Association of SARS-CoV-2 Vaccination During Pregnancy With Pregnancy Outcomes

[Fetal death: Expert consensus from the College of French Gynecologists and Obstetricians]

Fetal death is defined as the spontaneous cessation of cardiac activity after fourteen weeks of amenorrhea. In France, the prevalence of fetal death after 22 weeks is between 3.2 and 4.4/1000 births. Regarding the prevention of fetal death in the general population, it is not recommended to counsel for rest and not to prescribe vitamin A, vitamin D nor micronutrient supplementation for the sole purpose of reducing the risk of fetal death (Weak recommendations; Low quality of evidence). It is not recommended to prescribe aspirin (Weak recommendation; Very low quality of evidence). It is recommended to offer vaccination against influenza in epidemic periods and against SARS-CoV-2 (Strong recommendations; Low quality of evidence). It is not recommended to systematically look for nuchal cord encirclements during prenatal screening ultrasounds (Strong Recommendation; Low Quality of Evidence) and not to perform systematic antepartum monitoring by cardiotocography (Weak Recommendation; Very Low Quality of Evidence). It is not recommended to ask women to perform an active fetal movement count to reduce the risk of fetal death (Strong Recommendation; High Quality of Evidence). Regarding evaluation in the event of fetal death, it is suggested that an external fetal examination be systematically offered (Expert opinion). It is recommended that a fetopathological and anatomopathological examination of the placenta be carried out to participate in cause identification (Strong Recommendation. Moderate quality of evidence). It is recommended that chromosomal analysis by microarray testing be performed rather than conventional karyotype, in order to be able to identify a potentially causal anomaly more frequently (Strong Recommendation, moderate quality of evidence); to this end, it is suggested that postnatal sampling of the placental fetal surface for genetic purposes be preferred (Expert Opinion). It is suggested to test for antiphospholipid antibodies and systematically perform a Kleihauer test and a test for irregular agglutinins (Expert opinion). It is suggested to offer a summary consultation, with the aim of assessing the physical and psychological status of the parents, reporting the results, discussing the cause and providing information on monitoring for a subsequent pregnancy (Expert opinion). Regarding announcement and support, it is suggested to announce fetal death without ambiguity, using simple words and adapting to each situation, and then to support couples with empathy in the various stages of their care (Expert opinion). Regarding management, it is suggested that, in the absence of a situation at risk of disseminated intravascular coagulation or maternal vitality, the patient's wishes should be taken into account when determining the time between the diagnosis of fetal death and induction of birth. Returning home is possible if it's the patient wish (Expert opinion). In all situations excluding maternal life-threatening emergencies, the preferred mode of delivery is vaginal delivery, regardless the history of cesarean section(s) history (Expert opinion). In the event of fetal death, it is recommended that mifepristone 200mg be prescribed at least 24hours before induction, to reduce the delay between induction and delivery (Low recommendation. Low quality of evidence). There are insufficient data in the literature to make a recommendation regarding the route of administration (vaginal or oral) of misoprostol, neither the type of prostaglandin to reduce induction-delivery time or maternal morbidity. It is suggested that perimedullary analgesia be introduced at the start of induction if the patient asks, regardless of gestational age. It is suggested to prescribe cabergoline immediately in the postpartum period in order to avoid lactation, whatever the gestational age, after discussing the side effects of the treatment with the patient (Expert opinion). The risk of recurrence of fetal death after unexplained fetal death does not appear to be increased in subsequent pregnancies, and data from the literature are insufficient to make a recommendation on the prescription of aspirin. In the event of a history of fetal death due to vascular issues, low-dose aspirin is recommended to reduce perinatal morbidity, and should not be combined with heparin therapy (Low recommendation, very low quality of evidence). It is suggested not to recommend an optimal delay before initiating another pregnancy just because of the history of fetal death. It is suggested that the woman and co-parent be informed of the possibility of psychological support. Fetal heart rate monitoring is not indicated solely because of a history of fetal death. It is suggested that delivery not be systematically induced. However, induction can be considered depending on the context and parental request. The gestational age will be discussed, taking into account the benefits and risks, especially before 39 weeks. If a cause of fetal death is identified, management will be adapted on a case-by-case basis (expert opinion). In the event of fetal death occurring in a twin pregnancy, it is suggested that the surviving twin be evaluated as soon as the diagnosis of fetal death is made. In the case of dichorionic pregnancy, it is suggested to offer ultrasound monitoring on a monthly basis. It is suggested not to deliver prematurely following fetal death of a twin. If fetal death occurs in a monochorionic twin pregnancy, it is suggested to contact the referral competence center, in order to urgently look for signs of acute fetal anemia on ultrasound in the surviving twin, and to carry out weekly ultrasound monitoring for the first month. It is suggested not to induce birth immediately.

Current Approaches in Postapproval Vaccine Safety Studies Using Real-World Data: A Systematic Review of Published Literature

PURPOSE

Well-designed observational postmarketing studies using real-world data (RWD) are critical in supporting an evidence base and bolstering public confidence in vaccine safety. This systematic review presents current research methodologies in vaccine safety research in postapproval settings, technological advancements contributing to research resources and capabilities, and their major strengths and limitations.

METHODS

A comprehensive search was conducted using PubMed to identify relevant articles published from January 1, 2019, to December 31, 2022. Eligible studies were summarized overall by study design and other study characteristics (eg, country, vaccine studied, types of data source, and study population). An in-depth review of select studies representative of conventional or new designs, analytical approaches, or data collection methods was conducted to summarize current methods in vaccine safety research.

FINDINGS

Out of 977 articles screened for inclusion, 135 were reviewed. The review shows that recent advancements in scientific methods, digital technology, and analytic approaches have significantly contributed to postapproval vaccine safety studies using RWD. "Near real-time surveillance" using large datasets (via collaborative or distributed databases) has been used to facilitate rapid signal detection that complements passive surveillance. There was increasing appreciation for self-controlled case-only designs (self-controlled case series and self-controlled risk interval) to assess acute-onset safety outcomes, artificial intelligence, and natural language processing to improve outcome accuracy and study timeliness and emerging artificial intelligence-based analysis to capture adverse events from social media platforms.

IMPLICATIONS

Continued development in the area of vaccine safety research methodologies using RWD is warranted. The future of successful vaccine safety research, especially evaluation of rare safety events, is likely to comprise digital technologies including linking RWD networks, machine learning, and advanced analytic methods to generate rapid and robust real-world safety information.

Coronavirus Disease 2019 (COVID-19) Vaccination and Stillbirth in the Vaccine Safety Datalink

OBJECTIVE

Coronavirus disease 2019 (COVID-19) vaccination is recommended in pregnancy to reduce the risk of severe morbidity from COVID-19. However, vaccine hesitancy persists among pregnant people, with risk of stillbirth being a primary concern. Our objective was to examine the association between COVID-19 vaccination and stillbirth.

METHODS

We performed a matched case-control study in the Vaccine Safety Datalink (VSD). Stillbirths and live births were selected from singleton pregnancies among persons aged 16-49 years with at least one prenatal, delivery, or postpartum visit at eight participating VSD sites. Stillbirths identified through diagnostic codes were adjudicated to confirm the outcome, date, and gestational age at fetal death. Confirmed antepartum stillbirths that occurred between February 14, 2021, and February 27, 2022, then were matched 1:3 to live births by pregnancy start date, VSD site, and maternal age at delivery. Associations among antepartum stillbirth and COVID-19 vaccination in pregnancy, vaccine manufacturer, number of vaccine doses received, and vaccination within 6 weeks before stillbirth (or index date in live births) were evaluated using conditional logistic regression.

RESULTS

In the matched analysis of 276 confirmed antepartum stillbirths and 822 live births, we found no association between COVID-19 vaccination during pregnancy and stillbirth (38.4% stillbirths vs 39.3% live births in vaccinated individuals, adjusted odds ratio [aOR] 1.02, 95% CI, 0.76-1.37). Furthermore, no association between COVID-19 vaccination and stillbirth was detected by vaccine manufacturer (Moderna: aOR 1.00, 95% CI, 0.62-1.62; Pfizer-BioNTech: aOR 1.00, 95% CI, 0.69-1.43), number of vaccine doses received during pregnancy (1 vs 0: aOR 1.17, 95% CI, 0.75-1.83; 2 vs 0: aOR 0.98, 95% CI, 0.81-1.17), or COVID-19 vaccination within the 6 weeks before stillbirth or index date compared with no vaccination (aOR 1.16, 95% CI, 0.74-1.83).

CONCLUSION

No association was found between COVID-19 vaccination and stillbirth. These findings further support recommendations for COVID-19 vaccination in pregnancy.

Covid-19 infection and vaccination during first trimester and risk of congenital anomalies: Nordic registry based study

OBJECTIVES

To evaluate the risk of major congenital anomalies according to infection with or vaccination against covid-19 during the first trimester of pregnancy.

DESIGN

Prospective Nordic registry based study.

SETTING

Sweden, Denmark, and Norway.

PARTICIPANTS

343 066 liveborn singleton infants in Sweden, Denmark, and Norway, with an estimated start of pregnancy between 1 March 2020 and 14 February 2022, identified using national health registries.

MAIN OUTCOME MEASURE

Major congenital anomalies were categorised using EUROCAT (European Surveillance of Congenital Anomalies) definitions. The risk after covid-19 infection or vaccination during the first trimester was assessed by logistic regression, adjusting for maternal age, parity, education, income, country of origin, smoking, body mass index, chronic conditions, and estimated date of start of pregnancy.

RESULTS

17 704 (5.2%) infants had a major congenital anomaly. When evaluating risk associated with covid-19 infection during the first trimester, the adjusted odds ratio ranged from 0.84 (95% confidence interval 0.51 to 1.40) for eye anomalies to 1.12 (0.68 to 1.84) for oro-facial clefts. Similarly, the risk associated with covid-19 vaccination during the first trimester ranged from 0.84 (0.31 to 2.31) for nervous system anomalies to 1.69 (0.76 to 3.78) for abdominal wall defects. Estimates for 10 of 11 subgroups of anomalies were less than 1.04, indicating no notable increased risk.

