Peri-conceptional or pregnancy exposure of HPV vaccination and the risk of spontaneous abortion: a systematic review and meta-analysis

Does HPV vaccination during periconceptional or gestational period increase the risk of adverse pregnancy outcomes?-An updated systematic review and meta-analysis based on timing of vaccination

INTRODUCTION

The human papillomavirus (HPV) vaccine is crucial in preventing cervical cancer, and a significant number of women in 135 countries worldwide may have unknowingly received the vaccine during peri-pregnancy or pregnancy due to a lack of regular pregnancy testing. Previous studies on the safety of pregnancy outcomes with vaccination before and after pregnancy have not reached definitive conclusions. Thus, we subdivided the vaccination time frame and conducted an updated study to further examine whether exposure to the HPV vaccine during pregnancy or the periconceptional period increases the likelihood of adverse pregnancy outcomes.

MATERIAL AND METHODS

The clinical trials and cohort studies published before August 1, 2023, were retrieved from PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials. The Newcastle-Ottawa Scale and Cochrane risk of bias assessment tool were adopted to evaluate the risk of bias in the included studies. In addition, the quality assessment was carried out using the Review Manager 5.4 Software, and a meta-analysis was conducted using the Stata 16 Software.

RESULTS

Eleven studies were located. The results showed that receiving 4vHPV during the periconceptional or gestational period had no relationship with an increased risk of spontaneous abortion, stillbirth, preterm birth, birth defects, small for gestational age, and ectopic pregnancy. Neither receiving 2vHPV nor 9vHPV was associated with a higher risk of stillbirth, preterm birth, birth defects, small for gestational age, and ectopic pregnancy; however, receiving 2vHPV during the period from 45 days before last menstrual period (LMP) to LMP and 9vHPV during the period from 90 days before LMP to 45 days after LMP seemed to be related to an increased risk of spontaneous abortion (RR = 1.59, 95% CI: 1.04-2.45, RR = 2.04, 95% CI: 1.28-3.24).

CONCLUSIONS

In conclusion, the likelihood of an elevated risk of spontaneous abortion caused by HPV vaccination during the periconceptional or gestational period could not be completely ruled out. Given the lack of evidence, further research is needed to examine the effect of HPV vaccination on spontaneous abortion.

Receipt of hepatitis E vaccine and fetal loss in rural Bangladesh: further analysis of a double-blind, cluster-randomised, controlled trial

BACKGROUND

Vaccination constitutes an attractive control measure for hepatitis E virus (HEV), a major cause of maternal and perinatal mortality globally. Analysis of pregnant participants in an effectiveness trial of the HEV vaccine HEV239 showed possible HEV239-associated fetal losses. We aimed to conduct a detailed analysis of this safety signal.

METHODS

In a double-blind, cluster-randomised trial, 67 villages in Matlab, Bangladesh, were randomly allocated (1:1) to two vaccine groups, in which non-pregnant women aged 16-39 years received either HEV239 (HEV239 group) or Hepa-B (a hepatitis B vaccine; control group). We implemented weekly surveillance for pregnancy detection, and follow-up of pregnancies once every 2 weeks, using physician-confirmed diagnoses to evaluate fetal loss outcomes (miscarriage [spontaneous abortion], stillbirth, and elective termination). Data from a parallel system of reproductive health surveillance in Matlab were used to clarify study diagnoses when necessary. Miscarriage was assessed only among participants whose first positive pregnancy test and vaccination date (for whichever dose was closest to the date of last menstrual period [LMP]) were before 20 weeks' gestation. We defined the following analysis periods of interest: from 90 days before the LMP until the pregnancy outcome (the proximal period); from the LMP date until the pregnancy outcome (the pregnancy period); from 90 days before the LMP until the LMP date (90 days pre-LMP period); and from enrolment until 90 days before the LMP (the distal period). Both Poisson and Cox regression models were used to assess the associations between receipt of HEV239 and fetal loss outcomes. The trial was registered with ClinicalTrials.gov (NCT02759991).

FINDINGS

Among the 19 460 non-pregnant participants enrolled in the trial, 5011 were identified as having pregnancies within 2 years following vaccination and met the criteria for analysis (2407 in the HEV239 group and 2604 in the control group). Among participants vaccinated in the proximal period and evaluated for miscarriage, miscarriage occurred in 54 (8·9%) of 607 in the HEV239 group and 32 (4·5%) of 719 in the control group (adjusted relative risk [aRR] 2·0 [95% CI 1·3-3·1], p=0·0009). Similarly, the risk of miscarriages was increased in the HEV239 group versus the control group among participants inadvertently vaccinated during pregnancy (22 [10·5%] miscarriages among 209 participants in the HEV239 group vs 14 [5·3%] of 266 in the control group; aRR 2·1 [95% CI 1·1-4·1], p=0·036) and among those vaccinated within 90 days pre-LMP (32 [8·0%] of 398 vs 18 [4·0%] of 453; 1·9 [1·1-3·2], p=0·013). No increased risk of miscarriage was observed in those who received HEV239 in the distal period (93 [5·6%] of 1647 vs 80 [4·5%] of 1773; 1·3 [0·8-1·9], p=0·295). Stillbirth and elective termination showed no increased risk among women administered HEV239 versus those administered Hepa-B in any of the analysis periods.

