The impact of lacto-ovo-/lacto-vegetarian and vegan diets during pregnancy on the birth anthropometric parameters of the newborn

Veganism during pregnancy: Exploring experiences and needs of women following a plant-based diet

OBJECTIVE

The prevalence of pregnant women adhering to a vegan or strict plant-based diet is increasing. Despite a growing interest in veganism in pregnancy, there is a paucity of research exploring the experiences and needs of women who decided to continue the vegan diet during pregnancy. This qualitative study aims to explore the experiences and needs of pregnant women adhering to a vegan diet.

METHODS

We conducted fifteen semi-structured interviews among pregnant women and among women within the first twelve months postpartum who self-identified as vegan.

RESULTS

Thematic analysis revealed five core themes: (1) confidence and pride, (2) stigmatization, (3) barriers, (4) knowledge, and (5) support and acceptance. Although pregnant vegans often exhibit feelings of confidence and pride in their dietary choices, they also face challenges due to social stigma, misconceptions, cravings and nausea. Participants expressed that it was difficult to find reliable information regarding nutritional requirements and supplementation during pregnancy, and that healthcare providers lacked adequate knowledge. The level of support received from healthcare professionals and their surrounding varied but is deemed significant, underscoring the importance of a non-judgmental, accepting and supportive approach.

CONCLUSIONS

This study highlighted the confidence and pride pregnant vegans may experience, but also the challenges they face due to social stigma, misconceptions, cravings and nausea, and the need for better information and support. By addressing these challenges, healthcare professionals and communities can contribute to healthier and more informed vegan pregnancies, ultimately benefiting the well-being and health of both mothers and their infants.

Strict vegetarian diet and pregnancy outcomes: A systematic review and meta-analysis

Introduction

The increasing adoption of strict vegetarian diets during pregnancy has raised concerns about their effects on maternal and neonatal outcomes. This systematic review and meta-analysis aimed to assess the impact of strict vegetarian diets on key pregnancy outcomes, including neonatal birth weight, small-for-gestational-age (SGA) infants, gestational diabetes mellitus (GDM), hypertensive disorders, and gestational weight gain (GWG).

Methods

A comprehensive literature search across multiple databases yielded eight studies from various countries, involving a total of 72,284 participants. Primary outcomes included neonatal birth weight, SGA, preterm birth, GDM, and maternal hypertensive disorders.

Results

The meta-analysis found that strict vegetarian diets were significantly associated with an increased risk of delivering SGA infants, with a pooled odds ratio (OR) of 2.71 (95 % confidence interval [CI]: 1.24 to 5.95; p = 0.01). Additionally, infants born to strict vegetarian mothers had lower birth weights, with some studies reporting a mean difference of 240g compared to omnivores. For GDM, no significant differences were found between strict vegetarians and omnivores, with a pooled OR of 0.64 (95 % CI: 0.37 to 1.11; p = 0.11). While vegans showed lower gestational weight gain and reduced risk of excessive weight gain, there was considerable heterogeneity in results regarding hypertensive disorders and preterm birth.

Conclusions

Strict vegetarian diets during pregnancy are associated with an increased risk of SGA infants and lower birth weights. To mitigate these risks, specific dietary guidelines emphasizing adequate intake of critical nutrients such as vitamin B12, iron, omega-3 fatty acids, and iodine should be developed. Supplementation and tailored dietary counseling, incorporating fortified foods and plant-based sources like legumes, nuts, seeds, and algae-derived omega-3, are essential to ensure maternal and neonatal health. Further research is necessary to refine these guidelines and explore their impact on diverse populations.

Medical nutrition therapy in physiological pregnancy and in pregnancy complicated by obesity and/or diabetes: SID-AMD recommendations

Proper nutrition is essential during pregnancy to ensure an adequate supply of nutrients to the foetus and adequate maternal weight gain. In pregnancy complicated by diabetes (both gestational and pre-gestational), diet in terms of both the intake and quality of carbohydrates is an essential factor in glycaemic control. Maternal BMI at conception defines the correct weight increase during gestation in order to reduce maternal-foetal complications related to hypo- or hyper-nutrition. The recommendations presented here, which are based on national and international guidelines and the most recently published data on nutrition in physiological pregnancy and pregnancy complicated by hyperglycaemia and/or obesity, are designed to help healthcare professionals prescribe suitable eating patterns to safeguard the health of the mother and the foetus.

