Epidemiological profile of perinatal health among indigenous pregnant people in the Wayamu territory, Brazil

Abstract

Objective

To describe the epidemiological profile of prenatal care, childbirth, and live births among Indigenous women in the Wayamu Territory, located in the municipality of Oriximiná, Pará, Brazil, from 2013 to 2022.

Methods

This is a descriptive, retrospective, and quantitative study based on secondary data from the Live Birth Information System (SINASC), accessed via DATASUS. A total of 713 live births were analyzed. The study included the following variables: maternal age, type of delivery, number of prenatal consultations, place of birth, birth weight, Apgar score at 1 and 5 min, and newborn sex. Low birth weight was defined as < 2,500 g. Statistical analyses included descriptive statistics, Chi-square tests, Pearson correlation, and t-tests, with a significance level of p < 0.05.

Results

Most births were vaginal (81.35%), and the majority of mothers were aged 20–29 years (46.84%), followed by adolescents aged 10–19 years (24.96%). A total of 96.77% of Indigenous women attended at least one prenatal consultation, and 39.55% completed seven or more. Low birth weight was observed in 8.84% of newborns. A significant positive correlation was found between the number of prenatal consultations and birth weight (r = 0.789, p = 0.006). A Chi-square test showed that adolescent mothers were proportionally more represented than adult women aged 20–29 years (p < 0.001).

Conclusion

The maternal and neonatal outcomes observed among Indigenous women in the Wayamu Territory are similar to national patterns but reveal persistent challenges, including adolescent pregnancy, low prenatal consultation rates, and increasing medicalization of childbirth. These findings highlight the need for expanded public policies focused on culturally sensitive and equitable maternal and child healthcare for Indigenous populations in Brazil.

Introduction

Perinatal health disparities disproportionately affect Indigenous populations around the world. Studies from countries such as the United States and Canada have shown that American Indian and Alaska Native women experience higher rates of adverse birth outcomes, including preterm birth, low birth weight, and limited access to quality prenatal care. These findings reflect how structural inequities and cultural dissonance between Indigenous communities and healthcare systems contribute to preventable maternal and neonatal risks. Understanding the epidemiological patterns of perinatal health in marginalized populations is therefore essential for making obstetric science more equitable, representative, and responsive to diverse realities [1,2,3].

In Brazil, the Ministry of Health recorded 2,561,922 live births in 2022, with 289,158 occurring in the Northern Region, an area marked by geographic remoteness and cultural diversity. Of the national total, 27,508 births were identified as Indigenous. In the state of Pará, 1,533 Indigenous births were reported, including 104 in the municipality of Oriximiná, which encompasses traditional territories such as Wayamu [1]. These figures, though small in proportion, reveal the persistent invisibility of Indigenous perinatal experiences in national health agendas.

Pregnancy is a multifaceted process that encompasses physiological, emotional, and social transformations [2]. While childbirth marks the culmination of this cycle, the experience is shaped by cultural values and historical contexts [3]. For Indigenous women, these experiences are intertwined with ancestral knowledge and collective traditions, which often remain unacknowledged or undervalued within institutional health systems.

Brazil has developed public health policies aimed at improving maternal and child care, such as the National Policy for Indigenous Peoples’ Health. This policy is aligned with the principles of the Unified Health System (SUS) and seeks to ensure culturally appropriate care throughout the pregnancy-puerperal cycle, including family planning, prenatal consultations, labor and delivery care, and postpartum follow-up [4–5]. Its implementation, however, depends on intersectoral coordination and continuous professional training to deliver services that are both qualified and humanized [6].

Prenatal care plays a critical role in identifying maternal and fetal complications, reducing risks during pregnancy and childbirth [7]. Timely initiation—preferably in the first trimester—and an adequate number of visits are associated with lower maternal and infant mortality rates, better management of gestational complications, and increased access to vaccinations and nutritional support [8–9]. For Indigenous women, culturally respectful prenatal care must also address emotional and spiritual dimensions, in harmony with traditional knowledge and practices [10–11].

