Maternal and Neonatal Polyunsaturated Fatty Acid Intake and Risk of Neurodevelopmental Impairment in Premature Infants

The N3 and N6 long chain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are essential for proper neurodevelopment in early life. These fatty acids are passed from mother to infant via the placenta, accreting into fetal tissues such as brain and adipose tissue. Placental transfer of LCPUFA is highest in the final trimester, but this transfer is abruptly severed with premature birth. As such, efforts have been made to supplement the post-natal feed of premature infants with LCPUFA to improve neurodevelopmental outcomes. This narrative review analyzes the current body of evidence pertinent to neurodevelopmental outcomes after LCPUFA supplementation in prematurely born infants, which was identified via the reference lists of systematic and narrative reviews and PubMed search engine results. This review finds that, while the evidence is weakened by heterogeneity, it may be seen that feed comprising 0.3% DHA and 0.6% AA is associated with more positive neurodevelopmental outcomes than LCPUFA-deplete feed. While no new RCTs have been performed since the most recent Cochrane meta-analysis in 2016, this narrative review provides a wider commentary; the wider effects of LCPUFA supplementation in prematurely born infants, the physiology of LCPUFA accretion into preterm tissues, and the physiological effects of LCPUFA that affect neurodevelopment. We also discuss the roles of maternal LCPUFA status as a modifiable factor affecting the risk of preterm birth and infant neurodevelopmental outcomes. To better understand the role of LCPUFAs in infant neurodevelopment, future study designs must consider absolute and relative availabilities of all LCPUFA species and incorporate the LCPUFA status of both mother and infant in pre- and postnatal periods.

Human IgE does not bind to human FcRn

The neonatal Fc receptor (FcRn) is known to mediate placental transfer of IgG from mother to unborn. IgE is widely known for triggering immune responses to environmental antigens. Recent evidence suggests FcRn-mediated transplacental passage of IgE during pregnancy. However, direct interaction of FcRn and IgE was not investigated. Here, we compared binding of human IgE and IgG variants to recombinant soluble human FcRn with β2-microglobulin (sFcRn) in surface plasmon resonance (SPR) at pH 7.4 and pH 6.0. No interaction was found between human IgE and human sFcRn. These results imply that FcRn can only transport IgE indirectly, and thereby possibly transfer allergenic sensitivity from mother to fetus.

Clinical Pharmacology of Fentanyl in Infants and Children

Fentanyl is a systemic opioid related to the phenylpiperidines, it is used in anaesthetic practice and in analgesia and the analgesic effect is about 100 times higher than that of morphine. Fentanyl is highly lipid soluble, rapidly crosses the blood-brain-barrier, and fentanyl concentrations rapidly decline in plasma and cerebrospinal fluid. Fentanyl causes respiratory depression and decreases the heart rate through vagal activation. Fentanyl may be administered intravenously, orally, by transdermal, intranasal or by buccal application and the oral bioavailability is poor. In infants, fentanyl is given for short term use, sustained use, and during therapeutic hypothermia. In children, fentanyl is given intravenously, by transdermal application, or by buccal administration and the fentanyl dose varies with the child age and body-weight. Fentanyl has been found efficacy and safe in infants and children but it may induce adverse-effects and fentanyl causes different effects in infants and children. Following intravenous administration of fentanyl to infants and children, the fentanyl elimination half-life ranges from 208 to 1,266 min and the distribution volume ranges from 1.92 to 15.2 L/kg. Such variability is due to the wide variation of subject’s demographic characteristics. Fentanyl interacts with drugs, the treatment and trials with fentanyl have been studied in infants and children. Fentanyl freely crosses the human placenta and poorly migrates into the breast-milk. The aim of this study is to review fentanyl dosing, efficacy, safety, effects, adverse-effects, metabolism, pharmacokinetics, drug interaction, treatment, and trials in infants and children, and fentanyl placental transfer and migration into the breast-milk.

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.

Comprehensive Serological Profile and Specificity of Maternal and Neonatal Cord Blood SARS CoV-2 Antibodies