Obstetric healthcare experiences and information needs of Dutch women in relation to their vegan diet during pregnancy

Objectives

The prevalence of a vegan (strict plant-based) diet is increasing. Adequate access to nutritional information for pregnant women on a vegan diet is vital, as optimal maternal nutrition is important in order to prevent maternal and fetal complications. This study evaluated the obstetric healthcare experiences and information needs of pregnant women following a vegan diet in the Netherlands.

Methods

An online survey examined women's experiences with obstetric healthcare in relation to their vegan diet during pregnancy. In total, 195 women, all of whom followed a vegan diet during their pregnancy and gave birth between January 2018 and April 2020, completed an online survey about their experiences. Descriptive statistics were used to present the data.

Results

In total, 36.5% of participants reported that an obstetric healthcare provider had inquired about their diet in general during the first prenatal consultation, and an additional 43.1% of participants proactively informed their healthcare provider about their diet. Only 19.0% of all participants received specific information about their vegan diet during pregnancy, and 25.2% reported having had extra checks, mostly blood tests, during their pregnancy. Of all participants, 35.9% would have preferred to receive additional information regarding their diet.

Conclusions

Our data shows that only a minority of pregnant women following a vegan diet received information and recommendations about their diet from their healthcare providers. It is our recommendation that healthcare providers inquire about pregnant women's diets, and refer those following a vegan diet to reliable sources of dietary information or to a specialized dietitian.

The Association of a Vegan Diet during Pregnancy with Maternal and Child Outcomes: A Systematic Review

Background: With the increasing prevalence of pregnant women adhering to a vegan diet, gaining insight into their nutritional intake and its association with maternal and fetal outcomes is essential to providing recommendations and developing guidelines for general practice. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of the available scientific literature in Medline, Embase, and Cochrane was conducted in January 2024. Results: The titles and abstracts of 2211 unique articles were screened. Only six studies were eligible for inclusion and assessed for methodological quality using the (National Institutes of Health Study Quality (NIHSQ) Assessment Tool. The intake of protein and various micronutrients was significantly lower among vegan pregnant women compared to omnivorous women. Vitamin B12 supplements seemed sufficient in optimizing maternal and umbilical cord vitamin B12 levels amongst vegan mothers. Further, women on a vegan diet less often showed excessive pregnancy weight gain. However, children from women on a vegan diet had a significantly lower birth weight than those from women on an omnivorous diet. Conclusion: So far, only a few studies, with a large diversity of (assessment of) outcomes and insufficient power, have been published on this topic, limiting our ability to make firm conclusions about the effects of a vegan diet during pregnancy on maternal and fetal outcomes.

Associations of maternal dietary patterns during pregnancy and fetal intrauterine development

Dietary pattern is excellent in reflecting an individual's eating conditions. Longitudinal data on fetal growth can reflect the process of intrauterine growth. We aimed to evaluate the associations between maternal dietary patterns and intrauterine parameters in middle and late pregnancy. The present study was conducted within Jiangsu Birth Cohort (JBC) study. Dietary information was assessed with a food frequency questionnaire (FFQ) in the second and third trimester of gestation. B-ultrasound scans were performed to obtain fetal intrauterine parameters, including head circumference (HC), femur length (FL), abdominal circumference (AC), and estimated fetal weight (EFW). Exploratory factor analysis was used to extract dietary patterns. Multiple linear regression and linear mixed-effects model (LMM) were used to investigate the association between maternal dietary patterns and fetal growth. A total of 1,936 pregnant women were eligible for the study. We observed inverse associations of maternal "Vegetables and fish" and "Snack and less eggs" patterns during mid-pregnancy with fetal HC Z-score, respectively ("Vegetables and fish": β = -0.09, 95% CI -0.12, -0.06; "Snack and less eggs": β = -0.05, 95% CI -0.08, -0.02). On the contrary, "Animal internal organs, thallophyte and shellfish" pattern in the second trimester was associated with increased HC Z-scores (β = 0.04, 95% CI 0.02, 0.06). Consistently, score increase in "Vegetables and fish" pattern in the third trimester was inversely associated with the Z-scores of HC (β = -0.05, 95% CI -0.09, -0.02), while "Meat and less nuts" pattern was positively correlated with the Z-scores of HC (β = 0.04, 95% CI 0.02, 0.07). As compared to the fetus whose mothers at the lowest tertile of "Snack and less eggs" pattern in both trimesters, those whose mothers at the highest tertile demonstrated 1.08 fold (RR = 2.10, 95% CI 1.34-3.28) increased risk of small HC for gestational age (GA). No correlation was observed between maternal dietary patterns and other intrauterine parameters. Our results suggested the effects of maternal dietary patterns on fetal growth, particularly HC. These findings highlighted the adverse impact of unhealthy dietary pattern on fetal growth, might provide evidence for strategies to prevent intrauterine dysplasia and dietary guidelines during pregnancy.