CONCLUSIONS

Covid-19 infection and vaccination during the first trimester of pregnancy were not associated with risk of congenital anomalies.

Safety and Effectiveness of COVID-19 Vaccines During Pregnancy: A Living Systematic Review and Meta-analysis

BACKGROUND

Pregnant persons are susceptible to significant complications following COVID-19, even death. However, worldwide COVID-19 vaccination coverage during pregnancy remains suboptimal.

OBJECTIVE

This study assessed the safety and effectiveness of COVID-19 vaccines administered to pregnant persons and shared this evidence via an interactive online website.

METHODS

We followed Cochrane methods to conduct this living systematic review. We included studies assessing the effects of COVID-19 vaccines in pregnant persons. We conducted searches every other week for studies until October 2023, without restrictions on language or publication status, in ten databases, guidelines, preprint servers, and COVID-19 websites. The reference lists of eligible studies were hand searched to identify additional relevant studies. Pairs of review authors independently selected eligible studies using the web-based software COVIDENCE. Data extraction and risk of bias assessment were performed independently by pairs of authors. Disagreements were resolved by consensus. We performed random-effects meta-analyses of adjusted relative effects for relevant confounders of comparative studies and proportional meta-analyses to summarize frequencies from one-sample studies using R statistical software. We present the GRADE certainty of evidence from comparative studies. Findings are available on an interactive living systematic review webpage, including an updated evidence map and real-time meta-analyses customizable by subgroups and filters.

RESULTS

We included 177 studies involving 638,791 participants from 41 countries. Among the 11 types of COVID-19 vaccines identified, the most frequently used platforms were mRNA (154 studies), viral vector (51), and inactivated virus vaccines (17). Low to very low-certainty evidence suggests that vaccination may result in minimal to no important differences compared to no vaccination in all assessed maternal and infant safety outcomes from 26 fewer to 17 more events per 1000 pregnant persons, and 13 fewer to 9 more events per 1000 neonates, respectively. We found statistically significant reductions in emergency cesarean deliveries (9%) with mRNA vaccines, and in stillbirth (75-83%) with mRNA/viral vector vaccines. Low to very low-certainty evidence suggests that vaccination during pregnancy with mRNA vaccines may reduce severe cases or hospitalizations in pregnant persons with COVID-19 (72%; 95% confidence interval [CI] 42-86), symptomatic COVID-19 (78%; 95% CI 21-94), and virologically confirmed SARS-CoV-2 infection (82%; 95% CI 39-95). Reductions were lower with other vaccine types and during Omicron variant dominance than Alpha and Delta dominance. Infants also presented with fewer severe cases or hospitalizations due to COVID-19 and laboratory-confirmed SARS-CoV-2 infection (64%; 95% CI 37-80 and 66%; 95% CI 37-81, respectively).

CONCLUSIONS

We found a large body of evidence supporting the safety and effectiveness of COVID-19 vaccines during pregnancy. While the certainty of evidence is not high, it stands as the most reliable option available, given the current absence of pregnant individuals in clinical trials. Results are shared in near real time in an accessible and interactive format for scientists, decision makers, clinicians, and the general public. This living systematic review highlights the relevance of continuous vaccine safety and effectiveness monitoring, particularly in at-risk populations for COVID-19 impact such as pregnant persons, during the introduction of new vaccines.

CLINICAL TRIAL REGISTRATION

PROSPERO: CRD42021281290.

COVID-19 vaccination during pregnancy and adverse perinatal outcomes: a systematic review and meta-analysis

We aimed to estimate the associations between coronavirus disease 2019 (COVID-19) vaccination during pregnancy and the risks of adverse perinatal outcomes. We performed a literature search in PubMed, Web of Science and Embase to identify eligible studies published up to 24 September 2023, yielding 39 included studies. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated with a random effects model. The pooled results showed that COVID-19 vaccination during pregnancy (any type or dose of COVID-19 vaccination during any trimester) was not associated with an increased risk of adverse perinatal outcomes. In particular, COVID-19 vaccination in the third trimester was associated with a decreased risk of preterm birth (<37 weeks) (RR 0.85 [95% CI 0.74 to 0.98]), 5-min Apgar <7 (RR 0.87 [95% CI 0.78 to 0.97]) and neonatal intensive care unit (NICU) admission (RR 0.90 [95% CI 0.86 to 0.95]). The inverse associations were also found in analysis of one-dose vaccination during pregnancy and the risk of miscarriage (RR 0.83 [95% CI 0.72 to 0.96]) and preterm birth (<37 weeks) (RR 0.90 [95% CI 0.80 to 1.00]) and two-dose vaccination during pregnancy and the risk of NICU admission (RR 0.86 [95% CI 0.76 to 0.96]). COVID-19 vaccination during pregnancy does not increase the risk of negative outcomes for the mother or baby.

Association of BNT162b2 SARS-CoV-2 vaccination during pregnancy with postnatal outcomes in premature infants

AIM

The effect of COVID-19 vaccine given during pregnancy on premature infants is unknown. This study aims to determine the association between maternal COVID-19 vaccine with postnatal outcome in premature infants.

METHODS

This is a single-centre retrospective case-control study of infants born before 35 weeks gestation to mothers who received SARS-CoV-2 vaccine during pregnancy compared with infant born to non-vaccinated mothers.

RESULTS

A total of 78 infants in each group were included. Infants in the vaccinated group had less respiratory distress syndrome (RDS) (p = 0.02) and less need for respiratory support (p = 0.002), and maternal vaccine had a protective effect on RDS [adjustable OR 0.38 (0.17-0.85)]. Vaccination during the first compared to the second trimester was associated with earlier gestational age (32.3 ± 2.1 vs. 33.3 ± 1.1 weeks, p = 0.03).

CONCLUSION

We demonstrated that maternal SARS-CoV-2 vaccine is not associated with postnatal adverse effect in premature infants and potentially has a protective effect on RDS. Earlier gestational age among the infants born to mothers who received COVID-19 vaccine during the first trimester did not translate to higher rate of postnatal complications. These findings might suggest that COVID-19 vaccine is safe in high-risk pregnancies, but timing of administration should be considered. Further studies are needed to confirm our findings and the biological mechanism.

COVID-19 Vaccination in Pregnancy: Pilot Study of Plasma MicroRNAs Associated with Inflammatory Cytokines after COVID-19 mRNA Vaccination

BACKGROUND

The impact of mRNA COVID-19 vaccines on the immunological profiles of pregnant women remains a crucial area of study. This research aims to explore the specific immunological changes triggered by these vaccines in this demographic.

METHODS

In a focused investigation, we examined the effects of mRNA COVID-19 vaccination on microRNA expression in pregnant women. Key microRNAs, including miR-451a, miR-23a-3p, and miR-21-5p, were analyzed for expression changes post-vaccination. Additionally, we assessed variations in S1RBD IgG levels and specific cytokines to gauge the broader immunological response.

RESULTS

Post-vaccination, significant expression shifts in the targeted microRNAs were observed. Alongside these changes, we noted alterations in S1RBD IgG and various cytokines, indicating an adapted inflammatory response. Notably, these immunological markers displayed no direct correlation with S1RBD IgG concentrations, suggesting a complex interaction between the vaccine and the immune system in pregnant women.

CONCLUSIONS

Our pilot study provides valuable insights into the nuanced effects of the mRNA COVID-19 vaccine on immune dynamics in pregnant women, particularly emphasizing the role of microRNAs. The findings illuminate the intricate interplay between vaccines, microRNAs, and immune responses, enhancing our understanding of these relationships in the context of pregnancy. This research contributes significantly to the growing body of knowledge regarding mRNA COVID-19 vaccines and their specific impact on maternal immunology, offering a foundation for further studies in this vital area.

COVID-19 vaccine safety during pregnancy and breastfeeding in women with autoimmune diseases: results from the COVAD study

OBJECTIVES

We investigated coronavirus disease 2019 (COVID-19) vaccine safety in pregnant and breastfeeding women with autoimmune diseases (AID) in the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study.

METHODS

Delayed-onset (>7 days) vaccine-related adverse events (AE), disease flares and AID-related treatment modifications were analysed upon diagnosis of AID vs healthy controls (HC) and the pregnancy/breastfeeding status at the time of at least one dose of vaccine.

RESULTS

Among the 9201 participants to the self-administered online survey, 6787 (73.8%) were women. Forty pregnant and 52 breastfeeding patients with AID were identified, of whom the majority had received at least one dose of COVID-19 vaccine (100% and 96.2%, respectively). AE were reported significantly more frequently in pregnant than in non-pregnant patients (overall AE 45% vs 26%, P = 0.01; minor AE 40% vs 25.9%, P = 0.03; major AE 17.5% vs 4.6%, P < 0.01), but no difference was found in comparison with pregnant HC. No difference was observed between breastfeeding patients and HC with respect to AE. Post-vaccination disease flares were reported by 17.5% of pregnant and 20% of breastfeeding patients, and by 18.3% of age- and disease-matched non-pregnant and non-breastfeeding patients (n = 262). All pregnant/breastfeeding patients who experienced a disease flare were managed with glucocorticoids; 28.6% and 20% of them required initiation or change in immunosuppressants, respectively.

CONCLUSION

This study provides reassuring insights into the safety of COVID-19 vaccines administered to women with AID during the gestational and post-partum periods, helping overcome hesitant attitudes, as the benefits for the mother and for the fetus by passive immunization appear to outweigh potential risks.

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.

Perinatal outcomes and sinopharm BBIBP-CorV vaccination during pregnancy

BACKGROUND

After the outbreak of COVID-19, a huge part of the health care services was dedicated to preventing and treating this disease. In case of COVID-19 infection, severe COVID-19 is reported more in pregnant individuals. Afterward, Vaccination against SARS-CoV-2 became a hot topic due to known effects in preventing severe COVID-19 during pregnancy. Vaccination of pregnant individuals started in August 2021 with the Sinopharm vaccine in Iran. The aim of current study was to determine the incidence of perinatal outcomes in women who were vaccinated during pregnancy.