ObjectiveTo describe the profile and specificity of maternal and neonatal cord-blood antibody profile in response SARS-CoV-2 virus exposureMethodsThis is a Prospective cohort study of delivering patients at Thomas Jefferson University Hospital from April 2020-February 2021. Primary objective was to describe unique maternal and fetal antibody epitope titers and specificity in those patients with COVID-19 history. Serologic profile assessed with a multiplex platform. Antigens used were: HA-trimer Influenza A (Hong Kong H3), spike trimers for SARS-CoV-2, SARS-CoV-1, MERS-CoV, and betacoronaviruses HKU-1 and OC43, as well as the spike N-terminal domain (NTD), spike receptor binding domain (RBD), and nucleocapsid protein (N; full length) for SARS-CoV-2.Results112 maternal samples and 101 maternal and cord blood pairs were analyzed. Thirty-seven had a known history of COVID-19 (positive PCR test) in the pregnancy and of those, 17 (47%) were diagnosed with COVID-19 within 30 days of delivery. Fifteen of remaining seventy-six (20%) without a known diagnosis had positive maternal serology. For those with history of COVID-19 we identified robust IgG response in maternal blood to CoV2 nucleocapsid (N), spike (S) full-length and S (RBD) antigens with more modest responses to the S (NTD) antigen. By contrast, the maternal blood IgM response appeared more specific to S (full-length), than N, S (RBD) or S (NTD) epitopes. There were significantly higher maternal and cord blood IgG response not just to CoV2 spike (p < 10−18), but also CoV1 spike (p < 10−9) and MERS spike (p < 10−8). By contrast, maternal IgM responses were more specific to CoV2 (p < 10−19), but to a lesser degree for CoV1 (p < 10−5), and no significant differences for MERS. Maternal and cord-blood IgG were highly correlated for both S and N (R2 = 0.96 and 0.94).ConclusionsPlacental transfer is efficient, with robust N and S responses. Both nucleocapsid and spike antibody responses should be studied for a better understanding of COVID-19 immunity. IgG antibodies are cross reactive with related CoV-1 and MERS spike epitopes while IgM, which cannot cross placenta to provide neonatal passive immunity, is more SARS CoV-2 specific. Neonatal cord blood may have significantly different fine-specificity than maternal blood, despite the high efficiency of IgG transfer.

Clinical Pharmacology of Sildenafil in Infants and Children

Sildenafil is a competitive and selective inhibitor of phosphodiesterase 5. Sildenafil is cleared by hepatic CYP3A (major route) and CYP2C9 (minor route) and concomitant administration of potent CYP3A inducers (e.g., bosentan) causes decreases in plasma levels of sildenafil. CYP3A4 inhibitors (erythromycin and cimetidine) inhibit sildenafil metabolism prolonging the half-life and elevating blood levels of sildenafil. Sildenafil is a pulmonary arterial vasodilator and it has been used in the treatment of persistent pulmonary hypertension. The initial oral dose is 250 to 500 µg/kg 4 times-daily in infants and the oral dose is 10 to 20 mg thrice-daily in children with a body-weight up to 20 kg or > 20 kg, respectively. Sildenafil has been found efficacy and safe in infants and children but it may induce adverse-effects. Following an oral dosing, the absorption rate constant is 0.343 h-1, and the elimination half-life is 2.41 hours in children suggesting that sildenafil is rapidly absorbed and eliminated. The interaction of sildenafil with drugs and the metabolism of sildenafil have been extensively studied. The principal routes of sildenafil metabolism are: N-demethylation, oxidation, and aliphatic dihydroxylation, and the major metabolite is N-desmethyl sildenafil. The treatment of infants and children with sildenafil has been extensively studied. Sildenafil citrate and sildenafil cross the human placenta and sildenafil migrates into the breast-milk in significant amounts. The aim of this study is to review the sildenafil dosing, efficacy and safety, effects, adverse-effects, pharmacokinetics, interaction with drugs, metabolism, treatments, and sildenafil placental transfer and migration into the breast-milk.

Selective Transfer of Maternal Antibodies in Preterm and Term Children

Preterm newborns are more likely to suffer from infectious diseases at birth compared to children delivered at term. Whether this is due to compromised cellular, humoral, or organ-specific development remains unclear. Recent studies have shown that while preterm children have an aberrant cellular immune response, these infants receive similar maternal anti-viral IgG repertoires compared to term children, albeit at lower concentrations. These data point to selectivity in placental transfer at distinct gestational ages, to ensure that children are endowed with the most robust humoral immunity even if born preterm. To begin to define the mechanism by which preterm selective transfer may occur, the overall quantity and functional quality of an array of vaccine-, endemic pathogen-, and common antigen-specific antibodies were assessed across a cohort of 11 preterm and 12 term-delivered mother:infant pairs from birth through week 12. Although higher antibody levels were present in term infants, the overall functional profiles of antigen-specific antibodies were very similar. Temporal transfer differences were ascertained across distinct antibody subpopulations, with early transfer of functional antibodies capable of binding to FcRn and FcγR2-3 receptors followed by the transfer of distinct IgG subclasses. These results provide new insights on maternal:fetal immunity, highlighting novel immune axes that may be manipulated to enhance neonatal immune transfer of antibodies through gestation.