Determinants of gestational night blindness in pregnant women from Rio de Janeiro, Brazil

Prevalence of iron deficiency anemia in Brazilian women of childbearing age: a systematic review with meta-analysis

BACKGROUND

Iron deficiency anemia (IDA) is among the most common micronutrient deficiencies in women of childbearing age and may affect children's development. Brazil has several national programs to tackle this condition, such as food fortification and supplementation for pregnant women, but IDA prevalence in this population has not been systematically reviewed. We sought to determine the prevalence of IDA in Brazilian women of childbearing age through a systematic review with metanalysis.

METHODOLOGY

A protocol was previously published on the PROSPERO platform under the code CRD42020200960. A panel of the National Council for Scientific and Technological Development (CNPq) approved the protocol of this study under the public call number 26/2019. The main databases searched were MEDLINE, Web of Science, Scopus, Lilacs, and SciELO. In gray literature, the Brazilian Digital Library of Theses and Dissertations and the annals of the Brazilian Congress of Epidemiology and the Brazilian Congress of Public Health were accessed. The search strategy involved terms related to the condition (IDA) and the age group of the population of interest (teenagers and adults). Studies that had assessed the prevalence of IDA in Brazilian women of childbearing age (10-49 years) were included. Three independent reviewers read all titles and abstracts and extracted data from the included studies. Random effects meta-analyses using the Freeman-Tukey arcsine transformation were carried out with prevalence data, and meta-regression was conducted to test for subgroup differences. The quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

From 21,210 unique records screened, 237 full-texts were retrieved, of which 91 were included in the qualitative synthesis, and 83 were included in the meta-analysis. The overall IDA prevalence was 25% (95% CI [23-28], 83 studies). The subgroup of studies that used random sampling showed a prevalence of 22% (95% CI [17-27], 22 studies), whereas in those with non-random sampling, the prevalence was 27% (95% CI [23-30], 61 studies), without significant differences between subgroups in the metaregression (P = 0.13). High prevalence of IDA were found in the subgroups of studies conducted in the North and Northeast regions (30%; 95% CI [24-37]; seven studies, and 30%; 95% CI [26-34]; 27 studies, respectively), in studies conducted with indigenous population (53%; 95% CI [27-78], four studies), and with studies that had their collections after 2015 (28%; 95% CI [23-34], nine studies).

CONCLUSIONS

IDA in women of childbearing age remains a public health problem in Brazil, especially in the North and Northeast region. The national programs should be strengthened and more thoroughly supervised to decrease this condition nationally.

High prevalence of gestational night blindness and maternal anemia in a population-based survey of Brazilian Amazonian postpartum women

Nutrition during pregnancy is one of the key elements to good maternal and child health, as well as to lifetime landmarks. However, many pregnant women go undernourished in less developed settings. The purpose of this study was to estimate the prevalence and factors associated with gestational night blindness (GXN) and maternal anemia in a cross-sectional population-based study in Cruzeiro do Sul, Acre State, Western Brazilian Amazon. All women living in the municipality admitted at the only maternity-hospital in the city to delivery of a singleton infant were eligible to this study (n = 1,525). Recruitment of participants took place between July 2015 to June 2016. GXN was assessed in the postpartum period by WHO standardized interview. Maternal anemia was defined as hemoglobin at delivery < 110.0 g/L. We estimated prevalence rates and adjusted prevalence ratios (aPR), alongside 95% confidence intervals (95% CI), of the factors associated with the outcomes through multiple Poisson regression models with robust variance. Alarming prevalence of GXN (11.5%; 95% CI, 9.97-13.25) and maternal anemia (39.4%; 95% CI, 36.84-41.95) were found. Factors associated with GXN were (aPR; 95% CI): ≥ 5 residents in the household (2.06; 1.24-3.41), smoking during pregnancy (1.78; 1.15-2.78), and attending < 6 antenatal care visits (1.61; 1.08-2.40). Factors associated with maternal anemia were (aPR; 95% CI): maternal age < 19 years (1.18; 1.01-1.38), gestational malaria (1.22; 1.01-1.49), not taking micronutrient supplements during pregnancy (1.27; 1.01-1.62), and attending < 6 antenatal care visits (1.40; 1.15-1.70). High prevalence rates of GXN and maternal anemia in these postpartum women may reflect poor assistance during antenatal care, underlying the importance of rethinking current protocols related to nutrition in pregnancy.

Vitamin A and Pregnancy: A Narrative Review

Vitamin A is a crucial micronutrient for pregnant women and their fetuses. In addition to being essential for morphological and functional development and for ocular integrity, vitamin A exerts systemic effects on several fetal organs and on the fetal skeleton. Vitamin A requirements during pregnancy are therefore greater. Vitamin A deficiency (VAD) remains the leading cause of preventable blindness in the world. VAD in pregnant women is a public health issue in most developing countries. In contrast, in some developed countries, excessive vitamin A intake during pregnancy can be a concern since, when in excess, this micronutrient may exert teratogenic effects in the first 60 days following conception. Routine prenatal vitamin A supplementation for the prevention of maternal and infant morbidity and mortality is not recommended; however, in regions where VAD is a public health issue, vitamin A supplementation is recommended to prevent night blindness. Given the importance of this topic and the lack of a complete, up-to-date review on vitamin A and pregnancy, an extensive review of the literature was conducted to identify conflicting or incomplete data on the topic as well as any gaps in existing data.

