Association Between Maternal Human Papillomavirus Infection and Adverse Pregnancy Outcomes: Systematic Review and Meta-Analysis

Association between human papillomavirus and preterm delivery: A systematic review and meta-analysis

INTRODUCTION

The lifetime prevalence of human papillomavirus infection (HPV) is estimated to be around 80% and it is the most common sexually transmitted infection. Despite being well known for its oncologic relevance, it has been associated with adverse pregnancy outcomes, though available evidence is contradicting. Previous meta-analyses involved articles which based HPV infection on Pap smear results, leading to a significant source of bias. Therefore, we aimed to assess the burden of genetically proven HPV infection on adverse pregnancy outcomes.

MATERIAL AND METHODS

In our meta-analysis, pregnant women tested for HPV DNA were only considered eligible. We conducted a systematic search in three major databases (PubMed, Embase, and CENTRAL) on September 22, 2023. Cohort, cross-sectional, and case-control studies were eligible for the analysis. The exposed group consisted of HPV-infected patients. We assessed the odds ratios (OR) with a confidence interval (CI) of 95%. In order to reduce the heterogeneity, we performed subgroup analyses based on different strains (high risk HPV, HPV 16/18, study design). The study was prospectively registered on PROSPERO (CRD42022370228).

RESULTS

Our study involved 14 articles with 7008 women. A significant association was found between preterm delivery and HPV infection (OR: 1.94, CI: 1.31-2.87). No significant association was found when separately examining high-risk HPV-infected women (OR: 1.94, CI: 0.82-4.59), and HPV 16 or 18-infected women (OR: 2.08, CI: 0.50-8.63) in terms of preterm delivery. No significant association was found between spontaneous abortion and HPV infection (OR: 1.02, CI: 0.16-6.31).

CONCLUSIONS

Our analysis indicates an association between HPV infection and preterm delivery. It is imperative that future studies consider confounding variables more comprehensively. Additionally, the global implementation of HPV vaccination programs holds significance not only in oncology but also in obstetrics.

Association between Human Papillomavirus 16 Viral Load in Pregnancy and Preterm Birth

Recent evidence shows increased preterm birth risk with human papillomavirus-16 (HPV16) infection during pregnancy. This study aimed to measure the association between HPV16 viral load during pregnancy and preterm birth. We used data from participants in the HERITAGE study. The Linear Array assay was used for HPV DNA testing on vaginal samples collected during the first and third trimesters of pregnancy. The HPV16 viral load was measured with a real-time polymerase chain reaction. We used logistic regression to measure the associations between HPV16 viral load during pregnancy and preterm birth (defined as birth before 37 weeks of gestation). The adjusted odd ratios (aORs) and the 95% confidence intervals [CIs] were estimated with inverse probability treatment weighting of the propensity score. This study included 48 participants who tested positive for HPV16 during the first trimester of pregnancy. The aOR for the association between first-trimester HPV16 viral load (higher viral load categorized with a cutoff of 0.5 copy/cell) was 13.04 [95% CI: 1.58-107.57]). Similar associations were found using different cutoffs for the categorization of viral load during the first and third trimesters. Our findings suggest a strong association between a high HPV16 viral load during pregnancy and preterm birth, demonstrating a biological gradient that reinforces the biological plausibility of a causal association.

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Vaccination during pregnancy: A golden opportunity to embrace

Immunization strategies are part of routine pregnancy care to prevent infectious diseases in the mother, the fetus, and the newborn. Maternal immunization recommendations followed the recognition of the consequences of infectious diseases in pregnancy, including vertical transmission and perinatal consequences. The recent COVID-19 pandemic highlighted the issue of vaccination among pregnant individuals. Recommendations vary globally; however, Tdap, influenza, and, recently, COVID-19 vaccines are routinely recommended during pregnancy. There are several new maternal immunization products in the pipeline, including those directed against malaria, cytomegalovirus, Group B Streptococcus, herpes simplex virus, and respiratory syncytial virus. Important challenges must be addressed in all countries to guarantee that pregnant individuals and their babies receive the best care possible, including uptake of recommended immunizations by their entire target population groups. These challenges include disseminating appropriate data for vaccine recommendations and many others, such as ensuring stakeholder endorsement, achieving in-country distribution and administration, adequate vaccine supply, and a well-organized healthcare system, ideally offering the immunization free of charge. More recently, the hesitancy of pregnant women to receive immunizations highlights the relevance of cultural aspects and other contextual factors affecting vaccine uptake among pregnant individuals.

Papillomavirus Infection as Potential Cause of Miscarriage in the Early Gestational Age: A Prospective Study

The possible association between human papillomavirus (HPV) infection and negative pregnancy outcomes has been debated in the literature, with conflicting results from clinical trials. While some authors support a link between HPV and miscarriage, others argue that the mere detection of the virus does not necessarily indicate a causal relationship with negative pregnancy outcomes. In this study, we conducted a prospective, controlled investigation of the potential association between HPV infection and miscarriage. Our study included 59 women who had experienced a miscarriage and 57 women who had undergone voluntary termination of pregnancy (TOP) within the 12th week of gestation. We assessed HPV prevalence, maternal age, and HPV genotype in both groups and evaluated the relationship between these factors and pregnancy outcome. Unlike previous studies that only identified HPV in cases of abortion, we also correlated the positivity of chorionic villi with gestational age in both groups. We found a close correlation between positive chorionic villi and very early gestational age, with all 13 cases of virus-positive chorionic villi in the miscarriage group occurring in gestational periods of less than 8 + 5 weeks (<60 days) (RR = 28.6). Our analysis showed no correlation between HPV infection and maternal age or viral genotypes. The results suggest that the presence of HPV alone is not enough to cause spontaneous abortion, but a high viral load in early pregnancy may increase the risk of negative outcomes. These findings have important implications for the management of HPV infection during pregnancy and may provide a rationale for the use of HPV vaccines to reduce the incidence of spontaneous abortion and infertility due to preclinical spontaneous abortions.

