Artigos

Conteúdo (article):

FATORES ASSOCIADOS AO BAIXO PESO AO NASCER NA RURALIDADE REMOTA BRASILEIRA

FACTORS ASSOCIATED WITH LOW BIRTH WEIGHT IN REMOTE BRAZILIAN RURALITY

FACTORES ASOCIADOS AL BAJO PESO AL NACER EN ZONAS RURALES REMOTAS DE BRASIL

Edialy Cancian Tetemann – edialy@usp.br
ORCID https://orcid.org/0000-0003-4431-2420

Simone Schenkman – simoneschenkman@usp.br
ORCID https://orcid.org/0000-0003-1140-1056

Zilda Pereira da Silva - zildapereira@usp.br
ORCID: https://orcid.org/0000-0003-4648-113X

Aylene Emilia Moraes Bousquat – aylenebousquat@usp.br
ORCID https://orcid.org/0000-0003-2701-1570


Resumo
Analisou-se o desfecho do parto de nascidos vivos-NV com baixo peso-BPN no Brasil em mulheres residentes nos Municípios rurais remotos-MRR, vis a vis o deslocamento ao parto em outro município. Estudo quantitativo, com informações do Sistema de Informação de Nascidos Vivos-SINASC de 2013-19, Brasil. Analisados o desfecho de parto-BPN e deslocamento, comparando os desfechos em mulheres residentes-MRR e demais municípios brasileiros. Realizadas análises de regressão logística bi e multivariada, com Odds Ratios-OR, valores de p e IC 95%. No período, foram registrados 20.476.367 NV no Brasil, com 437.800-2,14% em MRR. Considerando todos os municípios, o parto com deslocamento apresenta 1,2 vezes a chance de BPN, potencializada em sua interação com os MRR. Morar em MRR foi fator protetor (OR=0,6). O modelo multivariado apresentou maiores chances de BPN - igualmente para MRR e o restante do Brasil - em gestações<37 semanas (16,2), gravidez múltipla-10,0, parto cesáreo-1,1, adolescentes-1,1, <7 consultas de pré-natal-PN-1,7, nascimento em outros locais-2,0, pretas-1,2 e ano de nascimento mais recente-1,02. Este estudo demonstrou que nascer em MRR foi fator protetor para BPN, ainda que em um cenário de menor número de consultas-PN, de maiores deslocamentos a outros municípios e de maior número de mães adolescentes que o restante do país.
Palavras-chave: Saúde da população rural, Zonas remotas, Cuidado pré-natal, Parto, Recém-nascido de baixo peso.

Abstract

We analyzed the outcome of the delivery of live births-LB with low birth weight-LBW in Brazil, focusing on women living in remote rural municipalities-RRM, vis-à-vis the need to travel to deliver in another municipality. Quantitative study, with information from the Live Births Information System-SINASC, 2013-19, Brazil. The outcome of childbirth-LBW and commuting to childbirth were analyzed, comparing the outcomes in women living in the RRM and other municipalities. Bi and multivariate logistic regression analysis was carried out, with Odds Ratios-OR, p-values and 95% CI. During the period, 20,476,367 LB were registered in Brazil, with 437,800-2.14% in RRM. Considering all municipalities, childbirth with relocation has 1.2 times the chance of LBW when interacting with RRM. Living in an RRM was a protective factor (OR=0.6). The multivariate model showed higher odds of LBW equally for RRM and the rest of Brazil in pregnancies <37 weeks-16.2, multiple pregnancies-10.0, cesarean delivery-1.1, teenager-1.1, <7 prenatal-PNC visits-1.7, other birthplaces-2.0, Black-1.2 and more recent year of birth-1.02. This study showed that being born in the RRM was a protective factor for LBW, although with fewer PC visits, higher proportions of traveling to other municipalities and more teenage mothers than in the rest of the country.

