Date Published: July 23, 2019
Publisher: Public Library of Science
Author(s): Bassel H. Al Wattar, Julie Dodds, Anna Placzek, Lee Beresford, Eleni Spyreli, Amanda Moore, Francisco J. Gonzalez Carreras, Frances Austin, Nilaani Murugesu, Tessa J. Roseboom, Maira Bes-Rastrollo, Graham A. Hitman, Richard Hooper, Khalid S. Khan, Shakila Thangaratinam, Lars Åke Persson
Abstract: BackgroundPregnant women with metabolic risk factors are at high risk of complications. We aimed to assess whether a Mediterranean-style diet reduces adverse pregnancy outcomes in high-risk women.Methods and findingsWe conducted a multicentre randomised trial in 5 maternity units (4 in London and 1 in Birmingham) between 12 September 2014 and 29 February 2016. We randomised inner-city pregnant women with metabolic risk factors (obesity, chronic hypertension, or hypertriglyceridaemia) to a Mediterranean-style diet with 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; low intake of red and processed meat; and avoidance of sugary drinks, fast food, and food rich in animal fat versus usual care. Participants received individualised dietary advice at 18, 20, and 28 weeks’ gestation. The primary endpoints were composite maternal (gestational diabetes or preeclampsia) and composite offspring (stillbirth, small for gestational age, or admission to neonatal care unit) outcomes prioritised by a Delphi survey. We used an intention-to-treat (ITT) analysis with multivariable models and identified the stratification variables and prognostic factors a priori.We screened 7,950 and randomised 1,252 women. Baseline data were available for 593 women in the intervention (93.3% follow-up, 553/593) and 612 in the control (95.6% follow-up, 585/612) groups. Over a quarter of randomised women were primigravida (330/1,205; 27%), 60% (729/1,205) were of Black or Asian ethnicity, and 69% (836/1,205) were obese. Women in the intervention arm consumed more nuts (70.1% versus 22.9%; adjusted odds ratio [aOR] 6.8, 95% confidence interval [CI] 4.3–10.6, p ≤ 0.001) and extra virgin olive oil (93.2% versus 49.0%; aOR 32.2, 95% CI 16.0–64.6, p ≤ 0.001) than controls; increased their intake of fish (p < 0.001), white meat (p < 0.001), and pulses (p = 0.05); and reduced their intake of red meat (p < 0.001), butter, margarine, and cream (p < 0.001). There was no significant reduction in the composite maternal (22.8% versus 28.6%; aOR 0.76, 95% CI 0.56–1.03, p = 0.08) or composite offspring (17.3% versus 20.9%; aOR 0.79, 95% CI 0.58–1.08, p = 0.14) outcomes. There was an apparent reduction in the odds of gestational diabetes by 35% (aOR 0.65, 95% CI 0.47–0.91, p = 0.01) but not in other individual components of the composite outcomes. Mothers gained less gestational weight (mean 6.8 versus 8.3 kg; adjusted difference −1.2 Kg, 95% CI −2.2 to −0.2, p = 0.03) with intervention versus control. There was no difference in any of the other maternal and offspring complications between both groups. When we pooled findings from the Effect of Simple, Targeted Diet in Pregnant Women With Metabolic Risk Factors on Pregnancy Outcomes (ESTEEM) trial with similar trials using random effects meta-analysis, we observed a significant reduction in gestational diabetes (odds ratio [OR] 0.67, 95% CI 0.53–0.84, I2 = 0%), with no heterogeneity (2 trials, 2,397 women). The study’s limitations include the use of participant reported tools for adherence to the intervention instead of objective biomarkers.ConclusionsA simple, individualised, Mediterranean-style diet in pregnancy did not reduce the overall risk of adverse maternal and offspring complications but has the potential to reduce gestational weight gain and the risk of gestational diabetes.Trial registrationClinicalTrials.gov NCT02218931.
Partial Text: One in four mothers enter pregnancy with preexisting obesity, chronic hypertension, or hyperlipidaemia [1,2]. In addition to complications in pregnancy, these mothers and their babies are at long-term risk of diabetes and cardiovascular complications . A Mediterranean-style diet, rich in mono- and polyunsaturated fatty acids, reduces the incidence of cardiovascular diseases in the nonpregnant population [4–6]. In pregnancy, such a diet has the potential to improve maternal and offspring outcomes by preventing gestational diabetes, preeclampsia, and foetal growth restriction [7–9].
We screened 7,950 women, recruited 3,421, and randomised 1,252 women with metabolic risk factors to the intervention (n = 627) or to the control group (n = 625). Baseline data were available for 99% (1,237/1,252) of the randomised participants; 93% (553/593) in the intervention and 96% (585/612) in the control groups were followed up and included in the analysis. Fig 1 depicts the enrolment, randomisation, and follow-up of participants in the ESTEEM trial.