Prenatal exposure to aluminum and status of selected essential trace elements in rural South African women at delivery

International Journal of Environmental Research and Public Health, Volume 15, No. 7, Year 2018

Interprétation

This study sought to evaluate the in utero exposure to aluminum and status of selected trace elements in South African women at delivery since aluminum is known to be toxic in all developmental stages even at low concentrations. Serum aluminum was negatively correlated with aluminum in urine, both uncorrected and corrected for creatinine, which suggests the retention of aluminum in body stores. Serum copper and zinc levels were found to be high in this study population. Serum copper levels were negatively correlated with aluminum in serum (β = −0.095; p = 0.05). There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood (β = −0.087; p = 0.08). Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates. There were a number of positive correlations between maternal characteristics and birth outcomes. Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden since their serum aluminum levels were found to be significantly lower. The findings of the current study can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations. This cross-sectional study took place in four rural sites situated along the coastal regions of South Africa. The study participants were women admitted for delivery at the local maternity sections at local public hospitals. Women were informed about the study by admitting medical personnel on duty and given an information sheet about the study. Women who agreed to participate in the study signed an informed consent form and agreed to donate blood and urine samples before delivery. Participants agreed to answer a socio-demographic questionnaire by interview and consented to access and use of hospital birth outcome data (including maternal characteristics and neonate characteristics such as weight, length, and head circumference, gestational age, Apgar score), as well as birth complications, if any, for research purposes. The participation rate was high with 96% of approached women agreeing to take part in our study. In total, samples of blood and urine were collected from 450 women. Participation in the study was voluntary, confidentiality was assured, and participants were informed that they could withdraw from the study at any time. From each pregnant woman participating in the study, two samples of venous blood were collected using the Venoject sterile system and BD collection tubes. The process included one sample into (10 mL) EDTA-containing BD Vacutainer tube for whole blood analyses and one sample into a non-additive tube for serum analyses. The serum tubes were centrifuged and the serum was transferred to acid-washed polypropylene tubes using acid-washed plastic pipettes. For the collection of blood samples, non-powder gloves were used when handling and collecting samples. Midstream urine was collected into (30 mL) polypropylene acid-washed containers and, thereafter, decanted into polypropylene acid-washed tubes. The plastic containers had no metal caps or glued inserts and were not colored due to the metals found in dyes. All precautions to eliminate and prevent contamination at collection and sample preparation were applied throughout. Samples of collected whole blood, serum (post-centrifugation), and urine were stored at −20 °C and couriered in a frozen state to the National Institute for Occupational Health (NIOH) laboratory, Johannesburg, South Africa for analysis. The NIOH participates in a proficiency testing scheme for whole blood and urine. For the measurement of Al, Cu, and Zn in serum, 0.5 mL volumes of serum samples, internal standard solution containing 45Sc, 72Ge, (50 μL), 65% ultrapure nitric acid (50 μL) and ultra-pure water (4.4 mL) were pipetted into a polypropylene tube. The diluted serum samples were analyzed for element content using an Agilent 7500ce Inductively Coupled Plasma Mass Spectrometer (ICP-MS) with an Octopole Reaction System. The instrument was calibrated with calibration standards prepared using SeronormTM Trace Elements in serum (Sero Ltd., Billingstad, Norway) for matrix matching. For 27Al, 45Sc was used as the internal standard and analysis was performed in the no gas acquisition mode. 63Cu and 66Zn were measured in the helium gas mode with 72Ge used as the internal standard. Aliquots of each sample were analyzed in triplicate. The detection limits for Al, Cu, and Zn were 0.17 μg/L, 0.50 μg/L, and 0.40 μg/L, respectively. SeronormTM Trace Elements in serum (Sero Ltd., Billingstad, Norway) were analyzed with every analytical run in intervals of 10 samples for quality assurance of all element measurements. For the Se assay, samples were diluted three-fold with equal amounts of a diluent solution (1.35% sodium chloride and 0.017% ammonium dihydrogen phosphate) and a palladium modifier solution (60% palladium 2000 mg/L in 0.5% Triton X-100). Se in serum measurements were carried out on a Thermo Scientific (Waltham, MA, USA) iCE3000 series spectrometer with graphite furnace and autosampler. A Se calibration curve was prepared by dilution of a 10 mg/L Se working stock solution so that the concentration ranged from 50 μg/L to 200 μg/L. ClinCheck serum control for trace elements level 1 and 2 were analyzed immediately after calibration and after every