Key words; Rural health, Remote area, Prenatal care, Parturition, Low birth weight

Resumen
Se analizó el resultado del parto de nacidos vivos (NV) con bajo peso al nacer (BPN) en Brasil en mujeres residentes en los Municipios Rurales Remotos (MRR), frente al desplazamiento para el parto a otro municipio. Estudio cuantitativo, con información del Sistema de Información de Nacidos Vivos (SINASC) de 2013-19, Brasil. Se analizaron el resultado del parto-BPN y el desplazamiento, comparando los resultados en mujeres residentes en MRR y los demás municipios brasileños. Se realizaron análisis de regresión logística bi y multivariada, con Odds Ratios (OR), valores de p e IC 95%. En el periodo, se registraron 20.476.367 NV en Brasil, con 437.800 (2,14%) en MRR. Considerando todos los municipios, el parto con desplazamiento presenta 1,2 veces la probabilidad de BPN, potenciada en su interacción con los MRR. Vivir en MRR fue un factor protector (OR=0,6). El modelo multivariado presentó mayores probabilidades de BPN —igualmente para los MRR y el resto de Brasil— en gestaciones <37 semanas (16,2), embarazo múltiple (10,0), parto por cesárea (1,1), adolescentes (1,1), <7 consultas de control prenatal (CP) (1,7), nacimiento en otros lugares (2,0), negras (1,2) y año de nacimiento más reciente (1,02). Este estudio demostró que nacer en un MRR fue un factor protector para el BPN, aun en un escenario de menor número de consultas de CP, de mayores desplazamientos a otros municipios y de un mayor número de madres adolescentes que en el resto del país.
Palabras clave: Salud de la población rural; Zonas remotas; Atención prenatal; Parto; Recién nacido de bajo peso.
INTRODUCTION
People living in rural and remote areas face major challenges in accessing public goods and services. Remoteness, population dispersion and geographical barriers, combined with the absence of sustainable regional development policies appropriate to the cultural characteristics of these populations, are some of the factors that contribute to difficulties in accessing services, including health services1,2.
These barriers affect the health of women and children living in these territories. Studies have shown that, in general, indicators related to prenatal care, childbirth, postpartum care and mortality are worse in these areas3,4. Low birth weight (LBW) is one of the outcomes for newborns that impacts health services and is linked to other factors, such as ensuring an adequate number of prenatal visits, type of delivery, place of birth, and is also associated with some maternal characteristics5,6. Ensuring quality care in these territories is a sine qua non condition for achieving the Sustainable Development Goals (SDGs) related to maternal and child health3,4.
In Brazil, the scenario is no different. Despite the implementation of the so-called Rede Cegonha (Stork Network - a national delivery and birth care policy ), inequities related to access to health services still persist7,8. One of these concerns regional disparities within the country, with the South and Southeast regions having higher indicators for the provision of childbirth care when compared to other regions9.
One of the striking issues in remote rural areas is the distance traveled for childbirth, where long journeys contribute to increased maternal and infant mortality. This often occurs due to the lack of Birthing Centers (Centro de Parto Normal-CPN) and/or maternity wards or trained professionals in these areas 6,8.
Almeida and Szwarcwald10 report that the smaller the municipality’s population, the greater the distance traveled to give birth, with the highest median distances observed in northern Brazil. The authors analyzed the infant mortality rate (IMR) from 2005 to 2007 and described an increase in all Brazilian regions, the greater the distance traveled. In the Northeast region, however, this difference was even greater when the distance traveled exceeded 50 km10.
According to Russell et al.11, health services must be guaranteed for the population, a condition classified as availability. It is worth remembering that relocation for the purpose of giving birth is not necessary in most cases; however, when considering the situation of pregnant women (high risk), traveling to municipalities that provide more specialized services becomes essential.
On analyzing the different rural-urban dynamics in Brazil, in 2017 the Brazilian Institute of Geography and Statistics12 (IBGE) suggested a new classification of Brazilian municipalities. This classification categorizes municipalities as urban, adjacent intermediate, remote intermediate, adjacent rural and remote rural (RRM).