INTERPRETATION

HEV239 given shortly before or during pregnancy was associated with an elevated risk of miscarriage. This association poses a possible safety concern for programmatic use of HEV239 in women of childbearing age.

FUNDING

Research Council of Norway and Innovax.

An immune window of opportunity to prevent spontaneous abortion: prepregnancy peripheral leukocytes and subsets were associated with a decreased risk of spontaneous abortion

STUDY QUESTION

Do prepregnancy peripheral leukocytes (PPLs) and their subsets influence the risk of spontaneous abortion (SAB)?

SUMMARY ANSWER

PPLs and their subsets are associated with the risk of SAB.

WHAT IS KNOWN ALREADY

Compelling studies have revealed the crucial role of maternal peripheral leukocytes in embryo implantation and pregnancy maintenance. Adaptive changes are made by PPLs and their subsets after conception.

STUDY DESIGN, SIZE, DURATION

This population-based retrospective cohort study was based on data from the National Free Pre-pregnancy Check-up Project (NFPCP) in mainland China. Couples preparing for pregnancy within the next six months were provided with free prepregnancy health examinations and counseling services for reproductive health. The current study was based on 1 310 494 female NFPCP participants aged 20-49 who became pregnant in 2016. After sequentially excluding 235 456 participants lost to follow-up, with multiple births, and who failed to complete blood tests, a total of 1 075 038 participants were included in the primary analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PPLs and their subset counts and ratios were measured. The main outcome was SAB. A multivariable logistic regression model was used to estimate the odds ratio (OR) and 95% CI of SAB associated with PPLs and their subsets, and restricted cubic spline (RCS) was used to estimate the nonlinear exposure-response relationship.

MAIN RESULTS AND ROLE OF CHANCE

Of the included pregnant participants, a total of 35 529 SAB events (3.30%) were recorded. Compared to participants with reference values of PPLs, the ORs (95% CIs) of leukopenia and leukocytosis for SAB were 1.14 (1.09-1.20) and 0.74 (0.69-0.79), respectively. The RCS result revealed a monotonous decreasing trend (Pnonlinear < 0.05). Similar relationships were observed for the neutrophil count and ratio, monocyte count, and middle-sized cell count and ratio. The lymphocyte ratio showed a positive and nonlinear relationship with the risk of SAB (Pnonlinear < 0.05). Both eosinophils and basophils showed positive relationships with the risk of SAB (eosinophil Pnonlinear > 0.05 and basophil Pnonlinear < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Chemical abortion events and the cause of SAB were not collected at follow-up. Whether women with abnormal PPLs had recovered during periconception was not determined.

WIDER IMPLICATIONS OF THE FINDINGS

PPLs and their subsets are associated with the risk of SAB. Leukopenia and neutropenia screening in women preparing for pregnancy and developing a feasible PPL stimulation approach should be emphasized to utilize the immune window of opportunity to prevent SAB.

STUDY FUNDING/COMPETING INTEREST(S)

This study was approved by the Institutional Research Review Board of the National Health and Family Planning Commission. This study was supported by the National Key Research and Development Program of China (grants 2021YFC2700705 [Y.Y.] and 2016YFC100307 [X.M.]) and the National Natural Science Foundation of China (grant no. 82003472 [L.W.]). The funding source was not involved in the study design, data collection, analysis and interpretation of the data, writing the report, or the decision to submit this article for publication. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Association of periconceptional or pregnancy exposure of HPV vaccination and adverse pregnancy outcomes: a systematic review and meta-analysis with trial sequential analysis

