Association of induced abortion with preterm birth risk in first-time mothers

The effect of previous induced abortion history on the assisted reproduction outcomes

PURPOSE

To study whether the history of induced abortion has an effect on the assisted reproduction outcomes in patients undergoing in vitro fertilization-embryo transfer (IVF-ET).

METHODS

3045 patients who underwent IVF-ET in the Department of Human Reproductive Center of Renmin Hospital from January 2017 to June 2021. They were divided into two groups according to whether there was a history of induced abortion in the past, and the outcomes were compared between the two groups.

RESULTS

The clinical pregnancy rate in the group with induced abortion history was lower than that in the group without induced abortion history (63.1% vs 67.1%), but the difference was not statistically significant (P = 0.059). The spontaneous abortion rate in the group with induced abortion history was higher than that in the group without induced abortion history (14.9% vs 11.2%) (P = 0.044). The live birth rate in the group with induced abortion history was lower than that in the group without induced abortion history (52.8% vs 59.0%) (P = 0.006). Stepwise logistic regression analysis showed that endometrial thickness (OR = 0.928, 95% CI = 0.886 ~ 0.972, P = 0.002) and live birth rate (OR = 0.682, 95% CI = 0.495 ~ 0.939, P = 0.019) were negatively correlated with induced abortion history. The rate of spontaneous abortion (OR = 1.452, 95% CI = 1.042 ~ 2.024, P = 0.028) was positively correlated with the history of induced abortion.

CONCLUSIONS

The previous history of induced abortion is related to the outcomes of IVF /ICSI-ET, the endometrial thickness on HCG trigger day decreased, the risk of spontaneous abortion increased and the live birth rate decreased in patients with induced abortion history when undergoing IVF/ICSI-ET.

Gestational age at birth in pregnancies with antenatal corticosteroid administration in relation to risk factors: a retrospective cohort study

Background

The aim was to investigate gestational age at birth of women after induction of fetal lung maturation (antenatal corticosteroids = ACS) because of imminent preterm birth (PTB), and to quantify incidence of late PTB (gestational age < 260 days) and extreme immaturity (gestational age < 196 days) in relation to several diagnoses (PPROM, placental bleeding, premature labor, preeclampsia, oligohydramnios, amniotic infection syndrome (AIS), cervical insufficiency) and risk factors (age > 35, history of preterm delivery, multifetal gestation, gestational diabetes, hypertension, nicotine abuse).

Methods

The study was designed as a retrospective cohort trial, in which the data of all births taking place in 2016 in the German federal state Rhineland-Palatinate were evaluated. Frequency analyses, subgroup analysis (Chi-square tests and Friedman's tests), as well as multinomial logistic regressions and linear regressions were used to determine odds ratios (OR).

Results

In total, N = 1,544 patients were included who had been hospitalized due to an imminent PTB and had received ACS, of whom 52% had a late PTB and 8% a PTB with extreme immaturity. Regarding the gestational age at birth, there were only minor differences between the individual risk factors and diagnoses, only AIS patients showed a significantly lower gestational age (mean: 207 days). A significantly increased risk of PTB with extreme immaturity was found in patients with AIS (OR = 5.57) or placental bleeding (OR = 2.10).

Conclusion

There is a need for further research in order to be able to apply therapeutic measures more accurately in relation to risk factors and diagnoses.

History of induced abortion and the risk of preterm birth: a retrospective cohort study

OBJECTIVES

To explore the relationship between a history of induced abortion and follow-up preterm birth.

METHODS

We performed a retrospective cohort study of 27,176 women aged 19 to 48 years old in the city of Dongguan. Participants were divided into two groups according to the history of induced abortion. We used log-binomial regression to estimate adjusted risk ratios of preterm birth (gestation at less than 37 weeks) and early preterm birth (gestation at less than 34 weeks) for women with a history of induced abortion. Four models adjusted for different baseline data were used to verify the stability of the results. We also performed a subgroup analysis and mediation effect analysis to control for the influence of confounding factors and analyzed the relationship between the number of abortions and subsequent preterm birth.

