Observational studyNutrients2021
Old Question Revisited: Are High-Protein Diets Safe in Pregnancy?
Observational study in Nutrients, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
What it found
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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
6 citing papers in PubMed, 1 synthesis or guideline pooled it, 19 citations in OpenAlex.
- Prevalence of preterm birth in Scandinavian countries: a systematic review and meta-analysis.The Journal of international medical research · 2023Pooled it
- Association of a high-protein and low-glycemic-index diet during pregnancy with offspring growth and obesity until the age of 18 years - a target trial emulation.European journal of clinical nutrition · 2025Observational
- Determinants of Adverse Perinatal Outcomes in Ibadan, Nigeria: The influence of maternal lifestyle.PLOS global public health · 2025Article
- Incidence of pre-eclampsia and its associated factors among pregnant women attending antenatal clinic at the 37 Military Hospital in Ghana.BMJ nutrition, prevention & health · 2025Article
- Adherence to different forms of plant-based diets and pregnancy outcomes in the Danish National Birth Cohort: A prospective observational study.Acta obstetricia et gynecologica Scandinavica · 2024Observational
- Dietary protein intake during pregnancy and birth weight among Chinese pregnant women with low intake of protein.Nutrition & metabolism · 2022Article
Corrections and comments
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Authors and funding
8 authors at 3 institutions in 4 countries.
Funding
Abstract
backgroundA previous randomized dietary intervention in pregnant women from the 1970s, the Harlem Trial, reported retarded fetal growth and excesses of very early preterm births and neonatal deaths among those receiving high-protein supplementation. Due to ethical challenges, these findings have not been addressed in intervention settings. Exploring these findings in an observational setting requires large statistical power due to the low prevalence of these outcomes. The aim of this study was to investigate if the findings on high protein intake could be replicated in an observational setting by combining data from two large birth cohorts.
methodsIndividual participant data on singleton pregnancies from the Danish National Birth Cohort (DNBC) (
resultsThe prevalence of preterm delivery, low birth weight and fetal and neonatal deaths was 4.77%, 2.93%, 0.28% and 0.17%, respectively. Mean protein intake (standard deviation) was 89 g/day (23). Overall high protein intake (>100 g/day) was neither associated with low birth weight nor fetal or neonatal death. Mean birth weight was essentially unchanged at high protein intakes. A modest increased risk of preterm delivery [odds ratio (OR): 1.10 (95% confidence interval (CI): 1.01, 1.19)] was observed for high (>100 g/day) compared to moderate protein intake (80-90 g/day). This estimate was driven by late preterm deliveries (weeks 34 to <37) and greater risk was not observed at more extreme intakes. Very low (<60 g/day) compared to moderate protein intake was associated with higher risk of having low-birth weight infants [OR: 1.59 (95%CI: 1.25, 2.03)].
conclusionsHigh protein intake was weakly associated with preterm delivery. Contrary to the results from the Harlem Trial, no indications of deleterious effects on fetal growth or perinatal mortality were observed.
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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.