Effectiveness and safety of COVID-19 vaccines on maternal and perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

To assess the effects of COVID-19 vaccines in women before or during pregnancy on SARS-CoV-2 infection-related, pregnancy, offspring and reactogenicity outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Major databases between December 2019 and January 2023.

STUDY SELECTION

Nine pairs of reviewers contributed to study selection. We included test-negative designs, comparative cohorts and randomised trials on effects of COVID-19 vaccines on infection-related and pregnancy outcomes. Non-comparative cohort studies reporting reactogenicity outcomes were also included.

QUALITY ASSESSMENT, DATA EXTRACTION AND ANALYSIS

Two reviewers independently assessed study quality and extracted data. We undertook random-effects meta-analysis and reported findings as HRs, risk ratios (RRs), ORs or rates with 95% CIs.

RESULTS

Sixty-seven studies (1 813 947 women) were included. Overall, in test-negative design studies, pregnant women fully vaccinated with any COVID-19 vaccine had 61% reduced odds of SARS-CoV-2 infection during pregnancy (OR 0.39, 95% CI 0.21 to 0.75; 4 studies, 23 927 women; I2=87.2%) and 94% reduced odds of hospital admission (OR 0.06, 95% CI 0.01 to 0.71; 2 studies, 868 women; I2=92%). In adjusted cohort studies, the risk of hypertensive disorders in pregnancy was reduced by 12% (RR 0.88, 95% CI 0.82 to 0.92; 2 studies; 115 085 women), while caesarean section was reduced by 9% (OR 0.91, 95% CI 0.85 to 0.98; 6 studies; 30 192 women). We observed an 8% reduction in the risk of neonatal intensive care unit admission (RR 0.92, 95% CI 0.87 to 0.97; 2 studies; 54 569 women) in babies born to vaccinated versus not vaccinated women. In general, vaccination during pregnancy was not associated with increased risk of adverse pregnancy or perinatal outcomes. Pain at the injection site was the most common side effect reported (77%, 95% CI 52% to 94%; 11 studies; 27 195 women).

CONCLUSION

COVID-19 vaccines are effective in preventing SARS-CoV-2 infection and related complications in pregnant women.

PROSPERO REGISTRATION NUMBER

CRD42020178076.

Global variations in the burden of SARS-CoV-2 infection and its outcomes in pregnant women by geographical region and country’s income status: a meta-analysis

Introduction

The prevalence of COVID-19 and its impact varied between countries and regions. Pregnant women are at high risk of COVID-19 complications compared with non-pregnant women. The magnitude of variations, if any, in SARS-CoV-2 infection rates and its health outcomes among pregnant women by geographical regions and country’s income level is not known.

Methods

We performed a random-effects meta-analysis as part of the ongoing PregCOV-19 living systematic review (December 2019 to April 2021). We included cohort studies on pregnant women with COVID-19 reporting maternal (mortality, intensive care admission and preterm birth) and offspring (mortality, stillbirth, neonatal intensive care admission) outcomes and grouped them by World Bank geographical region and income level. We reported results as proportions with 95% confidence intervals (CI).

Results

We included 311 studies (2 003 724 pregnant women, 57 countries). The rates of SARS-CoV-2 infection in pregnant women varied significantly by region (p<0.001) and income level (p<0.001), with the highest rates observed in Latin America and the Caribbean (19%, 95% CI 12% to 27%; 13 studies, 38 748 women) and lower-middle-income countries (13%, 95% CI 6% to 23%; 25 studies, 100 080 women). We found significant differences in maternal and offspring outcomes by region and income level. Lower-middle-income countries reported significantly higher rates of maternal mortality (0.68%, 95% CI 0.24% to 1.27%; 3 studies, 31 136 women), intensive care admission (4.53%, 95% CI 2.57% to 6.91%; 54 studies, 23 420 women) and stillbirths (1.09%, 95% CI 0.48% to 1.88%; 41 studies, 4724 women) than high-income countries. COVID-19 complications disproportionately affected South Asia, which had the highest maternal mortality rate (0.88%, 95% CI 0.16% to 1.95%; 17 studies, 2023 women); Latin America and the Caribbean had the highest stillbirth rates (1.97%, 95% CI 0.9% to 3.33%; 10 studies, 1750 women).