Despite policy efforts, structural barriers still compromise prenatal care in Indigenous territories. Geographic isolation, poor infrastructure, and a lack of trained personnel contribute to irregular or insufficient care delivery [12–13]. These obstacles reinforce health inequities and reduce the continuity and effectiveness of interventions intended to protect maternal and infant health.

The Live Birth Information System (SINASC) is Brazil’s primary tool for monitoring maternal and neonatal indicators. Based on data from Live Birth Declarations (DNVs), SINASC enables analysis of critical variables such as sex, weight, gestational age, delivery method, number of prenatal consultations, and Apgar score [14–15]. In recent years, an increase in hospital births and cesarean sections has been observed among Indigenous women, often driven by standardized institutional practices that may disregard cultural preferences and reduce Indigenous women’s autonomy during labor [16].

There is a lack of studies addressing indigenous maternal and child health in depth. Thus, this study aims to contribute to the understanding of indigenous births in traditional territories, providing data to formulate epidemiological and demographic indicators. These insights can support the planning and management of public policies focused on maternal and child healthcare in vulnerable populations.

The objective of this study is to describe the epidemiological profile of prenatal care, childbirth, and live births among indigenous women in the Wayamu territory, in the municipality of Oriximiná, from 2013 to 2022.

Methodology

This is a descriptive, retrospective, and quantitative study based on secondary data from the Live Birth Information System (Sistema de Informações sobre Nascidos Vivos– SINASC), accessed through the TABNET platform of the Department of Informatics of the Unified Health System (DATASUS), maintained by the Brazilian Ministry of Health. The study covers a ten-year period, from 2013 to 2022.

The study population includes all recorded live births to Indigenous mothers residing in the Wayamu Territory, located in the municipality of Oriximiná, state of Pará, Brazil. This territory encompasses three formally recognized Indigenous Lands (TIs): Katxuyana-Tunayana, Trombetas-Mapuera, and Nhamundá-Mapuera, which collectively span the municipalities of Faro and Oriximiná (Pará), Nhamundá and Urucará (Amazonas), and, in the case of Trombetas-Mapuera, also reach Caroebe and São João da Baliza (Roraima). Additionally, villages in areas of traditional Indigenous occupation not yet officially demarcated, especially along the lower Jatapu River, were included in the territorial scope. In total, 28 Indigenous villages distributed along the Trombetas, Mapuera, Cachorro, and Turuni rivers in Oriximiná were considered.

The inclusion criterion was: all live births from Indigenous mothers residing in the aforementioned territory and registered in SINASC during the study period. Exclusion criteria included records with missing or inconsistent information on key variables (e.g., undefined maternal age, delivery type, or birth weight), as well as duplicate entries.

Data were categorized into two main groups: maternal variables (maternal age, number of prenatal consultations, type of delivery—vaginal or cesarean, and place of birth—hospital, home, or Indigenous village) and newborn variables (sex, Apgar scores at 1 and 5 min, and birth weight).

Data collection was performed through structured queries using TABNET filters, focusing on live births identified as Indigenous by maternal race/color and geographic location codes corresponding to Oriximiná. The data were exported and organized using Microsoft Excel^® (Microsoft 365). Quality control measures included cross-verification with regional reports and removal of inconsistent entries.

Descriptive statistics were used to calculate absolute and relative frequencies for categorical variables, and means and standard deviations for continuous variables. For inferential analysis, the Chi-Square test (χ²) was applied to examine associations between delivery type and independent variables such as maternal age and number of prenatal consultations. Pearson correlation was used to assess the relationship between the number of prenatal visits and birth weight. Additionally, Student’s t-test was used to compare birth frequencies between adolescent mothers (10–19 years) and adult mothers (20–29 years). The significance level adopted was p < 0.05.

All statistical analyses were performed using Python software (with libraries such as Pandas, SciPy, and StatsModels). Although advanced modeling techniques (e.g., logistic regression or multivariate analysis) could provide deeper insights, the limitations inherent in the structure of secondary data—such as missing covariates or lack of control over data collection protocols—restricted the application of more complex statistical approaches in this study.