In this respect, the objective of this article is to analyze the factors associated with LBW (birth outcome) of newborns in Brazil, focusing on residents in RRMs, with regard to the need for relocation for the purpose of giving birth. This analysis aims to provide elements that contribute to the implementation of policies directed at these populations, thereby reducing the immense socio-spatial inequalities in Brazil.
METHODS
This is an exploratory study with a quantitative approach, based on information from the Live Birth Information System (SINASC) for the years 2013 to 2019 in Brazil, emphasizing the comparison with remote rural municipalities (RRM). There are 323 RRMs, distributed mainly across the North, Northeast and Central-West regions, with almost 4 million people12.
To analyze information on childbirth, the use of SINASC has been recommended in the literature, as it offers a high degree of completeness and coverage and is considered a high-quality database13. The data presented were extracted from the DataSus website for each state and year; subsequently, the data from the states were grouped in TabWin, creating a single file (Brazil).
As the scope of the study focuses on RRMs, which are characterized by small populations, the data were grouped over a seven-year period to reduce fluctuations in the indicators (2013 to 2019). The database created gathers information from all Brazilian municipalities containing 20,038,567 observations and all variables included in the Live Birth Certificate (LBC). The statistical program Stata 16 (StataCorp) was used for data analysis.
A variable called RRM was created to identify mothers residing in the 323 RRMs, resulting in 437,800 observations. In addition, depending on the need for relocation, a categorical variable was created according to whether the mother\'s municipality of residence was the same as or different from the municipality where the birth occurred.
The choice of dependent variable was based on the possibility of a proxy that reflected the quality of and access to health services. Low birth weight (LBW) was chosen, as it is one of the outcomes that, on the one hand, impacts health services and, on the other, may indicate inadequate prenatal care14,15.
The main independent variable (exposure) was whether childibirth ocurred in a municipality other than that of the mother’s origin. The other independent variables were considered covariates or potential confounding factors: gestational age; type of pregnancy; type of delivery; maternal age; prenatal visits (PNC); place of delivery; maternal color/race; year of birth. The variable maternal education was not used because it did not show a significant association with the exposure and outcome variables, especially when the adolescent mother category was added (previous analysis). An interaction variable between RRMs and relocation for delivery was also established to verify whether relocation could modify the effect, i.e. the chance of live births with LBW in RRMs. This variable was based on the observation that there was a difference in the association between the need to relocate and low birth weight, according to the municipality of origin (RRMs or other municipalities).
Initially, the absolute and relative frequencies of all independent variables were analyzed using their original SINASC categories, comparing RRMs with the rest of Brazil. Subsequently, data were stratified by the exposure and the dependent variables, both dichotomized, to deepen the analysis of the RRMs. We evaluated these associations using Pearson\'s chi-square test16.
Next, the associations between the dependent variable and the other variables were tested, according to logistic regression, both individually and jointly. The bivariate and multivariate models were constructed according to two strata: Brazil and MRR.
The other independent variables were subsequently categorized, assigning values = 1 to the categories of interest: gestational age (<37 weeks); type of pregnancy (multiple); type of delivery (cesarean); teenage mother (≤18 years); prenatal visits (<7); place of delivery (indigenous village/other); race (Black). The variable ‘place of delivery’ has a particularity, as the option ‘indigenous village’ was only included from 2013 onwards, with data completeness for this variable improving progressively from 2014 onwards.
The strength of association between variables was tested individually (bivariate analysis) using Odds Ratios (OR), p-values, and 95% confidence intervals (95% CI). An OR < 1 was considered a protective factor. Finally, multiple logistic regression was performed to verify which set of relevant variables remained in the final model. In the initial model, all those that had shown statistical significance in the bivariate analysis (p < 0.05) were tested.

