Cohort profile: the Maternal and Child Health and Nutrition in Acre, Brazil, birth cohort study (MINA-Brazil)

The Global Consortium of Oral Health Birth Cohort Studies-GLOBICS

This article highlights the transformative initiatives of the Global Consortium of Oral Health Birth Cohort Studies (GLOBICS) as a key response to the call for a global overhaul of the oral health agenda. Recognizing the critical role of birth cohort studies in public health, particularly in understanding the interplay between oral health, noncommunicable diseases (NCDs), and social inequalities, GLOBICS is spearheading efforts that are research driven and focused on translational pathways. GLOBICS is advancing an International Research Agenda with 8 key priorities aimed at addressing the most pressing questions in oral health research. These priorities shall guide pooled analyses from oral health birth cohort studies (OHBCS) spread across the globe, enabling the consortium to generate robust evidence answering core research questions. One of the major efforts of GLOBICS is data harmonization, which involves standardizing and integrating data from multiple sources to ensure consistency and comparability. This process is vital for generating reliable global insights and fostering collaborations with new research partners. GLOBICS also emphasizes the nurturing of the next generation of OHBCS researchers, ensuring that the field continues to grow and innovate. The consortium's commitment to disseminating and translating its findings is central to its mission. By supporting the development of clinical practice guidelines, policies, and public health information tailored to the specific contexts of its collaborators, GLOBICS is making strides toward tangible improvements in global oral health. This work is a testament to the power of collaborative research and an invitation for further contributions to this global effort.

Effect of ultra-processed food consumption on the gut microbiota in the first year of life: Findings from the MINA-Brazil birth cohort study

BACKGROUND AND AIMS

The first years of life are fundamental for the establishment of the gut microbiota, with diet being one of the main early exposures. During this period, the beneficial effect of breastfeeding on modulating the gut microbiota is well known; however, there are important gaps in the literature on the effects of ultra-processed food (UPF) consumption, particularly in longitudinal and large sample designs. Through a prospective birth cohort study, we investigated the effects of UPF consumption on the gut microbiota of children during the first year of life.

METHODS

This study included children from the MINA-Brazil birth cohort with gut microbiota data (16S rRNA) available at the 1-year follow-up (n = 728). Data on breastfeeding practices were collected after childbirth and during follow-up visits. Complementary feeding was measured using a semi-structured questionnaire, referring to the day before the interview at the 1-year follow-up. A combined variable was generated according to breastfeeding practices and UPF consumption and was used as an independent variable in the adjusted median regression models, with alpha diversity parameters as the dependent variable. Beta diversity was analyzed using PERMANOVA according to Bray-Curtis dissimilarity and Distance-based Redundancy Analysis (db-RDA) adjusted for covariates. Relative abundance was analyzed using ANCOM-BC (corrected by FDR) and MaAsLin2 adjusted for covariates.

RESULTS

Weaned children who consumed UPF showed a significant increase in alpha diversity for all parameters in the median regression models (Observed ASVs: p = 0.005; Shannon index: p = 0.036; Chao index: p = 0.026; Simpson index: p = 0.012) and in beta diversity (PERMANOVA: p = 0.006; db-RDA: p < 0.001) compared to breastfed children who did not consume UPF. Breastfed children who did not consume UPF had a higher relative abundance of Bifidobacterium than weaned children who consumed UPF (both p < 0.001 for ANCOM-BC and MaAsLin2) and a lower relative abundance of Firmicutes (p < 0.001 for MaAsLin2), Blautia (both p < 0.001 for ANCOM-BC and MaAsLin2), Sellimonas (p = 0.008 for ANCOM-BC) and Finegoldia (p = 0.045 for MaAsLin2) than weaned children who consumed UPF.

CONCLUSION

These findings suggest that UPF consumption may negatively impact the diversity and abundance of the gut microbiota, with a more pronounced effect in children who have already been weaned.

Development and cultural adaptation of text messages for promoting healthy eating among Amazonian schoolchildren

OBJECTIVE

To develop text messages for a mHealth intervention promoting healthy eating among Amazonian schoolchildren.

DESIGN

Two rounds of expert panel analysis and formative research interviews.

SETTING

Western Brazilian Amazon, Cruzeiro do Sul, Acre, Brazil.

PARTICIPANTS

Included 17 healthcare professionals and 40 caregivers of school-aged children enrolled in the Maternal and Child Health and Nutrition in Acre birth cohort study.

MAIN OUTCOME MEASURES

Evaluation focused on messages' cultural appropriateness, comprehensibility, and relevance, along with caregivers' understanding and intention to adhere to the recommendations.

ANALYSIS

Quantitative analysis employed the modified Cohen Kappa, the Scale-Content Validity Index Average (S-CVI-Ave), frequency calculations, and a ranking system.

RESULTS

Fifty-five text messages were drafted. In the initial stage, eight messages did not achieve a sufficient score and were subsequently revised and reevaluated, ultimately gaining approval. The S-CVI-Ave for each domain was as follows: cultural appropriateness = 0.97, comprehensibility = 0.96, and relevance = 0.97. Formative research indicated a 92% understanding rate and a 70% intention rate to adhere to the proposed suggestions.

CONCLUSIONS AND IMPLICATIONS

The final set of messages was successfully culturally adapted and will contribute to the translation and dissemination of Dietary Guidelines for Brazilian Population recommendations to Western Amazon families.

Impaired head circumference growth and behavioural problems in childhood: Longitudinal findings from the MINA-Brazil birth cohort

BACKGROUND

Previous evidence on the relation between early head circumference (HC) growth and behavioural outcomes in preschoolers has been inconsistent.

OBJECTIVE

We aimed to investigate whether HC growth from birth to 5 years of age was related to internalising or externalising behavioural problems at 5 years of age in a sex-specific manner.

METHODS

Among 303 girls and 318 boys from the MINA-Brazil birth cohort, we examined the associations between changes in HC from birth to 5 years of age and internalising and externalising behaviour problem scores at 5 years according to the Strengths and Difficulties Questionnaire for parents. HC values were transformed into sex- and age-specific z-scores (HCZ) using World Health Organisation standards, and the differences between values at 5 years of age and birth were classified into quintiles. We estimated adjusted mean differences with 95% confidence intervals in behavioural problem scores between HCZ change quintiles using multivariable linear regression by sex. To examine nonlinear associations, we included cubic spline terms.

RESULTS

Head circumference growth from birth to 5 years of age was inversely and nonlinearly associated with internalising problems in girls. Compared with girls at the lowest quintile of HC growth, those above had an adjusted 1.27 (95% confidence interval 0.28, 2.27) points lower mean internalising problems score. This association was mostly driven by HC growth during the first 2 years. We found no association between HC growth and externalising behaviour in either sex.

CONCLUSIONS

Impaired HC growth was related to higher mean internalising problem scores at 5 years of age in girls but not in boys. HC growth was not associated with externalising problems.

Patterns of complementary feeding introduction and associated factors in a cohort of Brazilian infants

BACKGROUND

Understanding the timing of food introduction in infants is essential for promoting optimal complementary feeding practices. However, existing studies often rely on cross-sectional data, limiting the ability to capture age-specific patterns. We aimed to describe food introduction during the first year of life by identifying patterns related to age at food introduction and associated factors in a cohort of Brazilian infants.

METHODS

Data were collected through standardized questionnaires administered to mothers via face-to-face interviews during the infant's first month of life and at 3, 6, 9, and 12 months of age. Additionally, two telephone interviews were conducted at 2 and 4 months of age. Information regarding food intake was assessed using a list of 48 foods, with two key aspects recorded: whether the food was introduced (yes/no) and the age at introduction. To define food introduction patterns, we employed k-means cluster analysis. Hierarchical Poisson multiple regression was employed to examine the associations between sociodemographic, biological, and healthcare factors and patterns of food introduction.

RESULTS

Three distinct patterns were identified and named according to their main characteristics: Pattern 1 - "Low Infant Formula and Timely CF Introduction"; Pattern 2 - "High Infant Formula and Early CF Introduction"; and Pattern 3 - "High Infant Formula and Later Ultra-processed Food Introduction". Breastfeeding at six months showed a positive association with Pattern 1 (PR = 1.40; 95% CI = 1.10-1.80), while bottle use at four months was negatively associated with Pattern 1 (PR = 0.68; 95% CI = 0.53-0.87). No variables studied exhibited an association with Pattern 2. For Pattern 3, higher prevalences were observed among children whose mothers were aged < 20 years (PR = 1.54; 95% CI = 1.13-2.01) or > 34 years (PR = 1.42; 95% CI = 1.04-1.93). Not receiving guidance on the recommended duration of breastfeeding and complementary feeding during prenatal care was associated with a higher prevalence of children in this pattern (PR = 1.35; 95% CI = 1.01-1.80).