METHOD

This retrospective cohort study included 129,488 singleton births from March 21, 2021, until March 21, 2022, in Tehran, Iran. The data was obtained from the Iranian Maternal and Neonatal (IMaN) Network and the Maternal Vaccination Registry. Adverse perinatal outcomes investigated in this study include preterm birth, extremely preterm birth, low birth weight, very low birth weight, intrauterine growth restriction, stillbirth, neonatal intensive care unit admission, congenital anomaly, neonatal death and low 5-minute Apgar score. The risk of all perinatal outcomes was evaluated using multiple logistic regression. The analysis was done using STATA version 14.

RESULTS

Of all 129,488 singleton births included in this study, 17,485 (13.5%) were vaccinated against SARS-CoV-2 (all with Sinopharm (BBIBP-CorV)). The exposure to the Sinopharm vaccine during pregnancy caused a significant decrease in the incidence of preterm birth (P =0.006, OR=0.91 [95% CI, 0.85 to 0.97]), extremely preterm birth (P =<0.001,OR=0.55 [95% CI, 0.45 to 0.66]), and stillbirth (P =<0.001, OR=0.60 [95% CI, 0.47 to 0.76]). Exposure to vaccination during the first trimester was associated with an increased risk of preterm birth (P =0.01, OR=1.27 [95% CI, 1.04 to 1.55]) Maternal vaccination during pregnancy was not associated with an increased risk of other adverse perinatal outcomes included in this study.

CONCLUSION

The finding of this population-based study indicated no adverse pregnancy outcome due to vaccination with the Sinopharm vaccine during the second and third trimesters of pregnancy. Overall risk of adverse pregnancy outcomes were lower in the vaccinated individuals compared to the unvaccinated group. Also, vaccination during the first trimester was associated with an increased risk of preterm birth.

Neonatal Outcomes After COVID-19 Vaccination in Pregnancy

Importance

Better knowledge about neonatal adverse events after COVID-19 vaccination during pregnancy could help address concerns about vaccine safety.

Objective

To evaluate the risks of neonatal adverse events after exposure to COVID-19 vaccination during pregnancy.

Design, Setting, and Participants

Population-based cohort study including all infants in Sweden and Norway born from June 2021 to January 2023. Unique personal identity numbers were used to link individual information from different national registers.

Exposure

Administration of any mRNA vaccine against COVID-19 during pregnancy, irrespective of previous vaccination, number of doses during pregnancy, or vaccine manufacturer.

Main Outcomes and Measures

Outcomes were neonatal conditions with bleeding/thrombosis or inflammation/infection; disorders of the central nervous system; circulatory, respiratory, or gastrointestinal problems; and neonatal mortality. Statistical methods included logistic regression adjusted for characteristics of the pregnant individuals, with additional restricted and stratified analyses.

Results

Of 196 470 newborn infants included (51.3% male, 93.8% born at term, 62.5% born in Sweden), 94 303 (48.0%) were exposed to COVID-19 vaccination during pregnancy. Exposed infants exhibited no increased odds of adverse neonatal outcomes, and they exhibited lower odds for neonatal nontraumatic intracranial hemorrhage (event rate, 1.7 vs 3.2/1000; adjusted odds ratio [aOR], 0.78 [95% CI, 0.61-0.99]), hypoxic-ischemic encephalopathy (1.8 vs 2.7/1000; aOR, 0.73 [95% CI, 0.55-0.96]), and neonatal mortality (0.9 vs 1.8/1000; aOR, 0.68 [95% CI, 0.50-0.91]). Subgroup analyses found a similar association between vaccination during pregnancy and lower neonatal mortality; subgroups were restricted to infants delivered by individuals unvaccinated before pregnancy, individuals vaccinated before pregnancy, individuals vaccinated after a general recommendation of vaccination during pregnancy was issued, and individuals without COVID-19 infection during pregnancy. Analyses restricted to term infants, singleton births, or infants without birth defects yielded similar results. Stratifying the analysis by vaccine manufacturer did not attenuate the association between vaccination and low neonatal mortality.

Conclusions and Relevance

In this large population-based study, vaccination of pregnant individuals with mRNA COVID-19 vaccines was not associated with increased risks of neonatal adverse events in their infants.

Description of maternal and neonatal adverse events in pregnant people immunised with COVID-19 vaccines during pregnancy in the CLAP NETWORK of sentinel sites. Nested case-control analysis of the immunization-associated risk: A study protocol

INTRODUCTION

COVID-19 is associated with higher morbimortality in pregnant people compared with non-pregnant people. At present, the benefits of maternal immunisation are considered to outweigh the risks, and therefore, vaccination is recommended during pregnancy. However, additional information is needed on the safety of the vaccines in this population.

METHODS AND ANALYSIS

This a retrospective cohort nested case-control study in pregnant people who attended maternity hospitals from eight Latin American and Caribbean countries. A perinatal electronic clinical history database with neonatal and obstetric information will be used. The proportion of pregnant people immunised with COVID-19 vaccines of the following maternal and neonatal events will be described: preterm infant, small for gestational age, low birth weight, stillbirth, neonatal death, congenital malformations, maternal near miss and maternal death. Moreover, the risk of prematurity, small for gestational age and low birth weight associated with exposure to COVID-19 vaccines will be estimated. Each case will be matched with two groups of three randomly selected controls. Controls will be matched by hospital and mother's age (±3 years) with an additional matching by delivery date and conception time in the first and second control groups, respectively. The estimated required sample size for the main analysis (exposure to any vaccine) concerning 'non-use' is at least 1009 cases (3027 controls) to detect an increased probability of vaccine-associated event risk of 30% and at least 650 cases (1950 controls) to detect 30% protection. Sensitivity and secondary analyses considering country, type of vaccine, exposure windows and completeness of immunisation will be reported.

ETHICS

The study protocol was reviewed by the Ethical Review Committee on Research of the Pan American Health Organization. Patient informed consent was waived due to the retrospective design and the utilisation of anonymised data (Ref. No: PAHOERC.0546.01). Results will be disseminated in open access journals.

Assessing the Impact of COVID-19 Vaccination on Preterm Birth: A Systematic Review with Meta-Analysis

During the coronavirus diseases 2019 (COVID-19) pandemic, the safety and efficacy of vaccination during pregnancy, particularly regarding the risk of preterm birth, have been a subject of concern. This systematic review aims to evaluate the impact of COVID-19 vaccination on preterm birth risk and to inform clinical practice and public health policies. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a database search included PubMed, Embase, and Scopus, conducted up until October 2023. Inclusion criteria focused on studies that examined COVID-19 vaccination during pregnancy and its correlation with preterm birth, defined as a birth before 37 weeks of gestation. Six studies met these criteria, encompassing 35,612 patients. A quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Collaboration's tool, with the risk of bias evaluated via a funnel plot analysis and an Egger's regression test. The studies demonstrated geographical diversity, mainly from Israel, Romania, and the United States, with a blend of prospective and retrospective designs. The patient cohort's mean age was 31.2 years, with common comorbidities such as gestational diabetes and obesity affecting 9.85% of the total population. The vaccination types varied across the studies, with BNT162b2 being the most used. The results indicated a low heterogeneity among the included studies, evidenced by a Cochran's Q statistic of 2.10 and an I2 statistic of 13%. The meta-analysis yielded a pooled odds ratio (OR) for a preterm birth risk post-vaccination of approximately 1.03 (95% CI: 0.82-1.30), suggesting no significant increase in preterm birth risk was associated with COVID-19 vaccination. Notable findings included a low preterm birth rate (as low as 0.6% and up to 6.1%) with minimal differences in neonatal outcomes, such as birth weight and APGAR (appearance, pulse, grimace, activity, and respiration) scores between vaccinated and unvaccinated groups. This study concludes that a COVID-19 vaccination during pregnancy does not significantly increase the risk of preterm birth. These findings are crucial for reassuring healthcare providers and pregnant women about the safety of COVID-19 vaccines and supporting their use in public health strategies during the pandemic.

Safety of COVID-19 Vaccination During Pregnancy and Lactation: A VigiBase Analysis

BACKGROUND

There is limited evidence on the safety of coronavirus disease 2019 (COVID-19) vaccination during pregnancy and lactation. Thus, we aimed to evaluate the association between COVID-19 vaccination during pregnancy and lactation and reporting risk of adverse pregnancy or lactation outcomes.

METHODS

Using VigiBase, we performed a disproportionality analysis with case/non case design. Cases were defined based on the Standardized MedDRA Queries (SMQs) of "pregnancy and neonatal topics" and non-cases were defined as all other adverse events. We included all reports with COVID-19 vaccines as the suspected cause. Using the full database as the comparators, reporting odds ratios (RORs) with 95% confidence intervals (CIs) were estimated by logistic regression while adjusting for maternal age. Infants' age and sex were additionally adjusted in analyzing the risk of COVID-19 vaccination during lactation.

RESULTS

We identified 10,266 and 6,474 reports with the SMQ of "pregnancy and neonatal topics" associated with COVID-19 vaccines during pregnancy and lactation, respectively. No significant RORs of adverse pregnancy outcomes associated with COVID-19 vaccines during pregnancy were observed; however, "functional lactation disorders" showed significant disproportionality during lactation with adjusted ROR of 1.48 (95% CI, 1.21-1.79). Further analysis that analyzed "functional lactation disorders" at a preferred term level, showed higher ROR in mastitis (2.76 [95% CI, 1.45-5.27]).

CONCLUSION

Overall, we did not observe a positive association between COVID-19 vaccination during pregnancy and risk of reporting adverse pregnancy outcomes. However, we found a significant disproportionate reporting association between COVID-19 vaccination during lactation and "functional lactation disorders", specifically mastitis. Continuous surveillance is warranted to confirm the safety of COVID-19 vaccine during pregnancy and lactation.

