First- or second-trimester SARS-CoV-2 infection and subsequent pregnancy outcomes

Trimester and severity of SARS-CoV-2 infection during pregnancy and risk of hypertensive disorders in pregnancy

OBJECTIVE

SARS-CoV-2 infection during pregnancy has been linked with an increased risk of hypertensive disorders of pregnancy (HDP). The aim of this study was to examine how both trimester and severity of SARS-CoV-2 infection impact HDP.

METHODS

We conducted a cohort study of SARS-CoV-2-infected individuals during pregnancy (n = 205) and examined the association between trimester and severity of infection with incidence of HDP using modified Poisson regression models to calculate risk ratios (RR) and 95% confidence intervals (CI). We stratified the analysis of trimester by severity to understand the role of timing of infection among those with similar symptomatology and also examined timing of infection as a continuous variable.

RESULTS

Compared to a reference cohort from 2018, SARS-CoV-2 infection did not largely increase the risk of HDP (RR: 1.17; CI:0.90, 1.51), but a non-statistically significant higher risk of preeclampsia was observed (RR: 1.33; CI:0.89, 1.98), in our small sample. Among the SARS-CoV-2 cohort, severity was linked with risk of HDP, with infections requiring hospitalization increasing the risk of HDP compared to asymptomatic/mild infections. Trimester of infection was not associated with risk of HDP, but a slight decline in the risk of HDP was observed with later gestational week of infection. Among patients with asymptomatic or mild symptoms, SARS-CoV-2 in the first trimester conferred a higher risk of HDP compared to the third trimester (RR: 1.70; CI:0.77, 3.77), although estimates were imprecise.

CONCLUSION

SARS-CoV-2 infection in early pregnancy may increase the risk of HDP compared to infection later in pregnancy.

Analysis of Fetal Growth and Pregnancy Outcome in Pregnant Women Infected with Novel Coronavirus in Mid-Pregnancy

Purpose

To investigate whether fetal prenatal ultrasound, fetal growth rate, and pregnancy outcome statistically differ between women infected with novel coronavirus (COVID-19) in mid-pregnancy and an uninfected control group.

Patients and Methods

A retrospective analysis of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), and z-scores for each among 46 pregnant women diagnosed with COVID-19 in mid-pregnancy between December 01, 2022 and June 31, 2023 was conducted. A control group included 92 pregnant women negative for COVID-19 during the same period and was also analyzed. To examine fetal growth, rate of increase in BPD, HC, AC, FL, and estimated fetal weight (EFW) between second and third trimester scans were analyzed. In addition, pregnancy outcome, maternal comorbidities, and neonatal prognosis were assessed.

Results

The occurrence of gestational diabetes differed significantly between groups, but the fetal growth rate and EFW did not. Similarly, pregnancy outcomes and neonatal prognoses did not differ significantly between groups.

Conclusion

Gestational diabetes was a complication that differed between patients with and without COVID-19 in this study. COVID-19 in pregnant women did not affect fetal development. Therefore, these preliminary data suggest that increased fetal monitoring is not necessary for women infected with COVID-19 during the second trimester, and these women should be reassured of the low risk of adverse fetal outcomes.

Association of SARS-CoV-2 infection during late pregnancy with maternal and neonatal outcomes

BACKGROUND

Limited data on the impact of the coronavirus disease 2019 (COVID-19) during pregnancy on newborn outcomes are available. This study aimed to characterize and compare the clinical outcomes of newborns from women with and without the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during late pregnancy.

METHOD

This was a retrospective cohort study of women who were either infected or not infected with the SARS-CoV-2 virus during late pregnancy. The neonatal complications associated with COVID-19-positive pregnant women were investigated and analyzed.

RESULTS

Among 2063 pregnant women over 28 weeks of gestation, 1.2%, 3.3%, and 18.7% of patients with multiple pregnancies, abnormal fetal positions, and lack of maternal or neonatal follow-up data, respectively, were excluded. Patients who were COVID-19-negative (60.6%) and -positive (16.2%) remained for further analysis. SARS-CoV-2 infection was significantly associated with higher SARS-CoV-2 infection rates in newborns (0% vs. 1.49%, P < 0.01) and longer duration of hospital stay (6.39 ± 2.2 vs. 4.92 ± 1.6, P < 0.01). However, comparing neonatal complications, including Apgar score, preterm birth, low birth weight, cesarean section rate, newborn hearing, neonatal congenital heart defects, and height and weight compliance rate of 6-month-old children, between non-infected and infected participants did not reach statistical significance.