Risk factors for preterm labor: An Umbrella Review of meta-analyses of observational studies

Preterm birth defined as delivery before 37 gestational weeks, is a leading cause of neonatal and infant morbidity and mortality. Understanding its multifactorial nature may improve prediction, prevention and the clinical management. We performed an umbrella review to summarize the evidence from meta-analyses of observational studies on risks factors associated with PTB, evaluate whether there are indications of biases in this literature and identify which of the previously reported associations are supported by robust evidence. We included 1511 primary studies providing data on 170 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections and vaccines. Only seven risk factors provided robust evidence. The results from synthesis of observational studies suggests that sleep quality and mental health, risk factors with robust evidence should be routinely screened in clinical practice, should be tested in large randomized trial. Identification of risk factors with robust evidence will promote the development and training of prediction models that could improve public health, in a way that offers new perspectives in health professionals.

Exploring the potential impact of human papillomavirus on infertility and assisted reproductive technology outcomes

Human papillomavirus (HPV) is a common sexually transmitted disease that has been linked to both cancer and reproductive health issues. While its impact on fertility and pregnancy success has been studied, there is still too little evidence about the influence of HPV on assisted reproductive technology (ART). Therefore, there exists a need for HPV testing in couples undergoing infertility treatments. Infertile men have been found to have a higher prevalence of seminal HPV infection, which can compromise sperm quality and reproductive function. As such, it could be important to investigate the correlation between HPV and ART outcomes in order to improve the quality of evidence. Understanding the potentially detrimental effects of HPV on ART outcomes may have promising important implications for the management of infertility. This minireview summarizes the so far limited developments in this area and highlights the major need for further well-designed studies to address this issue.

Spontaneous preterm birth risk among HPV-vaccinated and -unvaccinated women: a nationwide retrospective cohort study of over 240 000 singleton births

OBJECTIVE

To determine whether prior human papillomavirus (HPV) vaccination contributes to preterm birth risk.

DESIGN

Population-based retrospective cohort study.

SETTING

Denmark.

POPULATION

A cohort of 243 136 primiparous females born in the period 1961-2004 who had a singleton delivery at >22 weeks of gestation occurring from October 2006 to December 2018.

METHODS

High-quality nationwide registries were linked to provide information on demographics, birth outcomes, HPV vaccination status, smoking, body mass index (BMI), and cervical lesions and treatment history.

MAIN OUTCOME MEASURES

We assessed the association between HPV vaccination status and spontaneous preterm birth using logistic regression. To address age at vaccination, we performed a stratified analysis by vaccination before and after 17 years of age.

RESULTS

In age-adjusted and fully adjusted models, there was a nonsignificant difference in the odds of spontaneous preterm birth between vaccinated and unvaccinated women (OR 1.05 (95% CI 0.99-1.12) and OR 1.04 (95% CI 0.98-1.10), respectively). There was no difference in the odds of spontaneous preterm birth in relation to time between vaccination and pregnancy. In contrast, compared with unvaccinated women, the odds of preterm birth were lower among women vaccinated before the age of 17 years (fully adjusted OR 0.87, 95% CI 0.75-1.00). This association was not present for women vaccinated at ≥17 years of age.

CONCLUSIONS

In this large, population-based cohort, we found reduced odds of spontaneous preterm birth among women vaccinated against HPV at an early age compared with women who were unvaccinated. It seems conceivable that HPV vaccination may not only reduce the incidence of cervical cancer and severe precursors, but also reduce the risk of preterm birth related to HPV infection.

Maternal human papillomavirus infection during pregnancy and preterm delivery: A mother-child cohort study in Norway and Sweden

INTRODUCTION

Human papillomavirus (HPV) infection is common in women of reproductive age. Infection and inflammation are leading causes for preterm delivery (PTD), but the role of HPV infection in PTD and prelabor rupture of membranes (PROM) is unclear. We aimed to explore whether HPV infection during pregnancy in general, and high-risk-HPV (HR-HPV) infection specifically, increased the risk of PTD, preterm prelabor rupture of membranes (PPROM), PROM at term, and/or chorioamnionitis.

MATERIAL AND METHODS

In pregnant women, who were participating in a prospective multicenter cohort study from a general population in Norway and Sweden (PreventADALL, ClinicalTrials.gov NCT02449850), HPV DNA was analyzed in available urine samples at mid-gestation (16-22 weeks) and at delivery, and in the placenta after delivery with Seegene Anyplex II HPV28 PCR assay. The risk of PTD, PPROM, PROM, and chorioamnionitis was analyzed using unadjusted and adjusted logistic regression analyses for any 28 HPV genotypes, including 12 HR-HPV genotypes, compared with HPV-negative women. Further, subgroups of HPV (low-risk/possibly HR-HPV, HR-HPV-non-16 and HR-HPV-16), persistence of HR-HPV from mid-gestation to delivery, HR-HPV-viral load, and presence of multiple HPV infections were analyzed for the obstetric outcomes. Samples for HPV analyses were available from 950 women with singleton pregnancies (mean age 32 years) at mid-gestation and in 753 also at delivery.

