Maternal demographic and antenatal factors, low birth weight and preterm birth: findings from the mother and child in the environment (MACE) birth cohort, Durban, South Africa

Environmental exposures associated with early childhood recurrent wheezing in the mother and child in the environment birth cohort: a time-to-event study

BACKGROUND

Antenatal factors and environmental exposures contribute to recurrent wheezing in early childhood.

AIM

To identify antenatal and environmental factors associated with recurrent wheezing in children from birth to 48 months in the mother and child in the environment cohort, using time-to-event analysis.

METHOD

Maternal interviews were administered during pregnancy and postnatally and children were followed up from birth to 48 months (May 2013-October 2019). Hybrid land-use regression and dispersion modelling described residential antenatal exposure to nitrogen dioxide (NO2) and particulate matter of 2.5 µm diameter (PM2.5). Wheezing status was assessed by a clinician. The Kaplan-Meier hazard function and Cox-proportional hazard models provided estimates of risk, adjusting for exposure to environmental tobacco smoke (ETS), maternal smoking, biomass fuel use and indoor environmental factors.

RESULTS

Among 520 mother-child pairs, 85 (16%) children, had a single wheeze episode and 57 (11%) had recurrent wheeze. Time to recurrent wheeze (42.9 months) and single wheeze (37.8 months) among children exposed to biomass cooking fuels was significantly shorter compared with children with mothers using electricity (45.9 and 38.9 months, respectively (p=0.03)). Children with mothers exposed to antenatal ETS were 3.8 times more likely to have had recurrent wheeze compared with those not exposed (adjusted HR 3.8, 95% CI 1.3 to 10.7). Mean birth month NO2 was significantly higher among the recurrent wheeze category compared with those without wheeze. NO2 and PM2.5 were associated with a 2%-4% adjusted increased wheezing risk.

CONCLUSION

Control of exposure to ETS and biomass fuels in the antenatal period is likely to delay the onset of recurrent wheeze in children from birth to 48 months.

Regional with urban-rural variation in low birth weight and its determinants of Indian children: findings from National Family Health Survey 5 data

BACKGROUND

Low birth weight is a key indicator for child health, especially a concern in low-middle-income countries. However, health and medically-related reforms are being actively implemented in some middle-income countries like India. Identifying low birth weight (LBW) babies with their determinants across the whole country is essential to formulate regional and area-specific interventions. The objective of this study was to find out the burden and determinants of LBW on the regional and residential (rural-urban) divisions of India.

METHODS

The present study was based on the NFHS-5 dataset (2019-21), a nationally representative survey in India. A total of 209,223 births were included in this study. A newborn weighing less than 2500 g was considered as LBW. According to the objectives, we used frequency distribution, chi-square test and binary logistic regression analysis for analysing the data.

RESULTS

About 18.24% of the babies were LBW in India, significantly higher in rural areas than in urban areas (18.58% vs 17.36%). Regionally prevalence was more frequent in western (20.63%) and central (20.16%) rural areas. Regarding maternal concerns, in the eastern and southern regions of India, mothers aged 25-34 were less likely to have LBW children than mothers aged 35-49 years. It was found that the risk of LBW was more likely among the children born out of unintended pregnancies in almost all regions except for eastern part. In rural India, women who delivered children at home were more likely to have LBW children in India (AOR = 1.19, CI: 1.12-1.28, p < 0.001) and its central, northern, and southern regions than those who gave birth in institutions. The study indicates that LBW coexists with lower maternal education levels and poor household wealth index across all regions. About 58% and 57% of cumulative effects of independent variables on LBW can be distinguished in urban and rural India, respectively.

CONCLUSIONS

Targeted-specific strategies need to be undertaken as per region and geographical variations. Then only India should be able to decline LBW as proposed by National Health Policy.

Risk of low birthweight associated with the timing and frequency of antenatal care visits in Lao PDR: a retrospective cohort study

BACKGROUND

Antenatal care (ANC) plays an important role in preventing low birthweight (LBW). Whereas the government of Lao People's Democratic Republic (Lao PDR) has committed to increasing the usage of ANC, little attention has been given to the early initiation of ANC. The present study assessed the influence of delayed and fewer ANC visits on LBW in the country.

METHODS

This is a retrospective cohort study conducted at Salavan Provincial Hospital. Study participants were all pregnant women who gave birth at the hospital between 1 August 2016 and 31 July 31 2017. Data were collected from medical records. Logistic regression analyses were performed to quantify the relationship between ANC visits and LBW. We also investigated factors associated with inadequate ANC visits: first ANC visit after the first trimester or < 4 ANC visits.