RESULTS

Our study included 2,985 women who had undergone a prior induced abortion. Women who reported having a prior induced abortion were more likely to have preterm births before 37 weeks and 34 weeks, with risk ratios of 1.18 (95% CI 1.02-1.36) and 1.65 (95% CI 1.23-2.21), respectively. The above associations were stable in all models. We also found that a history of induced abortion was independently associated with a higher risk of preterm birth and early preterm birth in the subgroups. After controlling for the indirect effect of demographic data, the direct effect of abortion history on follow-up preterm delivery was still significantly different. The higher the number of abortions, the greater the risk of subsequent preterm birth.

CONCLUSIONS

This study suggests that induced abortion increases the risk of subsequent preterm birth.

Cultural considerations and beliefs surrounding preterm birth in Kenya and South Africa

BACKGROUND

Preterm birth (PTB) is a global health epidemic, sub-Saharan Africa is severely impacted due to its limited healthcare resources. Pregnancy knowledge, cultural beliefs and practices play a role in the identification of risk and management of PTB. This study explored knowledge, understandings, cultural beliefs and attitudes to pregnancy and PTB, as well as cultural considerations for the introduction of an intravaginal device which could be used to identify PTB risk.

METHODS

Qualitative research was conducted in South Africa and Kenya. In-depth interviews were conducted using semi-structured guides with women with a history of PTB (n = 10), healthcare providers (n = 16) and health systems experts (n = 10); and 26 focus group discussions with pregnant women seeking antenatal care (n = 132) and community male partners/fathers (n = 54). Interviews/discussions were transcribed, translated, and analysed thematically.

RESULTS

Pregnancy knowledge, especially for first time pregnancies was poor, with many reporting late entry to antenatal care. Knowledge about PTB was understood in terms of gestational age, weight or small size of baby, with concerns about long term health and stigma. Various risk factors for PTB were described, including those related to traditions and beliefs of witchcraft/curses. Cultural practices, such as the use of traditional medicines and pica, and religion and its impact on health seeking behaviour were also viewed as risk factors. Although insertion of intravaginal devices was not widely acceptable in traditional communities, especially during pregnancy, it was felt that the use of one to detect risk of PTB would be accepted if proven effective in reducing PTB risk.

CONCLUSIONS

Various culturally-informed beliefs exist which explain understandings of and attitudes toward pregnancy, pregnancy risk, and PTB. An inclusive exploratory process is critical to facilitate an understanding of the beliefs and traditions which could impact the introduction and design of a product to detect the risk of PTB.

Vaginal and oral probiotics effect in the prevention of preterm delivery in patients visiting Kamali Hospital, Karaj, Iran in 2020

INTRODUCTION

The prevalence of preterm labor (PTL) is growing, and annually one in ten babies is born prematurely. Various studies have examined the effect of oral or vaginal probiotics on the prevention of preterm labor, which has yielded contrasting results. This study aimed to compare the impact of vaginal and oral probiotics on the prevention of preterm delivery.

METHODS

This clinical trial was performed among 185 pregnant women with a gestational age greater than or equal to 25 weeks visiting Kamali Hospital, Karaj, Iran in 2020. The participants were divided into three groups; intervention group 1 receiving Oral probiotic pill once a day until 37 weeks of pregnancy, intervention group 2 receiving probiotic vaginal suppository once a day until 37 weeks of pregnancy, and control group not receiving any intervention. Patients were then followed up until the end of pregnancy.

RESULTS

Demographic characteristics and gestational age at the time of intervention were not significantly different among the three groups. Overall, 26.7 % in the control group, 30 % in intervention group 1 %, and 22.5 % in intervention group 2 had deliveries less than 37 weeks. There was no significant difference in the frequency of preterm labor and the duration of pregnancy among the groups (all p > 0.05).

CONCLUSION

Probiotics use does not increase the rate of preterm delivery or reduce the duration of pregnancy, but the rate of preterm delivery was lower in the oral probiotic group. Further clinical studies on the impact of probiotics on PTL can yield valuable results.

The type of previous abortion modifies the association between air pollution and the risk of preterm birth

BACKGROUND

Air pollution and previous abortion have been reported to be related to preterm birth (PTB). But rare study examined the effect of air pollution on PTB risk among mothers with previous abortion.

