ABSTRACT
Background: Studies suggest perinatal infection with SARSCoV- 2 can induce adverse birth outcomes, but studies published to date have substantial limitations. Most have identified cases based upon their presentation for clinical care, and very few have examined pandemic-related stress which may also impact adverse birth outcomes. Objective(s): To evaluate the relationships between SARSCoV- 2 infection in pregnancy and pandemic-related stress with birth outcomes. Study Design: We conducted an observational study of 211 mother-newborn dyads in three urban cohorts participating in the Environmental Influences on Child Health Outcomes (ECHO) Program. Serology for SARS-CoV-2 was assessed in a convenience sample of prenatal maternal, cord serum or dried blood spots from births occurring between January 2020-September 2021. Specimens were assessed for IgG, IgM, and IgA antibodies to nucleocapsid, S1 spike, S2 spike, and receptor-binding domain. A Pandemic-related Traumatic Stress (PTS) scale was based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition Acute Stress Disorder criteria. Result(s): 36% were positive for at least one antibody type, chiefly IgG. Self-report of infection was not significantly correlated with combined serology. There were no differences in gestational age (GA), birth weight, preterm birth (PTB), or low birth weight (LBW) among seropositive mothers. However, IgM seropositive mothers had children with lower BW (434g, 95% CI: 116- 752), BW Z score-for-GA (0.73 SD, 95% CI 0.10-1.36) and were more likely to deliver preterm (OR 8.75, 95% CI 1.22-62.4). Associations with LBW sustained in sensitivity analyses limited to pre-vaccine samples, and PTS symptoms were not associated with birth outcomes. The addition of PTS did not substantially change associations with BW, although associations with PTB attenuated to near-significance. Conclusion(s): We identified decreased birth weight and increased prematurity in mothers IgM seropositive to SARS-CoV-2, independent of PTS. Though there are limits to interpretation, the data support efforts to prevent SARS-CoV-2 infections in pregnancy.
ABSTRACT
Background. Despite extensive studies of human immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, research examining protective correlates of vertical transmission following maternal exposure in pregnancy remain limited. Here, we characterized antibody and cytokine responses in maternal and cord blood following infection or vaccination at various timepoints during gestation. Methods. Spike S1 protein-specific binding antibodies and antibodies capable of blocking the interaction between the receptor binding domain (RBD) and the angiotensin converting enzyme 2 (ACE2) were measured in maternal and cord blood by ELISA. Serum concentrations of 74 cytokines/chemokines were measured by multiplex assay. Humoral responses and cytokine levels from matched maternal and fetal cord sera were compared and examined for potential correlations. Results. We observed a highly significant correlation between Spike S1-specific antibody titer and RBD-ACE2 blocking antibody activity between maternal and fetal cord serum (p < 2.2e-16, R > 0.90). Blocking antibody activity was significantly higher for mothers infected during the 3rd trimester compared to earlier trimesters;however, vaccinated mothers developed and transferred higher antibody titers with greater RBD-ACE2 blocking antibody activity to their neonates than infected mothers. Furthermore, vaccine-induced Spike S1 IgG transfer ratios (fetal cord/maternal) were significantly higher than those induced by infection (p = 0.002). Multiplex assay showed significantly elevated levels of 33 cytokines/chemokines, mainly pro-inflammatory in infected maternal serum samples, while the paired fetal cord samples exhibited an anti-inflammatory cytokine predominance. Conclusion. Our data support selective vertical transmission of potentially protective humoral responses against SARS-CoV-2, especially following vaccination in the 3rd trimester. The anti-inflammatory cytokine predominance in cord blood that persists despite maternal SARS-CoV-2 infection may offset the adverse outcomes of inflammation in pregnancy for the neonate.
