Maternal COVID-19 vaccination status and association with neonatal congenital anomalies.

Introduction: Despite recommendations for COVID-19 vaccination in pregnant people, the effect of vaccination on neonatal outcomes remains unknown. We sought to determine the association between COVID-19 vaccination status in pregnancy and presence of neonatally diagnosed congenital anomalies. Methods: A comprehensive vaccine registry was combined with a delivery database to create a cohort including all patients aged 16-55 years with a delivery event between December 10, 2020 and December 31, 2021 at a hospital within the Mayo Clinic Health System. Pregnancy and neonatal outcomes were analyzed in relation to vaccination status and timing, including a composite measure of congenital anomalies diagnosed in neonatal life. Comparisons between cohorts were conducted using chi-square test for categorical and Kruskal-Wallis test for continuous variables. A multivariable logistic regression was modeled to assess the association with congenital anomalies. Results: 5,096 mother-infant pairs were analyzed. A total of 1,158 were vaccinated, with 314 vaccinated in the first trimester. COVID-19 vaccination status, including vaccination during the first trimester of pregnancy, was not associated with an increased risk of composite congenital anomalies. When further examining congenital anomalies by organ system, we did demonstrate a significant difference in eye, ear, face, neck anomalies between vaccinated and not vaccinated groups (Table 3, Not vaccinated = 2.3%, Vaccinated = 3.3%, p-value 0.04) however we did not demonstrate this difference between the 1st trimester and not vaccinated groups (Not vaccinated = 2.3%, 1st Trimester = 2.5%, p-value 0.77). No differences were found between not vaccinated, vaccinated, or 1st trimester vaccinated groups for any other organ systems. There were no differences in birthweight by gestational age, APGAR scores, incidence of NICU admission, or living status of the neonate by vaccination status. Conclusion: We add additional information regarding the safety of COVID-19 vaccination status and timing as it pertains to neonatal composite congenital anomalies, with no association demonstrated. Our findings agree with prior literature that COVID-19 vaccination is not associated with adverse pregnancy outcomes or small for gestational age neonates. Further research is needed to elucidate the association between COVID-19 vaccination and eye, ear, face, neck, anomalies.

A Simple Risk Adjustment for Hospital-Level Nulliparous, Term, Singleton, Vertex, Cesarean Delivery Rates and Its Implications for Public Reporting.

BACKGROUND: The Joint Commission uses nulliparous, term, singleton, vertex, cesarean delivery (NTSV-CD) rates to assess hospitals' perinatal care quality through the Cesarean Birth measurement (PC-02). However, these rates are not risk-adjusted for maternal health factors, putting this measure at odds with the risk adjustment paradigm of most publicly reported hospital quality measures. Here, the authors tested whether risk adjustment for readily documented maternal risk factors affected hospital-level NTSV-CD rates in a large health system. METHODS: Included were all consecutive NTSV pregnancies from January 2019 to April 2023 across 10 hospitals in one health system. Logistic regression, adjusting for age, obesity, diabetes, and hypertensive disorders. was used to calculate hospital-level risk-adjusted NTSV-CD rates by multiplying observed vs. expected ratios for each hospital by the systemwide unadjusted NTSV-CD rate. The authors calculated intrahospital risk differences between unadjusted and risk-adjusted rates and calculated the percentage of hospitals qualifying for different reporting status after risk adjustment using the 30% Joint Commission reporting threshold rate. RESULTS: Of 23,866 pregnancies, 6,550 (27.4%) had cesarean deliveries. Across 10 hospitals, the number of deliveries ranged from 393 to 7,671, with unadjusted NTSV-CD rates ranging from 21.0% to 30.5%. Risk-adjusted NTSV-CD rates ranged from 21.5% to 30.4%, with absolute intrahospital differences in risk-adjusted vs. unadjusted rates ranging from -1.33% (indicating lower rate after risk adjustment) to 3.37% (indicating higher rate after risk adjustment). Three of 10 (30.0%) hospitals qualified for different reporting statuses after risk adjustment. CONCLUSION: Risk adjustment for age, obesity, diabetes, and hypertensive disorders is feasible and resulted in meaningful changes in hospital-level NTSV-CD rates with potentially impactful consequences for hospitals near The Joint Commission reporting threshold.

Maternal SARS-CoV-2 infection in pregnancy disrupts gene expression in Hofbauer cells with limited impact on cytotrophoblasts.