CONCLUSIONS

We identified three distinct patterns of age at food introduction in the study population, although none perfectly aligned with Brazilian or WHO dietary recommendations. These findings underscore the need for targeted interventions to promote timely and healthy complementary feeding practices in Brazilian infants.

The HEALthy Brain and Child Development Study (HBCD) experience: Recruiting and retaining diverse families in a longitudinal, multi-method early childhood study

The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. Given its aim to examine the impact of adversity and protective factors on children's outcomes, the recruitment and retention of families who have a wide diversity in experiences are essential. However, the unfortunate history of inequitable treatment of underrepresented families in research and the risks with which some participants will contend (e.g., substance use) makes their recruitment and retention in social science and neuroscience research particularly challenging. This article explores strategies that the HBCD Study has developed to recruit and retain participants, including marginalized, underserved, and hard-to-reach populations, capitalizing on the extant literature and the researchers' own experiences. In this paper, we address strategies to recruit and retain families within HBCD, including: 1) creating experiences that engender trust and promote relationships; 2) maintaining connections with participants over time; 3) ensuring appropriate compensation and supports; 4) considerations for study materials and procedures; and 5) community engagement. The implementation of these strategies may increase representation and inclusiveness, as well as improve the quality of the resulting data.

Perspectives of healthcare professionals on training for quantitative G6PD testing during implementation of tafenoquine in Brazil (QualiTRuST Study)

Effective radical cure of Plasmodium vivax malaria is essential for malaria elimination in Brazil. P. vivax radical cure requires administration of a schizonticide, such as chloroquine, plus an 8-aminoquinoline. However, 8-aminoquinolines cause hemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, requiring prior screening to exclude those at risk. Brazil is pioneering the implementation of tafenoquine, a single-dose 8-aminoquinoline indicated for P. vivax patients with >70% of normal G6PD activity. Tafenoquine implementation in Manaus and Porto Velho, two municipalities located in the western Brazilian Amazon, included comprehensive training of healthcare professionals (HCPs) on point-of-care quantitative G6PD testing and a new treatment algorithm for P. vivax radical cure incorporating tafenoquine. Training was initially provided to higher-level facilities (phase one) and later adapted for primary care units (phase two). This study analyzed HCP experiences during training and implementation and identified barriers and facilitators. In-depth interviews and focus discussion groups were conducted 30 days after each training for a purposive random sample of 115 HCPs. Thematic analysis was employed using MAXQDA software, analyzing data through inductive and deductive coding. Analysis showed that following the initial training for higher-level facilities, some HCPs did not feel confident performing quantitative G6PD testing and prescribing the tafenoquine regimen. Modifications to the training in phase two resulted in an improvement in understanding the implementation process of the G6PD test and tafenoquine, as well as in the knowledge acquired by HCPs. Additionally, knowledge gaps were addressed through in situ training, peer communication via a messaging app, and educational materials. Training supported effective deployment of the new tools in Manaus and Porto Velho and increased awareness of the need for pharmacovigilance. A training approach for nationwide implementation of these tools was devised. Implementing quantitative G6PD testing and tafenoquine represents a significant shift in P. vivax malaria case management. Consistent engagement with HCPs is needed to overcome challenges in fully integrating these tools within the Brazilian health system.

Hypertensive disorders of pregnancy in Western Brazilian Amazon: Associated factors and neonatal outcomes

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) are responsible for several maternal and fetal complications. This study investigated the occurrence of HDP, associated factors, and neonatal complications in women living in the Western Brazilian Amazon.

METHODS

This is a population-based cross-sectional study with 1521 mother-child pairs enrolled in the Maternal and Child Health and Nutrition in Acre birth cohort (MINA-Brazil study). All parturients with HDP (registered in the medical records) were identified. Crude and adjusted prevalence ratios were calculated in Poisson regression models with robust variance.

RESULTS

The prevalence of HDP was 11.0% (95% CI: 9.5-12.7). Factors associated with the prevalence of HDP were maternal age ≥ 35 years (PR: 1.9; 95% CI: 1.3-3.0), primigravida status (PR: 2.0; 95% CI: 1.5-2.7), pre-pregnancy obesity (PR: 2.7; 95% CI: 1.9-4.0), higher gestational weight gain (highest quartile RP: 2.5; 95% CI: 1.6-3.8), chronic hypertension (RP: 3.6; 95% CI: 2.7-4.9), and diabetes in pregnancy (RP: 1.9; 95% CI: 1.1-3.2). HDP was associated with risk for caesarean delivery (PR: 1.8; 95% CI: 1.6-2.0) and prematurity (PR: 2.0; 95% CI: 1.3-3.2). Gestational malaria was not associated with HDP in Amazonian pregnant women.

CONCLUSIONS

Evaluating risk factors before pregnancy and during the prenatal period is essential for reducing adverse maternal and neonatal outcomes.

Current Approaches to Following Up Women and Newborns After Discharge From Childbirth Facilities: A Scoping Review

INTRODUCTION

The postpartum period is critical for the health and well-being of women and newborns, but there is limited research on the most effective methods of post-childbirth follow-up. This scoping review synthesizes evidence from high-, middle-, and low-income countries on approaches to following up individuals after discharge from childbirth facilities.

METHODS

Using a systematic search in Ovid MEDLINE, we identified quantitative studies describing post-discharge follow-up methods deployed up to 12 months postpartum. We searched for English-language, peer-reviewed articles published between January 1, 2007 and November 2, 2022, with search terms covering 2 broad areas: "postpartum/postnatal period" and "surveillance." We single-screened titles and abstracts and double-extracted all included articles, recording study design and location, population, health outcome, method, timing and frequency of data collection, and percentage of study participants reached.

RESULTS

We identified 1,654 records, of which 31 studies were included. Eight studies used in-person visits to follow up participants, 10 used telephone calls, 7 used self-administered questionnaires, and 6 used multiple methods. Across studies, the minimum length of follow-up was 1 week after delivery, and up to 4 contacts were made within the first year after delivery. Follow-up (response) rates ranged from 23% to100%. Postpartum infection was the most common outcome investigated. Other outcomes included maternal (ill-)health, neonatal (ill-)health and growth, maternal mental health and well-being, care-giving/-seeking behaviors, and knowledge and intentions.

CONCLUSION

Our scoping review identified multiple follow-up methods after discharge, ranging from home visits to self-administered electronic questionnaires, which could be implemented with high response rates. The studies demonstrated that post-discharge follow-up of women and newborns was feasible, well received, and important for identifying postpartum illness or complications that would otherwise be missed. Therefore, the identified methods have the potential to become an important component of fostering a continuum of care and measuring and addressing postpartum morbidity.

Birth-to-childhood tracking of linear growth and weight gain in the MINA-Brazil Study

OBJECTIVE

To investigate birth-to-childhood tracking of linear growth and weight gain across the distribution of length/height and weight for age z-scores and according to household wealth.

METHODS

Data from 614 children from the MINA-Brazil Study with repeated anthropometric measurements at birth and up to age five years were used. Z-scores were calculated for length/height (HAZ) and weight (WAZ) according to international standards. Birth-to-childhood tracking was separately estimated using quantile regression models for HAZ and WAZ, extracting coefficients and 95% confidence intervals (95%CI) at the 25th, 50th, and 75th quantiles. In a subgroup analysis, we estimated tracking between birth and age two years, and between ages two and five years. To investigate disparities in tracking, interaction terms between household wealth indexes (at birth and age five years) and newborn size z-scores were included in the models.