six samples for quality assurance of the Se determination. The detection limit for Se in serum was 6.5 μg/L. For the measurement of Mn in whole blood, 0.5 mL of the blood sample was pipetted into a polypropylene digestion tube, which is followed by the addition of 65% ultrapure nitric acid (1 mL). The mixture was digested at 90 °C for 2 h. Once cooled, 70 µL internal standard solution containing 45Sc was added and further diluted with ultrapure water to a final volume of 7 mL. The digested blood samples were analyzed using an Agilent 7500ce (ICP-MS) with an Octopole Reaction System. The instrument was calibrated with calibration standards prepared using SeronormTM Trace Elements in whole blood level 1 for matrix matching. The analysis was performed in a helium acquisition mode. Aliquots of each sample were analyzed in triplicate. The detection limit for Mn was 0.07 μg/L. Two certified reference controls known as SeronormTM Trace Elements in whole blood levels 1 and 2 (Sero Ltd., Billingstad, Norway) were analyzed with every analytical run in intervals of 10 samples for quality assurance of all element measurements. Urine samples (1 mL volumes) were acidified with 0.1 mL of 65% ultrapure nitric acid (Fluka, Munich, Germany). An internal standard solution containing 72Ge was added (50 μL) to all samples, reagent blanks, reference controls, blank urine collection tubes, and calibration standards. The measured solution held 5 mL (5 times sample dilution) with deionized water. Urinary Al levels were measured in the no gas acquisition mode. The percentage recovery, when using certified controls (Lyphochek level 1 and 2), was 95.1% and 97.6% for level 1 and 2, respectively. The detection limits for urinary Al was 1.71 (SD 0.41) μg/L. The creatinine concentration in urine samples was determined by using the Jaffé rate method and an automated Roche Cobas 111 analyzer. Urine samples were dispensed into the Cobas cups, which were automatically injected in a reaction cell containing an alkaline picrate solution (Cobas 111 creatinine Jaffé CREJ2 reagent 1 and 2). The sample combined with the reagent to produce a yellow-orange colored complex (alkaline-picrate creatinine complex), which is directly proportional to the creatinine concentration in the sample. The Cobas Calibrator for automated systems, Ref 10759300, was used for the assay. Certified controls, ‘Liquichek Urine Chemistry Control’, level 1 and 2 (Bio-Rad, Hercules, California, USA) were run before and after every 20 samples. Covariate information was obtained during the questionnaire-based interview and from medical records. Maternal weight and height were recorded at the hospital on admission. From the medical records, the neonate characteristics retrieved include birth weight (g), birth length (cm), head circumference (cm), and gestational age (weeks). Pre-term labor was defined as mothers giving birth at less than 37 weeks of gestational age. Education was categorized as no education to completed primary school, completed secondary school, and any level of tertiary education attained. Maternal tobacco smoking during pregnancy was defined as yes or no. Exposure to environmental tobacco smoke (ETS) was defined as exposure to tobacco smoke from smoking by others in the household. A binary classification was used for exposure to indoor smoke from the burning of fossil fuel (wood and coal) for the purpose of heating or cooking as well as separating study participants into those exposed to fossil fuel and those not exposed (for example, those using electricity). Dietary questions relating to the intake of proteins, carbohydrates, dairy products, tea, coffee, bottled water, fruits, and vine, root and leafy vegetables were assessed and classified as daily, at least once a week, and seldom (both for pre-pregnancy and during pregnancy). The statistical analyses were performed using STATA (StataCorp, 2013. Stata Statistical Software: Release 13. College Station, TX, USA: StataCorp LP). Al was detected in all serum and urine samples. Bivariate analyses between maternal serum Al exposure and covariates were evaluated by using the Spearman’s correlation coefficient. The distribution of maternal serum Al was skewed and was square-root-transformed after exploring the best fit for transformation. Multivariate linear regression was carried out using a backward deletion approach by starting with a full model of factors significantly associated with natural square-root-transformed maternal serum Al levels in the univariate analysis. All statistical tests were two-tailed and statistical significance was set at p < 0.05. The work was carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki). Ethics approval for the study was obtained from the Human Research Ethics Committee of the University of Witwatersrand in Johannesburg (Protocol no. {"type":"entrez-nucleotide","attrs":{"text":"M10742","term_id":"147973","term_text":"M10742"}}M10742), and from the relevant provincial Departments of Health. In addition, CEOs of the respective hospitals had to confirm that he/she allowed the research work to proceed. Identical procedures were followed in terms of obtaining consent from participants. Confidentiality was maintained by assigning identification numbers to all study participants. During the informed consent process, it was emphasized that participation was voluntary and could be withdrawn at any time.