As this study used anonymized, publicly available data from a government database, no ethical approval was required from a Research Ethics Committee. Nevertheless, all stages of the study respected principles of confidentiality, integrity, and responsible use of public data.

Results

Between 2013 and 2022, the Live Birth Information System (SINASC) registered 713 live births among Indigenous women residing in the Wayamu Territory, representing 4.89% of all births in the municipality of Oriximiná during this period.

The majority of Indigenous mothers were aged 20–29 years (46.84%), followed by adolescents aged 10–19 years (24.96%). Women aged 30–39 years represented 24.82% of the total, and those aged 40 years or older accounted for 3.08%. Only two cases (0.28%) involved mothers aged 50 or older (Table 1).

Table 1 Maternal age distribution among Indigenous women in Wayamu territory (2013–2022)

Regarding the mode of delivery, 81.35% of births were vaginal, while 18.37% were cesarean sections. Over the ten years analyzed, the annual average of vaginal births was 58, while cesarean sections averaged 13 per year. Although vaginal delivery remains predominant, an increase in the number of cesarean sections has been observed over the years (Fig. 1).

Fig. 1

Types of deliveries among indigenous women from the Wayamu Territory, in the municipality of Oriximiná, from 2013 to 2022

Most deliveries occurred in hospital settings (n = 670; 93.96%). Deliveries classified as occurring “at home” (n = 24; 3.37%) refer to domiciliary births outside of Indigenous village contexts, while “in Indigenous villages” (n = 13; 1.82%) refers to births taking place within traditional territories. Additionally, 2 deliveries occurred in other health facilities, and 4 in unspecified locations (Table 2).

Table 2 Place of delivery in the municipality of Oriximiná, from 2013 to 2022

Regarding the number of prenatal consultations, it was observed that 39.55% of indigenous pregnant women attended seven or more consultations, while 40.95% attended between four and six consultations. A percentage of 16.27% had only one to three consultations, and 3.23% did not have access to any prenatal consultations (Fig. 2).

Fig. 2

Number of prenatal consultations attended by indigenous women from the Wayamu Territory, in the municipality of Oriximiná, from 2013 to 2022

Source: MS/SVS/CGIAE - Live Birth Information System (SINASC)

At the 1st minute of life, 554 newborns (77.70%) had Apgar scores of 8–10, 133 (18.66%) scored between 5 and 7, and 26 (3.64%) scored 0–4. At the 5th minute, 649 newborns (91.00%) had scores of 8–10, 53 (7.42%) had scores between 5 and 7, and 11 (1.58%) scored 0–4 (Table 3).

Table 3 Apgar score distribution at 1st and 5th minutes (2013–2022)

In Fig. 3, which presents the characteristics of newborns, it was observed that there was a higher number of male newborns (54.98%), totaling 392 births, compared to female newborns (45.02%), with 321 births. During the initial years of the analyzed period, 2013 and 2014, more female newborns were recorded. However, from 2015 onward, this pattern shifted, with a higher number of male births. The sex ratio was 1.22, indicating a predominance of male births compared to female births.

Fig. 3

Sex of newborns from indigenous women in the Wayamu Territory, in the municipality of Oriximiná, from 2013 to 2022

Source: MS/SVS/CGIAE - Live Birth Information System (SINASC)

Among all newborns, 91.16% had adequate birth weight (≥ 2,500 g), while 8.84% were classified as low birth weight (< 2,500 g). The majority of those with low birth weight were in the 1,500 to 2,499 g range. Extreme low birth weights (< 1,500 g) were rare (Table 4).

Table 4 Birth weight distribution of newborns (2013–2022)

Inferential statistical tests were applied to examine associations and trends. No statistically significant association was found between maternal age and mode of delivery (Chi-square test, p = 0.714).

A strong positive correlation was observed between the number of prenatal consultations and birth weight (Pearson’s r = 0.789, p = 0.006), indicating that a greater number of consultations was associated with higher birth weights.

