Reproductive Factors and Risk of Spontaneous Abortion in the Jinchang Cohort

Predicting risk of the subsequent early pregnancy loss in women with recurrent pregnancy loss based on preconception data

BACKGROUND

For women who have experienced recurrent pregnancy loss (RPL), it is crucial not only to treat them but also to evaluate the risk of recurrence. The study aimed to develop a risk predictive model to predict the subsequent early pregnancy loss (EPL) in women with RPL based on preconception data.

METHODS

A prospective, dynamic population cohort study was carried out at the Second Hospital of Lanzhou University. From September 2019 to December 2022, a total of 1050 non-pregnant women with RPL were participated. By December 2023, 605 women had subsequent pregnancy outcomes and were randomly divided into training and validation group by 3:1 ratio. In the training group, univariable screening was performed on RPL patients with subsequent EPL outcome. The least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression were utilized to select variables, respectively. Subsequent EPL prediction model was constructed using generalize linear model (GLM), gradient boosting machine (GBM), random forest (RF), and deep learning (DP). The variables selected by LASSO regression and multivariate logistic regression were then established and compared using the best prediction model. The AUC, calibration curve, and decision curve (DCA) were performed to assess the prediction performances of the best model. The best model was validated using the validation group. Finally, a nomogram was established based on the best predictive features.

RESULTS

In the training group, the GBM model achieved the best performance with the highest AUC (0.805). The AUC between the variables screened by the LASSO regression (16-variables) and logistic regression (9-variables) models showed no significant difference (AUC: 0.805 vs. 0.777, P = 0.1498). Meanwhile, the 9-variable model displayed a well discrimination performance in the validation group, with an AUC value of 0.781 (95%CI 0.702, 0.843). The DCA showed the model performed well and was feasible for making beneficial clinical decisions. Calibration curves revealed the goodness of fit between the predicted values by the model and the actual values, the Hosmer-Lemeshow test was 7.427, and P = 0.505.

CONCLUSIONS

Predicting subsequent EPL in RPL patients using the GBM model has important clinical implications. Future prospective studies are needed to verify the clinical applicability.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry with the registration number of ChiCTR2000039414 (27/10/2020).

Prediction of pregnancy disorders in female workers in the industrial sector

Context

As female workers face a higher risk of exposure to workplace hazards than women in general, it is imperative that measures be put in place in the workplace to ensure safe and healthy pregnancies.

Objectives

This study aimed to analyze the effects of occupational hazards in the workplace environment on the potential for pregnancy disorders experienced by female workers.

Methods

This was an analytical, observational study with a case-control design. The participants were female workers who worked in industrial environments in both formal and nonformal industries. The inclusion criteria used in this study were female workers who had been or were pregnant at the time of the study, had worked in the industrial sector for at least one year, and did not smoke or consume alcohol. The samples were collected from 144 female workers. Midwives assisted in collecting data and conducting examinations of female workers. This study was conducted in Surabaya and Sidoarjo between June and December 2020. Data were analyzed descriptively, and a multivariable logistic regression test was performed. The study was conducted in accordance with the health protocols and prevention of COVID-19.

Results

The results showed that occupational hazards in the workplace environment that affect pregnancy disorders include workload (p = 0.004, OR = 28.676 (2.979-276.076); hot working environment (p = 0.014, OR = 3.077 (1.254-7.552); strong odors (p = 0.017, OR = 7.640 (1.436-40.656); shift work (p = 0.023, OR = 8.063 (1.337-48.623); irregular shift work (p = 0.018, OR = 7.371 (1.409-38.557); and night shift work (p = 0.015, OR = 11.780 (1.605-86.450).

Conclusions

Companies are expected to pay special attention to female workers regarding various workplace controls to prevent potential pregnancy-related disorders.

Reproductive factors and subsequent pregnancy outcomes in patients with prior pregnancy loss

BACKGROUND

At present, individualized interventions can be given to patients with a clear etiology of pregnancy loss to improve the subsequent pregnancy outcomes, but the current reproductive status of the patient cannot be changed. The aim of this study was to investigate the association between female reproductive status and subsequence pregnancy outcome in patients with prior pregnancy loss (PL).

