Infection-induced thrombin production: a potential novel mechanism for preterm premature rupture of membranes (PPROM).

BACKGROUND: Preterm premature rupture of membranes is a leading contributor to maternal and neonatal morbidity and death. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently preterm premature rupture of membranes. Although blood is suspected to be the likely source of thrombin in fetal membranes and amniotic fluid of patients with preterm premature rupture of membranes, this has not been proved. Ureaplasma parvum is emerging as a pathogen involved in prematurity, which includes preterm premature rupture of membranes; however, until now, prothrombin production that has been induced directly by bacteria in fetal membranes has not been described. OBJECTIVE: This study was designed to investigate whether Ureaplasma parvum exposure can induce prothrombin production in fetal membranes cells. STUDY DESIGN: Primary fetal membrane cells (amnion epithelial, chorion trophoblast, and decidua stromal) or full-thickness fetal membrane tissue explants from elective, term, uncomplicated cesarean deliveries were harvested. Cells or tissue explants were infected with live Ureaplasma parvum (1×105, 1×106 or 1×107 colony-forming units per milliliter) or lipopolysaccharide (Escherichia coli J5, L-5014; Sigma Chemical Company, St. Louis, MO; 100 ng/mL or 1000 ng/mL) for 24 hours. Tissue explants were fixed for immunohistochemistry staining of thrombin/prothrombin. Fetal membrane cells were fixed for confocal immunofluorescent staining of the biomarkers of fetal membrane cell types and thrombin/prothrombin. Protein and messenger RNA were harvested from the cells and tissue explants for Western blot or quantitative reverse transcription polymerase chain reaction to quantify thrombin/prothrombin protein or messenger RNA production, respectively. Data are presented as mean values ± standard errors of mean. Data were analyzed using 1-way analysis of variance with post hoc Dunnett's test. RESULTS: Prothrombin production and localization were confirmed by Western blot and immunostainings in all primary fetal membrane cells and tissue explants. Immunofluorescence observations revealed a perinuclear localization of prothrombin in amnion epithelial cells. Localization of prothrombin in chorion and decidua cells was perinuclear and cytoplasmic. Prothrombin messenger RNA and protein expression in fetal membranes were increased significantly by Ureaplasma parvum, but not lipopolysaccharide, treatments in a dose-dependent manner. Specifically, Ureaplasma parvum at a dose of 1×107 colony-forming units/mL significantly increased both prothrombin messenger RNA (fold changes in amnion: 4.1±1.9; chorion: 5.7±4.2; decidua: 10.0±5.4; fetal membrane: 9.2±3.0) and protein expression (fold changes in amnion: 138.0±44.0; chorion: 139.6±15.1; decidua: 56.9±29.1; fetal membrane: 133.1±40.0) compared with untreated control subjects. Ureaplasma parvum at a dose of 1×106 colony-forming units/mL significantly up-regulated prothrombin protein expression in chorion cells (fold change: 54.9±5.3) and prothrombin messenger RNA expression in decidua cells (fold change: 4.4±1.9). CONCLUSION: Our results demonstrate that prothrombin can be produced directly by fetal membrane amnion, chorion, and decidua cells. Further, prothrombin production can be stimulated by Ureaplasma parvum exposure in fetal membranes. These findings represent a potential novel underlying mechanism of Ureaplasma parvum-induced rupture of fetal membranes.

Research to knowledge: promoting the training of physician-scientists in the biology of pregnancy.

Common disorders of pregnancy, such as preeclampsia, preterm birth, and fetal growth abnormalities, continue to challenge perinatal biologists seeking insights into disease pathogenesis that will result in better diagnosis, therapy, and disease prevention. These challenges have recently been intensified with discoveries that associate gestational diseases with long-term maternal and neonatal outcomes. Whereas modern high-throughput investigative tools enable scientists and clinicians to noninvasively probe the maternal-fetal genome, epigenome, and other analytes, their implications for clinical medicine remain uncertain. Bridging these knowledge gaps depends on strengthening the existing pool of scientists with expertise in basic, translational, and clinical tools to address pertinent questions in the biology of pregnancy. Although PhD researchers are critical in this quest, physician-scientists would facilitate the inquiry by bringing together clinical challenges and investigative tools, promoting a culture of intellectual curiosity among clinical providers, and helping transform discoveries into relevant knowledge and clinical solutions. Uncertainties related to future administration of health care, federal support for research, attrition of physician-scientists, and an inadequate supply of new scholars may jeopardize our ability to address these challenges. New initiatives are necessary to attract current scholars and future generations of researchers seeking expertise in the scientific method and to support them, through mentorship and guidance, in pursuing a career that combines scientific investigation with clinical medicine. These efforts will promote breadth and depth of inquiry into the biology of pregnancy and enhance the pace of translation of scientific discoveries into better medicine and disease prevention.