Conclusion

The rates of SARS-CoV-2 infection in pregnant women vary globally, and its health outcomes mirror the COVID-19 burden and global maternal and offspring inequalities.

PROSPERO registration number

CRD42020178076.

SARS-CoV-2 positivity in offspring and timing of mother-to-child transmission: living systematic review and meta-analysis

OBJECTIVES

To assess the rates of SARS-CoV-2 positivity in babies born to mothers with SARS-CoV-2 infection, the timing of mother-to-child transmission and perinatal outcomes, and factors associated with SARS-CoV-2 status in offspring.

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Major databases between 1 December 2019 and 3 August 2021.

STUDY SELECTION

Cohort studies of pregnant and recently pregnant women (including after abortion or miscarriage) who sought hospital care for any reason and had a diagnosis of SARS-CoV-2 infection, and also provided data on offspring SARS-CoV-2 status and risk factors for positivity. Case series and case reports were also included to assess the timing and likelihood of mother-to-child transmission in SARS-CoV-2 positive babies.

DATA EXTRACTION

Two reviewers independently extracted data and assessed study quality. A random effects model was used to synthesise data for rates, with associations reported using odds ratios and 95% confidence intervals. Narrative syntheses were performed when meta-analysis was inappropriate. The World Health Organization classification was used to categorise the timing of mother-to-child transmission (in utero, intrapartum, early postnatal).

RESULTS

472 studies (206 cohort studies, 266 case series and case reports; 28 952 mothers, 18 237 babies) were included. Overall, 1.8% (95% confidence interval 1.2% to 2.5%; 140 studies) of the 14 271 babies born to mothers with SARS-CoV-2 infection tested positive for the virus with reverse transcriptase polymerase chain reaction (RT-PCR). Of the 592 SARS-CoV-2 positive babies with data on the timing of exposure and type and timing of tests, 14 had confirmed mother-to-child transmission: seven in utero (448 assessed), two intrapartum (18 assessed), and five during the early postnatal period (70 assessed). Of the 800 SARS-CoV-2 positive babies with outcome data, 20 were stillbirths, 23 were neonatal deaths, and eight were early pregnancy losses; 749 babies were alive at the end of follow-up. Severe maternal covid-19 (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), maternal death (14.1, 4.1 to 48.0), maternal admission to an intensive care unit (3.5, 1.7 to 6.9), and maternal postnatal infection (5.0, 1.2 to 20.1) were associated with SARS-CoV-2 positivity in offspring. Positivity rates using RT-PCR varied between regions, ranging from 0.1% (95% confidence interval 0.0% to 0.3%) in studies from North America to 5.7% (3.2% to 8.7%) in studies from Latin America and the Caribbean.

CONCLUSION

SARS-CoV-2 positivity rates were found to be low in babies born to mothers with SARS-CoV-2 infection. Evidence suggests confirmed vertical transmission of SARS-CoV-2, although this is likely to be rare. Severity of maternal covid-19 appears to be associated with SARS-CoV-2 positivity in offspring.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020178076.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication.

Effects of oral anticoagulation for atrial fibrillation after spontaneous intracranial haemorrhage in the UK: a randomised, open-label, assessor-masked, pilot-phase, non-inferiority trial

BACKGROUND

Oral anticoagulation reduces the rate of systemic embolism for patients with atrial fibrillation by two-thirds, but its benefits for patients with previous intracranial haemorrhage are uncertain. In the Start or STop Anticoagulants Randomised Trial (SoSTART), we aimed to establish whether starting is non-inferior to avoiding oral anticoagulation for survivors of intracranial haemorrhage who have atrial fibrillation.