METHODS

A prospective, dynamic population cohort study was carried out at the Second Hospital of Lanzhou University. From September 2019 to February 2022, a total of 1955 women with at least one previous PL were enrolled. Maternal reproductive status and subsequent reproductive outcomes were recorded through an electronic medical record system and follow-up. Logistic regression was used to evaluate the association between reproductive status and the risk of subsequent reproductive outcomes.

RESULTS

Among all patients, the rates of subsequent infertility, early PL, late PL, and live birth were 20.82%, 24.33%, 1.69% and 50.77% respectively. In logistic regression, we found that age (OR 1.08, 95% CI 1.04-1.13) and previous cesarean delivery history (OR 2.46, 95% CI 1.27-4.76) were risk factors for subsequent infertility in patients with PL. Age (OR 1.06, 95% CI 1.03-1.10), age at first pregnancy (OR 1.06, 95% CI 1.03-1.10), BMI (OR 1.06, 95% CI 1.02-1.11), previous PL numbers (OR 1.18, 95% CI 1.04-1.57) and without pre-pregnancy intervention (OR 1.77, 95% CI 1.35-2.24) were risk factors for non-live birth. Age (OR 1.06, 95% CI 1.03-1.09), age at first pregnancy (OR 1.06, 95% CI 1.02-1.09), BMI (OR 1.07, 95% CI 1.02-1.11), previous PL numbers (OR 1.15, 95% CI 1.02-1.31) and without pre-pregnancy intervention (OR 2.16, 95% CI 1.65-2.84) were risk factors for PL.

CONCLUSIONS

The reproductive status of people with PL is strongly correlated with the outcome of subsequent pregnancies. Active pre-pregnancy intervention can improve the subsequent pregnancy outcome.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry with the registration number of ChiCTR2000039414 (27/10/2020).

Role of increased IGFBP2 in trophoblast cell proliferation and recurrent spontaneous abortion development: A pilot study

Recurrent spontaneous abortion (RSA) is a serious condition that adversely affects women's health. Differentially expressed proteins (DEPs) in plasma of patients experiencing RSA is helpful to find new therapeutic targets and identified with mass spectrometry. In 57 DEPs, 21 were upregulated and 36 were downregulated in RSA. Gene ontology analyses indicated that identified DEPs were associated with cell proliferation, including significantly downregulated insulin-like growth factor binding protein 2 (IGFBP2). Immunohistochemical result using clinical decidual tissues also showed that IGFBP2 expression was significantly decreased in RSA trophoblasts. Cell proliferation assay indicated that IGFBP2 treatment increased the proliferation and mRNA expressions of PCNA and Ki67 in trophoblast cells. Transcriptome sequencing experiments and Kyoto Encyclopedia of Genes and Genomes analyses revealed that gene expression for components in PI3K-Akt pathway in trophoblasts was significantly upregulated following IGFBP2 treatment. To confirm bioinformatics findings, we did cell-based experiments and found that treatment of inhibitors for insulin-like growth factor (IGF)-1 receptor-PI3K-Akt pathway significantly reduced IGFBP2-induced trophoblast cell proliferation and mRNA expressions of PCNA and Ki67. Our findings suggest that IGFBP2 may increase trophoblast proliferation through the PI3K-Akt signaling pathway to affect pregnancy outcomes and that IGFBP2 may be a new target for future research and treatment of RSA.

Reproductive outcomes among female health care workers

OBJECTIVE

Occupational exposures may be associated with reproductive health and pregnancy outcomes. This study investigated the association between occupational exposures and reproductive health, pregnancy outcomes, and the lactation period among hospital staff.

MATERIALS AND METHODS

Seven hundred thirty-three female healthcare workers from hospitals affiliated with the Tehran University of Medical Sciences were invited to participate in this cross-sectional study. The measurement method for fertility consequences was self-report. Demographic characteristics, occupational data, medical history, and reproductive history were collected via data collection form. Finally, reproductive outcomes were evaluated in different occupational hazard categories.