CONCLUSION

SARS-CoV-2 infection in late pregnancy has no significant impact on neonatal outcomes. After six months of follow-up of the neonates, we observed that SARS-CoV-2 infection in the third trimester of pregnancy did not affect their growth and development. Hopefully, these findings will guide management strategies and clinical practice.

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.

Pregnancy and perinatal outcomes of women with SARS-CoV-2 infection during pregnancy

INTRODUCTION

This study aimed to compare the pregnancy and perinatal outcomes of women with and without severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy.

METHODS

Women who delivered in an obstetric unit from March 2022 to October 2022 were recruited. The history of vaccination and SARS-CoV-2 infection during pregnancy was recorded. The pregnancy and perinatal outcomes of women with and without SARS-CoV-2 infection were compared.

RESULTS

A total of 1015 women were recruited - 41.5% had SARS-CoV-2 infection during pregnancy and 25.2% were unvaccinated. The incidences of preeclampsia, gestational diabetes mellitus and caesarean section were similar between the two groups. There were more preterm deliveries (9.0% vs 5.1%, P = 0.01) and more late preterm deliveries of between 33 and 36 + 6 weeks (6.2% vs. 3.7%, P = 0.03) in the SARS-CoV-2 infection group. There were no statistically significant differences between the two groups in perinatal outcomes, including birthweight, incidence of small for gestational age, low Apgar scores, and neonatal intensive care or special care baby unit admissions. There were no differences in pregnancy and perinatal outcomes between women infected in the first/second trimester and those infected in the third trimester, except for lower mean birthweight (3180 g vs. 3292 g, P = 0.04). There were no major differences in pregnancy outcome between vaccinated and unvaccinated women.

CONCLUSION

The pregnancy and perinatal outcomes of women who were infected with SARS-CoV-2 during gestation appear favourable.

Outcomes of SARS-CoV-2 infection in early pregnancy-A systematic review and meta-analysis

INTRODUCTION

Available data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and pregnancy outcomes mostly refer to women contracting the infection during advanced pregnancy or close to delivery. There is limited information on the association between SARS-CoV-2 infection in early pregnancy and outcomes thereof.

MATERIAL AND METHODS

We aimed to systematically review the maternal, fetal and neonatal outcomes following SARS-CoV-2 infection in early pregnancy, defined as <20 weeks of gestation (PROSPERO Registration 2020 CRD42020177673). Searches were carried out in PubMed, Medline, EMBASE, and Scopus databases from January 2020 until April 2023 and the WHO database of publications on coronavirus disease 2019 (COVID-19) from December 2019 to April 2023. Cohort and case-control studies on COVID-19 occurring in early pregnancy that reported data on maternal, fetal, and neonatal outcomes were included. Case reports and studies reporting only exposure to SARS-CoV-2 or not stratifying outcomes based on gestational age were excluded. Data were extracted in duplicate. Meta-analyses were conducted when appropriate, using R meta (R version 4.0.5).

RESULTS

A total of 18 studies, 12 retrospective and six prospective, were included in this review, reporting on 10 147 SARS-CoV-2-positive women infected in early pregnancy, 9533 neonates, and 180 882 SARS-CoV-2 negative women. The studies had low to moderate risk of bias according to the Newcastle-Ottawa quality assessment Scale. The studies showed significant clinical and methodological heterogeneity. A meta-analysis could be performed only on the outcome miscarriage rate, with a pooled random effect odds ratio of 1.44 (95% confidence interval 0.96-2.18), showing no statistical difference in miscarriage in SARS-CoV-2-infected women. Individual studies reported increased incidences of stillbirth, low birthweight and preterm birth among neonates born to mothers affected by COVID-19 in early pregnancy; however, these results were not consistent among all studies.

CONCLUSIONS

In this comprehensive systematic review of available evidence, we identified no statistically significant adverse association between SARS-CoV-2 infection in early pregnancy (before 20 weeks of gestation) and fetal, neonatal, or maternal outcomes. However, a 44% increase in miscarriage rate is concerning and further studies of larger sample size are needed to confirm or refute our findings.