RESULTS

Tracking coefficients were significant and had similar magnitude across the distribution of anthropometric indices at age five years (HAZ, 50th quantile: 0.23, 95%CI: 0.11 to 0.35; WAZ, 50th quantile: 0.31, 95%CI: 0.19 to 0.43). Greater tracking was observed between ages two and five years, with coefficients above 0.82. Significantly higher tracking of linear growth was observed among children from wealthier households, both at birth, at the lower bounds of HAZ distribution (25th quantile: 0.30, 95%CI: 0.13 to 0.56), and during childhood, in the entire HAZ distribution at five years. For weight gain, stronger tracking was observed at the upper bounds of WAZ distribution at age five years among children from wealthier households at birth (75th quantile: 0.59, 95%CI: 0.35 to 0.83) and during childhood (75th quantile: 0.54, 95%CI: 0.15 to 0.93).

CONCLUSION

There was significant tracking of HAZ and WAZ since birth, with indication of substantial stability of nutritional status between ages two and five years. Differential tracking according to household wealth should be considered for planning early interventions for preventing malnutrition.

Prevalence and predictors of breastfeeding in the MINA-Brazil cohort

OBJECTIVE

To describe the prevalence and factors associated with exclusive (EBF) and continued breastfeeding (BF) practices among Amazonian children.

METHODS

Data from 1,143 mother-child pairs recorded on the Maternal and Child Health and Nutrition in Acre (MINA-Brazil) birth cohort were used. Information on EBF and BF was collected after childbirth (July 2015-June 2016) and during the follow-up visits at 1 and 6 months postpartum, 1, 2, and 5 years of age. For longitudinal analysis, the outcomes were EBF and BF duration. Probability of breastfeeding practices were estimated by Kaplan-Meier survival analysis. Associations between baseline predictors variables and outcomes among children born at term were assessed by extended Cox regression models.

RESULTS

EBF frequencies (95% confidence interval [95%CI]) at 3 and 6 months of age were 33% (95%CI: 30.2-36.0) and 10.8% (95%CI: 8.9-12.9), respectively. Adjusted hazard ratio for predictors of early EBF cessation were: being a first-time mother = 1.47 (95%CI: 1.19-1.80), feeding newborns with prelacteals = 1.70 (95%CI: 1.23-2.36), pacifier use in the first week of life = 1.79 (95%CI: 1.44-2.23) or diarrhea in the first two weeks of life = 1.70 (95%CI: 1.15-2.52). Continued BF frequency was 67.9% (95%CI: 64.9-70.8), 29.3% (95%CI: 26.4-32.4), and 1.7% (95%CI: 0.9-2.8) at 1, 2 and 5 years of age, respectively. Adjusted hazard ratio for predictors of early BF cessation were: male sex = 1.23 (95%CI: 1.01-1.49), pacifier use in the first week of life = 4.66 (95%CI: 2.99-7.26), and EBF less than 3 months = 2.76 (95%CI: 1.64-4.66).

CONCLUSIONS

EBF and continued BF duration among Amazonian children is considerably shorter than recommendations from the World Health Organization. Significant predictors of breastfeeding practices should be considered for evaluating local strategies to achieve optimal breastfeeding practices.

Maternal depression and offspring mental health at age 5: MINA-Brazil cohort study

OBJECTIVE

To identify longitudinal patterns of maternal depression between three months and five years after child's birth, to examine predictor variables for these trajectories, and to evaluate whether distinct depression trajectories predict offspring mental health problems at age 5 years.

METHODS

We used data from the Maternal and Child Health and Nutrition in Acre (MINA-Brazil) study, a population-based birth cohort in the Western Brazilian Amazon. Maternal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale (EPDS) at 3 and 6-8 months, and 1 and 2 years after delivery. Mental health problems in 5-year-old children were evaluated with the Strengths and Difficulties Questionnaire (SDQ) reported by parents. Trajectories of maternal depression were calculated using a group-based modelling approach.

RESULTS

We identified four trajectories of maternal depressive symptoms: "low" (67.1%), "increasing" (11.5%), "decreasing" (17.4%), and "high-chronic" (4.0%). Women in the "high/chronic" trajectory were the poorest, least educated, and oldest compared with women in the other trajectory groups. Also, they were more frequently multiparous and reported smoking and having attended fewer prenatal consultations during pregnancy. In the adjusted analyses, the odds ratio of any SDQ disorder was 3.23 (95%CI: 2.00-5.22) and 2.87 (95%CI: 1.09-7.57) times higher among children of mothers belonging to the "increasing" and "high-chronic" trajectory groups, respectively, compared with those of mothers in the "low" depressive symptoms group. These differences were not explained by maternal and child characteristics included in multivariate analyses.

CONCLUSIONS

We identified poorer mental health outcomes for children of mothers assigned to the "chronic/severe" and "increasing" depressive symptoms trajectories. Prevention and treatment initiatives to avoid the adverse short, medium, and long-term effects of maternal depression on offspring development should focus on women belonging to these groups.

Internal consistency of the Strengths and Difficulties Questionnaire in Amazonian children

OBJECTIVE

To describe the frequency of behavioral problems and the internal consistency of the parent version of the Strengths and Difficulties Questionnaire (SDQ-P) in Amazonian preschool children during the covid-19 pandemic.

METHODS

Data from the Maternal and Child Health and Nutrition in Acre (MINA-Brazil) study, a population-based birth cohort in the Western Brazilian Amazon, were used. The SDQ-P was applied in 2021 at the five-year follow-up visit to parents or caregivers of 695 children (49.4% of which were girls). This instrument is a short behavioral screening questionnaire composed of 25 items reorganized into five subscales: emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, and prosocial behavior. Cases of behavioral problems were defined according to the original SDQ cut-offs based on United Kingdom norms. Moreover, cut off points were estimated based on the SDQ-P percentile results of our study sample. Internal consistency was assessed by calculating Cronbach's alpha coefficient and McDonald's omega for each scale.

RESULTS

According to the cut-offs based on our studied population distribution, 10% of all children had high or very high total difficulty scores, whereas it was almost twice when the original SDQ cut-offs based on United Kingdom norms, were applied (18%). Differences were also observed in the other scales. Compared to girls, boys showed higher means of externalizing problem and lower means of prosocial behavior. The five-factor model showed a moderate internal consistency of the items for all scales (0.60 ≤ α ≤ 0.40), except for total difficulty scores, which it considered substantial (α > 0.61).

CONCLUSIONS

Our results support the usefulness of SDQ in our study population and reinforce the need for strategies and policy development for mental health care in early life in the Amazon.

Prevalence and correlates of childhood anemia in the MINA-Brazil birth cohort study

OBJECTIVE

This study aimed to describe the prevalence and predictors of childhood anemia in an Amazonian population-based birth cohort study.

METHODS

Prevalence of maternal anemia was estimated at delivery (hemoglobin [Hb] concentration < 110 g/L) in women participating in the MINA-Brazil birth cohort study and in their children, examined at ages one, two (Hb < 110 g/L), and five (Hb < 115 g/L). Moreover, ferritin, soluble transferrin receptor, and C-reactive protein concentrations were measured in mothers at delivery and in their 1- and 2-year-old children to estimate the prevalence of iron deficiency and its contribution to anemia, while adjusting for potential confounders by multiple Poisson regression analysis (adjusted relative risk [RRa]).

RESULTS

The prevalence 95% confidence interval (CI) of maternal anemia, iron deficiency, and iron-deficiency anemia at delivery were 17.3% (14.0-21.0%), 42.6% (38.0-47.2%), and 8.7% (6.3-11.6)%, respectively (n = 462). At one year of age (n = 646), 42.2% (38.7-45.8%) of the study children were anemic, 38.4% (34.6-42.3%) were iron-deficient, and 26.3 (23.0-29.9) had iron-deficiency anemia. At two years of age (n = 761), these values decreased to 12.8% (10.6-15.2%), 18.1% (15.5-21.1%), and 4.1% (2.8-5.7%), respectively; at five years of age (n = 655), 5.2% (3.6-7.2%) were anemic. Iron deficiency (RRa = 2.19; 95%CI: 1.84-2.60) and consumption of ultra-processed foods (UPF) (RRa = 1.56; 95%CI: 1.14-2.13) were significant contributors to anemia at 1 year, after adjusting for maternal schooling. At 2 years, anemia was significantly associated with maternal anemia at delivery (RRa: 1.67; 95%CI: 1.17-2.39), malaria since birth (2.25; 1.30-3.87), and iron deficiency (2.15; 1.47-3.15), after adjusting for children's age and household wealth index.

CONCLUSIONS

Anemia continues to be highly prevalent during pregnancy and early childhood in the Amazon. Public health policies should address iron deficiency, UPF intake, maternal anemia, and malaria to prevent and treat anemia in Amazonian children.

