Plant-based diets have been associated with numerous health benefits, however, it is essential that they are balanced and provide all the necessary nutrients, especially in key stages such as pregnancy. Now, a new study that analyzed data from 66,738 pregnant women who followed different types of diets – omnivorous, fish/poultry vegetarian, lacto/ovo-vegetarian or vegan – has revealed that those who followed a vegan diet for pregnancy “had children with a lower average birth weight and a higher risk of preeclampsia compared to omnivorous mothers.”
The results of the work have been published in Acta Obstetricia et Gynecologica and its authors highlight that “low protein intake could be a plausible explanation for the observed association with birth weight.” Dietary and supplementary intake was assessed using the Food Frequency Questionnaire at week 25 of pregnancy 25 and women were characterized as fish/poultry vegetarians, lacto/ovo-vegetarians, vegans, or omnivores, based on their self-report at week gestation 30.
98.7% of the participants (65,872) defined themselves as omnivores, while 1.0% (666), 0.3% (183) and 0.03% (18) identified themselves as fish vegetarians. /poultry, lacto/ovo-vegetarian or vegan, respectively. Protein intake was lower among lacto/ovo-vegetarians (13.3%) and vegans (10.4%) than among omnivores (15.4%), while micronutrient intake was also significantly lower among vegans, although when dietary supplements were taken into account no significant differences were observed.
Compared with omnivorous mothers, vegan mothers had a higher prevalence of preeclampsia and their children had on average -240 g (95% confidence interval: -450 to -30) less birth weight. Therefore, the authors have indicated in their article that “more research is needed on the possible causality between plant-based diets and pregnancy and childbirth outcomes to strengthen the basis for dietary recommendations.”
Vitamins, minerals, and other key nutrients in pregnancy
Duane Mellor, a registered dietitian and senior lecturer at Aston Medical School, Aston University, UK, who was not involved in the study, told SMC UK that “it may be more difficult to follow a diet. vegan and ensure that it is nutritionally complete, as there may be risks of lower intakes of iron, iodine and vitamins B12 and D, which can affect both the health of the mother and the development of the baby.
The expert emphasizes, however, that although the total number of women who participated in the study was large, only 18 identified themselves as vegans, which is why he believes that “the very small number of vegans who participated means that there is a risk of statistical error and that could explain the higher rates of preeclampsia reported in vegans. Since there were only two women who had preeclampsia and they were vegan, it could be due to variability and chance. “This study sought to consider protein as a mediating factor, but due to the small number of vegan women in the study, it is very difficult to fully interpret any meaning from these data.”
“The type of diet during pregnancy is not so important as long as it is balanced and includes the necessary nutrients, such as proteins, vitamins and minerals”
Ian Givens, professor of food chain nutrition at the University of Reading, said in statements to the same medium: “Several studies have reported lower intake and status of a number of micronutrients by vegans who do not receive supplements and, to a lesser extent, vegetarians. These are usually nutrients that plants cannot supply or provide very little and include iodine, vitamin B12, vitamin D and calcium. There have been reports of women with preeclampsia having lower urinary iodine concentrations than women without preeclampsia, but some studies have disagreed. Furthermore, a large case-control study conducted in Finland found no significant association between iodine level or measures of thyroid function with the risk of preeclampsia. More work is definitely needed on this. The present study and others have shown that supplementation can correct low intake of key micronutrients from foods associated with vegan and vegetarian dietary patterns, but care is needed and professional advice is advisable for many to ensure correct supplementation is achieved. ”.
“When planning and during pregnancy, whatever your dietary pattern and preferences, it is essential to follow a varied and balanced diet, including supplements as advised by health and government guidelines. If a diet is balanced and includes the necessary nutrients, including proteins, vitamins and minerals, the type of diet is not so important,” concludes Mellor.