Objective: To evaluate whether periconceptional or pregnancy exposure of human papillomavirus (HPV) vaccination would increase the risk of adverse pregnancy outcomes. Methods: The PubMed, Web of Science, Embase, the Cochrane Library of clinical trials were searched from inception to March 2023. We computed relative risk (RR) and 95% confidence intervals (CIs) and prediction intervals (PIs) regarding the association between HPV vaccination in periconceptional period or during pregnancy and the risks of adverse pregnancy outcomes by using R software Version 4.1.2 and STATA Version 12.0. A trial sequential analysis (TSA) was performed with TSA v0.9.5.10 Beta software. Results: Four randomized controlled trials (RCTs) and eight cohort studies were included in this meta-analysis. Analysis of RCTs showed that HPV vaccination in periconceptional period or during pregnancy did not increase the risks of spontaneous abortion (RR = 1.152, 95% CI: 0.909-1.460, 95% PI: 0.442-3.000), birth defects (RR = 1.171, 95% CI: 0.802-1.709, 95% PI: 0.320-4.342), stillbirth (RR = 1.053, 95% CI: 0.616-1.800, 95% PI: 0.318-3.540), preterm birth (RR = 0.940, 95% CI: 0.670-1.318) and ectopic pregnancy (RR = 0.807, 95% CI: 0.353-1.842, 95% PI: 0.128-5.335). In cohort studies, periconceptional or pregnancy exposures of HPV vaccine were not associated with the increased risk of spontaneous abortion (RR = 0.987, 95% CI: 0.854-1.140, 95% PI: 0.652-1.493), birth defects (RR = 0.960, 95% CI: 0.697-1.322, 95% PI: 0.371-2.480), stillbirth (RR = 1.033, 95% CI: 0.651-1.639, 95% PI: 0.052-21.064), small size for gestational age (SGA) (RR = 0.971, 95% CI: 0.873-1.081, 95% PI: 0.657-1.462) and preterm birth (RR = 0.977, 95% CI: 0.874-1.092, 95% PI: 0.651-1.444). Conclusion: HPV vaccine exposures in periconceptional period or during pregnancy did not increase the risks of adverse pregnancy outcomes, including spontaneous abortion, birth defects, stillbirth, SGA, preterm birth and ectopic pregnancy. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023399777.

Challenges and Needs of HPV-Positive Women

HPV is the most prevalent sexually transmitted diseases causing a variety of clinical manifestations ranging from warts to cancer. This study aimed to examine the challenges and needs of HPV-positive women. In this qualitative study, we analyzed data extracted from semi-structured face-to-face interviews with 31 Iranian HPV-positive women using a conventional content analysis approach using MAXQDA.10 software. Data were collected from her at the women's clinic from 21 January 2022 to her 19 February 2022. The sampling process was purposeful, and the accuracy of this study was ensured according to her 4 criteria suggested by Guba and Lincoln. Four themes were identified from the interviewing of HPV-positive women that include: Needing support and counseling to adapt to the disease, needing counseling and training to improve the disease, needing a qualified health care provider, needing proper health care services. HPV-positive women had many adverse such as reproductive health challenges (Menstruation cycle, delivery type, fertility, pregnancy, and breastfeeding), low control, confusion, cancer-related concerns, relationship problems, sexual concerns, uncertainty, stigma, low trust, social impact, non-disclosure of results, idiosyncratic prevention, indirect clinical interaction, changes in sexual behavior. HPV-positive women face many challenges and seek information to address them. Therefore, at the primary level, providers need to be aware of the needs of these patients needs in order to make the necessary consultations.

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.

Impact of industry sponsorship on the quality of systematic reviews of vaccines: a cross-sectional analysis of studies published from 2016 to 2019

BACKGROUND

Systematic reviews (SRs) provide the highest level of evidence and inform evidence-based decision making in health care. Earlier studies found association with industry to be negatively associated with methodological quality of SRs. However, this has not been investigated in SRs on vaccines.

METHODS

We performed a systematic literature search using MEDLINE and EMBASE in March 2020. The results were restricted to those published between 2016 and 2019 with no language restrictions. Study characteristics were extracted by one person and checked by an experienced reviewer. The methodological quality of the SRs was assessed with the AMSTAR 2 tool by multiple reviewers after a calibration exercise was performed. A summary score for each SR was calculated. The Mann-Whitney U test and Fisher's exact test were performed to compare both groups.

RESULTS

Out of 185 SRs that met all inclusion criteria, 27 SRs were industry funded. Those were matched with 30 non-industry funded SRs resulting in a total sample size of 57. The mean AMSTAR 2 summary score across all SRs was 0.49. Overall, the median AMSTAR 2 summary score was higher for the non-industry funded SRs than for the industry-funded SRs (0.62 vs. 0.36; p < .00001). Lower ratings for industry funded SRs were consistent across all but one AMSTAR 2 item, though significantly lower only for three specific items.

CONCLUSION

The methodological quality of SRs in vaccination is comparable to SRs in other fields, while it is still suboptimal. We are not able to provide a satisfactory explanation why industry funded SRs had a lower methodological quality than non-industry funded SRs over recent years. Industry funding is an important indicator of methodological quality for vaccine SRs and should be carefully considered when appraising SR quality.