Adolescent pregnancy in Cruzeiro do Sul, Acre, Brazil: socioeconomic characteristics, prenatal and obstetric care

The present study aimed to investigate the socioeconomic and obstetric characteristics of adolescent mothers and the complications they cause to maternal and neonatal health. This baseline data analysis of the MINA-Brazil birth cohort was conducted in the municipality of Cruzeiro do Sul, state of Acre, Brazil. The chi-square test was used to compare characteristics of adolescent and adult postpartum women, and multiple Poisson regression models with robust variance were used to assess associated factors. Among the postpartum women, 26.2% (95%CI: 24.0-28.4) were adolescents. Factors associated with childbirth in adolescence included: nine years or less of schooling (adjPR:1.36; 95%CI: 1.14-1.61), belongs to the lowest quartiles of the wealth index (1st quartile: adjPR:1.40; 95%CI: 1.08-1.80) (2nd quartile: adjPR:1.37; 95%CI: 1.08-1.74), primigravidae (adjPR:3.69; 95%CI: 2.98-4.57), low pre-pregnancy BMI (adjPR:1.28; CI95%: 1.04-1.57), urinary tract infection during pregnancy (adjPR:1.25; CI95%: 1.07-1.46) and less than six prenatal consultations (adjPR:1.42; 95%CI: 1.21-1.66). Poverty, little schooling, primigravidae, low pre-pregnancy BMI, urinary tract infection during pregnancy and few prenatal consultations were associated with childbirth during adolescence in a municipality in the Northern region of Brazil.

Exposure to ultra-processed foods during pregnancy and ultrasound fetal growth parameters

Periconceptional maternal ultra-processed food (UPF) consumption impairs embryonic growth. Impacts of exposure to UPF on distinct components of fetal growth in late pregnancy are unknown. We investigated the influence of frequency of UPF consumption during pregnancy on fetal head circumference (HC), abdominal circumference (AC) and femur length (FL). This study included 417 live-born singleton pregnancies prospectively followed-up since the antenatal period in the MINA-Brazil Study, with an available ultrasound scan at >24 gestational weeks. Frequency of food groups consumption in the previous month was categorised as no/monthly, weekly or daily. Ultrasound scans were conducted at 27·8 (sd: 1·7) gestational weeks. HC, AC and FL z-scores were calculated for gestational age using the INTERGROWTH-21st Project standards. Simultaneous-quantile regression models were fitted at the 10th, 50th and 90th percentiles of the distribution of each ultrasound parameter according to UPF consumption, with adjustment for potential confounders. Participants were aged on average 24·7 (sd: 6·5) years, 44·8 % were primiparous, and 26·9 % and 24·9 %, respectively, had weekly and daily UPF consumption. Compared with no/monthly intake, daily UPF consumption impaired HC across its distribution, with significant effect sizes varying from -0·24 to -0·40 z-score. Weekly UPF consumption decreased HC at the 90th percentile by -0·39 z-score (95 % CI: -0·78, -0·01) and FL at the 50th percentile by -0·32 z-score (95 % CI: -0·60, -0·04). No association was noted with AC. Frequency of UPF consumption was negatively associated with skeletal components of fetal growth in late pregnancy. Infant body composition may benefit from healthy food practices since pregnancy.

Suboptimal gestational weight gain and neonatal outcomes in low and middle income countries: individual participant data meta-analysis

OBJECTIVE

To estimate the associations between gestational weight gain (GWG) during pregnancy and neonatal outcomes in low and middle income countries.

DESIGN

Individual participant data meta-analysis.

SETTING

Prospective pregnancy studies from 24 low and middle income countries.

MAIN OUTCOME MEASURES

Nine neonatal outcomes related to timing (preterm birth) and anthropometry (weight, length, and head circumference) at birth, stillbirths, and neonatal death.

ANALYSIS METHODS

A systematic search was conducted in PubMed, Embase, and Web of Science which identified 53 prospective pregnancy studies published after the year 2000 with data on GWG, timing and anthropometry at birth, and neonatal mortality. GWG adequacy was defined as the ratio of the observed maternal weight gain over the recommended weight gain based on the Institute of Medicine body mass index specific guidelines, which are derived from data in high income settings, and the INTERGROWTH-21st GWG standards. Study specific estimates, adjusted for confounders, were generated and then pooled using random effects meta-analysis models. Maternal age and body mass index before pregnancy were examined as potential modifiers of the associations between GWG adequacy and neonatal outcomes.

RESULTS

Overall, 55% of participants had severely inadequate (<70%) or moderately inadequate (70% to <90%) GWG, 22% had adequate GWG (90-125%), and 23% had excessive GWG (≥125%). Severely inadequate GWG was associated with a higher risk of low birthweight (adjusted relative risk 1.62, 95% confidence interval 1.51 to 1.72; 48 studies, 93 337 participants; τ2=0.006), small for gestational age (1.44, 1.36 to 1.54; 51 studies, 93 191 participants; τ2=0.016), short for gestational age (1.47, 1.29 to 1.69; 40 studies, 83 827 participants; τ2=0.074), and microcephaly (1.57, 1.31 to 1.88; 31 studies, 80 046 participants; τ2=0.145) compared with adequate GWG. Excessive GWG was associated with a higher risk of preterm birth (1.22, 1.13 to 1.31; 48 studies, 103 762 participants; τ2=0.008), large for gestational age (1.44, 1.33 to 1.57; 47 studies, 90 044 participants; τ2=0.009), and macrosomia (1.52, 1.33 to 1.73; 29 studies, 68 138 participants; τ2=0) compared with adequate GWG. The direction and magnitude of the associations between GWG adequacy and several neonatal outcomes were modified by maternal age and body mass index before pregnancy.

CONCLUSIONS

Inadequate and excessive GWG are associated with a higher risk of adverse neonatal outcomes across settings. Interventions to promote optimal GWG during pregnancy are likely to reduce the burden of adverse neonatal outcomes, however further research is needed to assess optimal ranges of GWG based on data from low and middle income countries.

Improved estimates of foetal growth are associated with perinatal outcomes: A latent modelling approach in a population-based birth cohort

Background

We aimed to estimate latent foetal growth conditions and explore their determinants among maternal characteristics and ultrasound biometric parameters. We additionally investigated the influence of foetal growth conditions on perinatal variables.

Methods

We used data from live-born singletons in the Maternal and Child Health and Nutrition in Acre, Brazil (MINA-Brazil Study) population-based birth cohort. Maternal and perinatal characteristics were assessed in medical records from the maternity hospital and interviews with participants from July 2015 to June 2016. A sub-sample went through ultrasound examinations during the antenatal period, with assessment of foetal head and abdominal circumferences, and femur length. We estimated latent foetal growth conditions with a structural equation modelling framework, informed by the child's birth weight z-scores (BWZ) and birth length z-scores (BLZ) according to gestational age. Odds ratios and 95% confidence intervals (CIs) for the occurrence of perinatal events were estimated according to linear predictions of the latent variable.

Results

We included 1253 participants. Latent foetal growth conditions explained 88.3% of BWZ and 53.7% of BLZ variation. Maternal elevated blood pressure, primiparity, smoking, malaria, and insufficient gestational weight gain negatively impacted foetal growth conditions. In the subsample (n = 499), ultrasound biometric parameters assessed at 28 weeks were positively associated with the latent variable, with the largest contribution from foetal abdominal circumference. Each standardised unit of predicted foetal growth conditions halved the chance for preterm birth (95% CI = 0.26, 0.74) and longer hospital stay (>3 days) (95% CI = 0.28, 0.88). Conversely, BWZ and BLZ were not independently associated with these perinatal variables in separate logistic regression models.

Conclusions

Latent foetal growth conditions jointly encompassing weight gain and linear growth during gestation were negatively influenced by a scenario of dual burden of maternal morbidities, with perinatal implications.

Maternal pre-pregnancy body mass index, gestational weight gain and child weight during the first 2 years of life in an Amazonian birth cohort

BACKGROUND

In socially vulnerable populations, evidence is needed regarding the role of maternal nutritional status on child weight during the first 2 years of life.

OBJECTIVES

We aimed to assess the association of pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with offspring BMI-for-age z-scores (BAZs) during the first 2 years of life.