The relationship between human milk, a functional nutrient, and microbiota

The intestinal microbiota begins to take shape in the mother's womb, changes depending on many factors. It is known that the intestinal microbiota has an important role in the maturation of the immune system, also in the prevention of diseases that occur in newborn, childhood, adulthood. Nutrition is the main factor on the development of microbiota in infants after birth. The microbiota compositions of breastfed infants are different from formula-fed infants. Breast milk oligosaccharides play an important role in the development of infants' microbiota. The higher number of Bifidobacterium species and lower α and β diversity in breastfed infants are considered protective. A dysbiosis occurring in the microbiota can cause adverse effects on health. Human milk oligosaccharides also have protective effects on the microbiota. These protective effects are to promote the growth of intestinal microbiota, prevent the adhesion of viruses to the colon, promote the growth of Bifidobacterium with its prebiotic effect. Short-chain fatty acids resulting from their digestion, also have protective effects. Another component that shapes the gut microbiota is HM glycoproteins. The aim of this study is to examine the effect of breast milk on the development of microbiota, to present the results by scanning the literature.

Perspective: Striking a Balance between Planetary and Human Health: Is There a Path Forward?

The global adoption of predominantly plant-based sustainable healthy diets will help reduce the risk of obesity- and malnutrition-related non-communicable diseases while protecting the future health of our planet. This review examines the benefits and limitations of different types of plant-based diets in terms of health and nutrition, affordability and accessibility, cultural (ethical and religious) acceptability, and the environment (i.e., the four pillars underlying sustainable healthy diets). Results suggest that, without professional supervision, traditional plant-based diets (vegan, vegetarian and pescatarian diets) can increase the risk of nutritional deficiencies among infants, children/adolescents, adult females, pregnant/lactating women and the elderly. In contrast, flexitarian diets and territorial diversified diets (TDDs, e.g., Mediterranean and New Nordic diets) that include large quantities of plant-sourced foods, low levels of red meat and moderate amounts of poultry, fish, eggs and dairy can meet the energy and nutrition needs of different populations without the need for dietary education or supplementation. Compared to vegan, vegetarian and pescatarian diets, more diverse flexitarian diets and TDDs are associated with reduced volumes of food waste and may be more acceptable and easier to maintain for people who previously followed western diets. Although flexitarian diets and TDDs have a greater impact on the environment than vegan, vegetarian and pescatarian diets, the negative effects are considerably reduced compared to western diets, especially if diets include locally-sourced seasonal foods. Further studies are required to define more precisely optimal sustainable healthy diets for different populations and to ensure that diets are affordable and accessible to people in all countries.

The Safety of a Vegan Diet During Pregnancy

There is an increasing number of people who go vegetarian. Some young parents also switch to this diet. The safety of vegetarian diets, especially vegan diets, is very important, especially during pregnancy. Unfortunately, reference publications do not provide coherent data on the safety of vegetarian diets during pregnancy. On the one hand, the vegan diet has advantages because it reduces the risk of heart disease and gestational diabetes. On the other hand, vegetarians/vegans should be aware of potential deficiencies of some nutrients (iron, zinc, vitamin B12, vitamin D, omega-3 fatty acids, calcium, iodine) and the clinical consequences for the fetus. For example, iron deficiency may affect cognitive abilities, behavior, intelligence and increase the risk of preterm birth and low birth weight of infants. Plant food contains non-haem iron with variable absorption. Therefore, the vegan diet should include nutrients increasing the bioavailability of iron, e.g. ascorbic acid, carotene and retinol. Due to the fact that animal food is the main source of vitamin B12, vegans are at a very high risk of vitamin B12 deficiency, which will affect the infant’s weight at birth. Low level of vitamin D, which is prevalent in animal food, is the most common deficiency among vegans and lacto-ovo vegetarians. This vitamin prevents gestational diabetes, reduces insulin resistance and guarantees normal function of the musculoskeletal system. Zinc deficiency during pregnancy may lead to preterm birth, neural tube defects or even miscarriage. In view of the clinical consequences of potential deficiencies of nutrients, the vegetarian/vegan diet should be well balanced.

