Obstetric outcomes in pregnant COVID-19 women: the imbalance of von Willebrand factor and ADAMTS13 axis

Background: Thrombotic microangiopathy has been invoked as one of the most important mechanisms of damage in COVID-19 patients. Protease ADAMTS13 is a marker of microangiopathy responsible for controlling von Willebrand multimers size. Von Willebrand factor/ADAMTS13 ratio has been found impaired in COVID-19 patients outside pregnancy. Methods: We prospectively investigated 90 pregnant women admitted to two tertiary academic hospitals in Italy with a laboratory-confirmed diagnosis of SARS-CoV-2 infection. Demographic, clinical information and routine laboratory data were collected at the hospital admission and until discharge. We investigated whether vonWillebrand /ADAMTS13 axis imbalance is a predictor of adverse outcomes. Logistic regression analysis, which controlled for potential confounders, was performed to evaluate the association between laboratory parameters and clinical outcomes. Results: Most women (55.6%) were parae, with median gestational age at admission of 39 weeks. At hospital admission, 63.3% were asymptomatic for COVID-19 and 24.4% showed more than one sign or symptom of infection. Nulliparae with group O showed Willebrand / ADA MTS-13 ratios significantly lower than non-O, whereas in multiparae this difference was not observed. Logistic regression showed that ratio von Willebrand to ADAMTS13 was significantly and independently associated with preterm delivery (OR 1.9, 95%CI 1.1–3.5). Conclusion: This study shows an imbalance of vonWillebrand /ADAMTS13 axis in pregnant women with COVID-19, leading to a significantly higher and independent risk of preterm delivery. Monitoring these biomarkers might support decision making process to manage and follow-up pregnancies in this setting

The M2 haplotype in the ANXA5 gene is an independent risk factor for idiopathic small-for-gestational age newborns.

Hereditary thrombophilias can impair vascular placental functions and predispose to the birth of small-for-gestational age (SGA) babies. The placental anticoagulant protein annexin A5 (ANXA5) may contribute to this process. A functional haplotype (M2) within the ANXA5 gene is associated with fetal loss and venous thrombosis. This study investigated the prevalence of the M2 haplotype in a group of women with idiopathic SGA newborn babies. Seventy-eight women with at least one previous unexplained SGA birth and 195 controls all from Southern Italy were investigated. Hereditary thrombophilia was found in 13 (16.5%) cases and 21 (11%) controls (P < 0.05.). The M2 haplotype was found in 29% of cases (n = 23) and 15% of controls [n = 30; P = 0.001; OR = 2.3, 95% CI (1.17-4.48)]. Within the case group, 82.5% of the M2 haplotype carriers gave birth to babies with a birthweight below the 3rd percentile [P = 0.01; OR = 2.4, 95% CI (1.26-4.73)]. A logistic regression, corrected for age, parity and gravity showed that the M2 haplotype was independently associated with the delivery of an SGA new born [P = 0.029; OR = 2.6, 95% CI (1.1-6.0)]. In conclusion, the M2 haplotype of the ANXA5 gene confers a risk of delivering SGA babies