METHODS

A population-based birth cohort study was conducted with 900 mother-child pairs. Pre-pregnancy weight and weight at delivery were collected from medical records, and anthropometric data were measured at birth and at 6-month, 1-year and 2-year follow-up visits. Linear regression and linear mixed-effect models assessed associations with pre-pregnancy BMI, GWG and BAZ during the first 2 years of life.

RESULTS

Pre-pregnancy overweight and obesity and excessive GWG were positively associated with BAZ at birth and at 1- and 2-year follow-up visits. There were no significant additional BAZ changes per year based on the exposures up to age 2 years.

CONCLUSIONS

Elevated maternal pre-pregnancy BMI and GWG were associated with a child's higher BAZ at birth, and these differences remained constant throughout the first 2 years of life in Amazonian children. These findings highlight the importance of promoting adequate maternal weight before pregnancy and during prenatal care also in socially vulnerable populations.

Risk factors for inadequate and excessive gestational weight gain in 25 low- and middle-income countries: An individual-level participant meta-analysis

BACKGROUND

Many women experience suboptimal gestational weight gain (GWG) in low- and middle-income countries (LMICs), but our understanding of risk factors associated with GWG in these settings is limited. We investigated the relationships between demographic, anthropometric, lifestyle, and clinical factors and GWG in prospectively collected data from LMICs.

METHODS AND FINDINGS

We conducted an individual participant-level meta-analysis of risk factors for GWG outcomes among 138,286 pregnant women with singleton pregnancies in 55 studies (27 randomized controlled trials and 28 prospective cohorts from 25 LMICs). Data sources were identified through PubMed, Embase, and Web of Science searches for articles published from January 2000 to March 2019. Titles and abstracts of articles identified in all databases were independently screened by 2 team members according to the following eligibility criteria: following inclusion criteria: (1) GWG data collection took place in an LMIC; (2) the study was a prospective cohort or randomized trial; (3) study participants were pregnant; and (4) the study was not conducted exclusively among human immunodeficiency virus (HIV)-infected women or women with other health conditions that could limit the generalizability of the results. The Institute of Medicine (IOM) body mass index (BMI)-specific guidelines were used to determine the adequacy of GWG, which we calculated as the ratio of the total observed weight gain over the mean recommended weight gain. Study outcomes included severely inadequate GWG (percent adequacy of GWG <70), inadequate GWG (percent adequacy of GWG <90, inclusive of severely inadequate), and excessive GWG (percent adequacy of GWG >125). Multivariable estimates from each study were pooled using fixed-effects meta-analysis. Study-specific regression models for each risk factor included all other demographic risk factors measured in a particular study as potential confounders, as well as BMI, maternal height, pre-pregnancy smoking, and chronic hypertension. Risk factors occurring during pregnancy were further adjusted for receipt of study intervention (if any) and 3-month calendar period. The INTERGROWTH-21st standard was used to define high and low GWG among normal weight women in a sensitivity analysis. The prevalence of inadequate GWG was 54%, while the prevalence of excessive weight gain was 22%. In multivariable models, factors that were associated with a higher risk of inadequate GWG included short maternal stature (<145 cm), tobacco smoking, and HIV infection. A mid-upper arm circumference (MUAC) of ≥28.1 cm was associated with the largest increase in risk for excessive GWG (risk ratio (RR) 3.02, 95% confidence interval (CI) [2.86, 3.19]). The estimated pooled difference in absolute risk between those with MUAC of ≥28.1 cm compared to those with a MUAC of 24 to 28.09 cm was 5.8% (95% CI 3.1% to 8.4%). Higher levels of education and age <20 years were also associated with an increased risk of excessive GWG. Results using the INTERGROWTH-21st standard among normal weight women were similar but attenuated compared to the results using the IOM guidelines among normal weight women. Limitations of the study's methodology include differences in the availability of risk factors and potential confounders measured in each individual dataset; not all risk factors or potential confounders of interest were available across datasets and data on potential confounders collected across studies.

CONCLUSIONS

Inadequate GWG is a significant public health concern in LMICs. We identified diverse nutritional, behavioral, and clinical risk factors for inadequate GWG, highlighting the need for integrated approaches to optimizing GWG in LMICs. The prevalence of excessive GWG suggests that attention to the emerging burden of excessive GWG in LMICs is also warranted.

Gestational weight gain and breastfeeding practices in relation to offspring body mass index among Amazonian young children

OBJECTIVE

Excessive weight gain during childhood has been considered an early life risk factor for chronic disease in the long term. We examined the role of excessive gestational weight gain (GWG) and breastfeeding (BF) practices with the offspring's body mass index-for-age z-score (zBMI) at 2 years.

METHODS

Data from 743 Amazonian young children of the MINA-Brazil population-based birth cohort study were used. Linear regression models were run to estimate the associations between excessive GWG and BF practices (exclusive breastfeeding, EBF <3 months of age and BF <1 year) with zBMI.

RESULTS

Excessive GWG and BF <1 year were associated with an adjusted 0.24 units (95% CI: 0.08, 0.41) and 0.28 units (95% CI: 0.12, 0.44) higher zBMI at age 2 years, respectively.

CONCLUSIONS

Gain excessive weight during pregnancy and shorter BF duration (<1y) were associated with a higher body mass index at 2 years of age among Brazilian Amazonian children.

Factors associated with incomplete vaccination and negative antibody test results for measles, mumps, and hepatitis A among children followed in the MINA-BRAZIL cohort

Vaccination coverage has been dropping in Brazil and other countries. In addition, immune responses after vaccination may not be homogeneous, varying according to sociodemographic and clinical factors. Understanding the determinants of incomplete vaccination and negative antibody test results may contribute to the development of strategies to improve vaccination effectiveness. In this study, we aimed to investigate the frequency of vaccine adherence, factors associated with incomplete vaccination for measles, mumps, rubella (MMR) and hepatitis A, and factors associated with the seronegative test results for measles, mumps and hepatitis A at 2 years of age. This was a population-based cohort that addressed health conditions and mother/infant nutrition in Cruzeiro do Sul city, Brazil. Vaccination data were obtained from official certificates of immunization. The children underwent blood collection at the two-year-old follow-up visit; the samples were analyzed using commercially available kits to measure seropositivity for measles, mumps, and hepatitis A. We used modified Poisson regression models adjusted for covariates to identify factors associated with incomplete vaccination and negative serology after vaccination. Out of the 825 children included in the study, adherence to the vaccine was 90.6% for MMR, 76.7% for the MMRV (MMR + varicella), and 74.9% for the hepatitis A vaccine. For MMR, after the adjustment for covariates, factors associated with incomplete vaccination included: white-skinned mother; paid maternity leave; raising more than one child; lower number of antenatal consultations; and attending childcare. For hepatitis A, the factors included: white-skinned mother and not having a cohabiting partner. The factors with statistically significant association with a negative antibody test result included: receiving Bolsa Familia allowance for measles and mumps; incomplete vaccination for measles; and vitamin A deficiency for mumps. Strategies to improve the efficiency of vaccine programs are urgently needed. These include improvements in communication about vaccine safety and efficacy, and amplification of access to primary care facilities, prioritizing children exposed to the sociodemographic factors identified in this study. Additionally, sociodemographic factors and vitamin A deficiency may impact the immune responses to vaccines, leading to an increased risk of potentially severe and preventable diseases.

Prolonged breastfeeding, sugar consumption and dental caries at 2 years of age: A birth cohort study

OBJECTIVES

Previous cohort studies have found a positive association between prolonged breastfeeding (≥12 months) on dental caries, but few of them analysed the mediated effect of sugar consumption on this association. This study investigated whether prolonged breastfeeding is a risk factor for caries at 2-year follow-up assessment (21-27 months of age) and whether this effect is mediated by sugar consumption.

METHODS

A birth cohort study was performed in the Brazilian Amazon (n = 800). Dental caries was assessed using the dmf-t index. Prolonged breastfeeding was the main exposure. Data on baseline covariables and sugar consumption at follow-up visits were analysed. We estimated the OR for total causal effect (TCE) and natural indirect effect (NIE) of prolonged breastfeeding on dental caries using the G-formula.

