Are women’s diets before and during pregnancy healthy?

A new systematic review suggests that before and during pregnancy, women may not be following national and international dietary guidelines from major organizations. In particular, they may be consuming too few vegetables, cereal grains, iron and calcium and too much fat.

Published in Maternal & Child Nutrition, the conclusions were made by Australian researchers based on an analysis of literature in the CINAHL, AMED, EMBASE and Maternity and Infant Care databases from inception to March 2018. They sought to determine whether men and women during preconception and pregnant women were adherent to dietary guidelines, and if not, why not.

<Methods
The authors looked for observational studies assessing adherence to dietary guidelines and/or nutritional recommendations and/or factors associated with adherence. The participants were adult men and/or women aged 18 or older trying or intending to conceive, or pregnant women aged 18 and older. If a study included participants with known preexisting conditions, who were obese, or from only low or medium-high socioeconomic cohorts, it was excluded. The studies included looked at usual dietary and/or nutritional intake and/or dietary habits of participants related to food and beverages.

A total of 15 cross-sectional and three case-control studies, conducted in Australia, China, Pakistan, Canada, Spain, Japan, Portugal, and the Netherlands, were included in the systematic review. Five studies reported on dietary intake of women before conception and 17 reported on dietary intake during pregnancy.

Two studies compared dietary intakes to international guidelines and nine reported on factors predicting guideline adherence. Food frequency questionnaires were used in 11 studies and dietary recall in the remaining seven studies. Of the studies assessed, 56% were good quality and 44% fair quality.

Findings
The authors found that pregnant women did not meet iron or calcium intake requirements in 91% and 55% of included studies, respectively, and also exceeded fat intake recommendations in 55% of included studies. Higher-level education was associated with improved guideline adherence in pregnant women, whereas older age and non-smoking status were associated with greater guideline adherence in preconceptual and pregnant women.     

Conclusions
The researchers say one implication of the finding about education level as a predictor of dietary adherence is that the guidelines and nutritional recommendations need to be clear and accessible and that “consideration should be given to the role of nutrition education and counselling in clinical settings.” They also noted the absence of any studies examining dietary intake in males during the preconception period.