LA DIETA EN EMBARAZO Y LACTANCIA: UNA REVISIÓN DE LA ALIMENTACIÓN VEGANA Y VEGETARIANA

Background: Although well planned vegan/vegetarian diets are appropriate during all stages of the life cycle1, vegan/vegetarian people have an increased propensity to be deficient for important nutrients. This study is aimed to investigate advantages and disadvantages of vegan/vegetarian diets in pregnancy and breastfeeding.

Objectives: To review literature on vegan/vegetarian diets during pregnancy and breastfeeding, and their outcomes on fetus and newborn.

Methodology: PubMed was our main source, with research dating from 2005 to date aiming specifically on “pregnancy” “breastfeeding” coupled with “vegan-vegetarian diets” and “outcome on fetus and/or newborn”. We have used articles on pregnancy and/or breastfeeding women that follow vegan/vegetarian diets both in healthy, and malnourished. The high heterogeneity of the studies led to write a systematic review.

Main Results: We obtained 48 full texts from 86 references: 34 references reporting pregnancy and vegan/vegetarian diets outcome, 26 references reporting breastfeeding and vegan/vegetarian outcome. Of the 34 studies about pregnancy and vegan/vegetarian diet, only 4 studies analyzed vegan/vegetarian diets in poverty and malnutrition. No article was found about breastfeeding and vegan/vegetarian diets. Among the 34 studies, the majority confirmed that vegan/vegetarian pregnant women might be at risk of vitamin B12 and iron deficiencies. Nevertheless, none of the studies reported an increase in severe adverse outcomes or in major malformations, with the exception of one article that reported an increase on the incidence of hypospadias in newborns of vegetarian women. On the other hand, the major part of the studies on micronutrients in breastfeeding vegan/vegetarians suggest a correlation between vitamin B12 deficienies and neurological atrophy.

Conclusions: The main limit of this research was the lack of a common standard and adequate control groups among the different studies. This prevents us from distinguishing the effects of diet from other external factors. Within these limits, vegan/vegetarian diets may be considered safe in pregnancy and breastfeeding, provided that attention should be paid to vitamin and trace element requirements during all periods of pregnancy, including pre-pregnancy up to lactation.