RESULTS

The prevalence of caries was 22.8% (95% CI: 19.8%-25.8%). Children who were breastfed for 12-23 months (TCE = 1.13, 95% CI: 1.05-1.20) and for ≥24 months (TCE = 1.27, 95% CI: 1.14-1.40) presented a higher risk of caries at age of 2 years than those breastfed <12 months. However, this risk was slightly mediated by a decreased frequency of sugar consumption at age of 2 years only for breastfeeding from 12 to 23 months (NIE; OR = 0.95, 95% CI: 0.91-0.97).

CONCLUSIONS

In this study, the effect of prolonged breastfeeding on the increased risk of dental caries was slightly mediated by sugar consumption. Early feeding practices for caries prevention and promoting breastfeeding while avoiding sugar consumption should be targeted in the first 2 years of life.

Precision medicine via the integration of phenotype-genotype information in neonatal genome project

The explosion of next-generation sequencing (NGS) has enabled the widespread use of genomic data in precision medicine. Currently, several neonatal genome projects have emerged to explore the advantages of NGS to diagnose or screen for rare genetic disorders. These projects have made remarkable achievements, but still the genome data could be further explored with the assistance of phenotype collection. In contrast, longitudinal birth cohorts are great examples to record and apply phenotypic information in clinical studies starting at the neonatal period, especially the trajectory analyses for health development or disease progression. It is obvious that efficient integration of genotype and phenotype benefits not only the clinical management of rare genetic disorders but also the risk assessment of complex diseases. Here, we first summarize the recent neonatal genome projects as well as some longitudinal birth cohorts. Then, we propose two simplified strategies by integrating genotypic and phenotypic information in precision medicine based on current studies. Finally, research collaborations, sociological issues, and future perspectives are discussed. How to maximize neonatal genomic information to benefit the pediatric population remains an area in need of more research and effort.

Prolonged Breastfeeding and the Risk of Plasmodium vivax Infection and Clinical Malaria in Early Childhood: A Birth Cohort Study

BACKGROUND

Relatively few Amazonian infants have clinical malaria diagnosed, treated and notified before their first birthday, either because they are little exposed to an infection or remain asymptomatic once infected. Here we measure the proportion of children who have experienced Plasmodium vivax infection and malaria by 2 years of age in the main transmission hotspot of Amazonian Brazil.

METHODS

We measured IgG antibodies to 3 blood-stage P. vivax antigens at the 1- and 2-year follow-up assessment of 435 participants in a population-based birth cohort. Children's malaria case notifications were retrieved from the electronic database of the Ministry of Health. We used multiple Poisson regression models to identify predictors of serologically proven P. vivax infection and clinical vivax malaria during the first 2 years of life.

RESULTS

Overall, 23 [5.3%; 95% confidence interval (CI): 3.5-7.8%) children had antibodies to ≥2 antigens detected during at least one follow-up assessment, consistent with past P. vivax infection(s). Fifteen (3.4%; 95% CI: 2.1-5.6%) children had clinical vivax episodes notified during the first 2 years of life; 7 of them were seronegative. We estimate that half of the infections remained unnotified. Children born to women who experienced P. vivax infection during pregnancy were more likely to be infected and develop clinical vivax malaria, while those breast-fed for ≥12 months had their risk of being P. vivax -seropositive (which we take as evidence of blood-stage P. vivax infection during the first 2 years of life) decreased by 79.8% (95% CI: 69.3-86.7%).

CONCLUSION

P. vivax infections in early childhood are underreported in the Amazon, are associated with anemia at 2 years of age, and appear to be partially prevented by prolonged breastfeeding.

Common mental disorders in pregnancy and postnatal depressive symptoms in the MINA-Brazil study: occurrence and associated factors

OBJECTIVE

To investigate the occurrence and factors associated with common mental disorders in pregnancy and depressive symptoms in postpartum, as well as the association between both in the Brazilian Western Amazon.

METHODS

This is a prospective cohort in the MINA-Brazil study with women who received primary health care in the town of Cruzeiro do Sul, Acre State. We performed two clinical evaluations during pregnancy (the first: 16–20 weeks; the second: 28 gestational weeks) and three postpartum evaluations (at 3, 6 and 12 months), in which demographic and socioeconomic, gestational, lifestyle and clinical data were collected. We used the Self-Reported Questionnaire (score ≥ 8) to screen the gestational common mental disorder and the Edinburgh Postnatal Depression Scale (score ≥ 10) to identify postpartum depressive symptoms. We used adjusted ordinal logistic regression to investigate the relationship between the covariates and the occurrence of common mental disorders in pregnancy and postpartum depressive symptomatology.

RESULTS

A total of 461 women completed the two clinical evaluations in pregnancy; of these, 247 completed the three postpartum evaluations. The occurrence of common mental disorder during pregnancy was 36.2% and 24.5% in the first and second evaluations, respectively, and the cumulative incidence was 9.2%. In addition, 50.3% maintained the disorder between evaluations. During postpartum, approximately 20% of the mothers presented depressive symptoms during the first year of their children’s lives. Parity (≥ 2) was associated with common mental disorders, while low maternal education was associated with postpartum depressive symptoms. Women with a common mental disorder in both evaluations during pregnancy were 5.6 times more likely (95%CI: 2.50–12.60) to develop postpartum depressive symptoms.

CONCLUSION

The occurrence of common mental disorder at any time assessed during pregnancy, but especially its persistence from the second trimester, was strongly associated with depressive symptoms after childbirth. These findings highlight the need for early screening and monitoring of the mental health of pregnant women at the start of prenatal care in order to reduce possible negative impacts on the health of the mother-child binomial caused by such events.

Vitamin D insufficiency, excessive weight gain, and insulin resistance during pregnancy

BACKGROUND AND AIMS

Vitamin D insufficiency has been related to metabolic complications during pregnancy, including insulin resistance. There is evidence that excessive weight gain can negatively influence 25-hydroxyvitamin D (25(OH)D) concentrations. We aimed to investigate the association of vitamin D insufficiency during pregnancy (25(OH)D₃ < 75 nmol/L in the second and third trimesters) with insulin resistance, and explore whether excessive gestational weight gain (GWG) could modify such relationship.

METHODS AND RESULTS

A prospective longitudinal analysis was conducted within the MINA-Brazil Study among 444 pregnant women enrolled in antenatal care and with complete data on 25(OH)D₃, weight gain, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR). Quantile and logistic regression models were conducted with adjustment for sociodemographic, obstetric, and lifestyle characteristics, as well as gestational age and seasonality at outcome assessment. Predicted probabilities for insulin resistance (HOMA-IR>2.71) were estimated according to excessive GWG. Persistent vitamin D insufficiency was associated with increasing insulin concentrations (p for trend = 0.04); pregnant women with vitamin D insufficiency in the second or third trimester had an odds ratio of 1.83 (95% confidence interval (95% CI) = 1.03, 3.27) for insulin resistance, with significant modification by GWG (p = 0.038). Among participants without excessive GWG, the predicted probability for insulin resistance was 0.345 (95% CI = 0.224, 0.467) for those with persistent vitamin D insufficiency, and 0.134 (95% CI = 0.046, 0.221) for those who were sufficient in vitamin D. Probabilities for insulin resistance did not vary according to vitamin D status among participants with excessive GWG.

CONCLUSION

Vitamin D insufficiency was associated with insulin resistance in the third trimester of pregnancy, dependent on excessive GWG.

Associations of Gestational Weight Gain with Perinatal Outcomes in Western Brazilian Amazon

OBJECTIVE

To investigate the association between gestational weight gain (GWG) and perinatal outcomes in pregnant Amazonian women.

METHODS

Data from 1305 mother-child pairs from the MINA-Brazil population-based birth cohort study were used. GWG was classified according to two methods, the Institute of Medicine (IOM) guidelines and INTERGROWTH-21st standards. Poisson and linear regression analyses were conducted to evaluate associations with perinatal outcomes.

RESULTS

Following IOM guidelines (n = 1305), the rates of insufficient and excessive GWG were found to be similar (32%). Excessive GWG was associated with higher new-born birthweight (BW) z-scores; increased risks of macrosomia, large for gestational age (LGA), and caesarean delivery; and lower risks of low birthweight (LBW) and being small for gestational age (SGA). Insufficient GWG was associated with lower new-born BW z-scores. Among women with normal pre-pregnancy body mass indices (BMIs, n = 658), inappropriate GWG was high following both methods (IOM: 41.2% insufficient, 24.8% excessive; INTERGROWTH-21st: 25.2% below - 1 z-score, 16.9% above 1 z-score). Both methods also indicated that new-borns of women with excessive GWG had higher BW z-scores and increased risk of macrosomia and LGA. Women with GWG below the INTERGROWTH-21st standards were more likely to deliver an infant SGA and with lower BW z-scores.