RESULTS

At mid-gestation, 40% of women were positive for any HPV and 24% for HR-HPV. Of the 950 included women, 23 had PTD (2.4%), nine had PPROM (0.9%), and six had chorioamnionitis (0.6%). Of the term pregnancies, 25% involved PROM. The frequency of PTD was higher in HR-HPV-positive women (8/231, 3.5%) than in HPV-negative women (13/573, 2.3%) at mid-gestation, but the association was not statistically significant (odds ratio 1.55; 95% confidence interval 0.63-3.78). Neither any HPV nor subgroups of HPV at mid-gestation or delivery, nor persistence of HR-HPV was significantly associated with increased risk for PTD, PPROM, PROM, or chorioamnionitis. No HPV DNA was detected in placentas of women with PTD, PPROM or chorioamnionitis.

CONCLUSIONS

HPV infection during pregnancy was not significantly associated with increased risk for PTD, PPROM, PROM, or chorioamnionitis among women from a general population with a low incidence of adverse obstetric outcomes.

Worldwide prevalence of human papillomavirus among pregnant women: A systematic review and meta-analysis

Human papillomavirus (HPV) is the causative agent of cervical cancer and a suspected agent for ovarian and endometrial cancers in women. It is associated with adverse outcomes during pregnancy. To date, there is no estimate of the prevalence of HPV infection in pregnant women at the regional and global levels. This study evaluated the global prevalence of HPV infection based on all observational studies that had reported the prevalence of HPV among pregnant women between January 1980 and December 2021 in PubMed/MEDLINE, Scopus, Web of Science, Embase, and SciELO databases. We utilised a random-effect model to determine the global prevalence and related risk factors of HPV infection. Between-studies heterogeneity was assessed using I² statistic. Moreover, subgroup and meta-regression analyses were employed to assess the source of heterogeneity and the relationship between HPV prevalence and socio-demographic factors, respectively. Among 144 eligible studies comprising 189 datasets, the overall prevalence rates of HPV at the 95% confidence interval (CI) were estimated as 30.38% (26.88%-33.99%), 17.81% (9.81%-27.46%), 32.1% (25.09%-39.67%), 2.26% (0.1%-8.08%) and 25.5% (23.3%-27.8%) in cervico-vaginal, placenta, serum, amniotic fluid and urine samples, respectively. The highest prevalence rates were estimated for countries in the African region, while countries in the European and Eastern Mediterranean regions showed the lowest prevalence rates. HPV-16 and -18 were the most prevalent isolated strains. The pregnant women living with HIV and those with pregnancy disorders had significantly higher prevalence rates than general pregnant women (p < 0.05). The younger ages for first intercourse and pregnancy, multiple lifetime sexual partners, and lower education levels were primary risk factors for HPV infection. In conclusion, although the overall HPV prevalence varied markedly based on sampling sites and geographical locations, the highest prevalence rates were observed in less-developed countries. Our findings imply that implementing behavioural and therapeutic interventions as well as vaccination programs are crucial to prevent and reduce the current burden of HPV infection among pregnant women.

Reproductive health needs of Human papillomavirus (HPV) positive women: A systematic review

Objectives

Human papillomavirus is one of the most important causes of cervical cancer. Participating in an HPV test and receiving an HPV diagnosis can create questions about the needs and preferences. The present systematic review was conducted to determine the reproductive health needs of women with HPV.

Methods

We searched PubMed, Scopus, Web of Science, Google Scholar and Magiran, SID and Iranmedex. Without language restrictions and time constraints. We also searched the grey literature and carried out forward/backward citation searches.

Results

In the first, 1056 articles were retrieved, and, after removing them, 13 articles published were entered. The studies were qualitative (N = 9), quantitative (N = 3), and one was unclear. Most qualitative studies collected data using individual interviews (N = 7), two qualitative studies, narratives of HPV patients from a website of patient experiences and questions. Women wanted further information on different HPV viral types, transmission, implications for sexual partners, prevalence, latency and regression of HPV, their management options and the implications of infection for cancer risk and fertility. Women’s experience of searching the Internet for further information about HPV was reported as difficult, anxiety provoking and contributing to the stigma of the infection because information was often located in the context of other sexually transmitted infections, with multiple sexual partners highlighted as a risk factor for infection.

Conclusion

Surveys showed that the majority of women had unanswered questions about their HPV test results. The information that women thought was helpful in interpreting their test results included having a high-risk type of HPV, and cancer survival statistics for the virus. Women also needed information about sexual transmission, how HPV tested positive in a long-term relationship, and the potential consequences for their partners and the risk of re-infection. Younger women had questions about whether HPV could affect fertility.

