Association of maternal obesity with fetal and neonatal death: Evidence from South and South-East Asian countries

Non-linear associations of maternal pre-pregnancy body mass index with risk of stillbirth, infant, and neonatal mortality in over 28 million births in the USA: a retrospective cohort study

Background

Higher maternal pre-pregnancy body mass index (BMI) has been associated with higher risk of stillbirth, infant and neonatal mortality. Studies exploring underweight have varied in their conclusions. Our aim was to examine the risk of stillbirth, infant and neonatal mortality across the BMI distribution and establish a likely healthy BMI range.

Methods

In this retrospective cohort study, we used publicly available datasets (covering 1st January 2014 to 31st December 2021) from the US National Center for Health Statistics National Vital Statistics System. All births were eligible; analyses included those with non-missing data. Fractional polynomial multivariable logistic regression was used to examine the associations of maternal pre-pregnant BMI with stillbirth (birth with no signs of life at ≥24 weeks), infant mortality (death of a live born baby aged <365 days) and neonatal mortality (death of a live born baby aged <28 days).

Findings

There were 77,896/28,310,154 (2.8 per 1000 births) stillbirths, 143,620/28,231,807 (5.1 per 1000 live births) infant deaths and 94,246/28,231,807 (3.3 per 1000 live births) neonatal deaths among complete cases. Mean (SD) BMI was 27.1 kg/m2 (6.7 kg/m2). We found non-linear associations between BMI and all three outcomes; risk was elevated at both low and high BMIs although, for stillbirth, the increased risk at low BMI was less marked than for infant/neonatal mortality. The lowest risk was at a BMI of 21 kg/m2 for infant and neonatal mortality and 19 kg/m2 for stillbirth.

Interpretation

Public health messaging for preconception and postnatal care should focus on healthy weight to maximise maternal and child health, and not focus solely on maternal overweight or obesity.

Funding

European Research Council, US National Institute of Health, UK Medical Research Council and National Institute for Health and Care Research.

Proximate and distant determinants of maternal and neonatal mortality in the postnatal period: A scoping review of data from low- and middle-income countries

Global maternal and neonatal mortality rates remain unacceptably high. The postnatal period, encompassing the first hour of life until 42 days, is critical for mother-baby dyads, yet postnatal care (PNC) coverage is low. Identifying mother-baby dyads at increased risk for adverse outcomes is critical. Yet few efforts have synthesized research on proximate and distant factors associated with maternal and neonatal mortality during the postnatal period. This scoping review identified proximate and distant factors associated with maternal and neonatal mortality during the postnatal period within low- and middle-income countries (LMICs). A rigorous, systematic search of four electronic databases was undertaken to identify studies published within the last 11 years containing data on risk factors among nationally representative samples. Results were synthesized narratively. Seventy-nine studies were included. Five papers examined maternal mortality, one focused on maternal and neonatal mortality, and the rest focused on neonatal mortality. Regarding proximate factors, maternal age, parity, birth interval, birth order/rank, neonate sex, birth weight, multiple-gestation, previous history of child death, and lack of or inadequate antenatal care visits were associated with increased neonatal mortality risk. Distant factors for neonatal mortality included low levels of parental education, parental employment, rural residence, low household income, solid fuel use, and lack of clean water. This review identified risk factors that could be applied to identify mother-baby dyads with increased mortality risk for targeted PNC. Given risks inherent in pregnancy and childbirth, adverse outcomes can occur among dyads without obvious risk factors; providing timely PNC to all is critical. Efforts to reduce the prevalence of risk factors could improve maternal and newborn outcomes. Few studies exploring maternal mortality risk factors were available; investments in population-based studies to identify factors associated with maternal mortality are needed. Harmonizing categorization of factors (e.g., age, education) is a gap for future research.

Determinants of under-five mortality in Sri Lanka: A multilevel analysis of 2016 Sri Lankan DHS data

