Effects of Nutritional Interventions During Pregnancy on Maternal and Neonatal Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
In brief
Pregnancy food interventions add about 51 g to newborns' birth weight
Across six randomized trials involving 6,245 participants, food-based nutrition interventions increased newborns' average birth weight by about 51 g and length by 0.29 cm. The gains were small, and the analysis found no clear effect on low birth weight, head circumference, stillbirth, or miscarriage; whether the modest growth differences matter clinically remains uncertain.
- Journal
- Journal of clinical medicine (Q1)
- Published
- 19 September 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Zlatko Kirovakov, Andriana Jovanoska-Kirovakova, Pavel Dobrev, Nikolay Kostadinov, Plamen Penchev
- PMID
- 42796067
- DOI
- 10.3390/jcm15187297
Why clinicians should know about it
- Picked for Neonatology (top studies of the week, 27 September 2026).
Abstract
Background: Maternal undernutrition is associated with impaired fetal growth and adverse pregnancy outcomes, but the effects of food-based nutritional interventions during pregnancy remain uncertain. This systematic review and meta-analysis evaluated their effects on maternal and neonatal outcomes using evidence exclusively from randomized controlled trials (RCTs). Methods: PubMed, Embase, Scopus, and the Cochrane Library were searched from inception to 15 July 2026 for RCTs comparing food-based nutritional interventions with standard care, no supplementation, micronutrient supplementation, or an alternative nutritional intervention. Risk ratios (RRs) for binary outcomes were pooled using the Mantel-Haenszel method, while mean differences (MDs) for continuous outcomes were pooled using the inverse-variance method. Restricted maximum-likelihood random-effects models were applied, and heterogeneity was assessed using I2 and Cochran's Q test. The protocol was registered in PROSPERO (CRD420261465279). Results: Six RCTs comprising 6245 participants were included, of whom 3150 (50%) received a nutritional intervention. Nutritional interventions increased birth weight (MD 51.49 g; 95% CI 22.87-80.11; I2 = 42.7%; p < 0.01) and birth length (MD 0.29 cm; 95% CI 0.14-0.45; I2 = 21.6%; p < 0.01). No significant effects were observed on birth head circumference (MD -0.14 cm; 95% CI -0.62 to 0.34; I2 = 73.9%; p = 0.57), low birth weight (RR 0.76; 95% CI 0.35-1.68; I2 = 64.2%; p = 0.28), stillbirth (RR 0.96; 95% CI 0.78-1.19; I2 = 0%; p = 0.61), or miscarriage (RR 0.83; 95% CI 0.35-1.97; I2 = 0%; p = 0.45). Conclusions: Food-based nutritional intervention strategies were associated with small statistically significant increases in birth weight and birth length; however, the clinical importance of differences of approximately 51 g and 0.29 cm remains uncertain. Evidence was inconclusive for low birth weight, head circumference, stillbirth, and miscarriage.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.