Implication of viruses in the etiology of preeclampsia

Preeclampsia is one of the most common disorders that poses threat to both mothers and neonates and a major contributor to perinatal morbidity and mortality worldwide. Viral infection during pregnancy is not typically considered to cause preeclampsia; however, syndromic nature of preeclampsia etiology and the immunomodulatory effects of viral infections suggest that microbes could trigger a subset of preeclampsia. Notably, SARS-CoV-2 infection is associated with an increased risk of preeclampsia. Herein, we review the potential role of viral infections in this great obstetrical syndrome. According to in vitro and in vivo experimental studies, viral infections can cause preeclampsia by introducing poor placentation, syncytiotrophoblast stress, and/or maternal systemic inflammation, which are all known to play a critical role in the development of preeclampsia. Moreover, clinical and experimental investigations have suggested a link between several viruses and the onset of preeclampsia via multiple pathways. However, the results of experimental and clinical research are not always consistent. Therefore, future studies should investigate the causal link between viral infections and preeclampsia to elucidate the mechanism behind this relationship and the etiology of preeclampsia itself.

The association of post-embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study

BACKGROUND

The influence of SARS-CoV-2 infection after embryo transfer on early pregnancy outcomes in in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies.

OBJECTIVE

This study aimed to investigate the association between SARS-CoV-2 infection within 10 weeks after embryo transfer and early pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment.

STUDY DESIGN

This prospective cohort study was conducted at a single public in vitro fertilization center in China. Female patients aged 20 to 39 years, with a body mass index ranging from 18 to 30 kg/m2, undergoing in vitro fertilization/intracytoplasmic sperm injection treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks after embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study used single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes.

RESULTS

A total of 857 female patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days after embryo transfer did not have a significant negative association with the biochemical pregnancy rate (adjusted odds ratio, 0.74; 95% confidence interval, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days after embryo transfer had no significant association with the implantation rate (36.6% in infected vs 44.0% in uninfected group; P=.181). No statistically significant association was found with the clinical pregnancy rate after adjusting for confounding factors (adjusted odds ratio, 0.69; 95% confidence interval, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks after embryo transfer had no significant association with the early miscarriage rate (adjusted odds ratio, 0.77; 95% confidence interval, 0.35-1.71).

CONCLUSION

Our study suggests that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. It is important to note that these findings are specific to the target population of in vitro fertilization/intracytoplasmic sperm injection patients aged 20 to 39 years, without previous SARS-CoV-2 infection, and with a body mass index of 18 to 30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.

COVID-19 in pregnant women: a systematic review and meta-analysis on the risk and prevalence of pregnancy loss

BACKGROUND

Pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more likely to experience preterm birth and their neonates are more likely to be stillborn or admitted to a neonatal unit. The World Health Organization declared in May 2023 an end to the coronavirus disease 2019 (COVID-19) pandemic as a global health emergency. However, pregnant women are still becoming infected with SARS-CoV-2 and there is limited information available regarding the effect of SARS-CoV-2 infection in early pregnancy on pregnancy outcomes.

OBJECTIVE AND RATIONALE

We conducted this systematic review to determine the prevalence of early pregnancy loss in women with SARS-Cov-2 infection and compare the risk to pregnant women without SARS-CoV-2 infection.

SEARCH METHODS

Our systematic review is based on a prospectively registered protocol. The search of PregCov19 consortium was supplemented with an extra electronic search specifically on pregnancy loss in pregnant women infected with SARS-CoV-2 up to 10 March 2023 in PubMed, Google Scholar, and LitCovid. We included retrospective and prospective studies of pregnant women with SARS-CoV-2 infection, provided that they contained information on pregnancy losses in the first and/or second trimester. Primary outcome was miscarriage defined as a pregnancy loss before 20 weeks of gestation, however, studies that reported loss up to 22 or 24 weeks were also included. Additionally, we report on studies that defined the pregnancy loss to occur at the first and/or second trimester of pregnancy without specifying gestational age, and for second trimester miscarriage only when the study presented stillbirths and/or foetal losses separately from miscarriages. Data were stratified into first and second trimester. Secondary outcomes were ectopic pregnancy (any extra-uterine pregnancy), and termination of pregnancy. At least three researchers independently extracted the data and assessed study quality. We calculated odds ratios (OR) and risk differences (RDs) with corresponding 95% CI and pooled the data using random effects meta-analysis. To estimate risk prevalence, we performed meta-analysis on proportions. Heterogeneity was assessed by I2.