METHODS

SoSTART was a prospective, randomised, open-label, assessor-masked, parallel-group, pilot phase trial done at 67 hospitals in the UK. We recruited adults (aged ≥18 years) who had survived at least 24 h after symptomatic spontaneous intracranial haemorrhage, had atrial fibrillation, and had a CHA2DS2-VASc score of at least 2. Web-based computerised randomisation incorporating a minimisation algorithm allocated participants (1:1) to start or avoid long-term (≥1 year) full treatment dose open-label oral anticoagulation. The participants assigned to start oral anticoagulation received either a direct oral anticoagulant or vitamin K antagonist, and the group assigned to avoid oral anticoagulation received standard clinical practice (antiplatelet agent or no antithrombotic agent). The primary outcome was recurrent symptomatic spontaneous intracranial haemorrhage, and was adjudicated by an individual masked to treatment allocation. All outcomes were ascertained for at least 1 year after randomisation and assessed in the intention-to-treat population of all randomly assigned participants, using Cox proportional hazards regression adjusted for minimisation covariates. We planned a sample size of 190 participants (one-sided p=0·025, power 90%, allowing for non-adherence) based on a non-inferiority margin of 12% (or adjusted hazard ratio [HR] of 3·2). This trial is registered with ClinicalTrials.gov (NCT03153150) and is complete.

FINDINGS

Between March 29, 2018, and Feb 27, 2020, consent was obtained at 61 sites for 218 participants, of whom 203 were randomly assigned at a median of 115 days (IQR 49-265) after intracranial haemorrhage onset. 101 were assigned to start and 102 to avoid oral anticoagulation. Participants were followed up for median of 1·2 years (IQR 0·97-1·95; completeness 97·2%). Starting oral anticoagulation was not non-inferior to avoiding oral anticoagulation: eight (8%) of 101 in the start group versus four (4%) of 102 in the avoid group had intracranial haemorrhage recurrences (adjusted HR 2·42 [95% CI 0·72-8·09]; p=0·152). Serious adverse events occurred in 17 (17%) participants in the start group and 15 (15%) in the avoid group. 22 (22%) patients in the start group and 11 (11%) patients in the avoid group died during the study.

INTERPRETATION

Whether starting oral anticoagulation was non-inferior to avoiding it for people with atrial fibrillation after intracranial haemorrhage was inconclusive, although rates of recurrent intracranial haemorrhage were lower than expected. In view of weak evidence from analyses of three composite secondary outcomes, the possibility that oral anticoagulation might be superior for preventing symptomatic major vascular events should be investigated in adequately powered randomised trials.

FUNDING

British Heart Foundation, Medical Research Council, Chest Heart & Stroke Scotland.

Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis

OBJECTIVE

To determine the clinical manifestations, risk factors, and maternal and perinatal outcomes in pregnant and recently pregnant women with suspected or confirmed coronavirus disease 2019 (covid-19).

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Cochrane database, WHO COVID-19 database, China National Knowledge Infrastructure (CNKI), and Wanfang databases from 1 December 2019 to 6 October 2020, along with preprint servers, social media, and reference lists.

STUDY SELECTION

Cohort studies reporting the rates, clinical manifestations (symptoms, laboratory and radiological findings), risk factors, and maternal and perinatal outcomes in pregnant and recently pregnant women with suspected or confirmed covid-19.

DATA EXTRACTION

At least two researchers independently extracted the data and assessed study quality. Random effects meta-analysis was performed, with estimates pooled as odds ratios and proportions with 95% confidence intervals. All analyses will be updated regularly.