RESULTS

The mean birth weight was 2808.7 g [standard deviation: SD 455.6]. Among 1804 participants, 350 (19.4%) had babies with LBW, and 147 (8.2%) had inadequate ANC visits. In multivariate analyses, compared to participants with adequate ANC visits, those with ≥ 4 ANC visits and the first ANC visit after the second trimester, those with < 4 ANC visits, and those with no ANC visits had higher odds ratios (ORs) of LBW: 3.77 (95% confidence interval: CI = 1.66-8.57), 2.39 (95% CI = 1.18-4.83) and 2.22 (95% CI = 1.08-4.56), respectively. Younger maternal age (OR 1.42; 95% CI = 1.07-1.89), government subsidisation (OR 2.69; 95% CI = 1.97-3.68) and ethnic minority (OR 1.88; 95% CI = 1.50-2.34) were associated with increased risk of insufficient number of ANC visits after adjusting for covariates.

CONCLUSIONS

Frequent and early initiation of ANC was associated with a reduction in LBW in Lao PDR. Encouraging childbearing-aged women to receive sufficient ANC at proper timing may lead to a reduction in LBW and improvement in short- and long-term health outcomes of neonates. Special attention will be needed for ethnic minorities and women in lower socioeconomic classes.

Household Food Insecurity and Demographic Factors, Low Birth Weight and Stunting in Early Childhood: Findings from a Longitudinal Study in South Africa

BACKGROUND

Low birthweight (LBW) as well as early childhood stunting are risk factors for increased childhood morbidity in low-and middle-income countries (LMIC). The Covid 19 pandemic has exacerbated food insecurity and unemployment globally, prompting concerns for maternal and child health.

OBJECTIVES

We used data from the great recession of 2008 to examine the relationship between household food security and other risk factors with LBW and stunting using a longitudinal sample of South African women and their offspring.

METHODS

Food security indicators, alcohol use, blood pressure and other characteristics were examined in relation to LBW (≤ 2500 g), stunting (height for age ≤ 2SD) and severe stunting (height for age ≤ 3SD). Regression modelling with clustering at maternal ID level were employed to adjust for maternal characteristics and women who gave birth more than once during the reference period.

RESULTS

Birthweight data were available for 1173 children and height for age 1216 children. The prevalence of LBW was 14.7% while stunting and severe stunting was 17.8% and 14.5%. Child hunger in the household, maternal hypertension and alcohol use were associated with low birthweight. Food expenditure below the Stats SA poverty line and low dietary diversity was associated with stunting and severe stunting respectively. Maternal height and low birthweight were associated with both stunting and severe stunting.

CONCLUSIONS FOR PRACTICE

Interventions that can improve household food security and nutritional status during the periconceptional and antenatal period may reduce the prevalence of low birthweight and subsequent stunting in low- and middle-income countries.

Risk profile of postnatal women and their babies attending a rural district hospital in South Africa

Background

Maternal and neonatal mortality remain unacceptably high and inequitably distributed in South Africa, with the postnatal period being a dangerous time for both mother and baby. The aim of this paper is to describe the risk factors for poor postnatal outcomes, including postnatal mental health disorders, in a population of postnatal women and their babies utilising rural district hospital services in Limpopo Province, with a focus on HIV. We also describe health care provider compliance with relevant guidelines.

Methods

All women discharged from the postnatal ward of the district hospital who consented to participate were enrolled. A research nurse used a structured questionnaire to collect data about sociodemographic information, pregnancy and pre-existing conditions, complications during labour and birth, pregnancy outcomes and mental health risk factors.

Results

The questionnaire was completed for 882 women at the time of discharge. Only 354 (40.2%) of participants had completed secondary education, and 105 (11.9%) reported formal employment. Chronic hypertension was recorded in 20 women (2.3%), with an additional 49 (5.6%) developing a hypertensive disorder during pregnancy. HIV prevalence was 22.8%. 216 women (24.5%) had a mental health risk factor, with 40 reporting more than one (4.5%). Having no income, no antenatal care, having HIV and any hypertensive disorder were significantly associated with a positive mental health risk screen in multivariable analysis. There were 31 stillbirths and early neonatal deaths (3.5%), and 119 babies (13.4%) were born at a low birth weight. Stillbirth or early neonatal death was significantly associated with no antenatal care in multivariable analysis.

Conclusions

Women and babies in this study experienced multiple risk factors for poor outcomes in the postpartum period. Postnatal care should be strengthened in order to address the dominant risks to mothers and babies, including socioeconomic challenges, HIV and hypertension, and risks to mental health. Tools to identify mothers and babies at risk of postnatal complications would allow limited resources to be allocated where they are most needed.

