Maternal malnutrition is a major global public health problem. The United Nations International Children’s Emergency Fund estimated that the number of severely malnourished pregnant and lactating women in countries affected by the current food and nutrition crisis increased by 25% between 2020 (5.5 million) and 2022 (6.9 million), with more than 1 billion adolescent girls and women worldwide suffering from malnutrition (1). The Sustainable Development Goals (SDGs) issued by the United Nations General Assembly in 2015 proposed to end all forms of malnutrition and address the nutritional needs of adolescent girls and pregnant women by 2030 (2). Despite concerted efforts, the prevalence of malnutrition remains high, especially in low-and middle-income countries, and progress in reducing malnutrition remains slow (3).

The occurrence of maternal diseases is closely related to malnutrition. Pregnant women need to consume adequate nutrients during pregnancy, including protein, carbohydrate, fat, vitamins and minerals, to maintain their own physiological needs and the growth and development of the fetus (4). If a pregnant woman is chronically malnourished, it will lead to a decrease in immunity, leaving them vulnerable to inflammatory and infectious diseases (5). Iron deficiency in pregnant women can easily induce anemia and is also a high risk factor for postpartum hemorrhage (6). Inadequate thyroid hormone synthesis due to iodine deficiency during pregnancy increases the rate of miscarriage (7). Low vitamin B12 levels can lead to elevated homocysteine levels, which can precipitate adverse outcomes including miscarriage and preeclampsia (8). In addition, a cohort study based on 9,287 women giving birth showed an increased risk of hyperemesis gravidarum and postpartum hemorrhage in overweight women (9). In addition, due to socio-economic, gender bias, and racial discrimination, global inequalities in nutritional problems and maternal illnesses have resulted in more than one-third of 126 low-and middle-income countries being undernourished (10), with WHO estimating that sub-Saharan Africa alone will account for about 70% of global maternal deaths in 2020, with a maternal mortality ratio that is 136 times higher than that of Australia and New Zealand (11). It is clear that malnutrition can cause significant maternal disorders, posing a serious threat to maternal health and life, and is marked by serious inequalities.

Given the rising levels of maternal malnutrition, the serious life-threatening impact of maternal diseases and global inequalities, understanding the spatial–temporal pattern of the burden of maternal diseases caused by malnutrition is critical to developing a targeted global strategy for the prevention and control of maternal diseases, but no relevant studies are currently available. Therefore, this study utilized the latest data from the Global Burden of Disease (GBD) to provide a comprehensive quantitative assessment of the burden and changing patterns of maternal disorders attributable to malnutrition from 1990 to 2019, as well as a prediction of deaths from 2020 to 2035, to provide a scientific basis for maternal dietary interventions and health education, ultimately achieving a reduction in the burden of maternal disease.

This study systematically and quantitatively assessed and predicted the global burden of 10 maternal disorders attributable to malnutrition and their spatio-temporal trends. From 1990 to 2019, the number of deaths, DALYs, ASMR and ASDR of maternal disorders attributable to malnutrition showed a downward trend, indicating a reduction in the global burden of related diseases. And the number of deaths and ASMR are predicted to continue to decline from 2020 to 2035. However, the burden of disease remained high in the low SDI regions, especially among young pregnant women aged 20–29 years, and maternal malnutrition should not be underestimated in the context of the global food crisis.

The burden of maternal disease attributable to malnutrition across age groups varies among SDI regions. The study found that the burden of disease was higher among younger pregnant women (20–29 years) in low-and low-middle SDI regions, whereas it was higher among older pregnant women (30–39 years) in high SDI regions. Females in low-and low-middle SDI regions tend to marry and have children at an early age, such as 44 and 39% of girls in South Asia and sub-Saharan Africa, respectively, who marry before the age of 18 years, and are chronically malnourished (22). Evidence has shown that chronic malnutrition delays physical maturation and prolongs the adolescent growth beyond the age of 20 years (23). Therefore, while the nutrition they need for their own growth and development is not guaranteed, they also need additional nutrition to meet the needs of their fetus, which may ultimately exacerbate their own malnutrition. In high SDI countries, older pregnant women (over 35 years) are more likely to be undernourished because women in these countries marry and give birth later, such as in Germany and the United Kingdom, where the average age at birth is 31.50 and 30.48 years, respectively (24, 25). At the same time, there is also a preference for foods high in fat, sugar, and salt (26, 27). As people grow older, they may face more chronic diseases or metabolic diseases, such as hypertension and diabetes, which gradually reduce the body’s metabolism and absorption capacity, leading to malnutrition (28).

The burden of maternal disease attributable to malnutrition is negatively associated with SDI, which is consistent with the WHO study (29). The burden of disease is higher in sub-Saharan Africa and South Asia, where a combination of factors, such as backward economic development, suboptimal diets, and extreme climatic environments, prevent pregnant women from obtaining adequate, high-quality nutrients (30, 31). For example, the latest data from UNICEF show that 10 and 23% of women aged >18 years in sub-Saharan Africa and Southern Asia, respectively, have a low BMI (18.5 kg/m²), much higher than in Western Europe (2%) and North America (2%) (32). This study found that the burden of disease in East Asia decreased fastest. This was made possible by a series of policies implemented by the UNICEF East Asia and Pacific Regional Office to prevent malnutrition among women, such as the production of “Food and Nutrition Security Country Profiles” for 29 countries in East Asia and the Pacific in collaboration with FAO, and the promotion of legislation related to nutrition security for pregnant women (33). As the largest country in East Asia, China, with the development of economy and the improvement of people’s living standards, the government has also taken a series of nutrition improvement measures, including promoting scientific diet, strengthening food safety supervision, and carrying out nutrition education, which has significantly improved the nutritional intake and dietary structure of pregnant women. It has made a significant contribution to the rapid decline in the incidence of malnutrition (34). From 2002 to 2020, the incidence of anemia in pregnant women in China decreased from 22.5 to 13.6% (35, 36). Work to reduce inequalities was also ongoing worldwide, with the UN’s proposed Decade of Action on Nutrition in 2016 providing an enabling environment for all countries, regardless of their income levels and the characteristics of their food and health systems, to ensure that governments and stakeholders take action to develop and implement programs aimed at eliminating undernutrition (37).