Résumé de l’IA

Study Justification:

– The study aimed to evaluate the prenatal exposure to aluminum and the status of selected trace elements in South African women at delivery.
– Aluminum is known to be toxic, even at low concentrations, in all developmental stages.
– The study provides important information on the retention of aluminum in body stores and its potential effects on maternal and neonatal health.
– The findings can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations.

Study Highlights:

– Serum aluminum was negatively correlated with aluminum in urine, suggesting the retention of aluminum in body stores.
– Serum copper and zinc levels were found to be high in the study population.
– Serum copper levels were negatively correlated with aluminum in serum.
– There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood.
– Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates.
– Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden.

Study Recommendations:

– Further research should be conducted to investigate the long-term effects of aluminum exposure on maternal and neonatal health.
– Future studies should explore the mechanisms of aluminum retention in body stores and its potential impact on trace element status.
– Interventions should be developed to reduce aluminum exposure in vulnerable populations, particularly through dietary modifications.

Key Role Players:

– Researchers and scientists specializing in environmental health and toxicology.
– Medical personnel and staff at local public hospitals.
– Ethical review boards and committees.
– National Institute for Occupational Health (NIOH) laboratory in Johannesburg, South Africa.

Cost Items for Planning Recommendations:

– Research funding for conducting further studies and interventions.
– Laboratory equipment and supplies for sample collection and analysis.
– Personnel costs for researchers, scientists, and medical staff.
– Ethical review and approval fees.
– Transportation and courier costs for sample transportation.
– Data management and analysis software.
– Publication and dissemination costs.

Force de la preuve

The strength of evidence for this abstract is 7 out of 10.
The evidence in the abstract is moderately strong, but there are some areas for improvement. The study design is a cross-sectional study, which limits the ability to establish causality. Additionally, the sample size of 450 women is relatively small, which may affect the generalizability of the findings. To improve the strength of the evidence, future research could consider using a longitudinal design to better assess the relationship between prenatal aluminum exposure and trace element status. Increasing the sample size and including a more diverse population would also enhance the generalizability of the results. Furthermore, conducting additional statistical analyses, such as regression models adjusting for potential confounders, would provide a more robust assessment of the associations between aluminum exposure, trace element levels, and birth outcomes.