Prenatal exposure to ambient air pollution and adverse birth outcomes: An umbrella review of 36 systematic reviews and meta-analyses

Multiple systematic reviews and meta-analyses linked prenatal exposure to ambient air pollutants to adverse birth outcomes with mixed findings, including results indicating positive, negative, and null associations across the pregnancy periods. The objective of this study was to systematically summarise systematic reviews and meta-analyses on air pollutants and birth outcomes to assess the overall epidemiological evidence. Systematic reviews with/without meta-analyses on the association between air pollutants (NO₂, CO, O₃, SO₂, PM_2.5, and PM₁₀) and birth outcomes (preterm birth; stillbirth; spontaneous abortion; birth weight; low birth weight, LBW; small-for-gestational-age) up to March 30, 2022 were included. We searched PubMed, CINAHL, Scopus, Medline, Embase, and the Web of Science Core Collection, systematic reviews repositories, grey literature databases, internet search engines, and references of included studies. The consistency in the directions of the effect estimates was classified as more consistent positive or negative, less consistent positive or negative, unclear, and consistently null. Next, the confidence in the direction was rated as either convincing, probable, limited-suggestive, or limited non-conclusive evidence. Final synthesis included 36 systematic reviews (21 with and 15 without meta-analyses) that contained 295 distinct primary studies. PM_2.5 showed more consistent positive associations than other pollutants. The positive exposure-outcome associations based on the entire pregnancy period were more consistent than trimester-specific exposure averages. For whole pregnancy exposure, a more consistent positive association was found for PM_2.5 and birth weight reductions, particulate matter and spontaneous abortion, and SO₂ and LBW. Other exposure-outcome associations mostly showed less consistent positive associations and few unclear directions of associations. Almost all associations showed probable evidence. The available evidence indicates plausible causal effects of criteria air pollutants on birth outcomes. To strengthen the evidence, more high-quality studies are required, particularly from understudied settings, such as low-and-middle-income countries. However, the current evidence may warrant the adoption of the precautionary principle.

Racial discrimination and adverse pregnancy outcomes: a systematic review and meta-analysis

Introduction

Racial discrimination has been consistently linked to various health outcomes and health disparities, including studies associating racial discrimination with patterns of racial disparities in adverse pregnancy outcomes. To expand our knowledge, this systematic review and meta-analysis assesses all available evidence on the association between self-reported racial discrimination and adverse pregnancy outcomes.

Methods

Eight electronic databases were searched without language or time restrictions, through January 2022. Data were extracted using a pre-piloted extraction tool. Quality assessment was conducted using the Newcastle–Ottawa Scale (NOS), and across all included studies using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random effects meta-analyses were performed on preterm birth and small for gestational age. Heterogenicity was assessed using Cochran’s χ² test and I² statistic.

Results

Of 13 597 retrieved records, 24 articles were included. Studies included cohort, case–control and cross-sectional designs and were predominantly conducted in the USA (n=20). Across all outcomes, significant positive associations (between experiencing racial discrimination and an adverse pregnancy event) and non-significant associations (trending towards positive) were reported, with no studies reporting significant negative associations. The overall pooled odds ratio (OR) for preterm birth was 1.40 (95% CI 1.17 to 1.68; 13 studies) and for small for gestational age it was 1.23 (95% CI 0.76 to 1.99; 3 studies). When excluding low-quality studies, the preterm birth OR attenuated to 1.31 (95% CI 1.08 to 1.59; 10 studies). Similar results were obtained across sensitivity and subgroup analyses, indicating a significant positive association.

Conclusion

These results suggest that racial discrimination has adverse impacts on pregnancy outcomes. This is supported by the broader literature on racial discrimination as a risk factor for adverse health outcomes. To further explore this association and underlying mechanisms, including mediating and moderating factors, higher quality evidence from large ethnographically diverse cohorts is needed.

High-risk human papillomavirus infection in pregnant women: a descriptive analysis of cohorts from two centers

The aim was to descriptively analyze the clinical characteristics, cytopathology, and outcomes of pregnant patients with high-risk human papillomavirus (HPV) infection. Clinical data of 151,516 female patients with high-risk HPV infection were retrospectively collected. Baseline data, cervical cytology results, histopathology, HPV types, delivery mode, and follow-up outcomes were recorded for descriptive analysis. A total of 157 patients were identified as positive for high-risk HPV. There were 32 (24.2%), 6 (4.5%), and 107 (81.1%) cases of HPV-16, HPV-18, and other types, respectively. Additionally, 12 patients showed combined infection with HPV-18 or HPV-16 and other types. Cytopathological examinations showed that the most common type was low-grade squamous intraepithelial lesion (LSIL; 104 cases, 78.8%), followed by high-grade squamous intraepithelial lesion (HSIL; 17 cases, 12.8%), atypical squamous cells of undetermined significance (10 cases, 9.6%), and cervical cancer (1 case, 0.7%). Thirty-seven patients underwent colposcopic biopsy, of whom 9 (24.3%) showed normal results, while 12 (32.4%) and 13 (35.1%) patients had LSIL and HSIL, respectively. χ² tests demonstrated that different delivery modes did not show significant difference in patients' cervical cytopathology (p>0.05). However, therapeutic methods were statistically different among patients with different cytopathological types (p<0.05). Cervical alterations in pregnancy mostly go along with high-risk HPV infection. High-risk HPV infection in pregnancy with abnormal cervical cytology should be followed closely during the pregnancy and postpartum period.