The burden of maternal hemorrhage accounted for the highest proportion of the 10 maternal diseases attributable to malnutrition. WHO studies have shown that at least 30–40% of pregnant women are iron deficient (38), and almost all women studied (97.5%) had a total dietary folic acid intake that was lower than the WHO-recommended intake of folic acid during pregnancy and lactation (39). When pregnant women have insufficient dietary iron and folic acid intake, nutritional anemia often occurs, causing changes such as compensatory placental hypertrophy, leading to uterine inertia, and ultimately increasing the risk of postpartum hemorrhage (40). Higher proportion of late maternal deaths were found in high-income North America. The National Institute of Perinatal Epidemiology at the University of Oxford categorized the causes of late maternal deaths into four main groups: cardiovascular disease, thromboembolism, cancer, and suicide (41), and over-nutrition is more prevalent in high-income North America, with approximately 86 million adults in the United States aged 20 years and older having a total cholesterol level of more than 200 mg/dL (42), putting increased risk of cardiovascular diseases such as atherosclerosis and perinatal cardiomyopathy, which usually appear after only 1 month postpartum, thus contributing to late maternal mortality (43). The higher burden of maternal hypertension attributable to malnutrition in the Andean Latin American may be related to the increase of high-sugar, high-salt, and high-fat diets and ultra-processed foods in the region (44), from 2000 to 2013, the retail sales of ultra-processed products in Bolivia, Ecuador and Peru all increased, and Peru even increased by four times (45). It has been suggested that a low-sugar, low-fat, low-protein, and low-sodium dietary pattern may reduce the risk of hypertensive disorders during pregnancy by improving endothelial cell function, reducing oxidative stress, and having a positive effect on the renin-angiotensin-aldosterone system, thereby reducing the risk of hypertensive disorders in pregnancy (46). The high proportion of the burden of MAM in the Caribbean may be due to the predominance of refined grains in the staple diet of the region’s inhabitants and the low intake of fresh vegetables and fruits (such as Haiti, Jamaica, Cuba, Puerto Rico and the Dominican Republic) (47–49), resulting in insufficient dietary folate intake and an increase in plasma total homocysteine concentration, which may cause embryotoxicity and increase the risk of abortion by interfering with the body’s methylation reaction, damaging DNA, and destroying the normal cycle of embryonic cells (50, 51). In conclusion, malnutrition affects pregnant women differently at different ages and in different SDI regions. Targeted nutritional guidance and disease prevention strategies should be taken according to the specificity of their age, region and disease, such as the Food Systems Summit convened by the United Nations to seek solutions and action for all to change the way the world produces, consumes and thinks about food, thereby safeguarding health and advancing the SDGs (52).

There are some limitations in our study. First, all the data used in our study were obtained from GBD2019, which collects data from different sources, and therefore, there may be inconsistencies and incompatibilities between these data, which may result in bias. Second, our predictions were based on the BAPC model, which only simulates changes in age, period, and cohort effects in the current context, it may lead to less precise predictions. In addition, a comprehensive evaluation of the burden of disease should also include an evaluation of economic, household, and social dimensions, so multidimensional analyses should be added in future studies to provide more accurate results.

In summary, this study found that maternal malnutrition health is improving globally, but the burden of maternal disorders attributable to malnutrition remains high in low SDI regions and young pregnant women. Therefore, in countries and territories with low SDI, more attention should be paid to the development of preventive measures for maternal malnutrition, such as guaranteeing the food supply, carrying out nutritional education, and strengthening food safety regulation, etc. Only through an approach involving multi-sectoral cooperation across health, education, social protection, agriculture and other sectors to continuously reduce the burden of maternal disorders attributable to malnutrition, can the goal of eliminating all forms of hunger and malnutrition proposed in the UN SDGs be achieved as soon as possible.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding authors.

TX: Data curation, Formal analysis, Investigation, Software, Visualization, Writing – original draft, Writing – review & editing. CD: Data curation, Formal analysis, Investigation, Software, Visualization, Writing – original draft, Writing – review & editing. JS: Data curation, Formal analysis, Investigation, Software, Visualization, Writing – original draft, Writing – review & editing. CH: Visualization, Writing – review & editing. ZC: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. ZS: Conceptualization, Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. TY: Data curation, Methodology, Visualization, Writing – original draft. CG: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. WW: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. DR: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. XL: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. YH: Data curation, Formal analysis, Methodology, Visualization, Writing – original draft. JM: Conceptualization, Data curation, Funding acquisition, Methodology, Project administration, Visualization, Writing – review & editing. QN: Conceptualization, Data curation, Funding acquisition, Methodology, Project administration, Visualization, Writing – review & editing. YY: Conceptualization, Data curation, Funding acquisition, Methodology, Project administration, Visualization, Writing – review & editing.