Under-five mortality (U5M) is considered a major public health issue directly impacts a country's development. This study analyzed the prognostic factors of U5M in Sri Lanka using data from the 2016 Demographic and Health Survey (DHS) of 8123 children. The study employed both a binary logistic regression model (BLRM) and a binary logistic random intercept multilevel model (BLRIMM) and compared the accuracy of each model's prediction percentage. The results showed that the BLRIMM had a higher correct prediction percentage (98.67%) compared to the BLRM (98.31%). The study found that children who were not breastfed (Odds Ratio (OR) = 116.74, 95% Confidence Interval (CI) = 62.97-216.41), were part of multiple births (OR = 3.73, 95% CI = 1.21-11.51), did not have a normal delivery (OR = 1.86, 95% CI = 1.11-3.12), were born to mothers who had experienced previous miscarriages or child loss (OR = 2.27, 95% CI = 1.26-4.11), and were born to mothers with a higher Body Mass Index (BMI) (OR = 1.05, 95% CI = 1.003-1.10) had higher odds of U5M. The odds of U5M were found to be lower among Buddhists (OR = 0.06, 95% CI = 0.01-0.50), Hindus (OR = 0.05, 95% CI = 0.01-0.46), and Roman Catholics (OR = 0.032, 95% CI = 0.003-0.307) compared to the "Other Religions" category in the dataset. The estimated covariance parameter of the random intercept (0.8231, p-value = 0.0405) indicated significant unobserved cluster-level variation in U5M. The study's results emphasize the importance of addressing religion related differences of U5M and improving maternal education regarding healthy lifestyle, proper food intake, the significance of breastfeeding, safe delivery methods, safety measures during pregnancy and childbirth in cases of multiple births, and proper child care after birth.

Defining poor growth and stillbirth risk in pregnancy for infants of mothers with overweight and obesity

BACKGROUND

Mothers who are obese carry heavier fetuses and have lower rates of small for gestational age (<10th birthweight centile) infants. However, their infants may be growth-restricted (with an increased risk of stillbirth) at a higher birthweight centile compared with infants from healthy-weight women.

OBJECTIVE

This study aimed to quantify the birthweight centile at which the risk of stillbirth in infants born to obese women equaled that of <10th-centile infants born to healthy-weight women, and clarify the relationship between maternal body mass index, infant size, and stillbirth.

STUDY DESIGN

We conducted a retrospective cohort study on all infants born in Victoria, Australia, from 2009 to 2019 (754,946 cases for analysis). We applied uncustomized birthweight centiles to all infants, and stratified the maternal cohort by body mass index (<20 kg/m2, 20-25 kg/m2, 25-30 kg/m2, 30-35 kg/m2, 35-40 kg/m2, ≥40 kg/m2). For each body mass index category, we assessed proportions of infants born <10th centile and <3rd centile, stillbirth rates among infants of all sizes, and small for gestational age infants. We calculated the stillbirth rate (per 1000) and relative risk (risk of stillbirth if born <10th centile vs >10th centile) for healthy-weight women (body mass index, 20-25 kg/m2). We then determined the birthweight centile for infants born to mothers within other body mass index categories that equaled that rate or risk.

RESULTS

Stillbirth rates increased with increasing maternal body mass index. Infants classified as small for gestational age (<10th centile) from mothers with high body mass index had a higher risk of stillbirth (relative risk, 3.15; 95% confidence interval, 2.22-4.47; for mothers with body mass index ≥40 kg/m2 vs healthy-weight mothers [body mass index, 20-25 kg/m2]). The stillbirth rate (stillborn infants per 1000 births) among <10th-centile infants born to healthy-weight mothers was 7.5 per 1000. The same stillbirth rate was observed at higher birthweight centiles for infants of women with higher body mass index (<18th centile for those with a body mass index of 25-30 kg/m2, <25th centile for body mass index of 30-35 kg/m2, <31st centile for body mass index of 35-40 kg/m2, <41st centile for body mass index of ≥40 kg/m2). The relative risk of stillbirth among small for gestational age infants of healthy-weight mothers was 5.46 (95% confidence interval, 4.65-6.40). The birthweight centile with a comparable relative risk of stillbirth increased with increasing body mass index (<16th centile for women with body mass index of 25-30 kg/m2, <19th centile for body mass index of 30-35 kg/m2, <28th centile for body mass index of 35-40 kg/m2, <30th centile for body mass index ≥40 kg/m2).

CONCLUSION

Obesity affects the relationship between infant size and perinatal mortality. The stillbirth risk observed in <10th-centile infants from healthy-weight mothers occurs at higher birthweight centiles with overweight or obese mothers. Clinicians should be aware that the same infant risk exists at a higher birthweight centile for women with higher body mass index.

The effect of exercise on the prevention of gestational hypertension in obese and overweight pregnant women: An updated meta-analysis

Background

Gestational hypertension (GH) is a common disease that seriously threatens the safety and health of pregnant women and their newborns. Physical exercise (PE) is widely recognized as a health maintenance method and it has numerous benefits. Studies on the association between PE and the risk of GH in obese and overweight pregnant women have generated controversial findings. This updated meta-analysis was performed to reassess the effects of PE on GH.