S-Nitrosylated fetal hemoglobin in neonatal human blood.

BACKGROUND: Nitric oxide (NO) and its derivatives play important roles in the cardiopulmonary transition upon birth and in other oxygen-sensitive developmental milestones. One mechanism for the coupling of oxygen sensing and signaling by NO species is via the formation of an S-nitrosothiol (SNO) moiety on hemoglobin (Hb, forming SNO-Hb) and its release from the red blood cell in hypoxia. Although SNO-Hb formed on adult-type Hb (HbA, forming SNO-HbA) has been documented in physiological and pathophysiological human states, the fetal variant, SNO-HbF, has thus far not been isolated or characterized in human blood. METHODS AND RESULTS: We developed a technique capable of separating Hbs A and F under conditions that preserve SNO. We then measured SNO-HbF in the blood of healthy and premature or otherwise ill neonates using the gold standard for SNO measurement, mercury-coupled photolysis-chemiluminescence. SNO-HbF levels were in the range of those previously reported for HbA in adults. We found that SNO-HbF was more abundant at earlier gestational age (<30 weeks), even when accounting for the absolute HbF level. CONCLUSIONS: The ability to monitor SNO-HbF could provide new insights into fetal development and the perinatal transition, and has potential as a biomarker relevant to the management of neonatal diseases.

Inflammatory Response of Human Gestational Membranes to Ureaplasma parvum Using a Novel Dual-Chamber Tissue Explant System.

Preterm premature rupture of membranes (PPROM) is often associated with intra-amniotic inflammation and infection. Current understanding of the pathogenesis of PPROM includes activation of pro-inflammatory cytokines and proteolytic enzymes leading to compromise of membrane integrity. The impact of exposure to bacterial pathogens, including Ureaplasma parvum, on gestational membranes is poorly understood. Our objective was to develop a dual-chamber system to characterize the inflammatory response of gestational membranes to U. parvum in a directional nature. Full-thickness human gestational membrane explants, with either choriodecidua or amnion oriented superiorly, were suspended between two washers in a cylindrical device, creating two distinct compartments. Brilliant green dye was introduced into the top chamber to assess the integrity of the system. Tissue viability was evaluated after 72 h using a colorimetric cell proliferation assay. Choriodecidua or amnion was exposed to three doses of U. parvum and incubated for 24 h. Following treatment, media from each compartment were used for quantification of U. parvum (quantitative PCR), interleukin (IL)-8 (enzyme-linked immunosorbent assay), and matrix metalloproteinase (MMP)-2 and MMP-9 activity (zymography). We observed that system integrity and explant viability were maintained over 72 h. Dose-dependent increases in recovered U. parvum, IL-8 concentration, and MMP-2 activity were detected in both compartments. Significant differences in IL-8 concentration and MMP-9 activity were found between the choriodecidua and amnion. This tissue explant system can be used to investigate the inflammatory consequences of directional bacterial exposure for gestational membranes and provides insight into the pathogenesis of PPROM and infectious complications of pregnancy.

The Effect of Progestins on Tumor Necrosis Factor α-Induced Matrix Metalloproteinase-9 Activity and Gene Expression in Human Primary Amnion and Chorion Cells In Vitro.