BACKGROUND: Hofbauer cells (HBCs) and cytotrophoblasts (CTBs) are major cell populations in placenta. The indirect impact of maternal SARS-CoV-2 disease on these cells that are not directly infected has not been extensively studied. Herein, we profiled gene expression in HBCs and CTBs isolated from placentae of recovered pregnant subjects infected with SARS-CoV-2 during all trimesters of pregnancy, placentae from subjects with active infection, SARS-CoV-2 vaccinated subjects, and those who were unexposed to the virus. METHODS: Placentae were collected within 4 h post-delivery and membrane-free tissues were enzymatically digested for the isolation of HBCs and CTBs. RNA extracted from HBCs and CTBs were sequenced using 150bp paired-end reads. Differentially expressed genes (DEGs) were identified by DESeq2 package in R and enriched in GO Biological Processes, KEGG Pathway, Reactome Gene Sets, Hallmark Gene Sets, and Canonical Pathways. Protein-protein interactions among the DEGs were modelled using STRING and BioGrid. RESULTS: Pregnant subjects (n = 30) were recruited and categorized into six groups: infected with SARS-CoV-2 in i) the first (1T, n = 4), ii) second (2T, n = 5), iii) third (3T, n = 5) trimester, iv) tested positive at delivery (Delivery, n = 5), v) never infected (Control, n = 6), and vi) fully mRNA-vaccinated by delivery (Vaccinated, n = 5). Compared to the Control group, gene expression analysis showed that HBCs from infected subjects had significantly altered gene expression profiles, with the 2T group having the highest number of DEGs (1,696), followed by 3T and 1T groups (1,656 and 958 DEGs, respectively). These DEGs were enriched for pathways involved in immune regulation for host defense, including production of cytokines, chemokines, antimicrobial proteins, ribosomal assembly, neutrophil degranulation inflammation, morphogenesis, and cell migration/adhesion. Protein-protein interaction analysis mapped these DEGs with oxidative phosphorylation, translation, extracellular matrix organization, and type I interferon signaling. Only 95, 23, and 8 DEGs were identified in CTBs of 1T, 2T, and 3T groups, respectively. Similarly, 11 and 3 DEGs were identified in CTBs and HBCs of vaccinated subjects, respectively. Reassuringly, mRNA vaccination did not induce an inflammatory response in placental cells. CONCLUSIONS: Our studies demonstrate a significant impact of indirect SARS-CoV-2 infection on gene expression of inner mesenchymal HBCs, with limited effect on lining CTB cells isolated from pregnant subjects infected and recovered from SARS-CoV-2. The pathways associated with these DEGs identify potential targets for therapeutic intervention.

Virtual Obstetric Hospitalist Support for Obstetric Emergencies and Deliveries: The Mayo Clinic Experience.

Objective: To implement use of obstetric (OB) hospitalist telemedicine services (TeleOB) to support clinicians facing OB emergencies in low-resource hospital settings. Methods: TeleOB was staffed by OB hospitalists working at a tertiary maternity center. The service was available via real-time high-definition audio/video technology for providers at 17 outlying hospitals across a health system spanning two states. The initial 25 service activations are described. Results: TeleOB supported 17 deliveries, two postpartum emergency department (ED) consultations, and four antenatal ED consultations. In 10 of 17 (59%) deliveries, teleneonatology was jointly activated to support neonatal resuscitation. Sixteen (94%) deliveries occurred in multiparas, and five (29%) resulted from spontaneous preterm labor. Eighty percent (20/25) of activations occurred in facilities without maternity services. Conclusions: A TeleOB service staffed by OB hospitalists successfully supports hospitals in an integrated health care system. TeleOB is feasible for support of hospitals with no delivery facilities or with limited maternity care resources.

Effect of Anti-TNF Biologic Exposure During Pregnancy on Villitis of Unknown Etiology Diagnoses in Patients with Autoimmune Disease.

Tumor necrosis factor-α (TNF-α) antagonists are highly effective in controlling autoimmune diseases. This has led to speculation that they might also be useful in treating inflammatory placental conditions, such as chronic villitis of unknown etiology (VUE). VUE affects 10-15% of term placentas and is associated with recurrent fetal growth restriction (FGR) and pregnancy loss. We aimed to evaluate outcomes in patients with autoimmune diseases with and without anti-TNF-α biologic exposure during gestation. This retrospective cohort study compared pregnant women with autoimmune disease taking anti-TNF-α biologics (n = 89) to pregnant women with autoimmune disease but not taking a biologic (n = 53). We extracted data on all patients meeting our inclusion criteria over a 20-year period. Our primary outcome was the diagnosis of VUE by histology. Our secondary outcomes were maternal and neonatal complications such as preeclampsia, FGR, and neonatal intensive care admission. Kruskal-Wallis and chi-squared tests were performed as appropriate for statistical analysis. Maternal characteristics were comparable between groups, and there was no increase in adverse pregnancy outcomes based on anti-TNF-α treatment. Exposure to anti-TNF-α therapy had no significant effect on the incidence of VUE or other obstetric complications. Within the cohort exposed to anti-TNF-α biologics during pregnancy, the rate of VUE was 9.3%, which is comparable to the reported general population risk. Our data support the safety profile of biologic use in pregnancy.