RESULT

Chemical exposures (solvents) were a risk factor for stillbirth. Prolonged working hours were associated with spontaneous abortion and breastfeeding periods. Shift workers did not have a higher frequency of reproductive and pregnancy outcomes, but the breastfeeding period was significantly decreased in shift workers. Psychiatric disorders were associated with preterm labour, low birth weight, and stillbirth in sequence with nervousness, depression, and mood disturbance. Furthermore, depression affects the breastfeeding period. Moreover, we found a link between job titles and infertility. In addition, socioeconomic status was related to stillbirth and infertility.

CONCLUSION

The study revealed that chemical and ergonomic exposures have associations with some reproductive outcomes. We also conclude that shift work could adversely affect the breastfeeding period. So, implementing some organizational strategies to control adverse health effects of occupational hazards and modifying shift work and working hours for nursing mothers is recommended.

Recurrent Abortion and the Involvement of Killer-Cell Immunoglobulin-like Receptor (KIR) Genes, Activated T Cells, NK Abnormalities, and Cytokine Profiles

Immune tolerance at the feto-maternal interface is crucial for the growth of the semi-allograft fetus in the womb. The outcome of pregnancy is dependent on a fine balance between various immunological forces. For a long time, the potential role of the immune system in pregnancy disorders has remained enigmatic. Current evidence has revealed that natural killer (NK) cells are the predominant immune cell population in the uterine decidua. NK cells cooperate with T-cells to provide an optimal microenvironment for the growth of the developing fetus by producing cytokines, chemokines, and angiogenic factors. These factors support trophoblast migration and angiogenesis which regulates the process of placentation. NK cells differentiate between "self" and "non-self" through their surface receptors known as killer-cell immunoglobulin-like receptors (KIRs). They induce immune tolerance through communication via their KIR and fetal human leucocyte antigens (HLA). KIRs are surface receptors of NKs that comprise both activating and inhibiting receptors. Due to the wide diversity manifested by its genes, the KIR repertoire is different in each individual. Significant evidence has implicated KIRs in recurrent spontaneous abortion (RSA); however, maternal KIR gene diversity in RSA is still unclear. Research has shown that immunological aberrancies including activating KIRs, NK abnormalities, and T cell downregulation are risk factors for RSA. In this review, we discuss relevant data from experimental studies on NK cell abnormalities, KIR, and T-cells in the incidence of recurrent spontaneous abortion.

A predicting model of child-bearing-aged women' spontaneous abortion by co-infections of TORCH and reproductive tract

To develop a predicting model of child-bearing-aged women' spontaneous abortion (SA) by co-infections of TORCH and reproductive tract, in order to provide a reference tool for accurately predicting the risk of SA and guide the early prevention, diagnosis and treatment of SA. A prospective cohort study was designed based on 218 958 child-bearing-aged women following up in Hebei province in China from 2010 to 2017. Multivariable logistic regression analysis was used to select candidate predictive variables. Fisher's discriminant analysis was performed to build a predictive model, and the validity of the model was evaluated. The incidence rate of SA was 2.4%. Multivariable logistic regression analysis showed that age (OR = 3.507), adverse pregnancy history (OR = 1.509), co-infections status of Candida and HBsAg (OR_{Candida positive×HBsAg negative}  = 4.091, OR_{Candida negative×HBsAg positive}  = 3.327, and OR_{Candida positive×HBsAg positive}  = 13.762), and co-infections status of HBsAg, Rubella (IgG) and CMV (IgG) (OR_{HBs-Ag negative×Rubella (IgG) negative×CMV (IgG) positive}  = 1.789, OR_{HBs-Ag positive×Rubella (IgG) positive×CMV (IgG) negative}  = 3.809, and OR_{HBsAg positive×Rubella (IgG) positive×CMV (IgG) positive}  = 11.919) were the independent predictors of SA. The total discriminant rate reached 91%, with 82% of the sensitivity and 91% of the specificity. The predicting model of child-bearing-aged women' SA by co-infections status has a good performance. The co-infection status of TORCH and reproductive tract are suggested to be considered in pre-pregnancy physical examination.

