among North American, but not Danish, pregnancy planners.
Indexed as
Identifiers
What OpenQuestion holds
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.