A narrative review of COVID-19 vaccination in pregnancy and breastfeeding

The Coronavirus pandemic has affected millions of people due to the spread of the Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) virus. Pregnant individuals and infants are most vulnerable given the increased risk of developing severe complications from SARS-CoV-2 infection. Recently, COVID-19 vaccination is recommended for pregnant women and infants starting at 6 months of age to prevent disease contraction and minimize disease severity. We conducted a review of the literature on COVID-19 vaccination to discuss vaccine safety and efficacy, immunity after maternal vaccination, transplacental transfer and persistence of antibodies, and public health implications. Current evidence supports the safety and efficacy of vaccination during pregnancy. Maternal vaccination provides greater antibody persistence in infants compared to immunity from natural infection. Furthermore, vaccination has demonstrated an increased rate of passive antibody transfer through the placenta and breast milk. Public health interventions are important in achieving herd immunity and ultimately ending the pandemic. IMPACT: This article highlights the benefits of COVID-19 vaccination during pregnancy with a review of the data describing safety and efficacy, passive and active immunity after maternal immunization, trans-placental transfer and persistence of protective antibodies, and public health implications. With this information, healthcare providers can provide up-to-date knowledge to their pregnant patients to help them form an informed decision on vaccination and combat vaccine hesitancy.

Effects of COVID-19 vaccination on human fertility: a post-pandemic literature review

Although vaccination with the Coronavirus disease 2019 vaccine is important and effective in the prevention of SARS-CoV-2 infection, the public expressed concerns regarding the adverse effects of vaccine on fertility. Some reviews have focused on it, they have been unable to collect sufficient research data because of the earlier publication period. As relevant evidence has gradually increased, we reviewed these studies from the perspectives of males, females with or without pregnancy, and different vaccine types. The results suggest that although males may experience fluctuations in semen parameters within their physiological ranges after receiving the vaccine, it has not yet reached a level of influence on the partner's pregnancy probability. As to female without pregnancy, it is believed that vaccination will not affect fertility; however, more research is needed to explore the short-term impact. Vaccination during any trimester is considered safe in pregnant women.

Newborn and Early Infant Outcomes Following Maternal COVID-19 Vaccination During Pregnancy

Importance

The study team previously showed that maternal mRNA COVID-19 vaccination during pregnancy confers protection against SARS-CoV-2 infection and COVID-19-related hospital admission in newborns and young infants. In this study, the study team evaluated newborn and early infant safety outcomes following maternal messenger RNA (mRNA) COVID-19 vaccination during pregnancy, for which there is limited comparative epidemiological evidence.

Objective

To determine if maternal mRNA COVID-19 vaccination during pregnancy is associated with adverse newborn and early infant outcomes.

Design, Setting, and Participants

This population-based retrospective cohort study took place in Ontario, Canada, using multiple linked health administrative databases. Singleton live births with an expected delivery date between May 1, 2021, and September 2, 2022, were included. Data were analyzed from January 2023 through March 2023.

Exposure

Maternal mRNA COVID-19 vaccination (1 or more doses) during pregnancy.

Main Outcomes and Measures

Severe neonatal morbidity (SNM), neonatal death, neonatal intensive care unit (NICU) admission, neonatal readmission, and hospital admission up to 6 months of age. The study team calculated inverse probability of treatment weighted risk ratios (RRs) and fit weighted Cox proportional hazards regression models comparing outcomes in infants of mothers who received COVID-19 vaccination during pregnancy with those who received no COVID-19 vaccine doses before delivery.

Results

In total, 142 006 infants (72 595 male [51%]; mean [SD] gestational age at birth, 38.7 [1.7] weeks) were included; 85 670 were exposed to 1 or more COVID-19 vaccine doses in utero (60%). Infants of vaccinated mothers had lower risks of SNM (vaccine exposed 7.3% vs vaccine unexposed 8.3%; adjusted RR [aRR], 0.86; 95% CI, 0.83-0.90), neonatal death (0.09% vs 0.16%; aRR, 0.47; 95% CI, 0.33-0.65), and NICU admission (11.4% vs 13.1%; aRR, 0.86; 95% CI, 0.83-0.89). There was no association between maternal vaccination during pregnancy and neonatal readmission (5.5% vs 5.1%; adjusted hazard ratio, 1.03; 95% CI, 0.98-1.09) or 6-month hospital admission (8.4% vs 8.1%; adjusted hazard ratio, 1.01; 95% CI, 0.96-1.05).

Conclusions and Relevance

In this population-based cohort study in Ontario, Canada, maternal mRNA COVID-19 vaccination during pregnancy was associated with lower risks of SNM, neonatal death, and NICU admission. In addition, neonatal and 6-month readmissions were not increased in infants of mothers vaccinated during pregnancy.

COVID-19 and Pregnancy: Interrelationships With Asthma and Allergy

Pregnant individuals are at higher risk of complications from respiratory viruses such as coronavirus-19 disease (COVID-19). Altered lung function, vaccine hesitancy, and resistance to taking necessary medications because of a lack of safety data in pregnancy make this population especially vulnerable to the effects of COVID-19. Like many medical conditions, the treatment of allergic conditions, including asthma and allergic rhinitis, were affected during the pandemic, with decreased numbers of in-person visits and interruptions in medical treatment. There were initially no data to allow pregnant women with asthma know whether the condition put them at higher risk of complications from COVID-19. There are now increasing data for the efficacy and safety of vaccines for COVID-19 in at-risk populations, including pregnant women. Vaccine studies show no increased risk for spontaneous abortion, congenital anomalies, or pregnancy complications. Furthermore, infants of individuals vaccinated during pregnancy have been shown to obtain protective antibodies via the placenta, providing protection against COVID-19 after birth. Although overall risks are low, pregnant women who become infected with COVID-19 are at higher risk for maternal and pregnancy complications. Antiviral treatment is available for pregnant women with mild to moderate symptoms of COVID-19, with reassuring safety data to date. Dexamethasone is the mainstay of inpatient therapy.

Safety of COVID-19 vaccination in pregnant women and their neonatal outcome: a narrative Review

BACKGROUND

Even through the fact that pregnant women are more and more severely infected with COVID-19 disease, there are still doubts about vaccinating these people due to the lack of sufficient evidence base information. So in this systematic review, we decided to study vaccinated and unvaccinated pregnant women regarding maternal, fetal and neonatal complications and outcomes.

THE STRATEGY OF SEARCHING

Between 30 December 2019 and 15 October 2021, electronic searches were performed on the databases of PubMed, Scopus, Google Scholar, and Cochrane library by searching in English and free full text. Keywords searched included these: maternal outcome, neonatal outcome, pregnancy, and COVID-19 vaccination. Among 451 articles, finally, seven studies were included to study pregnancy outcomes in vaccinated women compared to unvaccinated for systematic review purposes.

RESULTS

In this study 30257 vaccinated women in their third trimester compared to 132339 unvaccinated women in terms of age, the root of delivery, neonatal adverse outcomes. There were no significant differences between two groups in terms of: IUFD, and 1 min Apgar score, C/S rate, and NICU admission between the two groups, however, the rate of SGA, IUFD, and also neonatal jaundice, asphyxia, and hypoglycemia was more significant in the unvaccinated group comparing to the vaccinated group as a result. Among them, the chance of preterm labor pain was reported more among vaccinated patients. Emphasizing that, except 7.3% of the case population, everyone in the second and third trimesters had been vaccinated with mRNA COVID-19 vaccines.

CONCLUSION

COVID-19 vaccination during the second and third trimesters appears to be the right choice due to the immediate impact of COVID-19 antibodies on the developing fetus and formation of neonatal prophylaxis, as well as the absence of adverse outcomes for both the fetus and mothers.

Reactogenicity, pregnancy outcomes, and SARS-CoV-2 infection following COVID-19 vaccination during pregnancy in Canada: A national prospective cohort study

OBJECTIVE

To describe self-reported reactogenicity, pregnancy outcomes, and SARS-CoV-2 infection following COVID-19 vaccination during pregnancy.

DESIGN

National, prospective cohort study.

SETTING

Participants across Canada were enrolled from July 2021 until June 2022.

POPULATION

Individuals pregnant during the COVID-19 pandemic, regardless of vaccination status, were included.

METHODS

The Canadian COVID-19 Vaccine Registry for Pregnant and Lactating Individuals (COVERED) was advertised through traditional and social media. Surveys were administered at baseline, following each vaccine dose if vaccinated, pregnancy conclusion, and every two months for 14 months. Changes to pregnancy or vaccination status, SARS-CoV-2 infections, or significant health events were recorded.

MAIN OUTCOME MEASURES

Reactogenicity (local and systemic adverse events, and serious adverse events) within 1 week post-vaccination, pregnancy and neonatal outcomes, and subsequent SARS-CoV-2 infection.

RESULTS

Among 2868 participants who received 1-2 doses of a COVID-19 vaccine during pregnancy, adverse events described included: headache (19.5-33.9%), nausea (4.8-13.8%), fever (2.7-10.2%), and myalgia (33.4-42.2%). Reactogenicity was highest after the 2nd dose of vaccine in pregnancy. Compared to 1660 unvaccinated participants, there were no statistically significant differences in adverse pregnancy or infant outcomes, aside from an increased risk of NICU admission ≥ 24 h among the unvaccinated group. During follow-up, there was a higher rate of participant-reported SARS-CoV-2 infection in the unvaccinated compared to the vaccinated group (18[47.4%] vs. 786[27.3%]).

CONCLUSIONS

Participant-reported reactogenicity was similar to reports from non-pregnant adults. There was no increase in adverse pregnancy and birth outcomes among vaccinated vs. unvaccinated participants and lower rates of SARS-CoV-2 infection were reported in vaccinated participants.

TWEETABLE ABSTRACT

No significant increase in adverse pregnancy or infant outcomes among vaccinated versus unvaccinated pregnant women in Canada.