Vertical Transmission of SARS-CoV-2-Specific Antibodies and Cytokine Profiles in Pregnancy.

Despite intensive characterization of immune responses after COVID-19 infection and vaccination, research examining protective correlates of vertical transmission in pregnancy are limited. Herein, we profiled humoral and cellular characteristics in pregnant women infected or vaccinated at different trimesters and in their corresponding newborns. We noted a significant correlation between spike S1-specific IgG antibody and its RBD-ACE2 blocking activity (receptor-binding domain-human angiotensin-converting enzyme 2) in maternal and cord plasma (P < .001, R > 0.90). Blocking activity of spike S1-specific IgG was significantly higher in pregnant women infected during the third trimester than the first and second trimesters. Elevated levels of 28 cytokines/chemokines, mainly proinflammatory, were noted in maternal plasma with infection at delivery, while cord plasma with maternal infection 2 weeks before delivery exhibited the emergence of anti-inflammatory cytokines. Our data support vertical transmission of protective SARS-CoV-2-specific antibodies. This vertical antibody transmission and the presence of anti-inflammatory cytokines in cord blood may offset adverse outcomes of inflammation in exposed newborns.

Maternal Factors and Placental Pathologies Associated with a Diagnosis of Chronic Villitis.

OBJECTIVE: To evaluate maternal risk factors associated with chronic villitis of unknown etiology (VUE) and to describe cooccurring placental pathologies. STUDY DESIGN: A retrospective case-control study was conducted using placental pathology records from deliveries ≥ 20 weeks between 2010 and 2018. Cases were placentas with documented chronic villitis without infectious cause, hereafter called VUE. Controls were placentas without this diagnosis, matched to the cases 2:1. Maternal and neonatal demographic and clinical data were collected. Descriptive statistics are reported with Fisher's exact test or a chi-squared test, as appropriate, and multivariable conditional logistic regression was conducted. RESULTS: Our study included 352 cases with VUE and 657 controls. A diagnosis of gestational diabetes (p = 0.03) and gestational hypertension (p = 0.06) was 1.5 times more likely to occur in those with a VUE diagnosis. A trend was also seen for chronic hypertension (odds ratio [OR] = 1.7, p = 0.07) and preeclampsia (OR = 1.5, p = 0.09) compared with controls. Placentas with VUE, specifically high-grade VUE, were more likely to be small for gestational age (p = 0.01), and to be diagnosed with other placental findings including lymphoplasmacytic or chronic deciduitis (p < 0.01), maternal (p < 0.01) and fetal vascular malperfusion (p = 0.02), and chorionitis (acute or chronic; p < 0.01). CONCLUSION: Gestational diabetes and hypertension were associated with a diagnosis of VUE, and overall, VUE placentas have more abnormal placental findings compared with control. Understanding VUE risk factors may facilitate prenatal care strategies and counseling to achieve the best outcomes for pregnant patients and their neonates. KEY POINTS: · VUE is a common inflammatory lesion of the placenta.. · Gestational diabetes and hypertension are associated with a VUE diagnosis.. · Findings of other placental pathologies increase in VUE..

Efficacy of Rubella Vaccination after Co-Inoculation with Rhogam.