Additionally, the Student’s t-test revealed a statistically significant difference in the number of births between adolescent mothers (10–19 years) and adult women aged 20–29 years (p = 0.000013), with adolescents accounting for a proportionally higher number of births.

Discussion

This study presents a detailed epidemiological profile of live births among Indigenous women in the Wayamu Territory, northern Brazil, over a ten-year period. The findings reveal important aspects related to adolescent pregnancy, delivery methods, prenatal care, neonatal outcomes, and systemic challenges in accessing culturally appropriate maternal health services.

A total of 24.96% of Indigenous mothers were adolescents aged 10 to 19 years. While this percentage is concerning from a biomedical standpoint, given the association between adolescent pregnancy and adverse perinatal outcomes, it must be interpreted within the sociocultural context of Indigenous communities. In several ethnic groups, adolescence is not viewed as a period of immaturity, but rather as a transition to adulthood, often marked by initiation rituals that prepare young women for marriage and motherhood [4]. Nonetheless, from a public health perspective, adolescent pregnancy is associated with increased obstetric risks such as preterm birth, low birth weight, and neonatal complications [17,18,19]. The World Health Organization (WHO) further highlights that girls under 16 years, or those with low height or body weight, are at increased risk of poor outcomes during pregnancy and childbirth [18]. Therefore, culturally sensitive reproductive health policies are essential to support Indigenous adolescents with information, access to contraception, and respectful prenatal care.

Regarding delivery methods, 81.35% of births were vaginal and 18.37% were cesarean. Although vaginal delivery remains predominant, there is a rising trend in cesarean sections over time. Compared with the Brazilian national average of over 55% cesarean births, the rate in this Indigenous population is low. However, it still warrants attention. In international terms, the cesarean rate was 32.1% in the United States in 2021, according to the Centers for Disease Control and Prevention (CDC) [20], and 28.2% in Canada in 2019–2020, as reported by the Canadian Institute for Health Information (CIHI) [21]. Among Indigenous populations in Latin America, cesarean rates have been reported to range from 25% to over 36%, depending on geographic region and access to services [22]. This suggests that while medicalization is expanding, traditional birth practices may still influence delivery patterns in Indigenous communities. Nonetheless, the increasing reliance on cesarean sections may reflect language barriers, lack of culturally competent care, and institutional routines that limit Indigenous women’s autonomy during childbirth [23, 24, 25, 26].

The classification of delivery locations revealed that 93.96% of births occurred in hospitals, while 3.37% occurred at “home” and 1.82% in “Indigenous villages.” It is important to note that the SINASC system separates these categories. However, from an Indigenous perspective, births that occur in the village are typically understood as home births. The use of “home” to designate non-village domiciles (often in urban areas) and “village” for traditional territories imposes a biomedical logic that does not always align with Indigenous cultural understandings. This distinction may obscure the presence of traditional midwifery and community-based birthing practices, and should be revisited in health surveillance systems to better capture culturally grounded care contexts.

Access to prenatal care was relatively high, with 96.77% of women attending at least one consultation. However, only 39.55% met the recommended seven or more consultations. These “prenatal consultations” in Brazil follow a standardized protocol under the SUS system, including physical exams, lab tests, immunizations, and educational guidance. This structured model differs from antenatal care frameworks in other countries, where visit frequency, clinical content, and continuity vary considerably. Clarifying this distinction is essential when comparing results internationally.

The analysis demonstrated a positive correlation between the number of prenatal consultations and birth weight (r = 0.789, p = 0.006), reaffirming the protective role of comprehensive prenatal monitoring. Similar findings have been reported in national studies, which highlight that greater prenatal care coverage reduces the risks of low birth weight and neonatal mortality [25, 27].

Low birth weight (< 2,500 g) was observed in 8.84% of newborns, which aligns with the national average reported in SINASC. While this rate is lower than in many low- and middle-income countries—such as South Asia (28%) and Sub-Saharan Africa (13%) [26] it still demands attention. Low birth weight remains one of the main predictors of neonatal morbidity and long-term developmental challenges, reinforcing the need for early intervention strategies in vulnerable populations.