Maternal HPV Infection and the Estimated Risks for Adverse Pregnancy Outcomes—A Systematic Review

Background: Human Papilloma Virus (HPV) represents the most prevalent genital infection in young women of reproductive age. Objective: This systematic review aims to estimate the effect of HPV infection during pregnancy and assess the correlation between HPV and adverse pregnancy outcomes. Materials and methods: The search strategy has been developed based on the PICOS framework: Population (pregnant women infected with HPV), Intervention (HPV infection confirmed by molecular tests), Comparator (pregnant women without HPV infection), Outcomes (adverse pregnancy outcomes) and Study design (observational studies). We searched PubMed, Web of Science, and Scopus databases on 8 January 2022 by using the following keywords: “HPV”, “prematurity”, “preterm birth”, “miscarriage”, “premature rupture of membranes”, “adverse pregnancy outcome”, “low birth weight”, “fetal growth restriction”, “pregnancy-induced hypertensive disorders”, “preeclampsia”. Selection criteria were HPV infection confirmed within maximum 2 years before pregnancy with a molecular test and adverse pregnancy outcomes. (Results: Although numerous studies are conducted on this topic, data are still controversial regarding identifying maternal HPV infection as a risk factor for adverse pregnancy outcomes. More prospective large cohort studies are needed to prove a causative relationship.

Breaking Down the Barrier: The Role of Cervical Infection and Inflammation in Preterm Birth

Approximately 40% of cases of spontaneous preterm birth (sPTB) are associated with ascending intrauterine infections. The cervix serves as a physical and immunological gatekeeper, preventing the ascent of microorganisms from the vagina to the amniotic cavity. The cervix undergoes remodeling during pregnancy. It remains firm and closed from the start until the late third trimester of pregnancy and then dilates and effaces to accommodate the passage of the fetus during delivery. Remodeling proceeds appropriately and timely to maintain the pregnancy until term delivery. However, risk factors, such as acute and chronic infection and local inflammation in the cervix, may compromise cervical integrity and result in premature remodeling, predisposing to sPTB. Previous clinical studies have established bacterial (i.e., chlamydia, gonorrhea, mycoplasma, etc.) and viral infections (i.e., herpesviruses and human papillomaviruses) as risk factors of PTB. However, the exact mechanism leading to PTB is still unknown. This review focuses on: (1) the epidemiology of cervical infections in pregnant patients; (2) cellular mechanisms that may explain the association of cervical infections to premature cervical ripening and PTB; (3) endogenous defense mechanisms of the cervix that protect the uterine cavity from infection and inflammation; and (4) potential inflammatory biomarkers associated with cervical infection that can serve as prognostic markers for premature cervical ripening and PTB. This review will provide mechanistic insights on cervical functions to assist in managing cervical infections during pregnancy.

Prevalence of oncogenic human papillomavirus in pregnant adolescents, association with colpocytological changes, risk factors and obstetric outcomes

PURPOSE

The authors aim to carry out an investigation on the impact of cervical oncogenic Human Papillomavirus (HPV) detection in pregnant adolescents, to clarify the prevalence and risk factors, considering the importance and lack of data on this topic in Brazil.

METHODS

A cross-sectional study was conducted with adolescents receiving prenatal care in a tertiary hospital in São Paulo, Brazil, with routine Pap smear and oncogenic HPV detection test in the uterine cervix. The authors sought to associate the results of these tests with demographic and obstetric variables.

RESULTS

A total of 303 pregnant adolescents whose mean age was 15.30 ± 1.22 years comprised the study subjects. The frequency of high-risk HPV cervical detection was 50.50%. Multivariate analysis revealed that a large number of partners in their lifetime (OR = 1.27) and having a religion (OR = 2.05) were risk factors for cervical detection of oncogenic HPV, while schooling appeared as a protective factor (OR = 0.85). There was an association between this detection and colpocytological alterations, reaching almost 30% of patients, but without association with obstetric and neonatal outcomes.

CONCLUSION

The prevalence found is one of the highest in Brazil and worldwide. A greater number of partners during their lifetime and having religion were detected as possible factors associated with cervical HPV detection. Detection of cervical HPV-DNA did not influence obstetric and neonatal outcomes. The findings of this study reinforce the need to implement educational measures capable of modifying the incidence of sexually transmitted infections in this population and capable of promoting adherence to HPV vaccination programs.

Successfully Pregnancy Outcome After LLETZ in Women with Cervical Intraepithelial Neoplasia: A Case Series

BACKGROUND: Human papillomavirus (HPV) has an important role in cervical cancer development and the incidence of cervical intraepithelial neoplasia (CIN) was 1.3–2.7/1000 pregnancies. The HPV and its treatments such as loop electrosurgical excisional procedure (LEEP) or large loop electrosurgical excisional procedure (LLETZ) have an association with poor obstetric outcomes. CASE REPORT: Here, we present four case studies of successful live birth after treatment of CIN. We reported that four patients had been performed LLETZ, with abnormal colposcopy results and liquidbased cytology results were one ASCUS, one ASCH, and two HSIL. The histopathology results were one CIN 1, one CIN 2, and two CIN 3. There was a higher rate of pregnancy for treated women than untreated women. The higher the CIN grades, the more prevalence of cesarean section rate. CONCLUSION: The HPV testing or cotesting at 3-year intervals is recommended after treatment due to the sensitivity of HPV testing. Although pregnancy could delay the progression of precancerous lesions, it is recommended to follow the individualized algorithm in the ASCCP guideline to reduce the risk of cervical cancer progression.