Abstrait

This cross-sectional study took place in four rural sites situated along the coastal regions of South Africa. The study participants were women admitted for delivery at the local maternity sections at local public hospitals. Women were informed about the study by admitting medical personnel on duty and given an information sheet about the study. Women who agreed to participate in the study signed an informed consent form and agreed to donate blood and urine samples before delivery. Participants agreed to answer a socio-demographic questionnaire by interview and consented to access and use of hospital birth outcome data (including maternal characteristics and neonate characteristics such as weight, length, and head circumference, gestational age, Apgar score), as well as birth complications, if any, for research purposes. The participation rate was high with 96% of approached women agreeing to take part in our study. In total, samples of blood and urine were collected from 450 women. Participation in the study was voluntary, confidentiality was assured, and participants were informed that they could withdraw from the study at any time. From each pregnant woman participating in the study, two samples of venous blood were collected using the Venoject sterile system and BD collection tubes. The process included one sample into (10 mL) EDTA-containing BD Vacutainer tube for whole blood analyses and one sample into a non-additive tube for serum analyses. The serum tubes were centrifuged and the serum was transferred to acid-washed polypropylene tubes using acid-washed plastic pipettes. For the collection of blood samples, non-powder gloves were used when handling and collecting samples. Midstream urine was collected into (30 mL) polypropylene acid-washed containers and, thereafter, decanted into polypropylene acid-washed tubes. The plastic containers had no metal caps or glued inserts and were not colored due to the metals found in dyes. All precautions to eliminate and prevent contamination at collection and sample preparation were applied throughout. Samples of collected whole blood, serum (post-centrifugation), and urine were stored at −20 °C and couriered in a frozen state to the National Institute for Occupational Health (NIOH) laboratory, Johannesburg, South Africa for analysis. The NIOH participates in a proficiency testing scheme for whole blood and urine. For the measurement of Al, Cu, and Zn in serum, 0.5 mL volumes of serum samples, internal standard solution containing 45Sc, 72Ge, (50 μL), 65% ultrapure nitric acid (50 μL) and ultra-pure water (4.4 mL) were pipetted into a polypropylene tube. The diluted serum samples were analyzed for element content using an Agilent 7500ce Inductively Coupled Plasma Mass Spectrometer (ICP-MS) with an Octopole Reaction System. The instrument was calibrated with calibration standards prepared using SeronormTM Trace Elements in serum (Sero Ltd., Billingstad, Norway) for matrix matching. For 27Al, 45Sc was used as the internal standard and analysis was performed in the no gas acquisition mode. 63Cu and 66Zn were measured in the helium gas mode with 72Ge used as the internal standard. Aliquots of each sample were analyzed in triplicate. The detection limits for Al, Cu, and Zn were 0.17 μg/L, 0.50 μg/L, and 0.40 μg/L, respectively. SeronormTM Trace Elements in serum (Sero Ltd., Billingstad, Norway) were analyzed with every analytical run in intervals of 10 samples for quality assurance of all element measurements. For the Se assay, samples were diluted three-fold with equal amounts of a diluent solution (1.35% sodium chloride and 0.017% ammonium dihydrogen phosphate) and a palladium modifier solution (60% palladium 2000 mg/L in 0.5% Triton X-100). Se in serum measurements were carried out on a Thermo Scientific (Waltham, MA, USA) iCE3000 series spectrometer with graphite furnace and autosampler. A Se calibration curve was prepared by dilution of a 10 mg/L Se working stock solution so that the concentration ranged from 50 μg/L to 200 μg/L. ClinCheck serum control for trace elements level 1 and 2 were analyzed immediately after calibration and after every six samples for quality assurance of the Se determination. The detection limit for Se in serum was 6.5 μg/L. For the measurement of Mn in whole blood, 0.5 mL of the blood sample was pipetted into a polypropylene digestion tube, which is followed by the addition of 65% ultrapure nitric acid (1 mL). The mixture was digested at 90 °C for 2 h. Once cooled, 70 µL internal standard solution containing 45Sc was added and further diluted with ultrapure water to a final volume of 7 mL. The digested blood samples were analyzed using an Agilent 7500ce (ICP-MS) with an Octopole Reaction System. The instrument was calibrated with