BACKGROUND: Current treatment modalities for preventing preterm premature rupture of membranes are limited, but progestins may play a role. Tumor necrosis factor α (TNFα) enhances matrix metalloproteinase-9 (MMP-9) gene expression and activity in fetal membranes, contributing to membrane weakening and rupture. We previously demonstrated that progestins attenuate TNFα-induced MMP-9 activity in a cytotrophoblast cell line. However, whether they have a similar effect in primary amnion and chorion cells of fetal membranes is unknown. In this study, we evaluated the effect of progestins on basal and TNFα-induced MMP-9 activity and gene expression in primary chorion and amnion cells harvested from the fetal membranes of term nonlaboring patients. METHODS: Primary amnion and chorion cells were isolated from fetal membranes obtained from term uncomplicated nonlaboring patients following elective cesarean delivery (n = 11). Confluent primary amnion and chorion cell cultures were both pretreated with vehicle (control), progesterone (P4), 17α-hydroxyprogesterone caproate (17P), or medroxyprogesterone acetate (MPA) at 10 M concentration for 6 hours followed by stimulation with TNFα at 10 ng/mL for an additional 24 hours. Cell cultures pretreated with the vehicle only served as the unstimulated control and the vehicle stimulated with TNFα served as the stimulated control. Both controls were assigned a value of 100 units. Cell culture medium was harvested for MMP-9 enzymatic activity quantification using gelatin zymography. Total RNA was extracted for quantifying MMP-9 gene expression using real-time quantitative PCR. Basal MMP-9 activity and gene expression data were normalized to the unstimulated control. TNFα-stimulated MMP-9 activity and gene expression were normalized to the stimulated control. The primary outcome was the effect of progestins on TNFα-induced MMP-9 enzymatic activity in term human primary amnion and chorion cells in vitro. Secondary outcomes included the effect of progestin therapy on TNFα-induced MMP-9 gene expression and on basal MMP-9 activity and gene expression in primary amnion and chorion cells in vitro. RESULTS: Primary cells were harvested from 11 patients. Compared with the unstimulated control, TNFα increased MMP-9 activity (P = 0.005 versus control in primary amnion cells and P < 0.001 versus control in primary chorion cells) and MMP-9 gene expression (P = 0.030 versus control in primary amnion cells, P < 0.001 versus control in primary chorion cells). Compared with the unstimulated controls, MPA, but not P4 or 17P, reduced basal MMP-9 activity [mean difference (95% CI) -49.6 (-81.9, -17.3) units, P = 0.001] and gene expression [mean difference (95% CI) -53.4 (-105.9, -0.9) units, P = 0.045] in primary amnion cells. Compared with the stimulated control, MPA also reduced TNFα-induced MMP-9 activity [mean difference (95% CI) -69.0 (-91.8, -46.3) units, P < 0.001] and gene expression [mean difference (95% CI) -86.0 (-120.7, -51.3) units, P < 0.001] in primary amnion cells. Progestin pretreatment had no significant effect on basal or TNFα-induced MMP-9 activity and gene expression in primary chorion cells. CONCLUSIONS: The inhibitory effect of MPA on both basal and TNFα-induced MMP-9 activity and gene expression in primary amnion cells demonstrate a possible mechanism by which progestins may prevent fetal membrane weakening leading to preterm premature rupture of membranes.

Geographic clustering of elevated blood heavy metal levels in pregnant women.

BACKGROUND: Cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) exposure is ubiquitous and has been associated with higher risk of growth restriction and cardiometabolic and neurodevelopmental disorders. However, cost-efficient strategies to identify at-risk populations and potential sources of exposure to inform mitigation efforts are limited. The objective of this study was to describe the spatial distribution and identify factors associated with Cd, Pb, Hg, and As concentrations in peripheral blood of pregnant women. METHODS: Heavy metals were measured in whole peripheral blood of 310 pregnant women obtained at gestational age ~12 weeks. Prenatal residential addresses were geocoded and geospatial analysis (Getis-Ord Gi* statistics) was used to determine if elevated blood concentrations were geographically clustered. Logistic regression models were used to identify factors associated with elevated blood metal levels and cluster membership. RESULTS: Geospatial clusters for Cd and Pb were identified with high confidence (p-value for Gi* statistic <0.01). The Cd and Pb clusters comprised 10.5 and 9.2 % of Durham County residents, respectively. Medians and interquartile ranges of blood concentrations (µg/dL) for all participants were Cd 0.02 (0.01-0.04), Hg 0.03 (0.01-0.07), Pb 0.34 (0.16-0.83), and As 0.04 (0.04-0.05). In the Cd cluster, medians and interquartile ranges of blood concentrations (µg/dL) were Cd 0.06 (0.02-0.16), Hg 0.02 (0.00-0.05), Pb 0.54 (0.23-1.23), and As 0.05 (0.04-0.05). In the Pb cluster, medians and interquartile ranges of blood concentrations (µg/dL) were Cd 0.03 (0.02-0.15), Hg 0.01 (0.01-0.05), Pb 0.39 (0.24-0.74), and As 0.04 (0.04-0.05). Co-exposure with Pb and Cd was also clustered, the p-values for the Gi* statistic for Pb and Cd was <0.01. Cluster membership was associated with lower education levels and higher pre-pregnancy BMI. CONCLUSIONS: Our data support that elevated blood concentrations of Cd and Pb are spatially clustered in this urban environment compared to the surrounding areas. Spatial analysis of metals concentrations in peripheral blood or urine obtained routinely during prenatal care can be useful in surveillance of heavy metal exposure.