Maternal HPV Infection: Effects on Pregnancy Outcome

The human papilloma virus (HPV) infection, caused by a ubiquitous virus typically transmitted through the direct contact of infected organs, either through the skin or mucosa, is the most common sexually transmitted infection, placing young women at a high risk of contracting it. Although the vast majority of cases spontaneously clear within 1-2 years, persistent HPV infection remains a serious concern, as it has repeatedly been linked to the development of multiple malignancies, including cervical, anogenital, and oropharyngeal cancers. Additionally, more recent data suggest a harmful effect of HPV infection on pregnancy. As the maternal hormonal environment and immune system undergo significant changes during pregnancy, the persistence of HPV is arguably favored. Various studies have reported an increased risk of adverse pregnancy outcomes among HPV-positive women, with the clinical impact encompassing a range of conditions, including preterm birth, miscarriage, pregnancy-induced hypertensive disorders (PIHD), intrauterine growth restriction (IUGR), low birth weight, the premature rupture of membranes (PROM), and fetal death. Therefore, understanding the mechanisms employed by HPV that negatively impact pregnancy and assessing potential approaches to counteract them would be of interest in the quest to optimize pregnancy outcomes and improve child survival and health.

The impact of HPV vaccination beyond cancer prevention: effect on pregnancy outcomes

While the benefits of human papillomavirus (HPV) vaccination relating to cervical cancer prevention have been widely documented, recent published evidence is suggestive of an impact on adverse pregnancy outcomes (APOs) in vaccinated mothers and their infants, including a reduction in rates of preterm births and small for gestational age infants. In this review, we examine this evidence and the possible mechanisms by which HPV vaccination may prevent these APOs. Large-scale studies linking HPV vaccination status with birth registries are needed to confirm these results. Potential confounding factors to consider in future analyses include other risk factors for APOs, and historical changes in both the management of cervical precancerous lesions and prevention of APOs. If confirmed, these additional benefits of HPV vaccination in reducing APO rates will be of global significance, due to the substantial health, social and economic costs associated with APOs, strengthening the case for worldwide HPV immunization.

Loop Electrosurgical Excision Procedure in Managing Persistent Low-Grade Abnormality or Human Papillomavirus Positivity

OBJECTIVES

The aims of the study were to estimate the rate and to identify predictors of high-grade abnormalities among women with persistent low-grade abnormalities or high-risk human papillomavirus (hrHPV) positivity for at least 2 years stratified by presence (high risk) or absence (low risk) of previous high-grade results or HPV 16/18.

MATERIALS AND METHODS

A retrospective cohort study of patients who underwent a loop electrosurgical excision procedure (LEEP) for persistent low-grade or hrHPV positivity was performed. Patients were stratified based on whether they had a history of high-grade and/or HPV 16/18 positivity. Rates of high-grade or worse abnormalities on LEEP were compared using Fisher exact tests. Logistic regression was used to evaluate the associations between patient characteristics and high-grade results on the LEEP.

RESULTS

Three hundred eleven LEEPs were performed for persistent low-grade or hrHPV positivity. The rates of occult high grade were 12% and 22% among the low- and high-risk groups, respectively. Compared with those 45 years and older, the adjusted odds of high grade was 3.79 (95% CI = 1.19-12.1) for women aged 25-29 years. The odds of high grade was higher among current versus never smokers (6.40; 95% CI = 2.01-20.4) and those with a history of high-grade abnormality (2.23; 95% CI = 1.12-4.43). At 2 years, approximately half had an abnormal cytology and/or hrHPV positivity result independent of whether high grade was identified on their LEEP specimen.

CONCLUSIONS

Patients with persistent low-grade abnormalities or persistent hrHPV should be counseled on the risks and benefits of a LEEP given that 12%-22% have a risk of occult high grade, especially if they have a history of high-grade dysplasia.

Association Between Human Papillomavirus Infection Among Pregnant Women and Preterm Birth

IMPORTANCE

Preterm birth remains a leading cause of perinatal mortality and lifelong morbidity worldwide. The cause of most preterm births is unknown, although several infectious processes have been implicated.

OBJECTIVE

To assess whether human papillomavirus (HPV) infection, a frequent infection among women of childbearing age, is associated with preterm birth.

DESIGN, SETTING, AND PARTICIPANTS

The prospective HERITAGE cohort study was conducted at 3 academic hospitals in Montreal, Québec, Canada, among 899 pregnant women recruited between November 8, 2010, and October 16, 2016. Follow-up was completed on June 15, 2017. Statistical analysis was conducted from February 6, 2020, to January 21, 2021.

EXPOSURES

Vaginal HPV DNA detection in the first and third trimesters of pregnancy and placental HPV infection.

MAIN OUTCOMES AND MEASURES

The main outcome was preterm birth (defined as a live birth or stillbirth between 20 weeks and 0 days and 36 weeks and 6 days of gestation). The association between HPV DNA detection and preterm birth was measured using logistic regression. Odds ratios (ORs) and 95% CIs were adjusted by inverse probability of treatment weights of the propensity score.

RESULTS

The study included 899 women (mean [SD] age, 31.3 [4.6] years [range, 19-47 years]) with singleton pregnancies. A total of 378 women (42.0%) had HPV DNA detected in vaginal samples collected during the first trimester, and it was detected in 91 of 819 placentas (11.1%) at delivery. Fifty-five participants experienced preterm birth (38 spontaneous and 17 medically indicated). Persistent vaginal HPV-16/18 detection was significantly associated with all preterm births (adjusted OR [aOR], 3.72; 95% CI, 1.47-9.39) and spontaneous preterm births (aOR, 3.32; 95% CI, 1.13-9.80), as was placental HPV infection (all preterm births: aOR, 2.53; 95% CI, 1.06-6.03; spontaneous preterm births: aOR, 2.92; 95% CI, 1.09-7.81). Results were similar when restricting the analysis to participants without a history of cervical intraepithelial neoplasia treatment.