calibration standards prepared using SeronormTM Trace Elements in whole blood level 1 for matrix matching. The analysis was performed in a helium acquisition mode. Aliquots of each sample were analyzed in triplicate. The detection limit for Mn was 0.07 μg/L. Two certified reference controls known as SeronormTM Trace Elements in whole blood levels 1 and 2 (Sero Ltd., Billingstad, Norway) were analyzed with every analytical run in intervals of 10 samples for quality assurance of all element measurements. Urine samples (1 mL volumes) were acidified with 0.1 mL of 65% ultrapure nitric acid (Fluka, Munich, Germany). An internal standard solution containing 72Ge was added (50 μL) to all samples, reagent blanks, reference controls, blank urine collection tubes, and calibration standards. The measured solution held 5 mL (5 times sample dilution) with deionized water. Urinary Al levels were measured in the no gas acquisition mode. The percentage recovery, when using certified controls (Lyphochek level 1 and 2), was 95.1% and 97.6% for level 1 and 2, respectively. The detection limits for urinary Al was 1.71 (SD 0.41) μg/L. The creatinine concentration in urine samples was determined by using the Jaffé rate method and an automated Roche Cobas 111 analyzer. Urine samples were dispensed into the Cobas cups, which were automatically injected in a reaction cell containing an alkaline picrate solution (Cobas 111 creatinine Jaffé CREJ2 reagent 1 and 2). The sample combined with the reagent to produce a yellow-orange colored complex (alkaline-picrate creatinine complex), which is directly proportional to the creatinine concentration in the sample. The Cobas Calibrator for automated systems, Ref 10759300, was used for the assay. Certified controls, ‘Liquichek Urine Chemistry Control’, level 1 and 2 (Bio-Rad, Hercules, California, USA) were run before and after every 20 samples. Covariate information was obtained during the questionnaire-based interview and from medical records. Maternal weight and height were recorded at the hospital on admission. From the medical records, the neonate characteristics retrieved include birth weight (g), birth length (cm), head circumference (cm), and gestational age (weeks). Pre-term labor was defined as mothers giving birth at less than 37 weeks of gestational age. Education was categorized as no education to completed primary school, completed secondary school, and any level of tertiary education attained. Maternal tobacco smoking during pregnancy was defined as yes or no. Exposure to environmental tobacco smoke (ETS) was defined as exposure to tobacco smoke from smoking by others in the household. A binary classification was used for exposure to indoor smoke from the burning of fossil fuel (wood and coal) for the purpose of heating or cooking as well as separating study participants into those exposed to fossil fuel and those not exposed (for example, those using electricity). Dietary questions relating to the intake of proteins, carbohydrates, dairy products, tea, coffee, bottled water, fruits, and vine, root and leafy vegetables were assessed and classified as daily, at least once a week, and seldom (both for pre-pregnancy and during pregnancy). The statistical analyses were performed using STATA (StataCorp, 2013. Stata Statistical Software: Release 13. College Station, TX, USA: StataCorp LP). Al was detected in all serum and urine samples. Bivariate analyses between maternal serum Al exposure and covariates were evaluated by using the Spearman’s correlation coefficient. The distribution of maternal serum Al was skewed and was square-root-transformed after exploring the best fit for transformation. Multivariate linear regression was carried out using a backward deletion approach by starting with a full model of factors significantly associated with natural square-root-transformed maternal serum Al levels in the univariate analysis. All statistical tests were two-tailed and statistical significance was set at p < 0.05. The work was carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki). Ethics approval for the study was obtained from the Human Research Ethics Committee of the University of Witwatersrand in Johannesburg (Protocol no. {"type":"entrez-nucleotide","attrs":{"text":"M10742","term_id":"147973","term_text":"M10742"}}M10742), and from the relevant provincial Departments of Health. In addition, CEOs of the respective hospitals had to confirm that he/she allowed the research work to proceed. Identical procedures were followed in terms of obtaining consent from participants. Confidentiality was maintained by assigning identification numbers to all study participants. During the informed consent process, it was emphasized that participation was voluntary and could be withdrawn at any time.