CONCLUSIONS

Inappropriate GWG remains a health concern irrespective of the method used to classify weight gain. GWG above the recommendations of both methods and below the INTERGROWTH-21st standard was associated with adverse perinatal outcomes. Therefore, INTERGROWTH-21st standards seem to be a better fit for healthy women in this population.

SARS-CoV-2 seropositivity and COVID-19 among 5 years-old Amazonian children and their association with poverty and food insecurity

Background

The epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children.

Methodology/Principal findings

We retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Juruá Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2–48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9–8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID-19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4–9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2–2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8–3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and–even more markedly–of having had clinically apparent COVID-19 by the age of 5 years.

Conclusions/Significance

Childhood SARS-CoV-2 infection and COVID-19-associated illness are substantially underdiagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease.

The epidemiology of childhood COVID-19 in the tropics remains a relatively neglected research topic, in part because SARS-CoV-2 typically causes fewer severe illnesses, hospitalizations, and deaths in children than in adults. Here we show that 45% of 660 participants in a birth cohort study in the Brazilian Amazon had SARS-CoV-2 antibodies at the age of 5 years, although only 5% of them reported previously diagnosed COVID-19 episodes–implying that as many as 8 in 9 SARS-CoV-2 infections had remained undiagnosed in these young children. Only 16% of the seropositive children had reportedly experienced cough, shortness of breath, and/or loss of taste or smell. The most socioeconomically vulnerable participants were more likely to have experienced SARS-CoV-2 infection and overt COVID-19 by the age of 5 years. Importantly, children exposed to household food insecurity, which affects 54% of our study participants, had their COVID-19 risk increased by 76%.

Cohort profile: maternal and child health and parenting practices during the COVID-19 pandemic in Ceará, Brazil: birth cohort study (Iracema-COVID)

PURPOSE

Maternal and child health and parenting practices during the COVID-19 pandemic in Ceará (Iracema-COVID) is a longitudinal, prospective population-based birth cohort designed to understand the effects of the pandemic and social withdrawal in maternal mental health, child development and parenting practices of mothers and families.

PARTICIPANTS

A sample of mothers who gave birth in July and August 2020 (n=351) was enrolled in the study in January 2021. Interviews were conducted by telephone. Data were collected through standardised questionnaires that, in addition to sociodemographic and economic data, collected information on breast feeding, mental health status and COVID-19.

FINDINGS TO DATE

Results from the first wave show that the majority of participants have 9-11 years of schooling (54.4%; 95% CI 61.0 to 70.9) and are of mixed race (71.5%; 95% CI 66.5 to 76.0). At the time of the survey, 27.9% of the participants were out of the labor force (95% CI 23.5 to 32.9) and 78.6% reported a decrease in family income after restrictions imposed due to the pandemic (95% CI 74.0 to 82.6). The prevalence of maternal common mental disorder symptoms was 32.5% (95% CI 27.8 to 37.6).

FUTURE PLANS

Follow-up visits are planned to occur every 6 months for the next five years (2021-2025). Additional topics will be included in future waves (eg, food insecurity and parenting practices). Communication strategies for bonding, such as picture cards, pictures of mothers with their children and phone calls to the participants, will be used to minimise attrition. Results of this prospective cohort will generate novel knowledge on the impact of the COVID-19 pandemic on maternal and child health and parenting practices in a population of women and children living in fifth largest city of Brazil.

Predictors of 25-hydroxyvitamin D concentrations during pregnancy: A longitudinal analysis in the Brazilian Amazon

OBJECTIVES

To determine predictors of 25-hydroxyvitamin D₃ (25(OH)D₃) concentrations (25^th, 50^th, and 75^th percentiles) in the third trimester of pregnancy.

SUBJECTS/METHODS

Data on sociodemographic, obstetric, lifestyle and pregnancy characteristics, including serum 25(OH)D₃ and retinol, were collected among 448 pregnant women who participated in the Maternal and Child Health and Nutrition in Acre, Brazil (MINA-Brazil Study) in Cruzeiro do Sul, Brazilian Amazon (latitude 7°S). Simultaneous-quantile regression was fitted to prospectively assess predictors at the 25^th, 50^th and 75^th percentiles of 25(OH)D₃ concentrations.

RESULTS

In the third trimester, 25(OH)D₃ <50 nmol/L was observed in 26% of pregnant women. Exposure to the Amazonian dry season during follow-up and vitamin D status ≥75 nmol/L in the second trimester of pregnancy were positively associated with 25(OH)D₃ concentrations in the third trimester. Pregnant women who were the main providers of family income presented lower 25(OH)D₃ concentrations (50^th and 75^th percentiles: -15 nmol/L, 95%CI -24; -3, p = 0.02, and -22 nmol/L, 95%CI -36; -7, p = 0.004, respectively), as well as those with sustained vitamin A insufficiency (25^th and 50^th percentiles: -27 nmol/L, 95%CI -40; -15, p < 0.001, and -17 nmol/L, 95%CI -33; -1, p = 0.04, respectively). Sun protection practices had a smaller negative impact on 25(OH)D₃, restricted to participants whose concentrations were at the 25^th percentile of the distribution.

CONCLUSIONS

Seasonality and vitamin A status were important predictors of 25(OH)D₃ concentrations in the third trimester. Adequate exposure to sunlight and dietary sources of vitamin A within safe intake levels may help ensuring a good nutritional status of vitamin D during pregnancy.

Consumo de alimentos ultraprocessados e fatores associados no primeiro ano de vida em Cruzeiro do Sul, Acre, Brasil

Resumo O objetivo deste artigo é avaliar o consumo de alimentos ultraprocessados (AUP) e fatores associados no primeiro ano de vida. Trata-se da análise de dados do seguimento de um ano da coorte de nascimentos MINA-Brasil. Foram coletados dados socioeconômicos, demográficos e obstétricos na maternidade e no seguimento de um ano (n = 774), investigando consumo alimentar do dia anterior à entrevista, a fim de avaliar o consumo de AUP. A razão de prevalência (RP) e o intervalo de confianças (IC 95%) para consumo ≥ 3 AUP foram estimados em modelo de regressão múltiplo de Poisson com variância robusta. A prevalência de consumo ≥ 1 AUP foi 87,5%; e ≥ 3 AUP de 40,5%, estando associado a: menor escolaridade materna (≤ 9 anos [RP: 1,97 IC 95% 1,38; 2,80] e entre 10-12 anos [RP: 1,58, IC 95% 1,13; 2,20) comparados com > 12 anos de escolaridade, índice de riqueza abaixo da média (RP: 1,26, IC 95% 1,04; 1,53) e ter mãe adolescente (RP: 1,28, IC 95% 1,06; 1,55). A ausência de diversidade da dieta foi inversamente associada ao desfecho (RP: 0,65, IC 95% 0,51; 0,81). O consumo ≥ 3 AUP se associou às características maternas de menores escolaridade, índice de riqueza e idade materna, e a diversidade da dieta ao maior consumo de AUP.

Mulheres Comem, Mães Cozinham: uma aproximação da construção da maternidade e das práticas culinárias domésticas na Amazônia Ocidental Brasileira

Resumo Este artigo objetiva descrever e discutir as maneiras como a maternidade é praticada e representada nas práticas culinárias domésticas das mulheres na Amazônia ocidental brasileira. Desenvolvemos um estudo qualitativo descritivo, conduzimos entrevistas em profundidade com 16 mulheres que eram mães e que cozinhavam em domicílio. Os dados foram analisados identificando as unidades de significância regulares, expressivas e significativas coletadas por meio das entrevistas. Essas mulheres, quando não tinham filhos, realizavam práticas culinárias atendendo suas demandas pessoais e horários do trabalho extradomiciliar. A partir da gestação, porém mais marcadamente após o parto, as mulheres modificam suas práticas culinárias se apropriando das ideias hegemônicas pré-construídas do que é ser uma mãe, desenvolvendo atividades culinárias mais rotineiras, não discricionárias, focadas no cuidado dos membros da família e com maior investimento de tempo e esforço. Estas mudanças reforçam a concepção de que a relação mãe e criança deve estar orientada para uma maternidade intensiva.