Feasibility of autologous cord blood cells for infants with hypoxic-ischemic encephalopathy.

OBJECTIVE: To assess feasibility and safety of providing autologous umbilical cord blood (UCB) cells to neonates with hypoxic-ischemic encephalopathy (HIE). STUDY DESIGN: We enrolled infants in the intensive care nursery who were cooled for HIE and had available UCB in an open-label study of non-cyropreserved autologous volume- and red blood cell-reduced UCB cells (up to 4 doses adjusted for volume and red blood cell content, 1-5 × 10(7) cells/dose). We recorded UCB collection and cell infusion characteristics, and pre- and post-infusion vital signs. As exploratory analyses, we compared cell recipients' hospital outcomes (mortality, oral feeds at discharge) and 1-year survival with Bayley Scales of Infant and Toddler Development, 3rd edition scores ≥85 in 3 domains (cognitive, language, and motor development) with cooled infants who did not have available cells. RESULTS: Twenty-three infants were cooled and received cells. Median collection and infusion volumes were 36 and 4.3 mL. Vital signs including oxygen saturation were similar before and after infusions in the first 48 postnatal hours. Cell recipients and concurrent cooled infants had similar hospital outcomes. Thirteen of 18 (74%) cell recipients and 19 of 46 (41%) concurrent cooled infants with known 1-year outcomes survived with scores >85. CONCLUSIONS: Collection, preparation, and infusion of fresh autologous UCB cells for use in infants with HIE is feasible. A randomized double-blind study is needed.

Health care providers' use of a drug information service for pregnancy-related inquiries.

OBJECTIVES: To characterize pregnancy and lactation-related medication inquiries to a drug information center to identify classes of medications of most concern to providers. A secondary objective was to identify any trends in provider inquiries over the study period. DESIGN: A retrospective descriptive study of pregnancy and lactation-related inquiries to the University of North Carolina Health Care System Drug Information Center database between January 2001 and December 2010. SETTING: University of North Carolina Health Care System Drug Information Center. INTERVENTION: Provider inquiries and responses were extracted and characterized by indication for treatment and reason for inquiry. Comparison of the first and second 5-year periods was performed to delineate trends. Descriptive statistics, Fisher's Exact and χ2 tests were used for analysis. MAIN OUTCOME MEASURES: Inquiry origin, time, and subject. RESULTS: 433 inquiries were retrieved over the study period from physicians (50%), pharmacists (21%), and nurses (18%). Inquiries were most often made during the antepartum period (34%), followed by the postpartum (28%) and preconception (22%) periods. The most frequent indications for inquiry were psychiatry (15%) and infectious diseases (14%), which remained constant throughout the study period. Safety was the most common reason for inquiry (52%). The responses provided to callers were limited due to lack of information availability 37% of the time. CONCLUSION: Psychiatry and infectious disease-related indications are the most frequent subjects of provider inquiry regarding medication use in pregnancy. Rates of inquiry remained constant throughout the past decade in most therapeutic areas. These findings are consistent with previous observations in other developed countries and suggest high-yield areas for pharmacist education.

DNA methylation at imprint regulatory regions in preterm birth and infection.