Matériaux

N/A

Innovations

Based on the provided information, here are some potential innovations that could be used to improve access to maternal health:

1. Mobile Health (mHealth) Applications: Develop mobile applications that provide pregnant women with access to information and resources related to maternal health, including prenatal care, nutrition, and potential risks such as exposure to toxic substances like aluminum.

2. Telemedicine Services: Implement telemedicine services that allow pregnant women in rural areas to consult with healthcare professionals remotely, reducing the need for travel and improving access to prenatal care.

3. Community Health Workers: Train and deploy community health workers in rural areas to provide education, support, and basic healthcare services to pregnant women, including monitoring for exposure to toxic substances and promoting healthy behaviors.

4. Maternal Health Clinics: Establish dedicated maternal health clinics in rural areas, staffed by healthcare professionals who specialize in prenatal care and can provide comprehensive services to pregnant women.

5. Health Education Programs: Develop and implement health education programs that specifically target pregnant women in rural areas, providing information on the importance of prenatal care, nutrition, and avoiding exposure to toxic substances.

6. Transportation Support: Provide transportation support for pregnant women in rural areas to access healthcare facilities for prenatal care and delivery, ensuring that they can receive the necessary care in a timely manner.

7. Partnerships with Local Organizations: Collaborate with local organizations, such as community-based groups and non-profit organizations, to improve access to maternal health services and resources in rural areas.

8. Maternal Health Hotline: Establish a dedicated hotline for pregnant women in rural areas to access information, support, and guidance related to maternal health, including concerns about exposure to toxic substances.

9. Maternal Health Awareness Campaigns: Conduct awareness campaigns in rural communities to raise awareness about the importance of maternal health, including the potential risks of exposure to toxic substances, and promote early and regular prenatal care.

10. Research and Policy Advocacy: Conduct further research on the impact of exposure to aluminum and other toxic substances on maternal health outcomes, and advocate for policies and regulations that protect pregnant women from harmful exposures.

These innovations aim to address the challenges faced by pregnant women in rural areas, improve access to maternal health services, and promote better health outcomes for both mothers and their babies.

AI Innovations Description

Based on the description provided, the recommendation to improve access to maternal health would be to conduct further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations. This study serves as a baseline for future research in this area. By understanding the effects of aluminum exposure on maternal health, interventions can be developed to reduce aluminum retention and increase the overall well-being of pregnant women. Additionally, the study highlights the importance of maternal characteristics and their correlation with birth outcomes, suggesting that addressing these factors can also contribute to improving maternal health.

AI Innovations Methodology

Based on the provided information, here are some potential recommendations to improve access to maternal health:

1. Increase awareness and education: Implement programs to educate pregnant women and their families about the importance of maternal health, including the potential risks of exposure to toxic substances like aluminum. This can be done through community workshops, health campaigns, and the distribution of informational materials.

2. Improve antenatal care services: Strengthen antenatal care services in rural areas by ensuring that pregnant women have access to regular check-ups, screenings, and necessary interventions. This can be achieved by increasing the number of skilled healthcare providers, improving infrastructure, and providing necessary equipment and supplies.

3. Enhance transportation systems: Develop and improve transportation systems in rural areas to ensure that pregnant women can easily access healthcare facilities. This can include providing affordable transportation options, establishing mobile clinics, and improving road infrastructure.

4. Expand telemedicine services: Utilize telemedicine technologies to provide remote healthcare consultations and support for pregnant women in rural areas. This can help overcome geographical barriers and provide access to specialized care and advice.

To simulate the impact of these recommendations on improving access to maternal health, a methodology could include the following steps:

1. Define the indicators: Identify specific indicators that can measure the impact of the recommendations, such as the number of pregnant women receiving antenatal care, the percentage of women with access to transportation services, or the level of awareness about maternal health.

2. Collect baseline data: Gather data on the current status of the indicators in the target population. This can be done through surveys, interviews, or analysis of existing data sources.

3. Develop a simulation model: Create a simulation model that incorporates the different factors and variables related to the recommendations. This model should consider the interactions and dependencies between the various components, such as the impact of increased awareness on healthcare utilization or the effect of improved transportation on access to antenatal care.

4. Input data and run simulations: Input the baseline data into the simulation model and run multiple simulations to assess the potential impact of the recommendations. This can involve adjusting different parameters and variables to explore different scenarios and outcomes.

5. Analyze results: Analyze the results of the simulations to determine the potential impact of the recommendations on improving access to maternal health. This can include quantifying the changes in the indicators and identifying any potential challenges or limitations.

6. Refine and validate the model: Refine the simulation model based on the analysis of the results and validate it using additional data or expert input. This can help ensure the accuracy and reliability of the model for future use.

7. Communicate findings and make recommendations: Present the findings of the simulation study to relevant stakeholders, such as policymakers, healthcare providers, and community organizations. Use the results to make informed recommendations for improving access to maternal health based on the potential impact identified in the simulations.

Auteur

Dima Health

Statistics:

Citations: 10

Identifiers:

DOI: 10.3390/ijerph15071494

ISSN: 16617827

Research Areas:

Environmental, Health System and Policy, Maternal Access, Maternal and Child Health, Quality of Care, Sexual and Reproductive Health, Social Determinants, Substance Abuse

Study Countries:

South Africa

Study Design:

Case-Control Study, Cross Sectional Study

Study Approach:

Quantitative

Participants Gender:

Female

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