Review of short-term and long-term adverse effects of covid-19 vaccination during pregnancy

BACKGROUND

The covid-19 pandemic sparked a debate about the safety of vaccines during pregnancy. However, pregnant women were excluded from the Pfizer-BioNTech vaccine phase 3 trials. As two years have passed since the first Covid-19 vaccine and more studies have been conducted, we want to evaluate the scientific literature to determine any actual risks in taking the vaccine during pregnancy.

METHODS

We conducted literature research using PubMed and Google Scholar databases from January to April 2023. As the review considers short- and long-term adverse effects it was divided into two parts. The first part was conducted as a systematic review. The second concerning long-term negative effects due to lack of research is a literature review. The inclusion criteria for the systematic review part were singleton pregnancies, women vaccinated during pregnancy, and studies from 2020 and later. The most common short-term pregnancy adverse effects were included in the search: preterm delivery, small gestation age, intrauterine death, congenital defects, stillborn, fetal growth retardation, spontaneous abortion. Maternal immune activation was the primary concern for the long-term adverse effects and whether vaccination could cause it. The search terms included maternal immune activation, fetal neurodevelopment, neuropsychiatric disorders and the studies used were from 2019.

RESULTS

Most studies showed no significant difference in short-term adverse effects between vaccinated and non-vaccinated women and their fetuses. However, the literature is insufficient to evaluate possible long-term adverse effects.

CONCLUSION

Available evidence supports the safety of administering SARS-CoV-2 vaccines to pregnant women, but further systematic reviews and meta-analyses are essential. Maternal immune activation caused by vaccination may impact a child's neurodevelopment and should be a concern for future studies.

Effect of COVID-19 vaccination and booster on maternal-fetal outcomes: a retrospective cohort study

BACKGROUND

COVID-19 in pregnant people increases the risk for poor maternal-fetal outcomes. However, COVID-19 vaccination hesitancy remains due to concerns over the vaccine's potential effects on maternal-fetal outcomes. Here we examine the impact of COVID-19 vaccination and boosters on maternal SARS-CoV-2 infections and birth outcomes.

METHODS

This was a retrospective multicentre cohort study on the impact of COVID-19 vaccination on maternal-fetal outcomes for people who delivered (n=106 428) at Providence St Joseph Health across seven western US states from Jan 26, 2021 to Oct 26, 2022. Cohorts were defined by vaccination status at delivery: vaccinated (n=35 926; two or more doses of mRNA-1273 Moderna or BNT162b2 Pfizer-BioNTech), unvaccinated (n=55 878), unvaccinated propensity score matched (n=16 771), boosted (n=10 927; three or more doses), vaccinated unboosted (n=13 243; two doses only), and vaccinated unboosted with propensity score matching (n=4414). We built supervised machine learning classification models, which we used to determine which people were more likely to be vaccinated or boosted at delivery. The primary outcome was maternal SARS-CoV-2 infection. COVID-19 vaccination status at delivery, COVID-19-related health care, preterm birth, stillbirth, and very low birthweight were evaluated as secondary outcomes.

FINDINGS

Vaccinated people were more likely to conceive later in the pandemic, have commercial insurance, be older, live in areas with lower household composition vulnerability, and have a higher BMI than unvaccinated people. Boosted people were more likely to have more days since receiving the second COVID-19 vaccine dose, conceive earlier in the pandemic, have commercial insurance, be older, and live in areas with lower household composition vulnerability than vaccinated unboosted people. Vaccinated pregnant people had lower rates of COVID-19 during pregnancy (4·0%) compared with unvaccinated matched people (5·3%; p<0·0001). COVID-19 rates were even lower in boosted people (3·2%) compared with vaccinated unboosted matched people (5·6%; p<0·0001). Vaccinated people were also less likely to have a preterm birth (7·9%; p<0·0001), stillbirth (0·3%; p<0·0002), or very low birthweight neonate (1·0%; p<0·0001) compared with unvaccinated matched people (preterm birth 9·4%; stillbirth 0·6%; very low birthweight 1·5%). Boosted people were less likely to have a stillbirth (0·3%; p<0·025) and have no differences in rates of preterm birth (7·6%; p=0·090) or very low birthweight neonates (0·8%; p=0·092) compared with vaccinated unboosted matched people (stillbirth 0·5%; preterm birth 8·4%; very low birthweight 1·1%).

INTERPRETATION

COVID-19 vaccination protects against adverse maternal-fetal outcomes, with booster doses conferring additional protection. Pregnant people should be high priority for vaccination and stay up to date with their COVID-19 vaccination schedule.

FUNDING

National Institute for Child Health & Human Development and the William O and K Carole Ellison Foundation.

Obstetrical and gynecologic implications of COVID-19: what have we learned over the first two years of the pandemic

The rapidly evolving nature of the coronavirus disease 2019 (COVID-19) pandemic has resulted in the publication of a breadth of information in the field of Obstetrics and Gynecology. This article is an examination of the impacts of COVID-19 on women's health, specifically on pregnancy, fertility, and delays to care. We review, in brief, the clinical presentation, transmission, and definitions of post-COVID conditions. Additionally, this article explores the reassuring evidence published regarding the use of mRNA vaccines in preconception and fertility treatments.

Burden of stillbirths among women vaccinated with COVID-19 vaccines: A systematic review and meta-analysis

OBJECTIVE

To estimate the global burden of stillbirths among pregnant women with the COVID-19 vaccination.

DATA SOURCE

In this systematic review and meta-analysis, a literature search was carried out in PubMed, Cochrane and Scopus until February 4, 2023, with language restriction (English).

STUDY SELECTION

Title-abstract screening followed by full text review was done independently by two authors, based on the research question, "What is the prevalence of stillbirths among the pregnant women vaccinated with COVID-19 vaccines?"

DATA EXTRACTION

Two authors independently extracted the relevant data from every study. The third author resolved the conflicts. This study was registered in PROSPERO and followed the PRISMA guidelines.

DATA ANALYSIS

A Random effects model was applied to assess the pooled estimate of stillbirths. The I2 test was used to assess the heterogeneity of the articles included in the study. For checking the publication bias, the Doi plot and the contour-enhanced funnel plot were utilized.

RESULTS

The database systematic search yielded 168 articles; 11 of them were determined to be eligible for systematic review and 8 of them ended up being included for meta-analysis. The pooled prevalence of stillbirth in pregnant women vaccinated against COVID-19 infection was 0.00509 (5 per 1000 live births delivered by pregnant women vaccinated against COVID-19 (95% CI: 0.00003-0.01676). Statistically significant heterogeneity was reported across studies (I2 = 98%; p < 0.01).

CONCLUSIONS

The study concluded that vaccination against COVID-19 among pregnant women had a low stillbirth rate. It adds to the existing evidence that the COVID-19 vaccine is safe and can be taken during pregnancy.

SARS-CoV-2 vaccination, booster, and infection in pregnant population enhances passive immunity in neonates

The effects of heterogeneous infection, vaccination and boosting histories prior to and during pregnancy have not been extensively studied and are likely important for protection of neonates. We measure levels of spike binding antibodies in 4600 patients and their neonates with different vaccination statuses, with and without history of SARS-CoV-2 infection. We investigate neutralizing antibody activity against different SARS-CoV-2 variant pseudotypes in a subset of 259 patients and determined correlation between IgG levels and variant neutralizing activity. We further study the ability of maternal antibody and neutralizing measurements to predict neutralizing antibody activity in the umbilical cord blood of neonates. In this work, we show SARS-CoV-2 vaccination and boosting, especially in the setting of previous infection, leads to significant increases in antibody levels and neutralizing activity even against the recent omicron BA.1 and BA.5 variants in both pregnant patients and their neonates.

Safety evaluation of COVID-19 vaccination during early pregnancy: A single-center prospective cohort study of Chinese pregnant women

This prospective cohort study aimed to evaluate the safety of an inactivated coronavirus disease 2019 (COVID-19) vaccine in pregnant women at a tertiary hospital in Hubei, China. Pregnancy outcomes were compared between pregnant vaccinated and unvaccinated women. Composite adverse pregnancy outcomes were defined as one or more of maternal adverse outcomes (prenatal pyrexia, postpartum hemorrhage, maternal intensive care unit admission, and a prethrombotic state) and adverse neonatal outcomes (premature delivery, intrauterine fetal death or induction of labor, fetal macrosomia, fetal growth restriction, small-for-gestational age, fetal abnormalities, neonatal admission to the neonatal intensive care unit, and birth asphyxia). Of a total of 845 participants in the delivery cohort, 41.2% (348/845) received at least one dose of the COVID-19 vaccination, and 33.6% (284/845) received two doses. In total, 25.3% (88/348) of the vaccinated group were vaccinated at 0-4 weeks of pregnancy. No significant difference was found in the composite adverse outcomes between the vaccinated and unvaccinated participants, regardless of whether vaccination occurred before (44/243 [18.1%] vs. 71/497 [14.3%]; P = .17) or during early pregnancy (14/105 [13.3%] vs. 71/497[14.3%]; P = .79). These findings indicate that the pregnancy outcomes of women who received the COVID-19 vaccination, even if they were vaccinated early in pregnancy, were comparable to those of unvaccinated women. This study was registered with the Chinese Clinical Trial Center (ChiCTR2100051756).

Pregnancy, fetal, and neonatal outcomes after a first booster dose of covid-19 vaccine during pregnancy in Ontario, Canada: population based, retrospective cohort study

Objective

To assess risk of adverse pregnancy, fetal, and neonatal outcomes after a third dose (first booster dose) of covid-19 vaccine during pregnancy among individuals who had completed both doses of primary covid-19 vaccine series before pregnancy.

Design

Population based, retrospective cohort study.

Setting

Ontario, Canada, from 20 December 2021 to 31 August 2022.