The relationship between vitamin D and spontaneous abortion among Iraqi women

Miscarriage is the most common complication of pregnancy. Moreover, vitamin D deficiency is a prevalent concern among women of reproductive age, particularly in the Arab world, where the link between vitamin D deficiency and miscarriage is still unknown. This study was conducted to determine the relationship between vitamin D and miscarriage by comparing the concentration of vitamin D among women with spontaneous abortion and pregnant women. A total of 80 subjects were enrolled in this study and divided into two groups. The first group included 40 women with spontaneous abortions aged between 18 and 40 years. The second group included 40 pregnant women without previous history of miscarriages. Total 25-hydroxy vitamin D (25-OH-VD) measurement was estimated with a Dry Fluorescence Immunoassay analyzer using the Lansionbio LS-1100 instrument. The relationship between the five age groups and the vitamin D status of women with spontaneous abortion was not significant (p>0.05). There was no significant relationship between the miscarriage trimesters and vitamin D status (p>0.05) and between the five age groups (p>0.05). In our study, 95% of women with spontaneous abortion had vitamin D deficiency, compared to only 17.5% of pregnant women. A normal range of vitamin D improves the growth of the fetus and prevents pregnancy complications and miscarriage, promoting the growth of blood vessels in the placenta and improving the function of immune cells.

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.

The Risk of Spontaneous Abortion Does Not Increase Following First Trimester mRNA COVID-19 Vaccination

Clinical trials for COVID-19 vaccines initially excluded pregnant women due to safety concerns, and when the vaccines were authorized for emergency use, they were not recommended for this population. However, observational studies discovered that pregnant women infected with COVID-19 have higher risks of negative pregnancy and delivery outcomes compared to non-pregnant women, raising the question of the risks–benefits of administering COVID-19 vaccines to pregnant women. By mid-2021, there was general consensus on the relative safety of COVID-19 vaccination during pregnancy; therefore, it is critical to investigate the safety issues related to these vaccines, considering the increasing acceptance among pregnant women. To address these concerns, we developed a research project to study the short-term effects and outcomes of COVID-19 vaccination during the first trimester of pregnancy. Our research followed an observational retrospective design for 12 months from the beginning of the vaccination campaign, and included 124 cases of spontaneous abortions and 927 ongoing pregnancies. The odds of spontaneous abortion were non-significant for both versions of the mRNA vaccine (Pfizer BNT162b2 AOR = 1.04, CI = 0.91–1.12; Moderna mRNA-1273 AOR = 1.02, CI = 0.89–1.08). Overall, our data indicated that the risk of spontaneous abortion after mRNA COVID-19 immunization during the first trimester of pregnancy is commensurate with the predicted risk in non-vaccinated pregnant women. These findings contribute to the growing body of information regarding the safety of mRNA COVID-19 vaccination during pregnancy.

Increased incidence of spontaneous abortions on exposure to cadmium and lead: a systematic review and meta-analysis

BACKGROUND

Spontaneous abortions are the most severe complication of early pregnancy and are a major reproductive health problem. Although this could be caused due to various cytogenetic, immunological, or endocrinological reasons, role of environmental toxicants cannot be ruled out. In order to explore the role of cadmium and lead in causing spontaneous abortions, current systematic review and meta-analysis had been carried out.

METHODOLOGY

Literature search was performed using appropriate keywords in PubMed, Science Direct, Cochrane Library, and Google Scholar databases up to December 25 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Metananalysis was carried out with the help of RevMan software (version 5.3).

RESULTS

Meta-analysis of nine studies on cadmium concentrations in blood of women with at least one spontaneous abortions and controls revealed standardized mean difference (SMD)=3.39, 95% CI (2.17, 4.61), with p < .05. Similarly, meta-analysis of eight studies on lead concentrations revealed standardized mean difference (SMD)=6.24, 95% CI (4.34, 8.14), with p < .05.

CONCLUSION

Populations exposed to heavy metals such as cadmium and lead are at higher risk of pregnancy loss. Therefore, couples experiencing repeated pregnancy losses may be screened for heavy metal load.

Association of M55L and Q192R polymorphisms of paraoxonase 1 gene (PON1) with recurrent pregnancy loss risk: A case-control study

Background

Recurrent pregnancy loss (RPL) refers to the incidence of two or more abortions before the first half of pregnancy. Oxidative stress has been hypothesized to play a central role in RPL.