CONCLUSIONS AND RELEVANCE

The study's results suggest that persistent HPV-16/18 infection is associated with an increased risk of preterm birth, independent of cervical treatment. Future studies should investigate the association of HPV vaccination and vaccination programs with the risk of preterm birth.

Human papillomavirus (HPV) in pregnancy - An update

Human papilloma viruses (HPV) are small epitheliotropic DNA viruses, of which there are 200 genotypes, 40 of which are known to cause genital infections and are also oncogenic. HPV is the most common sexually transmitted infection. Clinical features vary from asymptomatic (identified at routine cervical cancer screening) to large lesions on the vulva, vagina, cervix and some extragenital sites. Its prevalence in pregnancy varies from 5.5% to 65% depending on age, geography and gestational age (increasing with gestational age). Infection in pregnancy has been associated with adverse outcomes such as spontaneous miscarriage, preterm birth, placental abnormalities and fetal growth restriction. However, the evidence for these adverse outcomes is varied. Besides being oncogenic (and thus associated with cancer of the cervix in pregnancy), vertical transmission to the fetus/neonate can cause neonatal infections, especially juvenile-onset recurrent oral and respiratory papillomatosis (JORRP). Where there are very large lesions on the vulva, delivery may be obstructed. Diagnosis in pregnancy is mainly by viral PCR or from the clinical appearance of the characteristic lesions on the vulva. Treatment is local by either surgical or laser excision or application of trichloroacetic acid. Podophyllin/podophyllotoxin is contraindicated in pregnancy. HPV Infection is not an indication for caesarean delivery as this has not been shown to prevent vertical transmission. For those diagnosed at routine cervical cancer screening, management should follow guidelines for cervical cancer screening in pregnancy. Vaccination is currently not recommended for pregnant women, although studies on those inadvertently vaccinated in pregnancy have not shown any adverse effects on either the fetus or mother.

Prevalence of Human Papillomavirus and Genotype Distribution in Pregnant and Non-Pregnant Women in China

Purpose

The status of human papillomavirus (HPV) infection in pregnant and non-pregnant women in China remains unclear. This study aimed to compare the prevalence and genotype distributions of HPV between pregnant and non-pregnant women in China.

Patients and Methods

A case-control study was conducted of pregnant women during the second trimester and age-matched non-pregnant women attending the Fujian Maternity and Child Health Hospital between January 1, 2017 and December 31, 2018. Participants underwent cervical cytology testing and HPV genotyping. The genotyping test was able to identify 14 high-risk HPV (HR-HPV), four possible HR-HPV, and five low-risk HPV (LR-HPV) types. Further colposcopy and a cervical biopsy were performed if indicated. The primary outcomes were HPV prevalence and genotype distribution.

Results

In total, 1077 pregnant and 1077 non-pregnant women were enrolled. Compared with non-pregnant women, pregnant women had a higher prevalence of HPV (24.2% vs 14.8%), HR-HPV (20.2% vs 11.7%), and LR-HPV (8% vs 4.5%) infection. In pregnant women, the most prevalent HPV genotypes were HPV-52 (6.0%), -16 (3.5%), -58 (2.6%), -53 (2.5%), and -51 (2.5%), while in non-pregnant women the most prevalent genotypes were HPV-52 (3.6%), -81 (1.9%), -51 (1.8%), -68 (1.4%), and -16 (1.3%). In women aged ≥35 years, HR-HPV (P=0.002) and LR-HPV (P=0.001) prevalence were significantly higher in pregnant women. However, in women aged <35 years, only HR-HPV prevalence was higher in pregnant women. Pregnant and non-pregnant women with HPV-16 and HPV-58 infection had a high prevalence of high-grade squamous intra-epithelial lesions (HSIL) (HPV-16: P<0.001 and P=0.005, HPV-58: P=0.043 and P=0.005); but with other HR-HPV genotypes, only non-pregnant women had an increased HSIL prevalence.

Conclusion

In China, the HPV prevalence is higher in pregnant women than that in non-pregnant women and is also age- and genotype-dependent. HPV-infected pregnant women aged ≥35 years and those with HPV-16 should be closely monitored to enable rapid clinical intervention.

Maternal human papillomavirus infections at mid-pregnancy and delivery in a Scandinavian mother-child cohort study

OBJECTIVES

Human papillomavirus (HPV) infections are common, especially during women's reproductive years, with unclear obstetrical impact. This study aimed to identify HPV prevalence at mid-gestation and delivery, type-specific persistence from mid-gestation to delivery, and risk factors for HPV infection and persistence.

METHODS

In 757 women from a Scandinavian prospective mother-child cohort, HPV was analyzed in first-void urine samples at mid-gestation and delivery. We used Seegene Anyplex II HPV28 PCR assay for genotyping and semi-quantifying 28 genital HPV genotypes, including 12 high-risk HPVs (HR-HPV). Socio-demographic and health data were collected through e-questionnaires.