OBJECTIVE

To estimate the effect of air pollution on PTB and the potential effect modification of previous abortion on such an association in rural part of Henan province (China).

METHOD

Based on National Free Preconception Health Examination Project (NFPHEP), information from the medical records of 57,337 mothers with previous abortion were obtained. An inverse distance-weighted model was used to estimate exposure levels of air pollutants. The effect of air pollution on the risk of PTB was estimated with a multiple logistic regression model. Stratified and interaction analyses were undertaken to explore the potential effect modification of previous abortion on this association.

RESULTS

The risk of PTB was positively associated with exposure to levels of nitrogen dioxide (NO₂; OR: 1.03; 95%CI: 1.02-1.04)], and sulfur dioxide (SO₂; 1.04; 1.02-1.07), and negatively associated with ozone (O₃) exposure (0.97; 0.97-0.98) during the entire pregnancy. Besides, we observed a positive effect of carbon monoxide (CO) exposure during the third trimester of pregnancy on PTB (1.14; 1.01-1.29). The type of previous abortion could modify the effect of air pollution on the PTB risk (P-_interaction < 0.05). Compared with mothers with previous induced abortion, mothers with previous spontaneous abortion carried a higher risk of PTB induced by NO₂, CO, and O₃.

CONCLUSIONS

The risk of PTB was positively associated with levels of NO₂, SO₂ and CO, and negatively associated with the O₃ level. The types of previous abortion could modify the effect of air pollution on PTB. Mothers who had an abortion previously, especially spontaneous abortion, should avoid exposure to air pollution to improve their pregnancy outcome.

Establishment of an Artificial Neural Network Model Using Immune-Infiltration Related Factors for Endometrial Receptivity Assessment

Background: A comprehensive clinical strategy for infertility involves treatment and, more importantly, post-treatment evaluation. As a component of assessment, endometrial receptivity does not have a validated tool. This study was anchored on immune factors, which are critical factors affecting embryonic implantation. We aimed at establishing novel approaches for assessing endometrial receptivity to guide clinical practice. Methods: Immune-infiltration levels in the GSE58144 dataset (n = 115) from GEO were analysed by digital deconvolution and validated by immunofluorescence (n = 23). Then, modules that were most associated with M1/M2 macrophages and their hub genes were selected by weighted gene co-expression network as well as univariate analyses and validated using the GSE5099 macrophage dataset and qPCR analysis (n = 19). Finally, the artificial neural network model was established from hub genes and its predictive efficacy validated using the GSE165004 dataset (n = 72). Results: Dysregulation of M1 to M2 macrophage ratio is an important factor contributing to defective endometrial receptivity. M1/M2 related gene modules were enriched in three biological processes in macrophages: antigen presentation, interleukin-1-mediated signalling pathway, and phagosome acidification. Their hub genes were significantly altered in patients and associated with ribosomal, lysosomal, and proteasomal pathways. The established model exhibited an excellent predictive value in both datasets, with an accuracy of 98.3% and an AUC of 0.975 (95% CI 0.945–1). Conclusions: M1/M2 polarization influences endometrial receptivity by regulating three gene modules, while the established ANN model can be used to effectively assess endometrial receptivity to inform pregnancy and individualized clinical management strategies.

Evaluation of maternal risk factors for preterm delivery in Fatemieh Hospital of Hamadan, Iran, 2019: A case-control study

Background

The present study aimed to evaluate maternal risk factors of preterm delivery in Fatemieh Hospital in Hamadan, Iran, 2019.

Methods

In this case-control study, 7,478 hospital files of live-born neonates and their mothers in Hamadan Fatemieh Hospital in 2019 were examined. According to statistical estimates, 261 preterm deliveries and 736 term deliveries were studied. Information files of neonates and mothers were used to complete the study questionnaire. The data were compared in two separate groups and logistic regression was performed to estimate the crude relationship between demographic and clinical characteristics of term and preterm delivery.

Results

The mean age of women was 27.89 ± 6.48 years. Analysis of data revealed that academic education (OR: 2.02, P = 0.014), age group 25-34 years (OR: 1.5, P = 0.016), age of 35 years and above (OR: 1.66, P = 0.018), previous history of preterm delivery (OR: 5.3, P < 0.001), history of abortion (OR: 1.67, P = 0.004), history of surgery (OR: 1.54, P = 0.007), history of infertility (P = 0.016), and a history of cesarean (OR: 2.11, P < 0.001) were potentially associated with a higher odds of preterm delivery (P < 0.2).