RESULTS

192 studies were included. Overall, 10% (95% confidence interval 7% to 12%; 73 studies, 67 271 women) of pregnant and recently pregnant women attending or admitted to hospital for any reason were diagnosed as having suspected or confirmed covid-19. The most common clinical manifestations of covid-19 in pregnancy were fever (40%) and cough (41%). Compared with non-pregnant women of reproductive age, pregnant and recently pregnant women with covid-19 were less likely to have symptoms (odds ratio 0.28, 95% confidence interval 0.13 to 0.62; I2=42.9%) or report symptoms of fever (0.49, 0.38 to 0.63; I2=40.8%), dyspnoea (0.76, 0.67 to 0.85; I2=4.4%) and myalgia (0.53, 0.36 to 0.78; I2=59.4%). The odds of admission to an intensive care unit (odds ratio 2.13, 1.53 to 2.95; I2=71.2%), invasive ventilation (2.59, 2.28 to 2.94; I2=0%) and need for extra corporeal membrane oxygenation (2.02, 1.22 to 3.34; I2=0%) were higher in pregnant and recently pregnant than non-pregnant reproductive aged women. Overall, 339 pregnant women (0.02%, 59 studies, 41 664 women) with confirmed covid-19 died from any cause. Increased maternal age (odds ratio 1.83, 1.27 to 2.63; I2=43.4%), high body mass index (2.37, 1.83 to 3.07; I2=0%), any pre-existing maternal comorbidity (1.81, 1.49 to 2.20; I2=0%), chronic hypertension (2.0, 1.14 to 3.48; I2=0%), pre-existing diabetes (2.12, 1.62 to 2.78; I2=0%), and pre-eclampsia (4.21, 1.27 to 14.0; I2=0%) were associated with severe covid-19 in pregnancy. In pregnant women with covid-19, increased maternal age, high body mass index, non-white ethnicity, any pre-existing maternal comorbidity including chronic hypertension and diabetes, and pre-eclampsia were associated with serious complications such as admission to an intensive care unit, invasive ventilation and maternal death. Compared to pregnant women without covid-19, those with the disease had increased odds of maternal death (odds ratio 2.85, 1.08 to 7.52; I2=0%), of needing admission to the intensive care unit (18.58, 7.53 to 45.82; I2=0%), and of preterm birth (1.47, 1.14 to 1.91; I2=18.6%). The odds of admission to the neonatal intensive care unit (4.89, 1.87 to 12.81, I2=96.2%) were higher in babies born to mothers with covid-19 versus those without covid-19.

CONCLUSION

Pregnant and recently pregnant women with covid-19 attending or admitted to the hospitals for any reason are less likely to manifest symptoms such as fever, dyspnoea, and myalgia, and are more likely to be admitted to the intensive care unit or needing invasive ventilation than non-pregnant women of reproductive age. Pre-existing comorbidities, non-white ethnicity, chronic hypertension, pre-existing diabetes, high maternal age, and high body mass index are risk factors for severe covid-19 in pregnancy. Pregnant women with covid-19 versus without covid-19 are more likely to deliver preterm and could have an increased risk of maternal death and of being admitted to the intensive care unit. Their babies are more likely to be admitted to the neonatal unit.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020178076.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication. This version is update 1 of the original article published on 1 September 2020 (BMJ 2020;370:m3320), and previous updates can be found as data supplements (https://www.bmj.com/content/370/bmj.m3320/related#datasupp). When citing this paper please consider adding the update number and date of access for clarity.

Pre-Operative Vessel Mapping and Early Post-Operative Surveillance Duplex Scanning of Arteriovenous Fistulae

Purpose

To increase the proportion of dialysis patients using native arteriovenous fistulae (AVF), improved selection of the most appropriate procedure must be coupled with early access surveillance to determine which access would likely mature and when intervention might lead to access salvage. This study was aimed at auditing pre-operative vessel mapping and post-operative access surveillance against the primary outcome measure of AVF maturation.

Methods

Between January 2006 and August 2007, 113 AVF created in 101 patients were studied. Data on pre-operative vessel mapping, type of AVF, post-operative surveillance scans were analyzed against the outcome AVF.

Results

Pre-operative mapping and post-operative scanning were carried out in 86% and 91%, respectively. A maturing fistula on post-operative scan highly correlated with a satisfactory outcome (p<0.001). The sensitivity and specificity of the post-operative scan were 100% and 85%, respectively. There were 79 brachiocephalic and 34 radiocephalic fistulae with a primary failure rate of 23% and 47%, respectively, giving an overall failure rate of 30%. Nine fistulae had further intervention (angioplasty or thrombolysis) and five (56%) were salvaged. Seventy-two AVF matured satisfactorily giving a primary cumulative patency of 71% (72/102).