Objective

To investigate the relationship between Q192R and L55M polymorphisms of PON1 as antioxidant enzyme and the risk of RPL.

Materials and Methods

In this case–control study, 110 women with RPL (case) and 110 healthy fertile women (control) referred to the Research and Clinical Center for Infertility, Shiraz, Iran were enrolled. Genomic DNA was extracted from the peripheral blood in all participants. Polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism method.

Results

Statistical analysis of Q192R polymorphism showed a significant difference for the RR genotype between the case and control group (OR = 11, CI = 1.39–86.87, p = 0.005) but none for the QR and QQ genotypes. No significant association was observed between the R and Q allelic frequency in the RPL participants compared to the control group (p = 0.53). Also, statistical analysis of the L55M polymorphism for MM genotype in the case group compared with the control group showed a significant difference (OR = 3.59, CI = 0.97–13.30, p = 0.042), but none for the LM and LL genotypes.

Conclusion

The findings showed a significant correlation between the Q192R polymorphisms and the L55M PON1 enzyme and RPL in this study population.

Risk factors associated to neural tube defects among mothers who gave birth in North Shoa Zone Hospitals, Amhara Region, Ethiopia 2020: Case control study

INTRODUCTION

Neural tube defects affect the brain and the spinal cord of the developing embryo. The defects occur due to incomplete or failure of closure of the neural tube. The condition eventually causes death and lifelong disability. Worldwide, more than 300,000 babies are born with neural tube defects each year. The highest burden is in low- and middle-income countries. Therefore, this study aims to identify the risk factors associated with neural tube defects among mothers who gave birth in North Shoa Zone Hospitals.

METHODS

A hospital based unmatched case-control study was conducted among 243 (81 cases and 162 controls) study participants in North Shoa Zone Hospitals. The hospitals were selected using simple random sampling and all cases and randomly selected controls in the selected hospitals were included in the study. The data were collected by using pre-tested structured questionnaire.

RESULTS

Different factors were identified to have association with neural tube defect. Family annual cash income less than 24000ETB (AOR: 3.73, 95%CI: 1.35, 10.26), history of still birth (AOR: 3.63, 95%CI: 1.03, 12.2), history of abortion (AOR: 6.15, 95%CI: 2.63, 18.56), preconception tea use (AOR: 2.36, 95%CI: 1.15, 4.86) and pesticides/chemical exposure (AOR: 5.34, 95%CI: 1.77, 16.05) were positively associated factors. In contrast, preconception care (AOR: 0.14, 95%CI: 0.05, 0.39) and taking iron/folic acid/multivitamin during the current pregnancy (AOR: 0.16, 95%CI: 0.07, 0.33) showed a protective effect.

CONCLUSION

Family annual income less than 24000ETB, history of still birth, history of abortion, preconception tea uses and pesticides/chemical exposure were associated factors of neural tube defects. Preconception counseling and screening should be recommended for women who plan for pregnancy.

Risk factors for spontaneous abortion from a prevention perspective in rural China: a population-based follow-up study

OBJECTIVES

We conducted this study to investigate the risk factors for spontaneous abortion among rural Chinese women.

METHODS

Risk factors prior to pregnancy associated with spontaneous abortion were identified among 17,248 rural women enrolled in a prospective population-based follow-up study. The risk of spontaneous abortion was estimated with odds ratio (OR) and 95% confidence interval (CI) for several factors. A nonconditional logistic regression analysis was then performed to identify the independently associated factors.

RESULTS

The total sample of this study population consisted of 17,248 pregnant women including 921 of them whose pregnancies resulted in spontaneous abortion and the incidence of spontaneous abortion was 5.04%. After the adjustment of confounding factors, menarche age, serum creatinine, family genetic diseases or maternal congenital defects was associated with an increased risk of spontaneous abortion while folic acid supplementation reduced the risk among rural Chinese women.

CONCLUSIONS

The findings of our study suggest that multiple modifiable factors may increase the risk of spontaneous abortion which may help relevant departments better to guide detailed effectively prevention strategies toward spontaneous abortion to improve the reproductive quality of rural population. Further studies are required to elaborate these risk factors for spontaneous abortion.