Physical activity, physical exertion, and miscarriage risk in women textile workers in Shanghai, China

The epidemiology of pregnancy loss: global burden, variable risk factors, and predictions

STUDY QUESTION

Is the incidence of pregnancy loss correlated with various geographic, socio-demographic, and age stratifications at the societal and national levels, and what are the risk factors associated with pregnancy loss at the individual level?

SUMMARY ANSWER

The epidemiological trends and disease burden of pregnancy loss were correlated with various geographic, socio-demographic, and age stratifications, and we identified that poor health condition, smoking, sedentary behaviour, lower educational level, and lower maternal birth weight may significantly increase the risk of pregnancy loss.

WHAT IS KNOWN ALREADY

Several studies have used national, regional, or single-centre data to describe trends in the burden of pregnancy loss, and previous observational studies have identified some variable factors possibly associated with pregnancy loss. However, a comprehensive analysis of global trends and predictions of pregnancy loss are lacking, and the conclusions have been inconsistent.

STUDY DESIGN, SIZE, DURATION

We have utilized the data from Global Burden of Disease (GBD) 2019 to provide an overview of the trends in pregnancy loss in 204 countries and regions worldwide from 1990 to 2019, and have made a forecast for the next 10 years. Moreover, we applied a variety of statistical genetics methods to analyse 34 239 pregnancy loss and 89 340 non-pregnancy loss cases from the FinnGen consortium to comprehensively assess the bidirectional causality of variable factors with pregnancy loss from an individual perspective.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analysed trends in the incidence, disability-adjusted life years (DALYs), and maternal mortality of pregnancy loss at global, regional, national, socio-demographic index (SDI), and age levels. The autoregressive integrated moving average (ARIMA) model was used to predict trends by 2030. Finally, we used two-sample Mendelian randomization (MR) and multivariate MR (MVMR) analyses to explore the relationship between the pregnancy loss and variables closely related to physical condition, physical activity, lifestyle, sleep conditions, basic conditions.

MAIN RESULTS AND THE ROLE OF CHANCE

In 2019, there were approximately 42.39 million cases of pregnancy loss worldwide. Globally, the incidence, DALYs, and mortality of pregnancy loss showed a decreasing trend between 1990 and 2019, although the number was increasing in some countries. The age-standardized incidence, DALYs, and mortality rate were negatively correlated with SDI level and show a further decline by 2030. Based on MR analyses, we confirmed that genetically predicted overall health rating (inverse-variance weighted (IVW) odds ratio (OR), 1.68; 95% CI, 1.34-2.13; P = 5.10 × 10-6), smoking initiation (IVW OR, 1.26; 95% CI, 1.16-1.38; P = 1.90 × 10-9), sedentary behaviour (IVW OR, 1.56; 95% CI, 1.20-2.01; P = 2.76 × 10-5), educational level (IVW OR, 0.64; 95% CI, 0.55-0.73; P = 6.56 × 10-10), and maternal birth weight (IVW OR, 0.70; 95% CI, 0.58-0.85; P = 2.98 × 10-4) were significantly related to the risk of pregnancy loss, whereas body mass index (IVW OR, 1.10; 95% CI, 1.03-1.17; P = 5.31 × 10-3), alcohol consumption (IVW OR, 1.74; 95% CI, 1.03-2.95; P = 0.04), insomnia (IVW OR, 1.66; 95% CI, 1.14-2.42; P = 7.00 × 10-3), and moderate-to-vigorous physical activity (IVW OR, 0.59; 95% CI, 0.37-0.95; P = 2.85 × 10-2) were suggestively associated with the risk of pregnancy loss. These results were supported by sensitivity and directional analyses.

LIMITATIONS, REASONS FOR CAUTION

Despite efforts to standardize GBD data from all over the world, uncertainties in data quality control regarding ascertainment of pregnancy loss, medical care accessibility, cultural differences, and socioeconomic status still exist. Furthermore, the population in the MRstudy was limited to Europeans, which means that the results may not be extrapolated to people of other origins.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides for the first time an overview of the epidemiological trends and disease burden of pregnancy loss related with SDI, region, country, and age, and predicts changes in future trends up to 2030. In addition, findings support that genetic susceptibility, smoking, health condition, and sedentary behaviour may be powerful indicators of an increased risk of pregnancy loss. These results would be beneficial for policy makers of different countries and regions to improve prevention implementation.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants 2021JH2/10300093, from the Science and Technology Projects of Liaoning Province, China. All authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Heat stress and adverse pregnancy outcome: Prospective cohort study

OBJECTIVE

To explore the relationship between occupational heat exposure, physiological heat strain indicators and adverse outcomes in pregnant women.

DESIGN

Prospective cohort.

SETTING

Workplaces in Tamil Nadu, India.

