Background: Mediterranean diet has been shown to reduce the incidence of preterm birth. We wanted to investigate whether a Mediterranean-type diet (MD) could be associated with a lower risk of preterm birth in the Norwegian Mother and Child Cohort Study (MoBa).
Methods: The data collection was conducted as part of MoBa at the Norwegian Institute of Public Health. In MoBa, women answer a Food Frequency Questionnaire (FFQ) at week 18-22 of pregnancy. The MD criteria were intake of fish > or =2 times a week, fruit and vegetables > or =5 times a day, use of olive/canola oil, red meat intake < or = times 2 a week, and < or =2 cups of coffee a day.
Results: A total of 569 women (2.2%) met the MD criteria, 25,397 women (97.2%) met 1-4 criteria, and 159 women (0.01%) met none of the MD criteria. The number of preterm births in the MD group was 26 (4.6%), in those who met 1-4 criteria it was 1,148 (4.5%), and in those who met none of the criteria it was 10 (6.3%). The women who met the MD criteria did not have reduced risk of preterm birth compared with women meeting none of the MD criteria (OR: 0.73; 95% CI: 0.32, 1.68). Intake of fish twice or more a week was associated with a lower risk of preterm birth (OR: 0.84; 95% CI: 0.74, 0.95).
Conclusions: The women who fulfilled the criteria of a MD did not have a reduced risk of preterm birth.