RESULTS
Between 2013 and 2019, SINASC registered 20,476,367 live births in Brazil, of which 437,800 (2.14%) were born to mothers residing in RRMs. Data analysis shows that relocation was significantly higher for RRMs (40.65%) compared to other Brazilian municipalities (30.69%). In the RRMs, vaginal delivery (61.89%) was more frequent, while in the rest of Brazil, cesarean section was more common (56.51%). Regarding type of pregnancy, multiple gestation were less frequent in RRMs (1.50% vs. 2.11%; p<0.001), and there was no difference in gestational age between births to mothers residing in RRMs and in other Brazilian municipalities (Table 1).
Regarding the number of PNC visits, RRMs have twice the percentage of pregnant women without consultations when compared to the rest of the country (4.04% vs. 2.06%), while for seven or more PN visits, this ratio is reversed (48.81% vs. 68.52%). Regarding the place of birth, in RRMs the proportions were significantly higher for births in other health facilities (3.33% vs. 0.60%) and at home (7.14% vs. 0.54%).
Regarding maternal characteristics, compared to the rest of Brazil, RRMs showed higher proportions of Mixed-race mothers (75.66% vs. 56.04%) and Indigenous mothers (10.74% vs. 0.63%), and the proportion of adolescent mothers (≤18 years) was also high (21.09% vs. 8.23%). The proportion of LBW newborns was lower in RRMs (6.79% vs. 8.54%).
Table 2 shows the prenatal care and childbirth characteristics related to the need or otherwise for travel to give birth in the RRMs and the rest of Brazil. With regard to the type of delivery, there is a difference in vaginal deliveries between RRMs and the rest of Brazil when births take place in the in the mother\'s municipality of residence (45.52% vs. 71.85%). When the mother has to travel, the proportion of cesarean deliveries is higher for both, but remains higher among other Brazilian municipalities. In the RRMs, there is a reversal of the preponderance of normal deliveries when travel is necessary (47.37%); in the rest of Brazil, cesarean deliveries are the majority in both situations.
With regard to the number of PNC visits, the percentage of women without such consultations was higher in RRMs without relocation. However, when relocation was required, the proportion of pregnant women with seven or more visits is significantly higher in RRMs (56.07%).
Hospital deliveries in Brazil had the highest proportions (above 98%), regardless of the need to travel for the purpose of delivery, while in RRMs when no relocation occurred this figure was 80.47%. In this situation, home births (11.89% vs. 0.76%) and births in other health facilities (4.95% vs. 0.64%) were more frequent when compared to the rest of the country. In RRMs, a higher proportion of adolescent mothers was observed when there was no relocation to give birth (22.11% vs. 19.60%).
When analyzing the occurrence of relocation for childbirth and LBW in RRMs, significant differences were found in relation to certain variables (Table 3). The proportion of relocation was more frequent in the following strata: cesarean section (56.19%), hospital deliveries (45.60%), Asian (53.23%) and White (53.01%) women, and seven or more PNC visits (46.74%), following a progression from 2013 to 2019 (37.62% to 42.86%), 22 to 27 weeks of gestation (52.82%), and multiple pregnancy (63.82% for twins and 77.27% for triplets).
The proportion of LBW newborns was higher in the following situations: gestational age of 22 to 27 weeks (73.29%), multiple pregnancy (53.44% for twins and 80.68% for triplets), births in other health services (11.55%), and indigenous villages (9.28%), with up to three PNC visits (about 10%), and mothers of Asian and Indigenous mothers (7.94% and 7.67%). LBW followed a progression starting from 2015 (varying from 6.62% to 7.19%). No significant difference was found in relation to the type of delivery.
In the bivariate analysis (Table 4), statistically significant differences were found between the covariates and LBW. In the RRM group, the following characteristics stood out: relocation for childbirth (1.6 times); multiple pregnancies (14.2 times); gestational age <37 weeks (9.0 times). Birth in other health services showed an OR of 0.8 (protective factor) when compared to hospital births, while birth in other locations and in indigenous villages increased the odds of LBW (1.8 and 1.4 times).
Furthermore, being a teenage mother (1.5 times) and of Indigenous or Asian origin (1.2 times) and having fewer than seven PNC visits (1.9 times) increase the odds of LBW. There was also an increasing trend in the odds of LBW over time (1.03/year).
When analyzing the association between covariates and LBW in Brazil (Table 4), significant differences were found in relation to relocation (1.4 times), as well as gestation age < 37 weeks (20.7 times), multiple pregnancy (19.4 times), and birth in other locations (3.0 times). Regarding to maternal characteristics, being an adolescent mother or Black mother increases the odds of LBW by 1.1 and 1.2 times, respectively. Living in an RRM was a protective factor against LBW (OR=0.8).
The analysis of all covariates related to each other and LBW showed significant statistical differences (Table 5). Considering all Brazilian municipalities, relocation to give birth increases the odds of LBW by 1.2 times in its interaction with RRMs. Living in an RRM was a protective factor against LBW (OR=0.6). Adjustments to the multivariate model reinforced the results described above, with higher odds of LBW for gestational age below 37 weeks (16.2), multiple pregnancy (10.0), cesarean delivery (1.1), adolescent mothers (1.1), fewer than seven prenatal visits (1.7), birth in other locations (2.0), Black mothers (1.2) and more recent year of birth (1.02).

