BACKGROUND AND PURPOSE:

• Women with metabolic risk factors are at a higher risk of experiencing complications in pregnancy
• The Mediterranean diet appears to reduce risk of cardiovascular disease (CVD) in the general population
• Al Wattar et al. (PLOS Medicine, 2019) sought to determine whether a Mediterranean-style diet reduces adverse pregnancy outcomes in high-risk women

METHODS:

• Multicenter pragmatic randomized trial (RCT)
  • ESTEEM trial: Effect of Simple, Targeted Diet in Pregnant Women With Metabolic Risk Factors on Pregnancy Outcomes
• Participants
  • Inner-city pregnant women
  • Metabolic risk factors: Obesity | Chronic hypertension | Hypertriglyceridemia
• Exposures
  • Mediterranean diet
    • High intake of nuts, extra virgin olive oil, fruits, vegetables, nonrefined grains, and legumes
    • Moderate to high consumption of fish
    • Low to moderate intake of poultry and dairy products and low intake of red and processed meat
    • Avoidance of sugary drinks, fast food, and food rich in animal fat
  • Usual care
• Study design and data analysis
  • Individualized dietary advice at 18, 20, and 28 weeks’ gestation
  • Used an intention-to-treat (ITT) analysis with multivariable models
  • Identified the stratification variables and prognostic factors a priori
• Primary outcomes
  • Composite maternal outcomes: Gestational diabetes (GDM) | Preeclampsia
  • Composite offspring: Stillbirth | SGA | NICU admissions
• Secondary outcomes
  • Maternal outcomes (e.g., GDM, preeclampsia ICU admission, hemorrhage, mode of delivery etc.)
  • Offspring outcomes (e.g., NICU admission, SGA, stillbirths, neonatal deaths, birthweight etc.)

RESULTS:

• Intervention group: 593 women (93.3% follow-up)
• Control group: 612 women (95.6% follow-up, 585/612) group
• Participant data
  • Primigravida: 27% | Black or Asian ethnicity 60% | Obese 69%
• Women in the intervention group (Mediterranean diet)
  • Consumed more nuts than the control group
    • 70.1% versus 22.9%
    • adjusted odds ratio (aOR) 6.8, 95% CI, 4.3 to 10.6; p ≤ 0.001)
  • Consumed more extra virgin olive oil than the control group
    • 93.2% versus 49.0%
    • aOR 32.2 (95% CI, 16.0 to 64.6; p ≤ 0.001)
  • Increased their intake of fish (p < 0.001), white meat (p < 0.001), and legumes (p = 0.05)
  • Reduced their intake of red meat (p < 0.001), butter, margarine, and cream (p < 0.001)
• There was no statistical difference in reduction in the odds for primary outcomes noted for Mediterranean diet vs control
  • Maternal composite outcomes
    • 22.8% vs 28.6%
    • aOR 0.76 (95% CI 0.56 to 1.03; p = 0.08)
  • Offspring composite outcomes
    • 17.3% vs 20.9%
    • aOR 0.79 (95% CI, 0.58 to 1.08; p = 0.14)
• GDM risk was reduced in Mediterranean diet group vs control
  • 17.6% vs 24.9%   
  • aOR 0.65 (95% CI 0.47 to 0.91; p = 0.01)
• Mothers gained less gestation weight on the Mediterranean diet vs control
  • Mean weight gain: 6.8 vs 8.3 kg
  • adjusted difference: −1.2 Kg (95% CI, −2.2 to −0.2; p = 0.03)
• There was no difference in any other secondary outcomes between groups
• When authors combined data from the present study with other comparable trials, similar findings were seen for GDM
  • OR 0.67 (95% CI 0.53 to 0.84)

CONCLUSION:

• While composite pregnancy and offspring outcomes were not impacted by adoption of a Mediterranean style diet for pregnant women with metabolic risks (e.g. obesity) there may be benefit for GDM prevention
• Mediterranean diet reduced odds of GDM by 35% in this high-risk cohort

Learn More – Primary Sources:

Mediterranean-style diet in pregnant women with metabolic risk factors (ESTEEM): A pragmatic multicentre randomised trial

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