Participants

Individuals were included if they were pregnant with an expected date of delivery from 20 December 2021 (start date of third dose eligibility for everyone ≥18 years) to 31 August 2022, who had completed the two doses of primary covid-19 messenger RNA vaccine series before pregnancy, and became eligible for a third dose (≥six months since dose two) before the end of pregnancy.

Main outcome measures

Pregnancy outcomes included hypertensive disorders of pregnancy, placental abruption, caesarean delivery, chorioamnionitis, and postpartum hemorrhage. Fetal and neonatal outcomes included stillbirth, preterm birth, admission to neonatal intensive care unit for >24 h, newborn 5 min Apgar score <7, and small-for-gestational age infant (<10th percentile). We estimated hazard ratios and 95% confidence intervals for study outcomes, treating dose three as a time varying exposure and adjusting for confounding using inverse probability weighting.

Results

Among 32 689 births, 18 491 (56.6%) were born to individuals who received a third covid-19 dose during pregnancy. Compared with eligible individuals who did not receive a third dose during pregnancy, no increased risks were associated with receiving a third covid-19 vaccine dose during pregnancy for placental abruption (adjusted hazard ratio 0.84 (95% confidence interval 0.70 to 1.02)), chorioamnionitis (0.67 (0.49 to 0.90)), postpartum haemorrhage (1.01 (0.89 to 1.16)), caesarean delivery (0.90 (0.87 to 0.94)), stillbirth (0.56 (0.39 to 0.81)), preterm birth (0.91 (0.84 to 0.99)), neonatal intensive care unit admission (0.96 (0.90 to 1.03)), 5 min Apgar score<7 (0.96 (0.82 to 1.14)), or small-for-gestational age infant (0.86 (0.79 to 0.93)).

Conclusion

Receipt of a third covid-19 vaccine dose during pregnancy was not associated with an increased risk of adverse pregnancy, fetal, or neonatal outcomes. These findings can help to inform evidence based decision making about the risks and benefits of covid-19 booster doses during pregnancy.

A unique maternal and placental galectin signature upon SARS-CoV-2 infection suggests galectin-1 as a key alarmin at the maternal-fetal interface

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic imposed a risk of infection and disease in pregnant women and neonates. Successful pregnancy requires a fine-tuned regulation of the maternal immune system to accommodate the growing fetus and to protect the mother from infection. Galectins, a family of β-galactoside-binding proteins, modulate immune and inflammatory processes and have been recognized as critical factors in reproductive orchestration, including maternal immune adaptation in pregnancy. Pregnancy-specific glycoprotein 1 (PSG1) is a recently identified gal-1 ligand at the maternal-fetal interface, which may facilitate a successful pregnancy. Several studies suggest that galectins are involved in the immune response in SARS-CoV-2-infected patients. However, the galectins and PSG1 signature upon SARS-CoV-2 infection and vaccination during pregnancy remain unclear. In the present study, we examined the maternal circulating levels of galectins (gal-1, gal-3, gal-7, and gal-9) and PSG1 in pregnant women infected with SARS-CoV-2 before vaccination or uninfected women who were vaccinated against SARS-CoV-2 and correlated their expression with different pregnancy parameters. SARS-CoV-2 infection or vaccination during pregnancy provoked an increase in maternal gal-1 circulating levels. On the other hand, levels of PSG1 were only augmented upon SARS-CoV-2 infection. A healthy pregnancy is associated with a positive correlation between gal-1 concentrations and gal-3 or gal-9; however, no correlation was observed between these lectins during SARS-CoV-2 infection. Transcriptome analysis of the placenta showed that gal-1, gal-3, and several PSG and glycoenzymes responsible for the synthesis of gal-1-binding glycotopes (such as linkage-specific N-acetyl-glucosaminyltransferases (MGATs)) are upregulated in pregnant women infected with SARS-CoV-2. Collectively, our findings identify a dynamically regulated "galectin-specific signature" that accompanies the SARS-CoV-2 infection and vaccination in pregnancy, and they highlight a potentially significant role for gal-1 as a key pregnancy protective alarmin during virus infection.

COVID-19 and Pregnancy: An Updated Review about Evidence-Based Therapeutic Strategies

The COVID-19 pandemic posed a significant challenge for clinicians in managing pregnant women, who were at high risk of virus transmission and severe illness. While the WHO declared in May 2023 that COVID-19 is no longer a public health emergency, it emphasized that it remains a global health threat. Despite the success of vaccines, the possibility of new pandemic waves due to viral mutations should be considered. Ongoing assessment of the safety and effectiveness of pharmacological therapies is crucial in clinical practice. This narrative review summarizes the evidence-based therapeutic strategies for pregnant women with COVID-19, considering over three years of pandemic experience. The review discusses the safety and effectiveness of various drug regimens (antivirals, anticoagulants, corticosteroids, immunoglobulins, monoclonal antibodies, and therapeutic gases) and procedures (prone positioning and extracorporeal membrane oxygenation). Drugs with contraindications, inefficacy during pregnancy, or unknown adverse effects were excluded from our evaluation. The aim is to provide healthcare professionals with a comprehensive guide for managing pregnant women with COVID-19 based on lessons learned from the pandemic outbreak.

Effect of COVID-19 on Pregnancy and Neonate's Vital Parameters: A Systematic Review

Background

COVID-19 is a new pandemic, which was declared by the World Health Organization in 2019 as a threat to public health. According to numerous reports, it can have negative consequences for pregnant women, labour, and neonates born to infected mothers. The aim of this paper was to gather the evidence and to present a summary of the results of studies concerning COVID-19 in pregnant women and their neonates.

Methods

Articles from prestigious journals covering the period from 2020 to February 2023, relevant review papers, and original research articles from PubMed were analysed. In order to analyse the available research literature, the Web of Science, Scopus, and PubMed databases were used, in which the search for articles was conducted using terms ("pregnancy," "coronavirus," "SARS-CoV-2," and "newborn") and using PRISMA (Preferred Reporting Items for Systemic Reviews and Meta-Analysis) guidelines for clinical trials. Meta-analyses and systematic reviews (2022-2023) on symptoms, neonatal course, and risk of COVID-19 infection have been summarized. Summary of meta-analyses and systematic reviews (2022-2023) on the effect and adverse reaction of the COVID-19 vaccination is presented.

Results

As a result of the research conducted, it was confirmed that in most pregnant women, no serious signs of the infection were observed, although isolated cases of death related to COVID-19 in pregnant women were reported. Several authors called attention to the more severe course of the infection in pregnant women with obesity. It seemed that no vertical transmission from mother to child was occurring. Nevertheless, the information was not clinching. The condition of the neonates born to mothers with COVID-19 was in most cases described as normal; however, some papers reported deaths of infected neonates.

Conclusions

Due to insufficient data, further research is necessary. Further studies and follow-up are recommended, which would make possible an assessment of remote effects of COVID-19 on pregnancy and vital parameters of the newborn.

Mild/Asymptomatic Maternal SARS-CoV-2 Infection Leads to Immune Paralysis in Fetal Circulation and Immune Dysregulation in Fetal-Placental Tissues

Few studies have addressed the impact of maternal mild/asymptomatic SARS-CoV-2 infection on the developing neonatal immune system. In this study, we analyzed umbilical cord blood and placental chorionic villi from newborns of unvaccinated mothers with mild/asymptomatic SARSCoV-2 infection during pregnancy using flow cytometry, single-cell transcriptomics, and functional assays. Despite the lack of vertical transmission, levels of inflammatory mediators were altered in cord blood. Maternal infection was also associated with increased memory T, B cells, and non-classical monocytes as well as increased activation. However, ex vivo responses to stimulation were attenuated. Finally, within the placental villi, we report an expansion of fetal Hofbauer cells and infiltrating maternal macrophages and rewiring towards a heightened inflammatory state. In contrast to cord blood monocytes, placental myeloid cells were primed for heightened antiviral responses. Taken together, this study highlights dysregulated fetal immune cell responses in response to mild maternal SARS-CoV-2 infection during pregnancy.

An Update on COVID-19 Vaccination and Pregnancy

Pregnant women are more prone to experience severe COVID-19 disease, including intensive care unit (ICU) admission, use of invasive ventilation, extracorporeal membrane oxygenation (ECMO), and mortality compared to non-pregnant individuals. Additionally, research suggests that SARS-CoV-2 infection during pregnancy is linked to adverse pregnancy outcomes, such as preterm birth, preeclampsia, and stillbirth, as well as adverse neonatal outcomes, including hospitalization and admission to the neonatal intensive care unit. This review assessed the available literature from November 2021 to 19 March 2023, concerning the safety and effectiveness of COVID-19 vaccination during pregnancy. COVID-19 vaccination administered during pregnancy is not linked to significant adverse events related to the vaccine or negative obstetric, fetal, or neonatal outcomes. Moreover, the vaccine has the same effectiveness in preventing severe COVID-19 disease in pregnant individuals as in the general population. Additionally, COVID-19 vaccination is the safest and most effective method for pregnant women to protect themselves and their newborns from severe COVID-19 disease, hospitalization, and ICU admission. Thus, vaccination should be recommended for pregnant patients. While the immunogenicity of vaccination in pregnancy appears to be similar to that in the general population, more research is needed to determine the optimal timing of vaccination during pregnancy for the benefit of the neonate.

The risk of miscarriage following COVID-19 vaccination: a systematic review and meta-analysis

STUDY QUESTION

What is the risk of miscarriage among pregnant women who received any of the COVID-19 vaccines?

SUMMARY ANSWER

There is no evidence that COVID-19 vaccines are associated with an increased risk of miscarriage.

WHAT IS KNOWN ALREADY

In response to the COVID-19 pandemic, the mass roll-out of vaccines helped to boost herd immunity and reduced hospital admissions, morbidity, and mortality. Still, many were concerned about the safety of vaccines for pregnancy, which may have limited their uptake among pregnant women and those planning a pregnancy.