ABSTRACT
Background: Longitudinal assessment of SARS-CoV-2 antibody (Ab) response during pregnancy after infection and transplacental transfer may inform durability of maternally derived Ab for mothers and infants. Methods: Between October 2020-September 2021, pregnant people testing SARS-CoV-2 IgG positive by Abbott Architect chemiluminescent immunoassay (CMIA) for anti-nucleocapsid (N) antibody (semi-quantitative index ≥1.4 considered IgG+) during pregnancy or delivery in a seroprevalence study, or identified with RT-PCR+ results via medical records, were invited to enroll in a longitudinal evaluation of maternal Ab responses and transplacental transfer. Maternal blood collected at 1, 2, 3, and 6 months after enrollment and maternal and cord blood collected at delivery were tested with the same assay. Results: Among 40 participants testing IgG+ for anti-N, 31 (78%) had a prior RT-PCR+ result. Median age was 32 years (IQR 29-35);27 (68%) enrolled during pregnancy at median 18 weeks gestation (IQR 13-33), while 13 (33%) enrolled at delivery or early postpartum. Median Abbott index was 3.06 (IQR 1.96-5.74) at first IgG+ result obtained at a median of 9 weeks (IQR 4-16) after RT-PCR+ result, for those with a known RT-PCR. Among 23 participants with ≥2 samples, 50% had IgG results below positivity threshold at median 17 weeks (IQR 12-28) after first IgG+ result (Figure). Seventeen mother-infant pairs had delivery samples collected at median 66 days (IQR 60-71 days) from maternal RT-PCR+ result. Six (35%) maternal samples remained IgG+ (median Abbott index 2.97 [IQR 2.35-7.01]) at delivery (gestational age 30-40 weeks) with all 6 paired cord sera testing IgG+ (median Abbott index 4.30 [IQR 2.93-7.22]). Median placental transfer ratio of maternally derived IgG Abs based on a positive Abbott index was 1.13 (95%CI 0.98-1.30) among mothers with samples remaining IgG+ at delivery. Conclusion: Within 4 months after first IgG+ result primarily in second trimester, about half of pregnant persons had SARS-CoV-2 IgG anti-N Ab levels below the Abbott CMIA positive threshold. Among evaluable mother-infant pairs, two-thirds of mothers no longer tested anti-N IgG+ at delivery. Transplacental transfer of maternal antibodies was confirmed in all infants born to mothers with samples remaining IgG+ at delivery. Durability of maternal SARS-CoV-2 Ab response and transplacental transfer following infection has implications for maternal and neonatal susceptibility to SARS-CoV-2 infection.
ABSTRACT
Background: There are limited data on how COVID-19 disease severity and vaccination throughout different trimesters in pregnancy impact maternal neutralizing antibody responses and transplacental transfer to the neonate at birth. Further characterization of the antibody response of in utero SARS-CoV-2 may inform vaccination schedules in pregnancy in order to optimize maternal and neonatal protection. Methods: The COVID-19 Outcomes in Mother-Infant Pairs (COMP) study is a longitudinal cohort of mother-infant dyads diagnosed with PCR-confirmed SARS-CoV-2 at any point during pregnancy. Maternal and cord sera from delivery, as well as infant sera collected at 24 hours of life, were analyzed by enzyme-linked immunosorbent assay (ELISA) for IgA, IgG, and IgM targeting receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Neutralizing antibody (NAb) activity against the original L strain was evaluated in a subset of unvaccinated mother-infant dyads with evidence of IgG transfer or history of severe/critical COVID-19 in pregnancy. Results: Among 115 pregnant women, the NIH COVID-19 severity of illness categories were: 12% asymptomatic, 70% mild/moderate, 11% severe/critical disease, and 7% vaccinated prior to delivery following recovery. Fifty percent of the cohort was diagnosed in the 3rd trimester, and the median diagnosis date to delivery was 61.5 days (IQR 27.75-122.25). The majority (74%) of the cohort produced all three anti-SARS-CoV-2 isotypes, although 5% had no detectable antibody class. Transplacental transfer ratios increased with increasing duration between onset of infection and delivery (Figure 1, r2=0.17). Infant IgG levels (ng/mL) were the highest among neonates born to vaccinated mothers (Figure 1), and maternal IgG levels increased with disease severity, although vaccination elicited a comparable maternal antibody response to severe/critical disease (Figure 1). Among 50 maternal specimens, 80% demonstrated in vitro neutralization activity, and 52% of 33 neonatal specimens had NAb. Conclusion: While transplacental transfer of IgG was high with natural infection and correlates with increasing duration between onset of infection and delivery, only half of analyzed neonatal specimens demonstrated in vitro neutralization activity. Further research is needed to characterize the functionality and kinetics of both maternal and neonatal antibody responses elicited by in utero SARS-CoV-2 natural infection compared with COVID-19 vaccination.