The significant risks posed to mothers and fetuses by COVID-19 in pregnancy have sparked a worldwide debate surrounding the pros and cons of antenatal SARS-CoV-2 inoculation, as we lack sufficient evidence regarding vaccine effectiveness in pregnant women and their offspring. We aimed to provide substantial evidence for the effect of the BNT162b2 mRNA vaccine versus native infection on maternal humoral, as well as transplacentally acquired fetal immune response, potentially providing newborn protection. A multicenter study where parturients presenting for delivery were recruited at 8 medical centers across Israel and assigned to 3 study groups: vaccinated (n = 86); PCR-confirmed SARS-CoV-2 infected during pregnancy (n = 65), and unvaccinated noninfected controls (n = 62). Maternal and fetal blood samples were collected from parturients prior to delivery and from the umbilical cord following delivery, respectively. Sera IgG and IgM titers were measured using the Milliplex MAP SARS-CoV-2 Antigen Panel (for S1, S2, RBD, and N). The BNT162b2 mRNA vaccine elicits strong maternal humoral IgG response (anti-S and RBD) that crosses the placenta barrier and approaches maternal titers in the fetus within 15 days following the first dose. Maternal to neonatal anti-COVID-19 antibodies ratio did not differ when comparing sensitization (vaccine vs. infection). IgG transfer ratio at birth was significantly lower for third-trimester as compared with second trimester infection. Lastly, fetal IgM response was detected in 5 neonates, all in the infected group. Antenatal BNT162b2 mRNA vaccination induces a robust maternal humoral response that effectively transfers to the fetus, supporting the role of vaccination during pregnancy. Israel Science Foundation and the Weizmann Institute Fondazione Henry Krenter.

Objective Gestational diabetes mellitus (GDM) is a condition in which women without diabetes are diagnosed with glucose intolerance during pregnancy, typically in the second or third trimester. Early diagnosis, along with a better understanding of its pathophysiology during the first trimester of pregnancy, may be effective in reducing incidence and associated short-term and long-term morbidities. Design We comprehensively profiled the gut microbiome, metabolome, inflammatory cytokines, nutrition and clinical records of 394 women during the first trimester of pregnancy, before GDM diagnosis. We then built a model that can predict GDM onset weeks before it is typically diagnosed. Further, we demonstrated the role of the microbiome in disease using faecal microbiota transplant (FMT) of first trimester samples from pregnant women across three unique cohorts. Results We found elevated levels of proinflammatory cytokines in women who later developed GDM, decreased faecal short-chain fatty acids and altered microbiome. We next confirmed that differences in GDM-associated microbial composition during the first trimester drove inflammation and insulin resistance more than 10 weeks prior to GDM diagnosis using FMT experiments. Following these observations, we used a machine learning approach to predict GDM based on first trimester clinical, microbial and inflammatory markers with high accuracy. Conclusion GDM onset can be identified in the first trimester of pregnancy, earlier than currently accepted. Furthermore, the gut microbiome appears to play a role in inflammation-induced GDM pathogenesis, with interleukin-6 as a potential contributor to pathogenesis. Potential GDM markers, including microbiota, can serve as targets for early diagnostics and therapeutic intervention leading to prevention.

Purpose: Maternal thyroid gland dysfunction may adversely affect pregnancy outcome. We aimed to examine the association between subclinical thyroid dysfunction, both hypothyroidism and hyperthyroidism, to adverse pregnancy outcome. Materials and methods: Retrospective cohort study of all women with an available first trimester thyroid function testing and known pregnancy outcome, categorized to subclinical hypothyroidism, or hyperthyroidism and evaluated for complication during gestation and delivery. Results: Four thousand five hundred and four women were included in the final analysis – 3231 were euthyroid, 73 (1.6%) were categorized as subclinical hyperthyroidism and 1200 (26.6%) had subclinical hypothyroidism. Low thyroid-stimulating hormone (TSH) levels, i.e. subclinical hyperthyroidism, correlates with higher rates of placental abruption and extremely low birth weight, below 1500 g. Also, the risk for preterm delivery prior to 34 gestational weeks is higher among women with subclinical hypothyroidism, with greater risk among those with a higher TSH level. (OR 1.81, 95% CI 1.0–3.28 for TSH 2.5–4.0 mIU/L and OR 2.33, 95% CI 1.11–4.42 for those with TSH > 4 4.0 mIU/L). Conclusions: Subclinical hypothyroidism is associated with an increased risk for preterm delivery prior to 34 gestational weeks. Additionally, subclinical hyperthyroidism may also have a role in adverse pregnancy outcome – low birth weight and placental abruption – although this needs to be further explored.