SAMPLE

A cohort of 800 pregnant women engaged in moderate to heavy physical work in 2017-2019 and 2021-2022.

METHODS

Participants were recruited at between 8 and 14 weeks of gestation. Occupational heat exposure and heat strain indicators were captured each trimester. 'Heat exposed' was defined as heat stress exceeding the threshold limit value (TLV) for safe manual work (with maximum wet-bulb globe temperatures of 27.5°C for a heavy workload and 28.0°C for a moderate workload). Physiological heat strain indicators (HSIs) such as core body temperature (CBT) and urine specific gravity (USG) were measured before and after each shift. Heat-related health symptoms were captured using the modified HOTHAPS questionnaire.

MAIN OUTCOME MEASURES

The main outcome measures included (1) a composite measure of any adverse pregnancy outcome (APO) during pregnancy (including miscarriage, preterm birth, low birthweight, stillbirth, intrauterine growth restriction and birth defects), (2) a composite measure of adverse outcomes at birth (3) and miscarriage.

RESULTS

Of the 800 participants, 47.3% had high occupational heat exposure. A rise in CBT was recorded in 17.4% of exposed workers, and 29.6% of workers experienced moderate dehydration (USG ≥ 1.020). Heat-exposed women had a doubled risk of miscarriage (adjusted odds ratio, aOR 2.4; 95% confidence interval, 95% CI 1.0-5.7). High occupational heat exposure was associated with an increased risk of any adverse pregnancy and foetal outcome (aOR 2.3; 95% CI 1.4-3.8) and adverse outcome at birth (aOR 2.0; 95% CI 1.2-3.3).

CONCLUSIONS

High occupational heat exposure is associated with HSIs and adverse pregnancy outcomes in India.

A Comprehensive Review on Hot Ambient Temperature and its Impacts on Adverse Pregnancy Outcomes

INTRODUCTION

High workplace/ambient temperatures have been associated with Adverse Pregnancy Outcomes (APO). Millions of women working in developing nations suffer due to the rising temperatures caused by climate change. There are few pieces of research linking occupational heat stress to APO, and fresh evidence is required.

METHODOLOGY

We used databases including PubMed, Google Scholar, and Science Direct to search for research on high ambient/workplace temperatures and their effects. Original articles, newsletters, and book chapters were examined. The literature we analysed was categorised as follows: Heat, strain, and physical activity harming both mother and fetus. After categorising the literature, it was examined to identify the major results.

RESULTS

We found a definite association between heat stress and APOs such as miscarriages, premature birth, stillbirth, low birthweight, and congenital abnormalities in 23 research articles. Our work provides important information for future research into the biological mechanisms that create APOs and various prevention measures.

CONCLUSION

Our data suggest that temperature has long-term and short-term effects on maternal and fetal health. Though small in number, this study stressed the need for bigger cohort studies in tropical developing countries to create evidence for coordinated policies to safeguard pregnant women.

Association between Pet Ownership and Threatened Abortion in Pregnant Women: The China Birth Cohort Study

Background: The aim of this study was to assess the association between pet ownership and threatened abortion (TA) in pregnant Chinese women. Materials and Methods: We enrolled pregnant women from 18 provinces and autonomous regions across China between November 2017 and December 2020. Participants were grouped based on the presence or absence of pet ownership. Pet owners were further sub-grouped based on the presence or absence of close contact with their pets. Pet species included cats, dogs, and both. Generalised linear mixed models, with province as a random effect, were used to estimate the associations between pet ownership and TA. Results: Pet ownership, whether or not one had close contact with pets, was associated with greater odds of TA (OR: 1.30, 95% CI: 1.21, 1.40). Keeping pet cats (OR: 1.24, 95% CI: 1.11, 1.40), dogs (OR: 1.29, 95% CI: 1.18, 1.41), or both cats and dogs (OR: 1.36, 95% CI: 1.04, 1.68) during pregnancy were all risk factors for TA. We observed significant group differences (p for difference < 0.05) in pre-pregnancy body mass index, education levels, and annual household income. Conclusions: Cat or dog ownership during pregnancy was associated with an increased risk of TA, especially among overweight, less educated, or lower-income participants.

Occupational Factors Affecting Women Workers’ Sexual and Reproductive Health Outcomes in Oil, Gas, and Mining Industry: A Scoping Review

Objectives: Globally, female workers workforce in Oil, Gas, and Mining (OGM) industry have increased significantly. The complexities of the OGM operations and the extensive exposure to workplace hazards potentially affect the health status of workers, including sexual and reproductive health (SRH) outcomes of female workers. Yet, the current state of knowledge on SRH issues in OGM contexts seems to be limited and fragmented. This scoping review aims to identify the occupational factors that influence women’s SRH outcomes in OGM industry.