DISCUSSION
We found a significant association between relocation and LBW, adjusted for gestational age under 37 weeks, multiple pregnancy, cesarean deliveries, adolescent mothers, Black mothers, mothers with fewer than seven prenatal visits, more recent births, and births in other locations. However, RRM was a protective factor for LBW, even with a higher proportion of relocation, which leads us to examine and discuss the possible reasons that define this interaction.
The IBGE\'s12 new categorization, redefining Brazilian municipalities and expanding their classification beyond urban/rural, is recent. Thus, this article seeks to draw parallels with studies produced on rural territories, which share some characteristics with the remote rural municipalities.
In general, RRMs have health networks with few facilities and resources2, so the strong association between LBW and the need to relocate for childbirth reinforced its selection as a dependent variable. It is understood that in most situations LBW could be an indirect measure of the need for relocation, that is, a measure of the likelihood of needing to use more complex health equipment, with trained professionals and even neonatal intensive care units14.
The higher percentage of pregnant women residing in RRMs who relocate to other municipalities to give birth, as found in this study, reflects the structure of the RRM health networks17. The findings of Lima15 show that in the metropolitan region of Recife there is a higher concentration of obstetricians and ICU beds; in regions further away from urban centers, the lack of healthcare services has a negative impact on the neonatal mortality indicator. Sabroza18, in turn, analyzed relocation for childbirth, pointing out that the North region has the highest average distance between residence and maternity hospital, followed by the Midwest region, where the RRMs are concentrated.
Thus, they express results in the same direction. In any case, it is important to emphasize that this is not necessarily an indicator of poor quality of care, as the Brazilian healthcare system is designed to be comprehensive, to be implemented in the regionalized rather than the municipal healthcare network.
Regardind LBW, being born in an RRM was shown to be a protective factor. The literature is not unanimous in affirming that there is a relationship between rural areas and LBW, as well as fetal deaths. A study conducted in Afghanistan showed higher odds of LBW among residents of urban areas. In southern Ethiopia, LBW was higher in rural areas, as well as in Ghana, where women living in rural areas are 43% more likely to have LBW. Bangladesh, however, showed no difference between urban and rural areas, which demonstrates the non-homogeneity of these territories and the need for studies that address these differences19,20,21,22.
In Brazil, Viana et al.23 reported an increase in LBW in urban areas and in the Southeast and Southern regions of the country. Silva et al.24 found high LBW rates in the Southeast and Southern regions and lower rates in the North and Northeast regions. To explain what the authors call the “LBW paradox in Brazil,” several possible causes were cited, including: underreporting or low coverage of SINASC in less developed regions of the country, better quality of perinatal care in more developed regions, an increase in the number of multiple pregnancies and high demand for assisted reproduction in wealthier regions, as well as high rates of smoking during pregnancy. The authors found a greater association of LBW with improvements in the quality of health services and the availability of perinatal technologies, and no longer solely with socioeconomic factors23.
With regard to cesarean delivery, Silva et al.24 mention that, as the cesarean rate increased above 30%, LBW rates also increased, corroborating our findings. It is important to relate the increase in the cesarean rate to the childbirth care model, which combines economic and technological incentives, guided by the sociocultural context. Furthermore, excessive cesarean sections lead to an increase in borderline premature births and a higher incidence of low birth weight25. The presence of a smaller hospital network in RRMs may be one of the factors contributing to lower iatrogenesis in childbirth and a lower incidence of borderline premature births25.