OUTCOMES

We included 120 studies comprising a total of 168 444 pregnant women with SARS-CoV-2 infection; of which 18 233 women were in their first or second trimester of pregnancy. Evidence level was considered to be of low to moderate certainty, mostly owing to selection bias. We did not find evidence of an association between SARS-CoV-2 infection and miscarriage (OR 1.10, 95% CI 0.81-1.48; I2 = 0.0%; RD 0.0012, 95% CI -0.0103 to 0.0127; I2 = 0%; 9 studies, 4439 women). Miscarriage occurred in 9.9% (95% CI 6.2-14.0%; I2 = 68%; 46 studies, 1797 women) of the women with SARS CoV-2 infection in their first trimester and in 1.2% (95% CI 0.3-2.4%; I2 = 34%; 33 studies; 3159 women) in the second trimester. The proportion of ectopic pregnancies in women with SARS-CoV-2 infection was 1.4% (95% CI 0.02-4.2%; I2 = 66%; 14 studies, 950 women). Termination of pregnancy occurred in 0.6% of the women (95% CI 0.01-1.6%; I2 = 79%; 39 studies; 1166 women).

WIDER IMPLICATIONS

Our study found no indication that SARS-CoV-2 infection in the first or second trimester increases the risk of miscarriages. To provide better risk estimates, well-designed studies are needed that include pregnant women with and without SARS-CoV-2 infection at conception and early pregnancy and consider the association of clinical manifestation and severity of SARS-CoV-2 infection with pregnancy loss, as well as potential confounding factors such as previous pregnancy loss. For clinical practice, pregnant women should still be advised to take precautions to avoid risk of SARS-CoV-2 exposure and receive SARS-CoV-2 vaccination.

Neonatal outcomes of maternal prenatal coronavirus infection

The coronavirus disease 2019 (COVID-19) pandemic has led to significant changes in life and healthcare all over the world. Pregnant women and their newborns require extra attention due to the increased risk of adverse outcomes. Adverse pregnancy outcomes include intensive care unit (ICU) admission, pulmonary, cardiac, and renal impairment leading to mortality. Immaturity and variations of the neonatal immune system may be advantageous in responding to the virus. Neonates are at risk of vertical transmission and in-utero infection. Impaired intrauterine growth, prematurity, vertical transmission, and neonatal ICU admission are the most concerning issues. Data on maternal and neonatal outcomes should be interpreted cautiously due to study designs, patient characteristics, clinical variables, the effects of variants, and vaccination beyond the pandemic. Cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoidance of breast milk were performed to reduce transmission risk at the beginning of the pandemic in the era of insufficient knowledge. Vertical transmission was found to be low with favorable short-term outcomes. Serious fetal and neonatal outcomes are not expected, according to growing evidence. Long-term effects may be associated with fetal programming. Knowledge and lessons from COVID-19 will be helpful for the next pandemic if it occurs. IMPACT: Prenatal infection with SARS-CoV-2 is associated with adverse maternal and neonatal outcomes. Our review includes the effects of COVID-19 on the fetus and neonates, transmission routes, placental effects, fetal and neonatal outcomes, and long-term effects on neonates. There is a growing body of data and evidence about the COVID-19 pandemic. Knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

Neurodevelopmental outcomes in congenital and perinatal infections

PURPOSE OF REVIEW

Congenital infections are a major cause of childhood multidomain neurodevelopmental disabilities. They contribute to a range of structural brain abnormalities that can cause severe neurodevelopmental impairment, cerebral palsy, epilepsy, and neurosensory impairments. New congenital infections and global viral pandemics have emerged, with some affecting the developing brain and causing neurodevelopmental concerns. This review aims to provide current understanding of fetal infections and their impact on neurodevelopment.

RECENT FINDINGS

There are a growing list of congenital infections causing neurodevelopmental issues, including cytomegalovirus, Zika virus, syphilis, rubella, lymphocytic choriomeningitis virus, and toxoplasmosis. Fetal exposure to maternal SARS-CoV-2 may also pose risk to the developing brain and impact neurodevelopmental outcomes, although studies have conflicting results. As Zika virus was a recently identified congenital infection, there are several new reports on child neurodevelopment in the Caribbean and Central and South America. For many congenital infections, children with in-utero exposure, even if asymptomatic at birth, may have neurodevelopmental concerns manifest over time.