Conclusion

This study shows that preoperative vessel mapping provides useful information regarding the choice of AVF. Access surveillance duplex scanning at 6–8 weeks post-operatively is viable and has a high sensitivity and specificity for final outcome of fistula. Identifying AVF with potential problems early means that further intervention or surgery can be planned earlier, which will have a positive impact on patients.

Factors affecting the perception of recovery quality in horses after anaesthesia

REASONS FOR PERFORMING STUDY

A significant effect of gender, experience and background, i.e. an evaluator's relationship with horses as equine anaesthetists, orthopaedic surgeons, practitioners or owners, on perceptions of recovery quality after anaesthesia would reduce the validity of recovery quality scoring systems.

OBJECTIVES

To determine the effects of evaluator background, experience and gender on their perceptions of recovery quality; and questionnaire response rate as a function of background.

STUDY DESIGN

Cross-sectional survey.

METHODS

A total of 440 potential evaluators were invited to evaluate the video-recorded recoveries of 24 horses using a visual analogue scale (VAS) in which 0 = worst, 100 = best possible recovery. A mean score was generated for each of the 1-24 recoveries within each background group. These were compared using Spearman's rank correlation. The effect of gender and experience on VAS scores were analysed using an ordinal logistic regression after scores were categorised into 'intermediate, 'worst' and 'best' recovery categories based on median, 25th and 75th percentile VAS scores, respectively.

RESULTS

The overall response rate was 35%. The greatest was from the anaesthetists (78%) followed by surgeons (43%). The response rate among owners and practitioners was 26%. Correlation among VAS scores across all background groups was high (Spearman rank > 0.90; P < 0.001). Among the combined veterinarians, there was no significant gender (P = 0.551) or experience (P = 0.103) effect. Among horse owners, the effect of experience was not significant (P = 0.116) although gender was (P = 0.027). Male horse owners awarded significantly greater scores than females.

CONCLUSIONS

When VAS are used to grade recovery quality, neither the background nor the gender of veterinary evaluators affects quality perception. Male owners awarded greater scores than female owners, implying that they are less critical of recovery quality and a gender effect among horse owners must be considered when VAS are used to score recovery quality.

Reducing the oxygen concentration of gases delivered from anaesthetic machines unadapted for medical air

High fractional concentrations of inspired oxygen (FiO(2)) delivered over prolonged periods produce characteristic histological changes in the lungs and airway of exposed animals. Modern medical anaesthetic machines are adapted to deliver medical air (FiO(2)=0.21) for the purpose of reducing FiO(2); anaesthetic machines designed for the veterinary market have not been so adapted. Two inexpensive modifications that allow medical air to be added to the gas flow from veterinary anaesthetic machines are described. The advantages and disadvantages of each modification are discussed.

A 5-year audit of haemodialysis access

This is a review of our experience with vascular access procedures over a 5-year period at Derriford Hospital, Plymouth, UK. The aims of the study were to examine the outcome of vascular access procedures and factors influencing access survival. Between April 1995 and March 2000, 151 patients who underwent 221 vascular access procedures were studied. Of these, 136 had autogenous arteriovenous fistulae, whereas 85 had prosthetic AV grafts (41% in the thigh). The overall primary failure rate was 21% whereas the 1- and 5-year cumulative access survival rates were 60 and 41%, respectively. Thigh grafts have a mean survival of 36 months compared with 32 months for prosthetic upper limb and 43 months for autogenous fistulae. Age, diabetes and predialysis status did not significantly influence access survival. Thrombosis was responsible for access failure in 62 cases (28%). Avoiding subclavian vein canulation and performing vessel mapping prior to access placement should reduce the risk of access failure due to outflow obstruction.

Do Medicare patients with disabilities receive preventive services? A population-based study

OBJECTIVE

To compare health maintenance procedure rates of Medicare patients with different levels of disability.

STUDY DESIGN

Observational study analyzing data from the 1995 Medicare Current Beneficiary Survey (MCBS, n = 15,590). Self-reported Pap smears, mammograms, and influenza and pneumococcal vaccinations were compared between groups with different levels of health-related difficulties in six activities of daily living (ADL).