Conclusion

Based on the results, it is important to identify potential risk factors of preterm delivery in mothers and corrective interventions in strengthening consultation and education of pregnant women during pregnancy. Such a measure helps select the type of delivery and strengthen prenatal care in identifying mothers in high-risk groups and performing timely interventions.

Incidence and trend of preterm birth in China, 1990-2016: a systematic review and meta-analysis

OBJECTIVES

To update the WHO estimate of preterm birth rate in China in 1990-2016 and to further explore variations by geographic regions and years of occurrence.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Pubmed, Embase, Cochrane Library and Sinomed databases were searched from 1990 to 2018.

ELIGIBILITY CRITERIA

Studies were included if they provided preterm birth data with at least 500 total births. Reviews, case-control studies, intervention studies and studies with insufficient information or published before 1990 were excluded. We estimated pooled incidence of preterm birth by a random effects model, and preterm birth rate in different year, region and by livebirths or all births in subgroup analyses.

RESULTS

Our search identified 3945 records. After the removal of duplicates and screening of titles and abstracts, we reviewed 254 studies in full text and excluded 182, leaving 72 new studies. They were combined with the 82 studies included in the WHO report (154 studies, 187 data sets in total for the meta-analysis), including 24 039 084 births from 1990 to 2016. The pooled incidence of preterm birth in China was 6.09% (95% CI 5.86% to 6.31%) but has been steadily increasing from 5.36% (95% CI 4.89% to 5.84%) in 1990-1994 to 7.04% (95% CI 6.09% to 7.99%) in 2015-2016. The annual rate of increase was about 1.05% (95% CI 0.85% to 1.21%). Northwest China appeared to have the highest preterm birth rate (7.3%, 95% CI 4.92% to 9.68% from 1990 to 2016).

CONCLUSIONS

The incidence of preterm birth in China has been rising gradually in the past three decades. It was 7% in 2016. Preterm birth rate varied by region with the West having the highest occurrence.

Exploring the association between adverse maternal circumstances and low birth weight in neonates: a nationwide population-based study in Bangladesh

OBJECTIVE

This study is concerned with helping to improve the health and care of newborn babies in Bangladesh by exploring adverse maternal circumstances and assessing whether these are contributing towards low birth weight (LBW) in neonates.

STUDY DESIGNS AND SETTINGS

Data were drawn and analysed from the Bangladesh Demographic and Health Survey, 2014. Any association between LBW and adverse maternal circumstances were assessed using a Chi-square test with determinants of LBW identified by multivariate logistic regression analysis.

PARTICIPANTS

The study is based on 4728 children aged below 5 years and born to women from selected households.

RESULTS

The rate of LBW was around 19.9% (199 per 1000 live births) with the highest level found in the Sylhet region (26.2%). The rate was even higher in rural areas (20.8%) and among illiterate mothers (26.6%). Several adverse maternal circumstances of the women included in the survey were found to be significant for increasing the likelihood of giving birth to LBW babies. These circumstances included the women being underweight (adjusted odds ratio (AOR) 1.26, 95% CI 1.06 to 1.49); having unwanted births (AOR 1.22, 95% CI 1.03 to 1.44); had previous pregnancies terminated (AOR 1.28, 95% CI 1.05 to 1.57); were victims of intimate partner violence (AOR 1.23, 95% CI 1.05 to 1.45) and taking antenatal care <4 times (AOR 1.23, 95% CI 1.03 to 1.48). Other important risk factors that were revealed included age at birth <18 years (AOR 1.42, 95% CI 1.11 to 1.83) and intervals between the number of births <24 months (AOR 1.25, 95% CI 1.01 to 1.55). When taking multiple fertility behaviours together such as, the ages of the women at birth (<18 years with interval <24 months (AOR 1.26, 95% CI 1.02 to 1.57) and birth order (>3 with interval <24 months (AOR 1.68, 95% CI 1.18 to 2.37), then the risk of having LBW babies significantly increased.