SUMMARY

Congenital infections should be considered in the differential diagnosis of a child with neurodevelopmental impairments. Detailed pregnancy history, exposure risk, and testing should guide diagnosis and multidisciplinary evaluation. Children with congenital infections should have long-term follow-up to assess for neurodevelopmental delays and other neurosensory impairments. Children with confirmed delays or high-risk should be referred for rehabilitation therapies.

Maternal and neonatal outcomes following SARS-CoV-2 infection

Infection with SARS-CoV-2 causing COVID-19 in pregnancy is known to confer risks to both the pregnant patient and fetus. A review of the current literature demonstrates that pregnant individuals with SARS-CoV-2 infection are at risk for higher composite morbidity, intensive care unit admission, ventilatory support, pre-eclampsia, preterm birth, and neonatal intensive care unit admissions compared to pregnant individuals without SARS-CoV-2. Worse obstetric morbidity and mortality generally correlate with the severity of COVID-19. Comorbidities such as diabetes increase the risk of severe COVID-19. An increased risk of stillbirth appears to be predominantly confined to pregnancies affected in the Delta variant time period. Further, vaccination against SARS-CoV-2 has been demonstrated to be safe and effective in pregnancy and while breastfeeding. Therefore, continued counseling encouraging vaccination remains imperative. The long-term maternal and neonatal consequences of pregnancies affected by SARS-CoV-2 remain unknown, and therefore continued research in this regard is warranted.

Do Anti-SARS-CoV-2 Monoclonal Antibodies Have an Impact on Pregnancy Outcome? A Systematic Review and Meta-Analysis

Monoclonal antibodies (mAbs) have been used as a rescue strategy for pregnant women affected by COVID-19. To explore its impact on maternal-fetal health, we included all observational studies reporting maternal, fetal, delivery and neonatal outcomes in women who underwent mAbs infusion for COVID-19. Primary outcome was the percentage of preterm delivery. We used meta-analyses of proportions to combine data for maternal, fetal, delivery and neonatal outcome of women treated with mAbs for COVID-19 and reported pooled proportions and their 95% confidence intervals (CIs) for categorical variables or mean difference (MD) with their 95% confidence intervals for continuous variables. Preterm birth was observed in 22.8% of cases (95% CI 12.9-34.3). Fetal distress was reported in 4.2% (95% CI 1.6-8.2). Gestational hypertension and pre-eclampsia were observed in 3.0% (95% CI 0.8-6.8) and 3.4% (95% CI 0.8-7.5) of cases, respectively. Fetal growth restriction was observed in 3.2% of fetuses (95% CI 0.8-7.0). Secondary prophylaxis with mAbs is currently considered the best treatment option for people with mild to moderate COVID-19 disease. More attention should be paid to infants born from mothers who were treated with mAbs, for the risk of immunosuppression.

The impact of maternal SARS-CoV-2 infection and COVID-19 vaccination on maternal-fetal outcomes

The rapidly evolving COVID-19 pandemic has resulted in an upsurge of scientific productivity to help address the global health crisis. One area of active research is the impact of COVID-19 on pregnancy. Here, we provide an epidemiological overview about what is known about the effects of maternal SARS-CoV-2 infection and COVID-19 vaccination on maternal-fetal outcomes, and identify gaps in knowledge. Pregnant people are at increased risk for severe COVID-19, and maternal SARS-CoV-2 infection increases the risk of negative maternal-fetal outcomes. Despite this elevated risk, there have been high rates of vaccine hesitancy, heightened by the initial lack of safety and efficacy data for COVID-19 vaccination in pregnancy. In response, retrospective cohort studies were performed to examine the impact of COVID-19 vaccination during pregnancy. Here, we report the vaccine's efficacy during pregnancy and its impact on maternal-fetal outcomes, as well as an overview of initial studies on booster shots in pregnancy. We found that pregnant people are at risk for more severe COVID-19 outcomes, maternal SARS-CoV-2 infection is associated with worse birth outcomes, COVID-19 vaccine hesitancy remains prevalent in the pregnant population, and COVID-19 vaccination and boosters promote better maternal-fetal outcomes. The results should help reduce vaccine hesitancy by alleviating concerns about the safety and efficacy of administering the COVID-19 vaccine during pregnancy. Overall, this review provides an introduction to COVID-19 during pregnancy. It is expected to help consolidate current knowledge, accelerate research of COVID-19 during pregnancy and inform clinical, policy, and research decisions regarding COVID-19 vaccination in pregnant people.