Methods: This scoping review followed the Joanna Briggs Institute’s guidelines (PRISMA) and was conducted in five databases, including the citation chaining via Google Scholar and manual search through relevant organisations and Government websites. Sixteen articles met the inclusion criteria and were analysed.

Results: Despite the scarcity of evidence, chemical and physical are found to be the predominant factors greatly influencing women workers’ SRH outcomes in OGM. Most studies showed menstrual and cycle disorders, and risky pregnancy as key SRH issues. However, menstruation disorder was considerably linked with psychological and organisational factors.

Conclusion: This review suggests further empirical research on the relationship between OGM occupational hazards and women workers’ SRH. This will contribute to improvements in workplace safety legislations, measures, policies, and management systems taking into account women’s needs.

Experiences of women seeking post-abortion care services in a Regional Hospital in Ghana

Introduction

Abortions remain one of the highest contributors to maternal deaths in Ghana. In 2003, a policy on post-abortion care was introduced to help reduce abortion-related mortality and morbidity. However, depending on the method of pregnancy termination; women encounter varying experiences. This study examines the experiences of women seeking post-abortion care services in a Regional Hospital in Ghana.

Materials and methods

In-depth interview technique was used to collect data from 20 purposively selected post-abortion care clients at the Volta Regional Hospital. Data were analysed manually using a qualitative content analysis technique.

Results

The study found that medical abortion was the main method of pregnancy termination used by women who participated in the study to induce abortion. Spontaneous abortion, however, was attributed mainly to engaging in activities that required the use of excessive energy and travelling on bad roads by pregnant women. The study also revealed that, women do not seek early post-abortion care services due to stigma and poverty.

Conclusions

We found that severity of pain from complications, stigma and financial constraints were factors that influenced women’s decision to seek post-abortion care services. Our findings also suggest that women who experienced spontaneous abortion mainly received financial and emotional support from partners and other family members. To encourage women to seek early post-abortion care services, the Ministry of Health and the Ghana Health Service should take pragmatic steps to educate women on the dangers associated with delay in seeking post-abortion care services and the factors that expose women to spontaneous abortions.

Spontaneous and repeat spontaneous abortion risk in relation to occupational characteristics among working Korean women: a cross-sectional analysis of nationally representative data from Korea

Background

The association between spontaneous abortion (SA) and occupational characteristics among working women is not well-studied. This study aimed to assess the risk of SA and occupational factors such as occupational classification, working hours, and work schedules among working Korean women aged > 19 years.

Methods

In this cross-sectional study, 4078 working women were identified from among 25,534 workers in the Korea National Health and Nutrition Examination Surveys V (2010–2012) database, to obtain data on SA history and the number of SAs. Odds ratios (ORs) and 95% confidence intervals (CIs) for SA were calculated using multiple logistic regression models after adjusting for age, education, household income, cigarette smoking, alcohol consumption, and obesity status. The weighted prevalence for the number of SAs was calculated according to occupational characteristics to demonstrate the SA status among working Korean women.

Results

SA occurrence was reported in 5.7% of the study participants. The ORs (95% CIs) for SA were significantly higher in pink-, green-, and blue-collared workers than in white-collared workers. Regarding weekly working hours, compared with ≤50 h spent working, the ORs (95% CIs) for 51–60, 61–70, and > 70 h per week were 1.26 (0.87–1.84), 1.63 (1.04–2.56), and 1.73 (1.10–2.70), respectively. A significantly higher weighted prevalence of repeat SAs was observed in pink- and green-collared workers and in those who worked long hours.

Conclusion

We found a significant association between SA, repeat SA, and occupational characteristics among working Korean women.

Big Data Analytics in Healthcare

Sensors and mobile phones shine in the Big Data area due to their capabilities to retrieve a huge amount of real-time data; which was not possible previously. In the specific field of healthcare, we can now collect data related to human behavior and lifestyle for better understanding. This pushed us to benefit from such technologies for early miscarriage prediction. This research study proposes to combine the use of Big Data analytics and data mining models applied to smartphones real-time generated data. A K-means data mining algorithm is used for clustering the dataset and results are transmitted to pregnant woman to make quick decisions; with the intervention of her doctor; through an android mobile application that we created. As well, she receives recommendations based on her behavior. We used real-world data to validate the system and assess its performance and effectiveness. Experiments were made using the Big Data Platform Databricks.

Comprehensive miscarriage dataset for an early miscarriage prediction

We present risk factors for predicting miscarriage. Our data is created through an android mobile application that collects automatically real-time data about the pregnant woman. This process is done every 60 s while the mobile application is on active mode. We distinguish two types of data: data from mobile phone and data from healthcare sensors. Data generated is real and concerns real pregnant women to test and validate the proposed system and assess its performance and effectiveness.

