Maternal dietary patterns and associated nutrient intakes during each trimester of pregnancy.

Objective: To determine the main dietary patterns of pregnant women during each of the three trimesters of pregnancy and to examine associated nutrient intakes.

Design: Participants completed a 3 d food diary during each trimester of pregnancy. Thirty-six food groups were created and dietary patterns were derived using k-means cluster analysis.

Setting: National Maternity Hospital, Dublin, Ireland.

Subjects: Two hundred and eighty-five healthy pregnant women aged between 20 and 41 years.

Results: Two dietary patterns were identified at each time point. They were labelled 'Unhealthy' (n =143, 150 and 155 at trimester 1, 2 and 3, respectively) and 'Health Conscious' (n 142, 135 and 130 at trimester 1, 2 and 3, respectively). Women in the 'Health Conscious' cluster were significantly older, had lower BMI and were higher educated than those in the 'Unhealthy' cluster. Of those in the 'Unhealthy' cluster in the first trimester (n =143), 103 (72.0 %) continued in this dietary pattern into trimester 2 and eighty-one (56.6 %) continued into trimester 3. Of those in the 'Health Conscious' cluster in trimester 1 (n =142), ninety-five (66.9 %) continued in this dietary pattern into trimester 2 and sixty-nine (48.6 %) continued into trimester 3.

Conclusions: Cluster analysis produced two clearly defined dietary patterns at each stage of pregnancy. Knowledge of maternal dietary patterns is important for the development of pregnancy-specific dietary guidelines. Identifying women with an 'Unhealthy' dietary pattern in early pregnancy affords the opportunity for a dietary intervention which may positively impact both maternal and infant health.