STUDY DESIGN, SIZE, DURATION

For this systematic review and meta-analysis, we searched MEDLINE, EMBASE, and Cochrane CENTRAL from inception until June 2022 using a combination of keywords and MeSH terms.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included observational and interventional studies that enrolled pregnant women and evaluated any of the available COVID-19 vaccines compared to placebo or no vaccination. We primarily reported on miscarriage in addition to ongoing pregnancy and/or live birth.

MAIN RESULTS AND THE ROLE OF CHANCE

We included data from 21 studies (5 randomized trials and 16 observational studies) reporting on 149 685 women. The pooled rate of miscarriage among women who received a COVID-19 vaccine was 9% (n = 14 749/123 185, 95% CI 0.05-0.14). Compared to those who received a placebo or no vaccination, women who received a COVID-19 vaccine did not have a higher risk of miscarriage (risk ratio (RR) 1.07, 95% CI 0.89-1.28, I2 35.8%) and had comparable rates for ongoing pregnancy or live birth (RR 1.00, 95% CI 0.97-1.03, I2 10.72%).

LIMITATIONS, REASONS FOR CAUTION

Our analysis was limited to observational evidence with varied reporting, high heterogeneity and risk of bias across included studies, which may limit the generalizability and confidence in our findings.

WIDER IMPLICATIONS OF THE FINDINGS

COVID-19 vaccines are not associated with an increase in the risk of miscarriage or reduced rates of ongoing pregnancy or live birth among women of reproductive age. The current evidence remains limited and larger population studies are needed to further evaluate the effectiveness and safety of COVID-19 vaccination in pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

No direct funding was provided to support this work. M.P.R. was funded by the Medical Research Council Centre for Reproductive Health Grant No: MR/N022556/1. B.H.A.W. hold a personal development award from the National Institute of Health Research in the UK. All authors declare no conflict of interest.

REGISTRATION NUMBER

CRD42021289098.

Effects of COVID-19 vaccination during pregnancy on SARS-CoV-2 infection and maternal and neonatal outcomes: A systematic review and meta-analysis

SARS-CoV-2 infection during pregnancy is associated with adverse maternal and neonatal outcomes, but no systematic synthesis of evidence on COVID-19 vaccination during pregnancy against these outcomes has been undertaken. Thus, we aimed to assess the collective evidence on the effects of COVID-19 vaccination during pregnancy on maternal and neonatal outcomes. PubMed/MEDLINE, CENTRAL, and EMBASE were systematically searched for articles published up to 1 November 2022. A systematic review and meta-analysis were performed to calculate pooled effects size and 95% confidence interval (CI). We evaluated 30 studies involving 862,272 individuals (308,428 vaccinated and 553,844 unvaccinated). Overall pooled analyses in pregnant women during pregnancy showed reduced risks of SARS-CoV-2 infection by 60% (41%-73%), COVID-19 hospitalisation during pregnancy by 53% (31%-69%), and COVID-19 intensive care unit (ICU) admission by 82% (12%-99%). Neonates of vaccinated women were 1.78 folds more likely to acquire SARS-CoV-2 infection during the first 2, 4 and 6 months of life during the Omicron period. The risk of stillbirth was reduced by 45% (17%-63%) in association with vaccination (vs. no vaccination) in pregnancy. A decrease of 15% (3%-25%), 33% (14%-48%), and 33% (17%-46%) in the odds of preterm births before 37, 32 and 28 weeks' gestation were associated with vaccination (vs. no vaccination) in pregnancy, respectively. The risk of neonatal ICU admission was significantly lower by 20% following COVID-19 vaccination in pregnancy (16%-24%). There was no evidence of a higher risk of adverse outcomes including miscarriage, gestational diabetes, gestational hypertension, cardiac problems, oligohydramnios, polyhydramnios, unassisted vaginal delivery, cesarean delivery, postpartum haemorrhage, gestational age at delivery, placental abruption, Apgar score at 5 min below 7, low birthweight (<2500 g), very low birthweight (<1500 g), small for gestational age, and neonatal foetal abnormalities. COVID-19 vaccination during pregnancy is safe and highly effective in preventing maternal SARS-CoV-2 infection in pregnancy, without increasing the risk of adverse maternal and neonatal outcomes, and is associated with a reduction in stillbirth, preterm births, and neonatal ICU admission. Importantly, maternal vaccination did not reduce the risk of neonatal SARS-CoV-2 infection during the first 6 months of life during the Omicron period.

Effect of COVID-19 vaccination on the outcome of in vitro fertilization: A systematic review and meta-analysis

Background

Universal COVID-19 vaccination programs are now recommended in several countries and represent the most effective preventive measure against COVID-19. However, some reports suggest that vaccination may cause infertility or have adverse effects on pregnancy. Conflicting reports have led to vaccine hesitancy in women planning pregnancy.

Purpose

To determine whether vaccination against COVID-19 affects in vitro fertilization (IVF) outcomes, we conducted a meta-analysis.

Method

A systematic search was conducted using PubMed, Embase, MEDLINE, and Web of Science databases for all published literature on COVID-19 vaccines and outcomes of IVF. International Prospective Register of Systematic Reviews registration was completed on September 13, 2022 (CRD42022359771).

Results

We analyzed 20 studies totaling 18,877 individual cases undergoing IVF. COVID-19 vaccination had significant effect on clinical and ongoing pregnancy rate (risk ratio (RR): 0.97; 95% confidence interval (CI): 0.94–0.99; RR: 0.93; 95% CI: 0.87–0.99). These outcomes did not differ between vaccinated and unvaccinated individuals: biochemical pregnancy rate (RR: 0.95; 95% CI: 0.88–1.03), implantation rate (RR: 1.02; 95%CI: 0.97–1.07; P = 0.41), the number of oocytes (mean difference (MD): 0.12; 95% CI: −0.65–0.88) and MII/mature oocytes recovered (MD: 0.27; 95% CI: −0.36–0.90), blastocysts rate (MD: 0.01; 95% CI: −0.04, 0.06), and fertilization rate (MD: 1.08; 95% CI: −0.57, 2.73).

Conclusion

Our findings suggest that vaccination against COVID-19 does not adversely affect the biochemical pregnancy rates; number of oocytes and MII/mature oocytes obtained; implantation, blastocysts; and fertilization rates in women undergoing IVF treatment. Subgroup analysis showed that the mRNA vaccine had no statistical significance on all indexes (clinical, biochemical, or ongoing pregnancy rates; implantation, blastocysts, or fertilization rates; and the number of oocytes and MII/mature oocytes). The findings of this meta-analysis are anticipated to increase the willingness of women planning IVF treatment to receive COVID-19 vaccination and provide evidence-based medical guidance for the development and implementation of guidelines.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022359771.

No association of vaccination with inactivated COVID-19 vaccines before conception with pregnancy complications and adverse birth outcomes: A cohort study of 5457 Chinese pregnant women

Data on the safety of inactivated COVID-19 vaccines in pregnant women is limited and monitoring pregnancy outcomes is required. We aimed to examine whether vaccination with inactivated COVID-19 vaccines before conception was associated with pregnancy complications or adverse birth outcomes. We conducted a birth cohort study in Shanghai, China. A total of 7000 healthy pregnant women were enrolled, of whom 5848 were followed up through delivery. Vaccine administration information was obtained from electronic vaccination records. Relative risks (RRs) of gestational diabetes mellitus (GDM), hypertensive disorders in pregnancy (HDP), intrahepatic cholestasis of pregnancy (ICP), preterm birth (PTB), low birth weight (LBW), and macrosomia associated with COVID-19 vaccination were estimated by multivariable-adjusted log-binomial analysis. After exclusion, 5457 participants were included in the final analysis, of whom 2668 (48.9%) received at least two doses of an inactivated vaccine before conception. Compared with unvaccinated women, there was no significant increase in the risks of GDM (RR = 0.80, 95% confidence interval [CI], 0.69, 0.93), HDP (RR = 0.88, 95% CI, 0.70, 1.11), or ICP (RR = 1.61, 95% CI, 0.95, 2.72) in vaccinated women. Similarly, vaccination was not significantly associated with any increased risks of PTB (RR = 0.84, 95% CI, 0.67, 1.04), LBW (RR = 0.85, 95% CI, 0.66, 1.11), or macrosomia (RR = 1.10, 95% CI, 0.86, 1.42). The observed associations remained in all sensitivity analyses. Our findings suggested that vaccination with inactivated COVID-19 vaccines was not significantly associated with an increased risk of pregnancy complications or adverse birth outcomes.

Impact of variants of SARS-CoV-2 on obstetrical and neonatal outcomes

BACKGROUND

SARS-CoV-2 can lead to several types of complications during pregnancy. Variant surges are associated with different severities of disease. Few studies have compared the clinical consequences of specific variants on obstetrical and neonatal outcomes. Our goal was to evaluate and compare disease severity in pregnant women and obstetrical or neonatal complications between variants of SARS-CoV-2 that have circulated in France over a two-year period (2020-2022).

METHOD

This retrospective cohort study included all pregnant women with a confirmed SARS-CoV-2 infection (positive naso-pharyngeal RT-PCR test) from March 12, 2020 to January 31, 2022, in three tertiary maternal referral obstetric units in the Paris metropolitan area, France. We collected clinical and laboratory data for mothers and newborns from patients' medical records. Variant identification was either available following sequencing or extrapolated from epidemiological data.

RESULTS

There were 234/501 (47%) Wild Type (WT), 127/501 (25%) Alpha, 98/501 (20%) Delta, and 42/501 (8%) Omicron. No significative difference was found regarding two composite adverse outcomes. There were significantly more hospitalizations for severe pneumopathy in Delta variant than WT, Alpha and Omicron respectively (63% vs 26%, 35% and 6%, p<0.001), more frequent oxygen administration (23% vs 12%, 10% and 5%, p = 0,001) and more symptomatic patients at the time of testing with Delta and WT (75% and 71%) versus Alpha and Omicron variants (55% and 66% respectively, p<0.01). Stillbirth tended to be associated with variants (p = 0.06): WT 1/231 (<1%) vs 4/126 (3%), 3/94 (3%), and 1/35 (3%) in Alpha, Delta and Omicron cases respectively. No other difference was found.