Congenital rubella syndrome is a constellation of birth defects that can have devastating consequences, impacting approximately 100,000 births worldwide each year. The incidence is much lower in countries that routinely vaccinate their population. In the US, postnatal immunization of susceptible women is an important epidemiological strategy for the prevention of rubella as the Center for Disease Control (CDC) does not recommend administering this vaccine during pregnancy due to its nature as a live attenuated virus vaccine. However, concerns that the co-administration of rubella vaccine with other immunoglobins (i.e., Rhogam) could compromise vaccine efficacy has produced warnings that can delay the administration of rubella vaccination postpartum, leaving women susceptible to the disease in subsequent pregnancies. We aimed to address whether the co-administration of the measles, mumps, and rubella (MMR) vaccine and Rhogam decreased antibody responses compared to those receiving only MMR vaccination. This retrospective cohort study utilized clinical data from 78 subjects who received the MMR vaccine and Rhogam after delivery and 45 subjects who received the MMR vaccine alone. Maternal demographics, pregnancy complications and rubella status at the start of a subsequent pregnancy were recorded for analysis. Overall, the two cohorts had similar baseline characteristics; however, lower parity was noted in the participants that received both MMR vaccination and Rhogam. Making assessments based on maternal antibody IgG index for rubella during the next pregnancy, we observed that 88% of the Rhogam + MMR vaccine group had positive serology scores, which was not significantly different from the 80% rate in the MMR-vaccine-only cohort (p = 0.2). In conclusion, no differences were observed in rubella immunity status in subsequent pregnancies in those mothers given both the MMR vaccine and Rhogam concurrently. Given these findings, warnings against co-administration of vaccines in combination with Rhogam appear unwarranted.

Hospitalization in pregnancy due to human respiratory syncytial virus associated disease.

Background: Despite pregnancy being a state of physiologic immune alteration, it has not previously been described as a risk factor for hospitalization due to human respiratory syncytial virus (RSV). Case: This retrospective case series describes two cases of hospitalization due to RSV associated illness in pregnancy. Conclusion: It remains to be determined if the current RSV surge is more dangerous to pregnant patients than those in seasons past. These cases support the importance of maintaining RSV on the differential for respiratory illness in pregnancy.

Updates on the dermatopathology of pregnancy-associated skin conditions.

Pathologists provide valuable input in the dermatological care of pregnant patients in various contexts. This article provides dermatopathology updates on cutaneous changes associated with pregnancy, organized based on the following classification system: physiological skin changes in pregnancy, specific dermatoses of pregnancy, dermatoses modified in pregnancy, and skin neoplasms in pregnancy. Awareness of the impact of pregnancy on the skin by pathologists is important, as this is an opportunity to contribute to diagnostic precision in this patient population.

Effect of peripartum Clostridioides difficile infection on pregnancy and neonatal outcomes: an observational study.

Background: The incidence of Clostridioides difficile infection (CDI) in peripartum women is rising, but limited data on its effect on maternal and neonatal outcomes are available. Objective: To study the effect of peripartum CDI on pregnancy and neonatal outcomes. Design: Retrospective cohort study. Methods: Patients with peripartum CDI 12 weeks before pregnancy through 6 weeks postpartum (January 1996-February 2018) were matched with controls (peripartum women without CDI) 1:1 by age, year of delivery, and prior pregnancies. McNemar's test and conditional logistic regression were used to analyze the effect of CDI on pregnancy and neonatal outcomes (complications, mode of delivery). p < 0.05 was considered statistically significant. Results: Overall, 101 cases and 100 controls (1997-2018) were included; median age 27 (range, 20-41) years. Timing of CDI was as follows: pre-pregnancy: 15.8% (n = 16), during pregnancy: 51.5% (n = 52), and postpartum: 32.7% (n = 33). The commonest risk factor was outpatient/emergency room visits. Pregnancy and neonatal outcomes were analyzed for 67 matched pairs with CDI before or during pregnancy. Cases had higher odds of cesarean delivery (p = 0.02) and lower odds of Group B Streptococcus (GBS) infection/colonization (p = 0.03). Odds of cesarean delivery remained high after controlling for labor arrest disorders [odds ratio (OR): 17.23 (95% confidence interval (CI), 2.19-543.19; p = 0.004)]; odds of GBS remained low after controlling for antibiotic use (OR: 0.25, 95% CI, 0.04-0.99; p = 0.049). Neonatal outcomes were similar in cases and controls. CDI treatment did not affect treatment-related or delivery outcomes. Conclusion: Peripartum CDI was associated with higher odds of cesarean delivery and lower odds of GBS infections. Larger studies exploring the effect of CDI on pregnancy and neonatal outcomes are needed.

Development and multicenter international validation of a diagnostic tool to differentiate between pemphigoid gestationis and polymorphic eruption of pregnancy.