OBJECTIVE: To aid in understanding long-term health consequences of intrauterine infections in preterm birth, we evaluated DNA methylation at 9 differentially methylated regions that regulate imprinted genes by type of preterm birth (spontaneous preterm labor, preterm premature rupture of membranes, or medically indicated [fetal growth restriction and preeclampsia]) and infection status (chorioamnionitis or funisitis). STUDY DESIGN: Data on type of preterm birth and infection status were abstracted from medical records and standardized pathology reports in 73 preterm infants enrolled in the Newborn Epigenetics STudy, a prospective cohort study of mother-infant dyads in Durham, NC. Cord blood was collected at birth, and infant DNA methylation levels at the H19, IGF2, MEG3, MEST, SGCE/PEG10, PEG3, NNAT, and PLAGL1 differentially methylated regions were measured using bisulfite pyrosequencing. One-way analyses of variance and logistic regression models were used to compare DNA methylation levels by type of preterm birth and infection status. RESULTS: DNA methylation levels did not differ at any of the regions (P > .20) between infants born via spontaneous preterm labor (average n = 29), preterm premature rupture of membranes (average n = 17), or medically indicated preterm birth (average n = 40). Levels were significantly increased at PLAGL1 in infants with chorioamnionitis (n = 10, 64.4%) compared with infants without chorioamnionitis (n = 63, 57.9%), P < .01. DNA methylation levels were also increased at PLAGL1 for infants with funisitis (n = 7, 63.3%) compared with infants without funisitis (n = 66, 58.3%), P < .05. CONCLUSION: Dysregulation of PLAGL1 has been associated with abnormal development and cancer. Early-life exposures, including infection/inflammation, may affect epigenetic changes that increase susceptibility to later chronic disease.

Assessment of Adverse Reactions, Antibody Patterns, and 12-month Outcomes in the Mother-Infant Dyad After COVID-19 mRNA Vaccination in Pregnancy.

Importance: Longitudinal data on COVID-19 messenger RNA (mRNA) vaccine reactogenicity and immunogenicity in pregnancy and for the mother-infant dyad are needed. Objective: To examine COVID-19 mRNA vaccine reactogenicity and immunogenicity in pregnancy and observe longitudinal maternal and infant outcomes. Design, Setting, and Participants: This prospective cohort study of pregnant individuals enrolled in the COVID-19 Vaccination in Pregnancy and Lactation study from December 1, 2020, through December 31, 2021, with follow-up through March 31, 2022, was conducted at a large academic medical center in an urban metropolitan area in California. Pregnant individuals receiving COVID-19 mRNA vaccines (mRNA-1273 [Moderna] and BNT162b2 [Pfizer-BioNTech]) were eligible. Of 81 participants enrolled, 5 were excluded after enrollment: 1 terminated pregnancy, 1 received the third vaccine dose prior to delivery, and 3 delivered prior to completing the initial vaccine series. Exposure: COVID-19 mRNA vaccination at any time during pregnancy. Main Outcomes and Measures: The primary outcomes were vaccine response as measured by blood Immunoglobulin G (IgG) titers after each vaccine dose and self-reported postvaccination symptoms. Patients' IgG titers were measured in cord blood and in infant blood at intervals up to 1 year of life; IgG and IgA titers were measured in maternal milk. Clinical outcomes were collected from medical records. Results: Of 76 pregnant individuals included in final analyses (median [IQR] maternal age, 35 [29-41] years; 51 [67.1%] White; 28 [36.8%] primigravid; 37 [48.7%] nulliparous), 42 (55.3%) received BNT162b2 and 34 (44.7%) received mRNA-1237. There were no significant differences in maternal characteristics between the 2 vaccine groups. Systemic symptoms were more common after receipt of the second vaccine dose than after the first dose (42 of 59 [71.2%] vs 26 of 59 [44.1%]; P = .007) and after mRNA-1237 than after BNT162b2 (25 of 27 [92.6%] vs 17 of 32 53.1%; P = .001). Systemic symptoms were associated with 65.6% higher median IgG titers than no symptoms after the second vaccine dose (median [IQR], 2596 [1840-4455] vs 1568 [1114-4518] RFU; P = .007); mean cord titers in individuals with local or systemic symptoms were 6.3-fold higher than in individuals without symptoms. Vaccination in all trimesters elicited a robust maternal IgG response. The IgG transfer ratio was highest among individuals vaccinated in the second trimester. Anti-SARS-CoV-2 IgG was detectable in cord blood regardless of vaccination trimester. In milk, IgG and IgA titers remained above the positive cutoff for at least 5-6 months after birth, and infants of mothers vaccinated in the second and third trimesters had positive IgG titers for at least 5 to 6 months of life. There were no vaccine-attributable adverse perinatal outcomes. Conclusions and Relevance: The findings of this cohort study suggest that mRNA COVID-19 vaccination in pregnancy provokes a robust IgG response for the mother-infant dyad for approximately 6 months after birth. Postvaccination symptoms may indicate a more robust immune response, without adverse maternal, fetal, or neonatal outcomes.