RESULTS

Compared to those without disabilities, the most severely disabled women (limitations in 5 or 6 ADL) reported fewer Pap smears (age < or =70, 23% vs 41%, p < .001) and mammograms (age > or = 50, 13% vs 44%, p < .001). In a controlled analysis, individuals with this high level of disability were 57% (95% confidence interval [CI], 33% to 72%) and 56% (95% CI, 43% to 76%) less likely to report receiving Pap smears and mammograms, respectively, compared with able-bodied women, regardless of their age, whether they were in an HMO, or whether they lived in a long-term care facility. Functional limitations were not a deterrent to receiving vaccinations. In general, patients in HMOs reported more procedures than those in fee-for-service, while those in long-term care facilities reported fewer procedures than those living in the community.

CONCLUSIONS

Disability among Medicare patients is a significant, independent risk factor for not receiving mammograms and Pap smears. Efforts should be made to identify the most severely disabled because they are at particular risk.

Radiographic abnormalities in canine multicentric lymphoma: a review of 84 cases

The thoracic and abdominal radiographs of 84 dogs with multicentric lymphoma were examined to identify the radiological abnormalities. The frequency of occurrence of individual changes, role of radiography in diagnosis, relationship of radiographic changes to hypercalcaemia and prognostic relevance of radiographic findings were assessed. Multiple abnormalities were more commonly seen than solitary changes. No radiographic abnormalities were seen in approximately one quarter of thoracic radiographs and one fifth of abdominal radiographs. Lymphoma could not be diagnosed on the basis of radiographs alone. Many of the features of lymphoma were non-specific, having numerous possible causes. Cranial mediastinal disease was neither a prerequisite for, nor a disproportionately common finding in, hypercalcaemic patients. The absence of radiological abnormalities may be a positive prognostic indicator for the individual patient. The differential diagnoses for the radiographic abnormalities seen in lymphoma are discussed.

Relevance of human papillomavirus screening in management of cervical intraepithelial neoplasia

OBJECTIVE

To evaluate the utility of human papillomavirus detection in identifying women with abnormal Papanicolaou smears who can be safely followed up with cytologic study only, we conducted a study to determine the sensitivity, specificity, and negative and positive predictive values of a Food and Drug Administration-approved human papillomavirus test kit for detection of cervical intraepithelial neoplasia in colposcopically directed biopsy specimens.

STUDY DESIGN

We enrolled women with abnormal Papanicolaou smears referred to a colposcopy clinic serving indigent patients. All 1128 women had a referral Papanicolaou smear, a clinic Papanicolaou smear, and a sample for human papillomavirus deoxyribonucleic acid test; 1075 underwent colposcopically directed biopsies and endocervical curettage. We used the HPV Profile kit for human papillomavirus testing.

RESULTS

Of 486 women with low-grade squamous intraepithelial lesions on Papanicolaou smear, 35.4% had high-risk human papillomavirus deoxyribonucleic acid detected, and of 592 with high-grade lesions, 44.4% had high-risk human papillomavirus detected. Among 527 women with biopsy specimens showing cervical intraepithelial neoplasia and in 267 with cervical intraepithelial neoplasia grades 2 or 3, 38.7% and 56.2% had high-risk human papillomavirus deoxyribonucleic acid detected. However, the sensitivity of human papillomavirus deoxyribonucleic acid detection to identify biopsy-confirmed cervical intraepithelial neoplasia grades 2 or 3 was 55.7%, and the positive predictive value of the test was only 34.9%.

CONCLUSION

Human papillomavirus appears to be causally associated with cervical cancer but human papillomavirus screening does not appear to be of value to identify women with abnormal Papanicolaou smears who can be safely followed up with cytologic study alone.

The effect of different collagen types used as substrata on myogenesis in tissue culture

The effect of different collagen types prepared from muscle used as substrata on myogenesis in tissue culture was investigated. Myogenic cells cultured on type I collagen aligned in parallel in some regions of the culture dish and single myotubes could extend for several centimetres. Myotubes grown on type V collagen did not have a normal elongated appearance and were not aligned.