BACKGROUND: Pemphigoid gestationis (PG) and polymorphic eruption of pregnancy (PEP) may be similar morphologically but confer different maternal and fetal risks. Direct immunofluorescence is the gold standard test used to differentiate between the 2 diagnoses but is not always available. OBJECTIVE: To develop and validate a clinical scoring system to differentiate PG from PEP. METHODS: After developing a scoring system based on differentiating clinical factors reported in existing literature, we tested its diagnostic accuracy in a retrospective international multicenter validation study in collaboration with the European Academy of Dermatology and Venereology's Skin Diseases in Pregnancy Taskforce. RESULTS: Nineteen pregnancies (16 patients) affected by PG and 39 pregnancies (39 patients) affected by PEP met inclusion criteria. PG had a mean score of 4.6 (SD, 2.5) and PEP had a mean score of -0.3 (SD, 2.0). The area under the curve was 0.93 (95% CI, 0.86-1.00). Univariate analysis revealed that almost all criteria used in the scoring system were significantly different between the groups (P < .05), except for skip pregnancy and multiple gestations, which were then removed from the final scoring system. LIMITATIONS: Small retrospective study. CONCLUSION: The Pregnancy Dermatoses Clinical Scoring System may be useful to differentiate PG from PEP in resource-limited settings.

Evaluating the cost-effectiveness of testing pregnant women for penicillin allergy.

INTRODUCTION: True penicillin allergy is rare and is commonly incorrectly reported. In fact, less than five percent of patients who report a penicillin allergy will have a currently active clinically-significant IgE- or T-cell-mediated hypersensitivity when appropriately tested. Penicillin is the agent of choice for intrapartum antibiotic prophylaxis to reduce the risk of group B streptococcus early-onset disease in the newborn. Inaccurate penicillin allergy status may lead to inappropriate antibiotic use, as most alternative drugs are more expensive and broader spectrum than penicillin. Penicillin allergy testing has been found to be safe in pregnancy and cost-effective in other patient populations. OBJECTIVE: To evaluate the cost-effectiveness of penicillin allergy testing and appropriate antibiotic treatment (test then treat strategy) compared to usual care among pregnant women. METHODS: We developed a decision tree to evaluate the cost of providing appropriate care via a test then treat strategy for pregnant women who report a penicillin allergy, compared to usual care. RESULTS: Using the test then treat strategy the additional cost to ensure appropriate care for all pregnant women who report a penicillin allergy, was $1122.38 per person. Adopting a test then treat strategy increased the number of appropriate antibiotic use from 7,843/10,000 to 10,000/10,000 simulations. CONCLUSION: Our results show that a test then treat strategy for pregnant women who report a penicillin allergy is a good-value intervention.

Impact of labor characteristics on maternal and neonatal outcomes of labor: A machine-learning model.

INTRODUCTION: Since Friedman's seminal publication on laboring women, numerous publications have sought to define normal labor progress. However, there is paucity of data on contemporary labor cervicometry incorporating both maternal and neonatal outcomes. The objective of this study is to establish intrapartum prediction models of unfavorable labor outcomes using machine-learning algorithms. MATERIALS AND METHODS: Consortium on Safe Labor is a large database consisting of pregnancy and labor characteristics from 12 medical centers in the United States. Outcomes, including maternal and neonatal outcomes, were retrospectively collected. We defined primary outcome as the composite of following unfavorable outcomes: cesarean delivery in active labor, postpartum hemorrhage, intra-amniotic infection, shoulder dystocia, neonatal morbidity, and mortality. Clinical and obstetric parameters at admission and during labor progression were used to build machine-learning risk-prediction models based on the gradient boosting algorithm. RESULTS: Of 228,438 delivery episodes, 66,586 were eligible for this study. Mean maternal age was 26.95 ± 6.48 years, mean parity was 0.92 ± 1.23, and mean gestational age was 39.35 ± 1.13 weeks. Unfavorable labor outcome was reported in 14,439 (21.68%) deliveries. Starting at a cervical dilation of 4 cm, the area under receiver operating characteristics curve (AUC) of prediction models increased from 0.75 (95% confidence interval, 0.75-0.75) to 0.89 (95% confidence interval, 0.89-0.90) at a dilation of 10 cm. Baseline labor risk score was above 35% in patients with unfavorable outcomes compared to women with favorable outcomes, whose score was below 25%. CONCLUSION: Labor risk score is a machine-learning-based score that provides individualized and dynamic alternatives to conventional labor charts. It predicts composite of adverse birth, maternal, and neonatal outcomes as labor progresses. Therefore, it can be deployed in clinical practice to monitor labor progress in real time and support clinical decisions.

Analgesic considerations for induction of labor.