Association of cord blood methylation fractions at imprinted insulin-like growth factor 2 (IGF2), plasma IGF2, and birth weight.

PURPOSE: Altered methylation at Insulin-like Growth Factor 2 (IGF2) regulatory regions has previously been associated with obesity, and several malignancies including colon, esophageal, and prostate adenocarcinomas, presumably via changes in expression and/or loss of imprinting, but the functional significance of these DNA methylation marks have not been demonstrated in humans. We examined associations among DNA methylation at IGF2 differentially methylated regions (DMRs), circulating IGF2 protein concentrations in umbilical cord blood (UCB) and birth weight in newborns. METHODS: Questionnaire data were obtained from 300 pregnant women recruited between 2005 and 2009. UCB DNA methylation was measured by bisulfite pyrosequencing. UCB plasma concentrations of soluble IGF2 were measured by ELISA assays. Generalized linear regression models were used to examine the relationship between DMR methylation and IGF2 levels. RESULTS: Lower IGF2 DMR methylation was associated with elevated plasma IGF2 protein concentrations (ß = -9.87, p < 0.01); an association that was stronger in infants born to obese women (pre-pregnancy BMI > 30 kg/m(2), ß = -20.21, p < 0.0001). Elevated IGF2 concentrations were associated with higher birth weight (p < 0.0001) after adjusting for maternal race/ethnicity, pre-pregnancy BMI, cigarette smoking, gestational diabetes, and infant sex. These patterns of association were not apparent at the H19 DMR. CONCLUSION: Our data suggest that variation in IGF2 DMR methylation is an important mechanism by which circulating IGF2 concentrations, a putative risk factor for obesity and cancers of the colon, esophagus, and prostate, are modulated; associations that may depend on pre-pregnancy obesity.

Insulin-like growth factor 2/H19 methylation at birth and risk of overweight and obesity in children.

OBJECTIVE: To determine whether aberrant DNA methylation at differentially methylated regions (DMRs) regulating insulin-like growth factor 2 (IGF2) expression in umbilical cord blood is associated with overweight or obesity in a multiethnic cohort. STUDY DESIGN: Umbilical cord blood leukocytes of 204 infants born between 2005 and 2009 in Durham, North Carolina, were analyzed for DNA methylation at two IGF2 DMRs by using pyrosequencing. Anthropometric and feeding data were collected at age 1 year. Methylation differences were compared between children >85th percentile of the Centers for Disease Control and Prevention growth charts weight-for-age (WFA) and children ≤ 85th percentile of WFA at 1 year by using generalized linear models, adjusting for post-natal caloric intake, maternal cigarette smoking, and race/ethnicity. RESULTS: The methylation percentages at the H19 imprint center DMR was higher in infants with WFA >85th percentile (62.7%; 95% CI, 59.9%-65.5%) than in infants with WFA ≤ 85th percentile (59.3%; 95% CI, 58.2%-60.3%; P = .02). At the intragenic IGF2 DMR, methylation levels were comparable between infants with WFA ≤ 85th percentile and infants with WFA >85th percentile. CONCLUSIONS: Our findings suggest that IGF2 plasticity may be mechanistically important in early childhood overweight or obese status. If confirmed in larger studies, these findings suggest aberrant DNA methylation at sequences regulating imprinted genes may be useful identifiers of children at risk for the development of early obesity.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and infancy.

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. Here, we evaluate the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during late pregnancy. We find no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we find time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persists during early infancy. Additionally, using phage immunoprecipitation sequencing, we find a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. Timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.

Neutralizing antibody activity against SARS-CoV-2 variants in gestational age-matched mother-infant dyads after infection or vaccination.

Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines (from December 2020 through August 2021) were matched with 30 naturally infected women (from March 2020 through January 2021) by gestational age of exposure. Neutralization activity against the 5 SARS-CoV-2 spike sequences was measured by a SARS-CoV-2-pseudotyped spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared with WT spike protein, these nAbs were less effective against the Delta and Mu spike variants. Vaccination during the third trimester induced higher cord-nAb levels at delivery than did infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared with infection during the first trimester. The transfer ratio (cord nAb level divided by maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicits effective nAbs with differing neutralization kinetics that are influenced by gestational time of exposure.

ß-Arrestin mediates oxytocin receptor signaling, which regulates uterine contractility and cellular migration.

Desensitization of the oxytocin receptor (OXTR) in the setting of prolonged oxytocin exposure may lead to dysfunctional labor, which increases the risk for cesarean delivery, and uterine atony, which may result in postpartum hemorrhage. The molecular mechanism for OXTR desensitization is through the agonist-mediated recruitment of the multifunctional protein ß-arrestin. In addition to its desensitizing function, ß-arrestins have recently been shown to simultaneously activate downstream signaling. We tested whether oxytocin stimulation promotes ß-arrestin-mediated OXTR desensitization in vivo and activates ß-arrestin-mediated mitogen-activated protein kinase (MAPK) growth signaling. Uterine muscle strips isolated from wild-type mice exhibited diminished uterine contractility following repeated exposure to oxytocin, whereas uterine muscle strips from ß-arrestin-1 and ß-arrestin-2 knockout mice showed no desensitization. Utilizing siRNA knockdown of ß-arrestin-1 and ß-arrestin-2 in HEK-293 cells expressing the OXTR, we demonstrated oxytocin-mediated MAPK signaling that was dependent on ß-arrestin-1 and ß-arrestin-2. Wild-type and ß-arrestin-1 and ß-arrestin-2 knockout mice receiving intravenous oxytocin also demonstrated oxytocin-mediated MAPK signaling that was dependent on ß-arrestin-1 and ß-arrestin-2. Finally, to test the significance of ß-arrestin-mediated signaling from the OXTR, HEK-293 cells expressing the OXTR showed ß-arrestin-dependent proliferation in a cell migration assay following oxytocin treatment. In conclusion, ß-arrestin is a multifunctional scaffold protein that mediates both desensitization of the OXTR, leading to decreases in uterine contractility, and MAPK growth signaling following stimulation by oxytocin. The development of unique OXTR ligands that prevent receptor desensitization may be a novel approach in the treatment of adverse clinical events secondary to prolonged oxytocin therapy.

Folic acid supplementation before and during pregnancy in the Newborn Epigenetics STudy (NEST).

BACKGROUND: Folic acid (FA) added to foods during fortification is 70-85% bioavailable compared to 50% of folate occurring naturally in foods. Thus, if FA supplements also are taken during pregnancy, both mother and fetus can be exposed to FA exceeding the Institute of Medicine's recommended tolerable upper limit (TUL) of 1,000 micrograms per day (µg/d) for adult pregnant women. The primary objective is to estimate the proportion of women taking folic acid (FA) doses exceeding the TUL before and during pregnancy, and to identify correlates of high FA use. METHODS: During 2005-2008, pre-pregnancy and pregnancy-related data on dietary supplementation were obtained by interviewing 539 pregnant women enrolled at two obstetrics-care facilities in Durham County, North Carolina. RESULTS: Before pregnancy, 51% of women reported FA supplementation and 66% reported this supplementation during pregnancy. Before pregnancy, 11.9% (95% CI = 9.2%-14.6%) of women reported supplementation with FA doses above the TUL of 1,000 µg/day, and a similar proportion reported this intake prenatally. Before pregnancy, Caucasian women were more likely to take FA doses above the TUL (OR = 2.99; 95% = 1.28-7.00), compared to African American women, while women with chronic conditions were less likely to take FA doses above the TUL (OR = 0.48; 95%CI = 0.21-0.97). Compared to African American women, Caucasian women were also more likely to report FA intake in doses exceeding the TUL during pregnancy (OR = 5.09; 95%CI = 2.07-12.49). CONCLUSIONS: Fifty-one percent of women reported some FA intake before and 66% during pregnancy, respectively, and more than one in ten women took FA supplements in doses that exceeded the TUL. Caucasian women were more likely to report high FA intake. A study is ongoing to identify possible genetic and non-genotoxic effects of these high doses.