RESULTS

Any-HPV genotype (any of 28 assessed) was detected in 38% of the study cohort at mid-gestation and 28% at delivery, and HR-HPVs in 24% and 16%, respectively. The most prevalent genotype was HPV16: 6% at mid-gestation and 4% at delivery. Persistence of Any-HPV genotype was 52%, as was HR-HPV genotype-specific persistence. A short pre-conception relationship with the child's father and alcohol intake during pregnancy increased HPV infection risk at both time points. Low viral load at mid-gestation was associated with clearance of HPV infections at delivery.

CONCLUSION

HPV prevalence was higher at mid-gestation compared with delivery, and low viral load was associated with clearance of HPV at delivery.

Associations of treated and untreated human papillomavirus infection with preterm delivery and neonatal mortality: A Swedish population-based study

BACKGROUND

Treatment of cervical intraepithelial neoplasia (CIN) is associated with an increased risk of preterm delivery (PTD) although the exact pathomechanism is not yet understood. Women with untreated CIN also seem to have an increased risk of PTD. It is unclear whether this is attributable to human papillomavirus (HPV) infection or other factors. We aimed to investigate whether HPV infection shortly before or during pregnancy, as well as previous treatment for CIN, is associated with an increased risk of PTD and other adverse obstetric and neonatal outcomes.

METHODS AND FINDINGS

This was a retrospective population-based register study of women with singleton deliveries registered in the Swedish Medical Birth Register 1999-2016 (n = 1,044,023). The study population had a mean age of 30.2 years (SD 5.2) and a mean body mass index of 25.4 kg/m2 (SD 3.0), and 44% of the women were nulliparous before delivery. Study groups were defined based on cervical HPV tests, cytology, and histology, as registered in the Swedish National Cervical Screening Registry. Women with a history of exclusively normal cytology (n = 338,109) were compared to women with positive HPV tests (n = 2,550) or abnormal cytology (n = 11,727) within 6 months prior to conception or during the pregnancy, women treated for CIN3 before delivery (n = 23,185), and women with CIN2+ diagnosed after delivery (n = 33,760). Study groups were compared concerning obstetric and neonatal outcomes by logistic regression, and comparisons were adjusted for socioeconomic and health-related confounders. HPV infection was associated with PTD (adjusted odds ratio [aOR] 1.19, 95% CI 1.01-1.42, p = 0.042), preterm prelabor rupture of membranes (pPROM) (aOR 1.52, 95% CI 1.18-1.96, p < 0.001), prelabor rupture of membranes (PROM) (aOR 1.24, 95% CI 1.08-1.42, p = 0.002), and neonatal mortality (aOR 2.69, 95% CI 1.25-5.78, p = 0.011). Treatment for CIN was associated with PTD (aOR 1.85, 95% CI 1.76-1.95, p < 0.001), spontaneous PTD (aOR 2.06, 95% CI 1.95-2.17, p < 0.001), pPROM (aOR 2.36, 95% CI 2.19-2.54, p < 0.001), PROM (aOR 1.11, 95% CI 1.05-1.17, p < 0.001), intrauterine fetal death (aOR 1.35, 95% CI 1.05-1.72, p = 0.019), chorioamnionitis (aOR 2.75, 95% CI 2.33-3.23, p < 0.001), intrapartum fever (aOR 1.24, 95% CI 1.07-1.44, p = 0.003), neonatal sepsis (aOR 1.55, 95% CI 1.37-1.75, p < 0.001), and neonatal mortality (aOR 1.79, 95% CI 1.30-2.45, p < 0.001). Women with CIN2+ diagnosed within 3 years after delivery had increased PTD risk (aOR 1.18, 95% CI 1.10-1.27, p < 0.001). Limitations of the study include the retrospective design and the fact that because HPV test results only became available in 2007, abnormal cytology was used as a proxy for HPV infection.

CONCLUSIONS

In this study, we found that HPV infection shortly before or during pregnancy was associated with PTD, pPROM, PROM, and neonatal mortality. Previous treatment for CIN was associated with even greater risks for PTD and pPROM and was also associated with PROM, neonatal mortality, and maternal and neonatal infectious complications.

Uptake of Human Papillomavirus Vaccine and Intention to Vaccinate among Healthy Pregnant Women in Serbia: A Cross-Sectional Study on Awareness, Knowledge, and Attitudes

We aimed to assess awareness, knowledge, and attitudes of healthy pregnant women towards human papillomavirus (HPV), to estimate factors associated with a positive attitude towards HPV immunization and to assess the uptake of the vaccine among their children. A cross-sectional study was conducted at the University Clinic of Gynecology and Obstetrics, Belgrade, Serbia among pregnant women attending their regular gynecological check-ups at the 12th gestational week. Knowledge about HPV and HPV vaccine was assessed using a specifically designed 12-item and 5-item questionnaires. Out of total 265 included women, 79.3% had heard of HPV, and 37.5% knew that HPV vaccine exists. HPV vaccine knowledge score was associated with higher odds for a positive attitude towards vaccination of both female (OR = 4.10, 95% CI 1.50-11.29) and male (OR = 3.71, 95% CI 1.52-9.01) child. The number of children (OR = 1.32, 95% CI 1.04-1.67) and high vaccine knowledge score (OR = 1.64 95% CI 1.13-2.39) were independent predictors associated with willingness to vaccinate child against HPV. The gynecologist was the preferable point of reference for information seeking about the HPV vaccine. Despite relatively high HPV awareness and knowledge among pregnant women in Serbia, about one-third of them are HPV vaccine aware, and are willing to vaccinate their children against HPV.