Relationships between Women's and Men's Modifiable Preconception Risks and Health Behaviors and Maternal and Offspring Health Outcomes: An Umbrella Review

Parental health before conception effects maternal and offspring health outcomes. Preconception care provides healthcare to prospective parents addressing modifiable preconception risks and health behaviors. This umbrella review aimed to consolidate evidence on women's and men's modifiable preconception risks or health behaviors associated with maternal and offspring health outcomes. MEDLINE, EMBASE, Maternity and Infant Care, CINAHL, and PsycINFO were searched from March 4, 2010, to March 4, 2020. Eligible studies were systematic reviews or meta-analyses of observational studies examining associations between modifiable preconception risks or health behaviors and maternal and offspring health outcomes. Screening, data extraction, and methodological quality assessment (AMSTAR 2) occurred independently by two reviewers. Degree of overlap was examined. Findings were summarized for evidence synthesis. Twenty-seven systematic reviews were included. Modifiable preconception risks and health behaviors were identified across categories: body composition (e.g., overweight, obesity), lifestyle behaviors (e.g., caffeine, smoking), nutrition (e.g., micronutrients), environmental exposures (e.g., radiation), and birth spacing (e.g., short interpregnancy intervals). Outcomes associated with exposures affected embryo (e.g., embryonic growth), maternal (e.g., gestational diabetes mellitus), fetal/neonate (e.g., preterm birth), and child (e.g., neurocognitive disorders) health. For real-world practice and policy relevance, evidence-based indicators for preconception care should include body composition, lifestyle, nutrition, environmental, and birth spacing.

Preconception exposures and adverse pregnancy, birth and postpartum outcomes: Umbrella review of systematic reviews

BACKGROUND

Preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, the reports, statements and guidelines of national and international health organisations vary in what they recommend individuals should monitor, avoid, reduce or practise in the preconception period.

OBJECTIVES

To synthesise and evaluate the evidence across systematic reviews for associations between exposures before conception and adverse pregnancy, birth and postpartum outcomes.

DATA SOURCES

MEDLINE, Embase, Epistemonikos (to May 2020) and reference lists of included reviews, without language or date restrictions.

STUDY SELECTION, DATA EXTRACTION AND SYNTHESIS

Systematic literature reviews of observational and/or interventional studies reporting associations between preconception exposures in women and/or men of reproductive age and pregnancy, birth or postpartum health outcomes were included. The methodological quality of reviews and the certainty of the evidence underlying each exposure-outcome association were assessed using AMSTAR 2 and the GRADE approach.

RESULTS

We identified 53 eligible reviews reporting 205 unique exposure-outcome associations. Methodological quality was generally low with only two reviews rated as 'high' quality and two as 'moderate'. We found high-certainty, randomised trial evidence that maternal folate supplementation reduces the risk of neural tube defects and anomaly-related terminations. Moderate-certainty, observational evidence was found that maternal physical activity is associated with reduced risk of pre-eclampsia and gestational diabetes, and that paternal age of ≥40 years and maternal body mass index (BMI) and interpregnancy weight gain are associated with increased risk of various adverse pregnancy and birth outcomes. Low- and very low-certainty evidence was found for other associations.

CONCLUSIONS

Clinicians and policymakers can be confident that maternal folate supplementation should be encouraged during the preconception period. There is moderate certainty in the evidence base that maternal physical activity, BMI and interpregnancy weight gain and advanced paternal age are important preconception considerations. High-quality research is required to better understand other exposure-outcome associations.

'Does HPV affect my fertility?' Reproductive concerns of HPV-positive women: a qualitative study

Background

Reproductive health changes can occur following infection with Human papillomavirus. HPV is the most prevalent sexually transmitted infection causing a variety of clinical manifestations ranging from warts to cancer. This study aimed to explore the reproductive concerns of women infected with HPV.

Methods

In this qualitative study, we used the conventional content analysis approach, with the aid of MAXQDA.10 software, to analyze data extracted from the face-to-face semi-structured interviews with 20 Iranian HPV-positive women (sampled by maximum variation purposive sampling). The accuracy of this research was ensured according to the four criteria proposed by Guba and Lincoln.

Results

Exploring participants' reproductive concerns, three main categories were identified from the interviews including concerns about fertility potential, pregnancy and non-pregnancy reproductive issues. HPV-positive women concerned about reduced female/ male fertility due to HPV, the impact of the HPV on the fetal health, adverse pregnancy outcomes such as miscarriage and preterm delivery, and mother-to-child transmission of HPV during breastfeeding. HPV-positive women with abnormal cytology results were anxious that becoming pregnant or taking hormonal contraception might worsen their abnormalities. Most married women were reluctant to use a condom. Participants requested further information about the potential reproductive risks of the HPV vaccine. They also wanted to know about the safety of HPV vaccine during pregnancy and breastfeeding.

Conclusions

HPV-positive women had some reproductive concerns that should be considered in the designing of educational-consulting interventions. Women need to be better understood and informed about the impact of HPV on their reproductive health. Health care providers may lack knowledge about these specific areas, and they could benefit from additional up-to-date information to address women's reproductive concerns.