Effect of short-term exposure to ambient nitrogen dioxide and particulate matter on repeated lung function measures in infancy: A South African birth cohort

BACKGROUND

The developing lung is highly susceptible to environmental toxicants, with both short- and long-term exposure to ambient air pollutants linked to early childhood effects. This study assessed the short-term exposure effects of nitrogen dioxide (NO₂) and particulate matter (PM₁₀) on lung function in infants aged 6 weeks, 6, 12 and 24 months, the early developmental phase of child growth.

METHODS

Lung function was determined by multiple breath washout and tidal breathing measurement in non-sedated infants. Individual exposure to NO₂ and PM₁₀ was determined by hybrid land use regression and dispersion modelling, with two-week average estimates (preceding the test date). Linear mixed models were used to adjust for the repeated measures design and an age*exposure interaction was introduced to obtain effect estimates for each age group.

RESULTS

There were 165 infants that had lung function testing, with 82 of them having more than one test occasion. Exposure to PM₁₀ (μg/m³) resulted in a decline in tidal volume at 6 weeks [-0.4 ml (-0.9; 0.0), p = 0.065], 6 months [-0.5 ml (-1.0; 0.0), p = 0.046] and 12 months [-0.3 ml (-0.7; 0.0), p = 0.045]. PM₁₀ was related to an increase in respiratory rate and minute ventilation, while a decline was observed for functional residual capacity for the same age groups, though not statistically significant for these outcomes. Such associations were however less evident for exposure to NO₂, with inconsistent changes observed across measurement parameters and age groups.

CONCLUSION

Our study suggests that PM₁₀ results in acute lung function impairments among infants from a low-socioeconomic setting, while the association with NO₂ is less convincing.

Educational attainment and offspring birth weight: A bidirectional Mendelian randomization study

Background: The association between educational attainment (EA) and offspring birth weight (BW) has been reported by several traditional epidemiological studies. However, evidence for this association tends to be mixed and confounded. This study aimed to investigate the causal association between EA of parents and offspring BW. Methods: Here, we carried out a two-sample bidirectional Mendelian randomization (MR) analysis to examine the causal association between EA of males (n = 131,695) and females (n = 162,028) and offspring BW using genetic instruments. Summary statistics of EA associated single nucleotide polymorphisms (SNPs) were extracted from a GWAS incorporating 293,723 individuals of European descent performed by the Social Science Genetic Association Consortium (SSGAC), and the effects of these SNPs on offspring BW were estimated using a GWAS meta-analysis of 86,577 participants of European descent from 25 studies. Univariable MR analyses were conducted using the inverse-variance weighted (IVW) method and four other methods. Further sensitivity analyses were carried out to test the viability of the results. Multivariable MR was used to examine the confounders between the exposure and outcome. Results: The result shows evidence that the offspring BW is positively causally affected by female EA. Each one standard deviation (SD) increase in female EA was associated with 0.24 SD higher of offspring BW (95% confidence interval [CI], 0.10 to 0.37, p < 0.001 for the IVW method). Similarly, change in offspring BW was 0.21 SD (95% CI: 0.07 to 0.34, p = 2.82 × 10-3) per one SD higher in male EA. No causal effect of BW on EA was found by any of the five methods. The causal association between female EA and offspring BW maintained after adjusting for alcoholic drinks per week and BMI. The effect of male EA on offspring BW was attenuated when we adjusted for BMI and alcoholic drinks per week using multivariable MR analysis. Conclusion: Our study indicated that female EA is positively causally associated with offspring BW. The association between male EA and offspring BW may be confounded by alcoholic drinks per week and BMI.

Association between paracetamol use during pregnancy and perinatal outcomes: Prospective NISAMI cohort

Background

Paracetamol is widely used to manage fever and pain during pregnancy worldwide. However, paracetamol may affect the pregnant woman and fetus, once this drug crosses the placental barrier after therapeutic doses and may impair fetal liver function, affecting fetus growth and development. Thus, this study aimed to investigate the association between paracetamol use during pregnancy and perinatal outcomes as preterm birth, low birth weight, and small for gestational age.

Methods and findings

Data from 760 pregnant women within the NISAMI Cohort between June 2012 and February 2014 were analyzed. Logistic regression was used to estimate the association among paracetamol use during pregnancy and preterm birth, low birth weight, and small for gestational age. Multivariate analyses were adjusted for socioeconomic, maternal, pregnancy, and newborn covariates. Around 14% of women were exposed to paracetamol during pregnancy. A decrease in paracetamol use throughout pregnancy was observed. Lower risk of low birth weight in infants born to women exposed to the drug (OR 0.21; IC 95% 0.01–0.99) was found. Paracetamol use during pregnancy was not statistically associated with preterm birth or small for gestational age.

Conclusions

The findings of this study do not suggest an increased risk of perinatal outcomes. However, it should not be assumed that paracetamol is a risk-free medication and its use must be rational.