Prevalence of Vitamin D Deficiency during Second Trimester of Pregnancy in Shanghai China, Risk Factors and Effects on Pregnancy Outcomes

BACKGROUND

Vitamin D plays important roles in various physiological processes. Vitamin D deficiency is common among pregnant women in some regions, such as China. Our study aimed to determine the prevalence of Vitamin D deficiency during second trimester of pregnancy in Shanghai China, and explore its risk factors and effects on pregnant outcomes.

METHODS

Overall, 23100 pregnant women (2013 to 2017, Shanghai, China) were included and vitamin D concentrations were measured at 16 weeks of gestation. Correlations between vitamin D concentrations and participants' general data and maternal and infant outcomes were analyzed by chi square test. Non-conditional multivariate logistic regression analysis was used to screen the independent risk factors for vitamin D deficiency.

RESULTS

Vitamin D deficiency was significantly correlated with aging, education level, smoking, dirking, BMI before pregnancy, body weight gain during pregnancy (P<0.01), the use of vitamin D supplement and milk consumption, and older than 30 years, drinking, smoking, BMI before pregnancy> 36, body weight gain during pregnancy< 40g per day, no daily milk consumption, no vitamin D supplement, and education lever below college were independent risk factors for vitamin D deficiency in second trimester of pregnancy. In addition, vitamin D deficiency in second trimester of pregnancy was closely correlated with the occurrence of a serious of adverse maternal and infant outcomes.

CONCLUSION

Vitamin D deficiency was still common among women in second trimester of pregnancy in Shanghai China. Vitamin D deficiency was closely correlated with the occurrence of a serious of adverse maternal and infant outcomes.

Reproductive Health Concerns Among Female Firefighters

There has been little research conducted on the reproductive health of female firefighters. The purpose of this study was to determine whether female reproductive health is a concern among firefighters and to identify key associated issues. Eighty-seven United States (US) firefighters participated in focus groups or interviews. Themes were created using grounded theory with NVivo analysis software and a three-phase coding process. The major finding emerging from the study is that female firefighter reproductive health is a significant concern among firefighters.

Miscarriage and occupational activity: a systematic review and meta-analysis regarding shift work, working hours, lifting, standing, and physical workload

OBJECTIVE

Previous studies have indicated that shift work, long working hours, and prevalent workplace exposures such as lifting, standing, and physical workload increase the risk of miscarriage, but the evidence is conflicting. We conducted a systematic review of original research reports.

METHODS

A search in Medline and EMBASE 1966-2012 identified 30 primary papers reporting the relative risk (RR) of miscarriage according to ≥1 of 5 occupational activities of interest. Following an assessment of completeness of reporting, confounding, and bias, each risk estimate was characterized as more or less likely to be biased. Studies with equivalent measures of exposure were pooled to obtain a weighted common risk estimate. Sensitivity analyses excluded studies most likely to be biased.

RESULTS

Working fixed nights was associated with a moderately increased risk of miscarriage (pooled RR 1.51 [95% confidence interval (95% CI) 1.27-1.78, N=5), while working in 3-shift schedules, working for 40-52 hours weekly, lifting >100 kg/day, standing >6-8 hours/day and physical workload were associated with small risk increments, with the pooled RR ranging from 1.12 (3-shift schedule, N=7) to 1.36 (working hours, N=10). RR for working hours and standing became smaller when analyses were restricted to higher quality studies.

CONCLUSIONS

These largely reassuring findings do not provide a strong case for mandatory restrictions in relation to shift work, long working hours, occupational lifting, standing, and physical workload. Considering the limited evidence base, however, it may be prudent to advise women against work entailing high levels of these exposures and women with at-risk pregnancies should receive tailored individual counseling.

Prevalence of exposure to occupational risks during pregnancy in Spain

OBJECTIVES

We describe reported exposures to main categories of occupational agents and conditions in Spanish pregnant workers.

METHODS

Women were recruited at 12th week of pregnancy from main public gynaecological consults to be included in the INMA Spanish cohorts study (n=2,058). Through personal interviews with structured questionnaires, information on working situation and working conditions during pregnancy was obtained.

RESULTS

Fifty percent of the women reported frequent exposure to physical load (standing, heavy lifting) and 45% reported exposure to three or more indicators of job strain. Exposure to at least one physical agent (noise, vibrations, etc.) affected 25% of the women. Exposure to chemicals was reported by 20% of the women, mostly including solvents and cleaning products. Eight percent of the women worked at night shifts. Job strain was more prevalent in office workers and industrial operators. Industrial workers showed the highest prevalence of exposure to chemical and physical pollutants.

CONCLUSIONS

Our data suggest that working conditions of pregnant women may need increased control in Spain.