Vaginal Mycoplasmataceae colonization and association with immune mediators in pregnancy.

OBJECTIVE: To determine the prevalence of Mycoplasmataceae species in pregnant women and evaluate their association with immune system mediators. METHODS: Women were prospectively enrolled between 16-22 weeks' gestation. Vaginal swabs were self-collected and analyzed with PCR for Mycoplasma hominis (MH) and Mycoplasma genitalium (MG) as well as Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) (collectively, Myc). Immune mediators were measured via Luminex multiplex assay. Women with vaginal Mycoplasmataceae were compared to women without Myc, and women with Mycoplasma species (MH or MG) were compared to women without MH or MG. Linear regression models were used to investigate the relationship of the presence of Mycoplasmataceae on log-transformed immune mediators while controlling for confounders using propensity scores. RESULTS: One-hundred-twenty women were enrolled and had complete lab data available. Colonization was 20.8, 2.5, 10.0, and 48.3% for MH, MG, UU, and UP, respectively. Women with any Mycoplasmataceae were more likely to be younger, of the Black race, and have public insurance. There were no significant differences in immune mediators between women with vaginal Mycoplasmataceae versus those without. After controlling for confounders, women with MH and/or MG had significantly elevated levels of IL-1ß compared to women without MH or MG (estimate = 1.12; 95% CI = 0.33, 1.93). There were no other significant differences in immune mediators in women with MH and/or MG compared to those without. CONCLUSIONS: Colonization rates were highest for UP and lowest for MG. Higher IL-1ß levels were seen in the presence of MH and/or MG, indicating that these less frequently encountered organisms may incite a stronger host response. There were no other significant differences in immune mediator levels.

COVID-19 mRNA Vaccination in Lactation: Assessment of adverse events and vaccine related antibodies in mother-infant dyads.

BACKGROUND: Data regarding adverse events observed in the lactating mother-infant dyad and their immune response to COVID-19 mRNA vaccination during lactation are needed to inform vaccination guidelines. METHODS: From a prospective cohort of 50 lactating individuals who received mRNA-based vaccines for COVID-19 (mRNA-1273 and BNT162b2), blood and milk samples were collected prior to first vaccination dose, immediately prior to 2nd dose, and 4-10 weeks after 2nd dose. Symptoms in mother and infant were assessed by detailed questionnaires. Anti-SARS-CoV-2 antibody levels in blood and milk were measured by Pylon 3D automated immunoassay and ELISA. In addition, vaccine-related PEGylated proteins in milk were measured by ELISA. Blood samples were collected from a subset of infants whose mothers received the vaccine during lactation (4-15 weeks after mothers' 2nd dose). RESULTS: No severe maternal or infant adverse events were reported in this cohort. Two mothers and two infants were diagnosed with COVID-19 during the study period. PEGylated proteins, were not found at significant levels in milk after vaccination. After vaccination, levels of anti-SARS-CoV-2 IgG and IgM significantly increased in maternal plasma and there was significant transfer of anti-SARS-CoV-2-Receptor Binding Domain (anti-RBD) IgA and IgG antibodies to milk. Milk IgA levels after the 2nd dose were negatively associated with infant age. Anti-SARS-CoV-2 IgG antibodies were not detected in the plasma of infants whose mothers were vaccinated during lactation. CONCLUSIONS: COVID-19 mRNA vaccines generate robust immune responses in plasma and milk of lactating individuals without severe adverse events reported.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and early infancy.

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. We evaluated the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during pregnancy. We found no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we found time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persisted during early infancy. Additionally, using phage immunoprecipitation sequencing, we found a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. In conclusion, products of mRNA vaccines are not transferred to the fetus during pregnancy, however timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and early infancy.

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. We evaluated the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during pregnancy. We found no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we found time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persisted during early infancy. Additionally, using phage immunoprecipitation sequencing, we found a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. In conclusion, products of mRNA vaccines are not transferred to the fetus during pregnancy, however timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.