With regard to neonatal vitality, 91% of newborns had Apgar scores between 8 and 10 at the fifth minute of life. International guidelines from WHO and ACOG recognize the 5-minute Apgar score as a more reliable predictor of neonatal outcomes than the 1-minute score. Thus, this study emphasized results at five minutes. While some studies suggest an association between the number of prenatal consultations and higher Apgar scores [28], the current analysis did not establish such a relationship. Further analysis would be required using continuous or categorical variables (e.g., Apgar < 7) to examine this link with statistical validity.

One limitation of this study lies in the use of secondary data from SINASC, which may suffer from underreporting or misclassification, especially for variables such as place of birth and prenatal consultations. The system also does not capture qualitative aspects of care, such as the involvement of traditional midwives, the cultural acceptability of services, or the presence of community health agents. Future research should integrate mixed-method or participatory approaches to better reflect the complex realities of Indigenous maternal health.The lack of a statistically significant association between the type of delivery (vaginal or cesarean) and maternal age (p = 0.714) suggests that the choice of delivery method may be influenced by other determinants, such as the availability of healthcare services and hospital practices. Studies indicate that in some regions, the decision for a cesarean section is not directly related to the clinical condition of the pregnant woman but rather to hospital infrastructure, healthcare system organization, and institutionalized obstetric practices [29]. Among indigenous populations, this influence may be even more pronounced, as many indigenous women face vulnerabilities when placed in hospital settings, where communication barriers make medical decisions less participatory [30].

Furthermore, the t-test revealed that adolescents had a significantly higher proportion of births compared to women aged 20 to 29 years, reinforcing the vulnerability of this group and the need for targeted strategies to prevent early pregnancy. The literature highlights that adolescent pregnancy is associated with increased obstetric risks, including preterm birth, low birth weight, and childbirth complications, as well as socioeconomic and educational impacts on young mothers [31]. In indigenous communities, early pregnancy is perceived differently, as many ethnic groups consider that a woman is ready for motherhood after menarche [32]. However, from a public health perspective, adolescence is a high-risk period for pregnancy, requiring effective policies that ensure access to family planning, high-quality prenatal care, and humanized assistance for adolescent mothers [33].

Given these findings, it is essential to implement strategies to address the identified challenges, ensuring that indigenous women have access to respectful prenatal and childbirth care that considers their cultural specificities while promoting high-quality and equitable maternal and child health services. Additionally, strengthening the training of healthcare professionals and actively involving indigenous communities in the planning and execution of public policies are crucial steps toward improving maternal and child health indicators among this population.

Conclusion

The analysis of the epidemiological profile of live births among Indigenous women in the Wayamu Territory revealed both advances and persistent gaps in maternal and child healthcare in this population. While most women accessed prenatal care and hospital delivery services, a significant proportion still received inadequate follow-up, and adolescent pregnancy remained notably high. These findings underscore the need for targeted interventions that address structural barriers, improve access to culturally adapted prenatal services, and expand reproductive health education for Indigenous adolescents.

The predominance of hospital births, along with a gradual increase in cesarean sections, suggests a trend toward the medicalization of childbirth that may overlook traditional practices and Indigenous women’s autonomy. Strengthening culturally respectful care models—integrating biomedical protocols with Indigenous knowledge—is essential to ensure safety, trust, and humanization in perinatal care.

This study also highlights the importance of differentiating care strategies to meet the sociocultural specificities of Indigenous communities. Expanding decentralized healthcare services, training professionals in intercultural health, and involving Indigenous leaders in the planning and evaluation of policies are critical steps toward more equitable healthcare delivery.

As a limitation, the use of secondary data may involve incomplete records and does not capture the qualitative dimensions of care or Indigenous women’s perceptions. Future research should include participatory and mixed-method approaches to better reflect the lived experiences and health priorities of these communities.

Ultimately, promoting maternal and child health in Indigenous territories requires more than technical solutions—it demands listening to and empowering Indigenous voices to shape policies that are effective, inclusive, and culturally coherent.