Food Classifications by Brazilian Amazon Mothers: Interactions With Eating Practices

OBJECTIVE

To assess how mothers classify foods and how their eating practices interact with these classifications, with special attention to meanings and uses given to ultra-processed foods.

DESIGN

Qualitative research with in-depth interviews and pile sorts.

SETTING

Urban Brazilian Amazon.

PARTICIPANTS

A sample of 34 mothers were selected through theoretical sampling.

ANALYSIS

Content analysis for in-depth interviews and multidimensional scaling and cluster analysis for pile sorts.

PHENOMENON OF INTEREST

Food classification.

RESULTS

Classifications were based on context (ie, a time or a situation in which the food is eaten) and foods' healthiness. Five food groupings based on mothers' classifications were defined: (1) main meal foods, (2) fruits and fruit juices, (3) convenient foods, (4) leisure foods, and (5) canned sardines. Ultra-processed foods were classified differently from non-ultra-processed foods and considered unhealthy, consumed on special occasions or when there was no time or desire to cook.

CONCLUSIONS AND IMPLICATIONS

Results highlight the potential of incorporating context-based categories and personal experiences to guide nutrition interventions and the potential of pile sorts to tailor messages to target populations.

Low-level Plasmodium vivax exposure, maternal antibodies, and anemia in early childhood: Population-based birth cohort study in Amazonian Brazil

Background

Malaria causes significant morbidity and mortality in children under 5 years of age in sub-Saharan Africa and the Asia-Pacific region. Neonates and young infants remain relatively protected from clinical disease and the transplacental transfer of maternal antibodies is hypothesized as one of the protective factors. The adverse health effects of Plasmodium vivax malaria in early childhood–traditionally viewed as a benign infection–remain largely neglected in relatively low-endemicity settings across the Amazon.

Methodology/Principal findings

Overall, 1,539 children participating in a birth cohort study in the main transmission hotspot of Amazonian Brazil had a questionnaire administered, and blood sampled at the two-year follow-up visit. Only 7.1% of them experienced malaria confirmed by microscopy during their first 2 years of life– 89.1% of the infections were caused by P. vivax. Young infants appear to be little exposed to, or largely protected from infection, but children >12 months of age become as vulnerable to vivax malaria as their mothers. Few (1.4%) children experienced ≥4 infections during the 2-year follow-up, accounting for 43.4% of the overall malaria burden among study participants. Antenatal malaria diagnosed by microscopy during pregnancy or by PCR at delivery emerged as a significant correlate of subsequent risk of P. vivax infection in the offspring (incidence rate ratio, 2.58; P = 0.002), after adjusting for local transmission intensity. Anti-P. vivax antibodies measured at delivery do not protect mothers from subsequent malaria; whether maternal antibodies transferred to the fetus reduce early malaria risk in children remains undetermined. Finally, recent and repeated vivax malaria episodes in early childhood are associated with increased risk of anemia at the age of 2 years in this relatively low-endemicity setting.

Conclusions/Significance

Antenatal infection increases the risk of vivax malaria in the offspring and repeated childhood P. vivax infections are associated with anemia at the age of 2 years.

Plasmodium vivax malaria causes frequent hospital admissions of infants and toddlers in areas of intense transmission in the Asia-Pacific region, often due to severe anemia, but its epidemiology and burden have been understudied in children from other endemic settings. Here we characterize the cumulative impact of P. vivax infections in infants and toddlers exposed to relatively low levels of malaria transmission in the Brazilian Amazon. We have previously shown that vivax malaria in pregnancy is associated with increased risk of maternal anemia and impaired fetal growth in this population. Now we show that the adverse effects of malaria extend to early childhood. Children born to mothers who had one or more infections during pregnancy are at an elevated risk of P. vivax malaria in their early life, although the transfer of maternal antibodies to the fetus may provide some short-term protection. Children who are repeatedly infected with P. vivax since birth are more likely to be anemic at the age of 2 years. These findings further challenge the traditional view of vivax malaria as a relatively benign infection in pregnancy and early childhood in the Amazon.

Factors associated with breastfeeding in the first year of life in Cruzeiro do Sul, Acre

Abstract Objectives: to investigate the factors associated with continued breastfeeding (BF). Methods: All the parturients at a local maternity from July 2015 to June 2016 were invited to participate in a cohort study in Cruzeiro do Sul, Acre. Data on socioeconomic, demographic, obstetric and neonatal of the babies were obtained for the interview. Multiple Poisson regression models with robust variance were used to estimate the prevalence ratio (PR) and 95% confidence intervals (95%CI). Results: among the 1551 mothers contacted, 305 lived in the rural area, leaving 1,246 eligible mothers living in urban area. For the 1-year cohort follow-up, 74 non-twin babies were assessed. Most of the mothers reported to have mixed skin color (79%), are over 21 years old (72°%o), more than 10 years of schooling (72%>) and with unpaying job (54%). The children’s age ranged from 10 to 15 months. The frequency of continued breastfeeding was 69,4%> (95%oCI=66.0-72.6). The factors negatively associated with continued breastfeeding were the use of bottle feeding (PR=1.44; CI95%> =1,33-1.56) and pacifier (PR=2.54; CI95%> =1.98-3.27), after adjusting for maternal age and socioeconomic variables. Conclusion: the frequency of continued breastfeeding in Cruzeiro do Sul was higher than the national estimates, but below the WHO recommendations for breastfeeding up to two years of age.

Prenatal care and preterm birth in the Western Brazilian Amazon: A population-based study

Brazil is among the top ten countries in preterm delivery worldwide. This study assesses the factors associated with preterm birth in the Western Brazilian Amazon. A population-based cross-sectional study was held between July 2015 to June 2016 in Cruzeiro do Sul, Brazilian Amazon. A total of 1525 births were included in this analysis. Preterm birth was defined as births at gestational age < 37 weeks. A stepwise multiple logistic regression was used to identify factors associated with preterm delivery. The prevalence rate of preterm birth was 7.9% (n = 120; 95% CI: 6.5-9.3). After adjusting for confounding factors, a positive association with preterm birth was observed for pregnant women who completed less than six antenatal care visits (OR: 2.93; 95% CI: 1.89-4.56), who had a birth interval of < 18 months (OR: 2.65; 95% CI: 1.04-6.75), and who experienced bleeding (OR: 2.17; 95% CI: 1.39-3.38) and hypertension during pregnancy (OR: 1.74; 95% CI: 1.07-2.82). Factors associated with preterm birth in the Western Brazilian Amazon were mostly related to the aspects of health care provided to women, and thus could be prevented. Proper, timely, and regular antenatal care visits can help reduce adverse outcomes, such as hypertension and bleeding.

Agreement between antenatal gestational age by ultrasound and clinical records at birth: A prospective cohort in the Brazilian Amazon

This study aimed to assess agreement between antenatal estimates of gestational age by ultrasound and clinical records at birth in the Brazilian Amazon. Ultrasound examinations were scheduled during the second trimester for 578 pregnant women prospectively screened at primary health care units, following a standardized protocol for image quality control. A multistage algorithm was used to assess the best estimate of gestational age during the antenatal period, considering reliability of last menstrual period (LMP) and acceptable differences in relation to ultrasound estimates derived from fetal biparietal diameter and femur length. Agreement of antenatal estimates of gestational age confirmed by ultrasound and clinical records at birth was analyzed with Bland-Altman plots and kappa coefficients (preterm and postterm births). Overall, ultrasound examinations presented high quality (>90% of satisfactory images), and were adopted as the best estimate of gestational age among 83.4% of pregnant women, confirming reliable LMP in the remaining proportion. On average, difference in gestational age between antenatal estimates and clinical records was 0.43 week (95% CI: 0.32, 0.53). Classification of preterm births had a good agreement (kappa: 0.82, p<0.001), but a poor performance was observed for postterm births (kappa: -0.06, p = 0.92). Higher differences in gestational age were noted for participants with >11 years of education and cases of caesarean deliveries. In conclusion, high-quality ultrasound images from the second trimester of pregnancy based the assessment of gestational age, while reliability of LMP was limited. Information from clinical records at birth presented an acceptable agreement on average and for classification of preterm births, which is relevant for properly interpreting perinatal outcomes. Discrepancies in caesarean deliveries may warrant further investigation.