Methods

The articles from inception to April 2022, presenting studies investigating exercise intervention and pregnancy outcomes were explored across several online databases. Heterogeneity among the included studies was estimated and tested by Q test and I ² statistic. Risk ratios (RRs) and 95% confidence intervals (CI) were calculated through either random-effect or fixed-effect models. Subgroup analyses, sensitivity analyses, and publication bias diagnoses were also conducted.

Results

Twelve with 1,649 subjects were included. PE was associated with a reduced risk of GH in obese and overweight pregnant women (Pooled RR = 0.58, 95% CI = 0.42-0.81, P = 0.001; I ² = 24.3%). Subgroup analysis found significant trends amongst Eastern countries (RR = 0.59, 95% CI = 0.36-0.96, P = 0.033). Sensitivity analysis suggested the results were stable. No publication bias was detected based on Begg's test and Egger's test.

Conclusion

PE was associated with reduced risk of GH in obese and overweight pregnant women, especially in Eastern countries. More well-designed studies are still needed to further elaborate on these associations.

Systematic review registration

CRD42022326183.

Frequency of watching television, owning a mobile phone and risk of being overweight/obese among reproductive-aged women in low- and lower-middle-income countries: A pooled analysis from Demographic and Health Survey data

People who are overweight and obese suffer from significant health impacts that have increased globally. Concurrently, usage of information and communication devices such as television and mobile phones have also been growing, affecting people's weight. This study examined the association between watching television and owning a mobile phone with overweight and obesity among reproductive-aged women in low- and lower-middle-income countries (LLMICs). Data of 21 LLMICs reported between 2015 and 2020 were collected from the Demographic and Health Surveys. Multivariate logistic regression was performed to determine the association into three pooled segments: a group of 21 countries, the World Bank income classification and the regional categorisation of the countries. The all-inclusive prevalence of overweight or obesity was found at 27.1% among 175,370 reproductive-aged women, and this prevalence varied among countries. Overall, the odds of being overweight or obese were 1.20 (adjusted odds ratio [AOR]=1.20, 95% confidence interval [CI]: 1.15-1.24), 1.40 (AOR=1.40, 95% CI: 1.35-1.44) and 1.18 (AOR=1.18, 95% CI: 1.03-1.35) times higher among those who watched television less than once a week, at least once a week and almost every day, respectively, compared with those who did not watch television. Besides, women's mobile phone ownership is more likely to experience overweight or obesity (AOR=1.72, 95% CI: 1.67-1.77). Consistent results were found for the countries categorised according to the World Bank income and regional classification. Focus on sedentary behaviour, such as television watching and mobile phone use, of women and regional or country-specific innovative strategies and programs are of great immediate importance to decrease the prevalence of overweight and obesity.

Overweight, obesity and excessive weight gain in pregnancy as risk factors for adverse pregnancy outcomes: a narrative review

The global prevalence of overweight and obesity in pregnancy is rising and this represents a significant challenge for the management of pregnancy and delivery. Women who have a pre‐pregnancy body mass index greater than 25 kg m^–2 are more likely than those with a body mass index in the ideal range (20–24.99 kg m^–2) to have problems conceiving a child and are at greater risk of miscarriage and stillbirth. All pregnancy complications are more likely with overweight, obesity and excessive gestational weight gain, including those that pose a significant threat to the lives of mothers and babies. Labour complications arise more often when pregnancies are complicated by overweight and obesity. Pregnancy is a stage of life when women have greater openness to messages about their lifestyle and health. It is also a time when they come into greater contact with health professionals. Currently management of pregnancy weight gain and the impact of overweight tends to be poor, although a number of research studies have demonstrated that appropriate interventions based around dietary change can be effective in controlling weight gain and reducing the risk of pregnancy complications. The development of individualised and flexible plans for avoiding adverse outcomes of obesity in pregnancy will require investment in training of health professionals and better integration into normal antenatal care.

Overweight and obesity before pregnancy and excessive gestational weight gain are major determinants of risk for pregnancy loss, gestational diabetes, hypertensive conditions, labour complications and maternal death.

Pregnancy is regarded as a teachable moment when women are at their most receptive to messages about their health. However, unclear guidance on diet and physical activity, weight stigma from health professionals, inexperience and reluctance among professionals about raising issues about weight, and stretched resources put the health of women and babies at risk.

Excessive weight gain in pregnancy and post‐partum weight retention compromise future fertility and increase risk for future pregnancies.

Large randomised controlled trials have had little success in addressing excessive gestational weight gain or antenatal complications. Individualised, culturally sensitive and responsive interventions appear to have greater success.