Current evidence on the role of pre-pregnancy diets on child health outcomes

In a recent scoping review published in the Journal of Preventive Medicine and Public Health, researchers explored the existing evidence on pre-pregnancy diet and maternal and child outcomes.

The study completed this review to outline what has been researched on pre-pregnancy diet and child health to outline a path for future research.

Study: Pre-pregnancy Diet to Maternal and Child Health Outcome: A Scoping Review of Current Evidence. Image Credit: Groundpicture/Shutterstock.com

Background

Pre-pregnancy health has drawn attention as a convenient window to prepare for a healthy pregnancy and includes nutrition and lifestyle aspects, such as diet.

Healthy diets can prevent malnutrition and reduce the risk of associated non-communicable diseases. Evidence suggests an association between females' pre-pregnancy nutritional status and maternal/child outcomes.

Still, the contribution of the pre-pregnancy diet to these outcomes is less defined.

About the study

In the present study, researchers explored the evidence of the pre-pregnancy diet regarding maternal and child health outcomes. They systematically searched the PubMed database using the population, intervention, comparison, outcomes, and study design (PICOS) framework. Peer-reviewed articles published in the English or Indonesian language were selected.

Additionally, they searched the Science and Technology Index (SINTA) and Google Scholar databases using local (Indonesian) terms. Preprint, conference, and methodological articles were excluded.

Two authors independently screened titles and abstracts for relevance, followed by full-text reviews. Selected papers were stratified into primary and secondary research.

They extracted data on the study design, population, sample size, participants' age, country, outcome variables, dietary assessment, and maternal/child health outcomes.

The study quality was assessed using the quality assessment tools from the National Institute of Health (NIH), and articles were classified as having poor, fair, or good quality.

Findings

Initially, 296 records were identified from the indicated databases, and 286 were screened for relevance after duplicate removal.

After screening and exclusions, 42 articles were included for analysis; 37 were primary research papers, and five were secondary research articles. Primary research studies were published between 2009 and 2022.

Twenty-five studies were from high-income countries, and 12 were conducted in low-income, lower-middle-income, or upper-middle-income countries.

Diet as the exposure was measured via food frequency questionnaires, 24-hour dietary recall, or interviews. Thirteen studies included pregnant subjects, relying on dietary recall of the pre-pregnancy phase.

Fifteen studies recruited participants at a maximum of six months before pregnancy to follow pregnancy outcomes. Secondary research papers were published between 2012 and 2022. The team estimated the average study quality at 70%.

Three articles had poor quality, ten were fair, and 29 were good. Poor quality articles included one randomized controlled trial and two reviews.

Fair-rated studies did not justify sample size, study power, and effect and failed to report whether investigators were blinded to the exposure status explicitly.

Fair-rated studies relied on self-reported information and were deemed as having a high risk of bias. There were 13 and 16 observations of dietary patterns and quality, respectively.

Gestational diabetes mellitus was the most discussed among maternal outcomes. Hypertension disorder in pregnancy and asthma represented the second most assessed maternal outcomes.

Fetal/neonatal anthropometry, neonatal morbidity, and preterm birth were the most evaluated among child health outcomes.

Conclusions

The authors noted that a significant proportion of research on pre-pregnancy diets was conducted in high-income countries, particularly in the United States (US) and Canada, with the least in the African region.

Dietary patterns and quality were the studies' most frequently observed/assessed diet-associated exposures.

Gestational diabetes mellitus, hypertension disorder in pregnancy, and fetal/neonatal anthropometry were the most frequently evaluated outcomes. Overall, the current evidence on pre-pregnancy diets is limited, and research should be encouraged in low- and middle-income countries.

Future studies should focus on less-studied outcomes like anemia, congenital abnormalities, and micronutrient deficiencies.

Written by

Tarun Sai Lomte

Tarun is a writer based in Hyderabad, India. He has a Master’s degree in Biotechnology from the University of Hyderabad and is enthusiastic about scientific research. He enjoys reading research papers and literature reviews and is passionate about writing.