CONCLUSION

Although the Delta variant was associated with more severe disease in pregnant women, we found no difference regarding neonatal and obstetrical outcomes. Neonatal and obstetrical specific severity may be due to mechanisms other than maternal ventilatory and general infection.

Safety of COVID-19 vaccines during pregnancy: A systematic review and meta-analysis

Background

Assessment of COVID-19 vaccines safety during pregnancy is urgently needed.

Methods

We conducted a systematic review and meta-analysis to evaluate the safety of COVID-19 vaccines, including their components and technological platforms used in other vaccines during pregnancy and animal studies to complement direct evidence. We searched literature databases from its inception to September 2021 without language restriction, COVID-19 vaccine websites, and reference lists of other systematic reviews and the included studies. Pairs of reviewers independently selected, data extracted, and assessed the risk of bias of the studies. Discrepancies were resolved by consensus. (PROSPERO CRD42021234185).

Results

We retrieved 8,837 records from the literature search; 71 studies were included, involving 17,719,495 pregnant persons and 389 pregnant animals. Most studies (94%) were conducted in high-income countries, were cohort studies (51%), and 15% were classified as high risk of bias. We identified nine COVID-19 vaccine studies, seven involving 309,164 pregnant persons, mostly exposed to mRNA vaccines. Among non-COVID-19 vaccines, the most frequent exposures were AS03 and aluminum-based adjuvants.

A meta-analysis of studies that adjusted for potential confounders showed no association with adverse outcomes, regardless of the vaccine or the trimester of vaccination.

Neither the reported rates of adverse pregnancy outcomes nor reactogenicity exceeded expected background rates, which was the case for ASO3- or aluminum-adjuvanted non-COVID-19 vaccines in the proportion meta-analyses of uncontrolled studies/arms. The only exception was postpartum hemorrhage after COVID-19 vaccination (10.40%; 95% CI: 6.49-15.10%), reported by two studies; however, the comparison with non-exposed pregnant persons, available for one study, found non-statistically significant differences (adjusted OR 1.09; 95% CI 0.56-2.12). Animal studies showed consistent results with studies in pregnant persons.

Conclusion

We found no safety concerns for currently administered COVID-19 vaccines during pregnancy. Additional experimental and real-world evidence could enhance vaccination coverage. Robust safety data for non-mRNA-based COVID-19 vaccines are still needed.

COVID-19 Pharmacotherapy in Pregnancy: A Literature Review of Current Therapeutic Choices

The clinical management of COVID-19 in pregnant women, who are considered a vulnerable population, remains uncertain even as the pandemic subsides. SARS-CoV-2 affects pregnant individuals in multiple ways and has been associated with severe maternal morbidity and mortality, as well as neonatal complications. The unique anatomy and physiology of gestation make managing COVID-19 in this population a complex and challenging task, emphasizing the importance of spreading knowledge and expertise in this area. Therapeutic interventions require distinct clinical consideration, taking into account differences in pharmacokinetics, vertical transmission, drug toxicities, and postnatal care. Currently, there is limited data on antiviral and immunomodulating COVID-19 pharmacotherapy in pregnancy. Some medication has been shown to be safe and well tolerated among pregnant women with COVID-19; however, the lack of randomized clinical trials and studies in this patient population is evident. Available vaccines are considered safe and effective, with no evidence of harm to the fetus, embryo development, or short-term postnatal development. Pregnant women should be counseled about the risks of SARS-CoV-2 infection and informed of available ways to protect themselves and their families. Effective treatments for COVID-19 should not be withheld from pregnant individuals, and more research is needed to ensure the best outcomes.

Severe COVID-19 during pregnancy in Sweden, Norway, and Denmark

INTRODUCTION

Pregnancy is a risk factor for severe coronavirus disease 2019 (COVID-19) and adverse pregnancy outcomes. We aimed to explore maternal characteristics, pregnancy outcomes, vaccination status, and virus variants among pregnant women admitted to intensive care units (ICU) with severe COVID-19.

MATERIAL AND METHODS

We identified pregnant women admitted to ICU in Sweden (n = 96), Norway (n = 31), and Denmark (n = 16) because of severe COVID-19, from national registers and clinical databases between March 2020 and February 2022 (Denmark), August 2022 (Sweden), or December 2022 (Norway). Their background characteristics, pregnancy outcome, and vaccination status were compared with all birthing women and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test-positive pregnant women during the same time period. We calculated the number admitted to ICU per 10 000 birthing and per 1000 SARS-CoV-2 test-positive women during the Index, Alpha, Delta, and Omicron periods.

RESULTS

Women admitted to ICU had a higher mean body mass index, were more often of non-Scandinavian origin, had on average lower education and income levels, had a higher proportion of chronic and pregnancy-related conditions, delivered preterm, had neonates with low Apgar scores, and had more infants admitted to neonatal care, compared with all birthing and test-positive pregnant women. Of those admitted to ICU, only 7% had been vaccinated before admission. Overall, the highest proportion of women admitted to ICU per birthing was during the Delta period (4.1 per 10 000 birthing women). In Norway, the highest proportion admitted to ICU per test-positive pregnant women was during the Delta period (17.8 per 1000 test-positive), whereas the highest proportion of admitted per test-positive in Sweden and Denmark was seen during the Index period (15.4 and 8.9 per 1000 test-positive, respectively).

CONCLUSIONS

Admission to ICU because of COVID-19 in pregnancy was a rare event in the Scandinavian countries, but women who were unvaccinated, of non-Scandinavian origin, and with lower socio-economic status were at higher risk of admission to ICU. In addition, women admitted to ICU for COVID-19 had higher risk of adverse pregnancy outcomes.

Temporal trends and determinants of COVID-19 vaccine coverage and series initiation during pregnancy in Ontario, Canada, December 2020 to December 2021: A population-based retrospective cohort study

BACKGROUND

Population-based COVID-19 vaccine coverage estimates among pregnant individuals are limited. We assessed temporal patterns in vaccine coverage (≥1 dose before or during pregnancy) and evaluated factors associated with vaccine series initiation (receiving dose 1 during pregnancy) in Ontario, Canada.

METHODS

We linked the provincial birth registry with COVID-19 vaccination records from December 14, 2020 to December 31, 2021 and assessed coverage rates among all pregnant individuals by month, age, and neighborhood sociodemographic characteristics. Among individuals who gave birth since April 2021-when pregnant people were prioritized for vaccination-we assessed associations between sociodemographic, behavioral, and pregnancy-related factors with vaccine series initiation using multivariable regression to estimate adjusted risk ratios (aRR) and risk differences (aRD) with 95% confidence intervals (CI).

RESULTS

Among 221,190 pregnant individuals, vaccine coverage increased to 71.2% by December 2021. Gaps in coverage across categories of age and sociodemographic characteristics decreased over time, but did not disappear. Lower vaccine series initiation was associated with lower age (<25 vs. 30-34 years: aRR 0.53, 95%CI 0.51-0.56), smoking (vs. non-smoking: 0.64, 0.61-0.67), no first trimester prenatal care visit (vs. visit: 0.80, 0.77-0.84), and residing in neighborhoods with the lowest income (vs. highest: 0.69, 0.67-0.71). Vaccine series initiation was marginally higher among individuals with pre-existing medical conditions (vs. no conditions: 1.07, 1.04-1.10).

CONCLUSIONS

COVID-19 vaccine coverage among pregnant individuals remained lower than in the general population, and there was lower vaccine initiation by multiple characteristics.

Pregnancy Outcomes in Patients After Completion of the mRNA Coronavirus Disease 2019 (COVID-19) Vaccination Series Compared With Unvaccinated Patients

OBJECTIVE

To compare frequency of perinatal death between pregnant patients who completed the mRNA coronavirus disease 2019 (COVID-19) vaccination series and unvaccinated patients.

METHODS

This retrospective cohort study included 15,865 pregnant patients who delivered 16,132 newborns after 20 weeks of gestation within a large regional health system between January 1, 2021, and December 31, 2021. Patients who received two doses of mRNA vaccine (Pfizer-BioNTech [BNT162b2] or Moderna [mRNA-1273]) were included in the vaccinated group and were compared with unvaccinated patients. Exclusions included partial vaccination, viral-vector vaccine, major congenital anomalies, and higher-order multiple gestation. Our primary outcome was perinatal death, including stillbirth and neonatal death, which was evaluated by logistic regression. Unadjusted odds ratios and adjusted odds ratios (aORs) were reported, controlling for age, body mass index (BMI), diabetes, hypertension, smoking, twin gestation, and insurance status. Propensity score matching was also performed.

RESULTS

A total of 15,865 patients were included in the final analysis: 2,069 in the vaccination group and 13,796 in the control group. Only 13.0% of the cohort was included in the vaccination group; however, the vaccination rate increased over the course of the study period as the vaccine became more widely available and accepted. Vaccinated patients were older, with higher rates of people of non-Black racial non-Hispanic ethnic backgrounds, people with private insurance, and those with higher BMIs. Vaccination was associated with a lower incidence of perinatal death (0.5% vaccinated group vs 0.8% unvaccinated group, aOR 0.20 0.05-0.88). Vaccination against COVID-19 was also associated with lower rates of preterm delivery (aOR 0.63, 0.48-0.82), neonates with very low birth weight (aOR 0.35, 0.15-0.84), and neonatal intensive care unit (NICU) admission (aOR 0.66, 0.52-0.85). The association between vaccination and lower rates of perinatal death was no longer significant after propensity score matching.

CONCLUSION

In a large retrospective cohort study, receipt of the primary mRNA COVID-19 vaccination series was associated with a lower rate of several adverse pregnancy outcomes, including perinatal death, preterm delivery, neonates with very low birth weight, and NICU admission. Although the decreased rates of perinatal death did not remain significant after propensity score matching, there was evidence of directional benefit for vaccinated patients.