CONCLUSION

This study finds that adverse maternal circumstances combined with high-risk fertility behaviours are significantly associated with LBW in neonates. This situation could severely impede progress in Bangladesh towards achieving the sustainable development goal concerned with the healthcare of newborns.

Association of induced abortion with hypertensive disorders of pregnancy risk among nulliparous women in China: a prospective cohort study

The relationship between induced abortion(IA) and hypertensive disorders of pregnancy(HDP) is inconclusive. Few studies have been conducted in China. In order to clarify the association between previous IA and risk of HDP, including gestational hypertension(GH) and pre-eclampsia(PE), we performed a community-based prospective cohort study enrolling 5191 eligible nulliparous women in selected 2 districts and 11 towns of Liuyang from 2013 to 2015. Multivariable logistic regression was conducted to examine whether IA was associated with HDP, GH and PE. Of the gravidea, 1378(26.5%) had a previous IA and 258(5.0%) diagnosed with HDP, including 141(2.7%) GH and 117(2.3%) PE. The difference in the incidence of GH and PE between gravidae having one versus those with two or more IAs was minimal. After adjustment for maternal age, body mass index at first antenatal visit, education, virus infection and history of medical disorders, previous IA was significantly associated with HDP (OR = 0.67, 95%CI = 0.49 to 0.91) and PE (OR = 0.61, 95%CI = 0.38 to 0.97), but not with GH (OR = 0.73, 95%CI = 0.49 to 1.10). Additional adjustment for occupation, living area, anemia, gestational diabetes mellitus, psychological stress, conception climate and infant sex, multivariable analysis provided similar results. In conclusion, previous IA was associated with a lower risk of PE among nulliparous women.

Determinants and adverse perinatal outcomes of low birth weight newborns delivered in Hawassa University Comprehensive Specialized Hospital, Ethiopia: a cohort study

Objective

Globally an estimated 15% to 20% of all births are low birth weight, representing more than 20 million births a year. Low birth weights are at a greater risk of both short and long-term sequels. Therefore, this study was conducted to assess determinants and perinatal outcomes of low birth weight newborns delivered in Hawassa University Comprehensive Specialized Hospital, Southern Ethiopia.

Results

A total of 420 mothers were included in the study with a response rate of 97%. The mean birth weights of the neonate were 3360 (± 870 SD) grams and the incidence of low birth weight was found to be 16.6% (95% CI 13.46–18.38). Previous abortion [RR = 1.87 (2.53, 12.5)], hypertensive disorder [RR = 4.59 (4.93, 42.7)], having < 4 antenatal visits [RR = 3.45 (2.35, 13.8)] and prematurity [RR = 18.2 (6.24, 34.5)] was increased the risk of low birth weight. Low birth weight neonates were associated with a low Apgar score [RR = 18.2 (6.24, 34.5)] and early neonatal death [RR = 18.2 (6.24, 34.5)]. For this, identifying populations at the greatest risk of previous abortion, hypertensive disorders of pregnancy and prematurity were the major priorities aimed at reducing low birth weight. Incorporate mental health in the prenatal visit, improving the care for a high-risk pregnant woman was also recommended.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4155-x) contains supplementary material, which is available to authorized users.

Prediction of Preterm Birth: Maternal Characteristics, Ultrasound Markers, and Biomarkers: An Updated Overview

There is not a single or combined screening method for preterm birth with high sensitivity which will truly identify the women at risk for preterm birth while also with high specificity to prevent unnecessary interventions and high treatment costs. Measurement of cervical length is the most cost-effective method that is used in clinical practice. Bedside tests have also been developed for detecting markers like fetal fibronectin, insulin-like growth factor binding protein-1 (IGFBP-1), interleukin-6, and placental alpha-macroglobulin-1. Taking the maternal history, health condition, and sociodemographical factors into consideration is recommended. Ultrasound markers apart from cervical length measurements as uterocervical angle and placental strain ratio are studied. Investigations on metabolomics, proteomics, and microRNA profiling have brought a new aspect on this subject. Maybe in the future, with clear identification of women at true risk for preterm birth, development of more effective preventive strategies will not be unfeasible.