Induction of labor may be indicated to minimize maternal and fetal risks. The rate of induction is likely to increase as recent evidence supports elective induction at 39 weeks gestation. We review methods of induction and then analgesic options as they relate to indications and methods to induce labor. We specifically focus on parturients at high risk for anesthetic complications including those requiring anticoagulation, and those with cardiac disease, obesity, chorioamnionitis, prior spinal instrumentation, elevated intracranial pressure, known or anticipated difficult airway, thrombocytopenia, and preeclampsia. Guidelines regarding timing of anticoagulation dosing with neuraxial anesthetic techniques have been defined through consensus statements. Early epidural placement may be beneficial in patients with cardiac disease, obesity, anticipated difficult airway, and HELLP syndrome. Questions remain regarding how early is too early for epidural placement, what options are safest for patients with bacteremia, and what pain relief should be offered to those unable to tolerate cervical exams in early labor.

Medicaid Cost and Reimbursement for Low-Risk Prenatal Care in the United States.

INTRODUCTION: We calculate the financial margins for delivery of routine antenatal care as reimbursed by Medicaid. Prenatal care cost varies with overhead, health care provider type, and number of office visits. Antenatal care is only one component of the global maternity bundle, which also includes intrapartum and postpartum care. METHODS: Time for provision of low-risk antenatal care was determined prospectively from a study of 133 low-risk pregnant patients. Health care provider time cost was estimated using mean wages for obstetricians and midwives. Margins were estimated by subtracting cost of provider services and overhead for the antenatal component of maternity care from total Medicaid reimbursement for the pregnancy global package (CPT 59400) using 2015 dollars. The maternity bundle elements of routine prenatal laboratory tests, ultrasounds, intrapartum care, and postpartum care were not included in our analysis of cost components. RESULTS: Patients received an average of 215 minutes of direct provider time per pregnancy. At the 50th percentile for physician payment and assuming overhead is 53.4% of revenue, practice margins varied by state from -$1067 to +$675, with a median of -$357. Median margins for midwifery care were +$15, with a range of -$579 to +$885. Margins were negative if overhead costs exceeded 33% of revenue for physician care and 55% of revenue for midwifery care. DISCUSSION: In many states, Medicaid reimbursement for the global maternity package is less than the actual cost of antenatal care alone. Improving reimbursement or decreasing costs is necessary to make maternity care more cost-effective.

Pregnancy and birth outcomes after SARS-CoV-2 vaccination in pregnancy.

BACKGROUND: SARS-CoV-2 infection during pregnancy is associated with significant maternal morbidity and increased rates of preterm birth. For this reason, COVID-19 vaccination in pregnancy has been endorsed by multiple professional societies, including the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine, despite the exclusion of pregnant women from initial clinical trials of vaccine safety and efficacy. However, to date, little data exist regarding the outcomes of pregnant patients after COVID-19 vaccination. OBJECTIVE: To assess the safety and efficacy of COVID-19 vaccines in pregnant patients. STUDY DESIGN: A comprehensive vaccine registry was combined with a delivery database for an integrated healthcare system to create a delivery cohort that included vaccinated patients. Maternal sociodemographic data were examined to identify factors associated with COVID-19 vaccination. Pregnancy and birth outcomes were analyzed, including a composite measure of maternal and neonatal pregnancy complications, the Adverse Outcome Index. RESULTS: Of 2002 patients in the delivery cohort, 140 (7.0%) received a COVID-19 vaccine during pregnancy, and 212 (10.6%) experienced a COVID-19 infection during pregnancy. The median gestational age at first vaccination was 32 weeks (range, 13 6/7-40 4/7 weeks), and patients vaccinated during pregnancy were less likely than unvaccinated patients to experience COVID-19 infection before delivery (2/140 [1.4%] vs 210/1862 [11.3%]; P<.001). No maternal COVID-19 infection occurred after the vaccination of pregnant patients. Factors significantly associated with increased likelihood of vaccination in a multivariable logistic regression model included older age, higher level of maternal education, being a nonsmoker, use of infertility treatment for the current pregnancy, and lower gravidity. Compared with unvaccinated patients, no significant difference in the composite adverse outcome (7/140 [5.0%] vs 91/1862 [4.9%]; P=.95) or other maternal or neonatal complications, including thromboembolic events and preterm birth, was observed in vaccinated patients. CONCLUSION: In this birth cohort, vaccinated pregnant women were less likely than unvaccinated pregnant patients to experience COVID-19 infection, and COVID-19 vaccination during pregnancy was not associated with increased pregnancy or delivery complications. The cohort was skewed toward late pregnancy vaccination, and thus, findings may not be generalizable to vaccination during early pregnancy.