Indicators and Recommendations for Assessing Sustainable Healthy Diets

Research coupling human nutrition and sustainability concerns is a rapidly developing field, which is essential to guide governments' policies. This critical and comprehensive review analyzes indicators and approaches to "sustainable healthy diets" published in the literature since this discipline's emergence a few years ago, identifying robust gauges and highlighting the flaws of the most commonly used models. The reviewed studies largely focus on one or two domains such as greenhouse gas emissions or water use, while overlooking potential impact shifts to other sectors or resources. The present study covers a comprehensive set of indicators from the health, environmental and socio-economic viewpoints. This assessment concludes that in order to identify the best food option in sustainability assessments and nutrition analysis of diets, some aspects such as the classification and disaggregation of food groups, the impacts of the rates of local food consumption and seasonality, preservation methods, agrobiodiversity and organic food and different production systems, together with consequences for low-income countries, require further analysis and consideration.

The Safety of TheVegan Diet During Pregnancy

There is an increasing number of people who go vegetarian. Some young parents also switch to this diet. The safety of vegetarian diets, especially ve-gan diets, is very important, especially during pregnancy. Unfortunately, reference publications do not provide coherent data on the safety of vegetar-ian diets during pregnancy. On the one hand, the vegan diet has advantages because it reduces the risk of heart disease and gestational diabetes. On the other hand, vegetarians/vegans should be aware of potential deficiencies of some nutrients (iron, zinc, vitamin B12, vitamin D, omega-3 fatty acids, cal-cium, iodine) and the clinical consequences for the foetus. For example, iron deficiency may affect cognitive abilities, behaviour, intelligence and increase the risk of preterm birth and low birth weight of infants. Plant food contains non-haem iron with variable absorption. Therefore, the vegan diet should include nutrients increasing the bioavailability of iron, e.g. ascorbic acid, carotene and retinol. Due to the fact that animal food is the main source of vitamin B12, vegans are at very high risk of vitamin B12 deficiency, which will affect the infant’s weight at birth. Low level of vitamin D, which is prevalent in animal food, is the most common deficiency among vegans and lacto-ovo vegetarians. This vitamin prevents gestational diabetes, reduces insulin resistance and guarantees normal function of the musculoskeletal system. Zinc deficiency during pregnancy may lead to preterm birth, neural tube defects or even miscarriage. In view of the clinical consequences of po-tential deficiencies of nutrients, the vegetarian/vegan diet should be well balanced.

Does vegan diet influence umbilical cord vitamin B12, folate, and ferritin levels?

PURPOSE

To determine the influence of maternal diets on maternal and umbilical cord blood levels of vitamin B12, folic acid, ferritin, and hemoglobin.

METHODS

A prospective observational study on women who maintained the same diet for at least 3 months prior to, and throughout current pregnancy. Women were divided according to their diet. Diet questionnaires were filled in during the 3rd trimester. Blood samples for complete blood counts and levels of ferritin, vitamin B12, folate, and albumin were taken from the women prior to delivery and from the umbilical cord immediately after delivery.

RESULTS

The 273 enrolled women included 112 omnivores, 37 pescatarians, 64 vegetarians, and 60 vegans. There were no significant differences in the maternal B12 levels between the study groups (P = 0.426). Vegans had lower maternal ferritin levels compared to pescatarians (27 ± 17 vs 60 ± 74 ng/ml, respectively, P = 0.034), but not compared to vegetarians (P = 0.597), or omnivores (P = 1.000). There were no significant differences in the umbilical cord B12, folate, ferritin, and hemoglobin levels between the study groups. A sub-analysis that compared women who consumed multivitamins, B12 and iron supplements during pregnancy to women who did not, revealed differences in the levels of umbilical-cord B12 (1002 ± 608 vs 442 ± 151 pg/ml, respectively, P = 0.000) and maternal blood B12 (388 ± 209 vs 219 ± 95 pg/ml, respectively, P = 0.030) only among vegans, but not among omnivores.

CONCLUSION

Vegan diet does not change the umbilical cord levels of B12, folic acid, ferritin, and hemoglobin. Vegans who do not take any vitamin supplementation are at greater risk for B12 deficiency than omnivores.