Predictors of vitamin A status among pregnant women in Western Brazilian Amazon

Determining the predictors of serum retinol at mid-pregnancy is relevant for planning interventions aimed at improving vitamin A status of pregnant women and their offspring. This prospective study assessed predictors of serum retinol at the beginning of the third trimester of pregnancy. We enrolled 442 pregnant women living in the urban area of Cruzeiro do Sul, Western Brazilian Amazon. Demographic, socio-economic, environmental and clinical characteristics as well as obstetric history, anthropometric, dietary and biochemical data, including serum retinol, were gathered between 16 and 20 gestational weeks. Serum retinol also measured at the beginning of the third trimester of pregnancy (approximately 28 gestational weeks) was the outcome of interest. Multiple linear regression models were used to evaluate associations with the outcome. Overall, the following variables explained serum retinol at the beginning of the third trimester of pregnancy in the adjusted model (R 2 = 11·1 %): seasonality (winter season - November to April; β=0·134; 95 % CI 0·063, 0·206), weekly consumption of Amazonian fruits (β=0·087; 95 % CI 0·012, 0·162) and retinol concentrations between 16 and 20 gestational weeks (β=0·045; 95 % CI 0·016, 0·074) were positively associated, whereas having a smoker in the house was negatively associated (β=-0·087; 95 % CI: -0·166, -0·009). Consumption of pro-vitamin A-rich fruits by pregnant women should be encouraged. Passive smoking may play a role in decreasing vitamin A status as a proxy of smoking exposure during pregnancy.

The Prevalence of Vitamin A Deficiency and Associated Factors in Pregnant Women Receiving Prenatal Care at a Reference Maternity Hospital in Northeastern Brazil

Vitamin A is essential for mother and child; however, vitamin A deficiency (VAD) remains a public health issue in various countries, affecting around 19 million pregnant women. In Brazil, the scarcity and inconsistency of data have prevented the prevalence and epidemiological status of VAD from being established. This study aimed to analyze vitamin A nutritional status in women receiving prenatal care at a reference center in northeastern Brazil. A cross-sectional study was conducted with a sample of 676 women. Serum retinol was measured by high-performance liquid chromatography. Subclinical infection was detected by measuring C-reactive protein (CRP). The World Health Organization criteria were used in the prevalence analysis, VAD classification level, and CRP effect evaluation. The prevalence of VAD (serum retinol <0.70 μmol/L) was 6.2% (95% confidence interval 4.5–8.3). In the univariate analysis, the variables significantly associated with VAD (p < 0.05) were having <12 years of schooling, being in the third trimester of pregnancy, and anemia. In the final multivariate model, the variables that remained significantly associated (p < 0.05) were being in the third trimester of pregnancy and anemia. VAD constituted a mild public health problem in this sample of pregnant women and was associated with the third trimester of pregnancy and maternal anemia.

Roux-en-Y Gastric Bypass Aggravates Vitamin A Deficiency in the Mother-Child Group

OBJECTIVE

The objectives of this study are to compare the nutritional status of vitamin A in women who previously underwent Roux-en-Y gastric bypass (RYGB) who became pregnant or did not, in the same period after surgery, and to assess its effects on mother and child health.

METHODOLOGY

A retrospective longitudinal study conducted with women who previously underwent RYGB, paired by age and BMI measured before surgery, divided into group 1 (G1) comprising 77 women who did not become pregnant and group 2 (G2) with 39 women in their third gestational trimester. Both groups were assessed before surgery (T0) and in the same interval after surgery: less than or equal to 1 year (T1) or over 1 year (T2), during a maximum of 2 years. Serum concentrations of retinol and β-carotene, night blindness (NB), and gestational and neonatal complications were investigated [urinary tract infection, iron deficiency anemia, hypertensive syndrome of pregnancy, dumping syndrome, birth weight, gestational age at birth (GAB), and correlation between weight and GAB]. Data were analyzed by the Statistical Package for Social Sciences 21.0 (p < 0.05).

RESULTS

RYGB reduced the serum levels of retinol and β-carotene, especially before the first postsurgical year. When associated with pregnancy, inadequacy rate was 55% higher in T1 and T2. Comparing G1 to G2, we noted that pregnancy in women undergoing RYGB can contribute to increased inadequacy of retinol and β-carotene, reaching a higher percentage of women with NB after 1 postsurgical year. High prevalence of pregnancy/neonatal complications was found in T1 and T2. NB was correlated with inadequacy of β-carotene.

CONCLUSION

Pregnancy after RYGB aggravates vitamin A deficiency, increases the percentage of NB cases, and can contribute to pregnancy and neonatal complications even in 1 postsurgical year.