When considering the type of delivery, the percentage of vaginal deliveries in RRMs was higher than in other Brazilian municipalities. Although the distribution of the number of PNC visits in RRMs is worse than in the rest of the country, despite the pre-established ranges in which 4 to 6 visits are aggregated, this factor is possibly offset by the higher proportion of vaginal deliveries, with a reduced risk of prematurity and lower LBW.
The proportion of home births among mothers residing in RRMs was higher than in other municipalities and was associated with not relocating for childbirth, suggesting that the findings in this study demonstrate that non-relocation acts as a protective factor for LBW. Home births in Brazil are more common in the Northern region of the country, but underreporting of home births must be considered in this context. According to Menezes, Portella, and Bispo,26 these regional inequalities contribute to home births occurring in regions where there is less health service coverage.
Another important finding relates to being born in an indigenous village as a risk factor for LBW in the RRMs and throughout Brazil since 2014. According to Barreto27, no significant differences were found between LBW and being born in an indigenous village or in a hospital. LBW (in indigenous villages) was associated with primiparity, fewer than six prenatal visits, anemia and sources of energy for cooking food27. Our study showed that being born in other places (in vehicles, schools or workplaces) or indigenous villages was a risk factor for LBW.
Almeida et al.28 found a relationship between adolescent mothers and spontaneous preterm birth, associated with social vulnerability and higher proportions in the North and Northeast regions, mainly among Black adolescents from lower socioeconomic classes. The number of PNC visits was less than five, and more than 90% of these adolescents received prenatal care in the public health service.
In our study, Black women presented a higher risk for LBW in the complete model (Brazil). Born et al.29 found similar results, the main causes of which were associated with socioeconomic inequalities, difficulties in accessing health services and low levels of education. For Indigenous mothers, environmental factors and geographic location add to the risk of LBW.28,29
This initial approach to understanding the context of geographical relocation for childbirth in RRMs and its relationship with LBW showed that such relocation has a protective effect on LBW. However, when analyzing other indicators, it is necessary to rethink specific public policies for these territories, with the aim of improving access to good-quality prenatal care, especially for Indigenous women.
The main limitation of this study is the use of secondary data, which may contain inaccuracies in collection and data entry, in addition to the lack of variables more appropriate to the remote rural context. However, as we have been working with the same high-quality database over the years, with few changes during the period, these issues have been minimized. Future studies may extend the analysis of LBW related to intrauterine growth restriction, as well as analyze the occurrence of low-weight fetal deaths in RRMs.

CONCLUSION
In addition to reinforcing the similar risk factors between RRMs and other Brazilian municipalities, it is worth noting that remote rural areas, even though involving more travel for childbirth, still constitute a protective space for LBW. In a way, it is possible that relocation for childbirth, due to the conditions of remoteness, limits high-risk pregnancy situations. Home delivery or delivery in other health services is more common in RRMs.
Even with the differences observed in the international literature regarding travel in remote rural areas and its association with LBW, in Brazil it is clear that relocation for childbirth occurs due to the lack of specialized services for high-risk pregnancies in remote rural areas. Although our study does not analyze relocation within the health region, there is no doubt that an improvement in the regionalized health service network, expanding the scope of care for high-risk pregnant women, could minimize long-distance travel to large centers and capitals and reduce fetal deaths. Another suggestion worth highlighting would be policies to strengthen CPN (Birthing Centers) in RRMs, especially with the recruitment of midwives.


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