Management and outcomes of newborns at risk for inherited antithrombin deficiency

Background As levels of antithrombin (AT) are low at birth, diagnosing inherited AT deficiency in newborns is challenging. In Stockholm, Sweden, pregnant women with known AT deficiency are referred to the Karolinska University Hospital, where local guidelines for management of newborns at risk of inherited AT deficiency have been established. Data on pregnancy, obstetric, and neonatal outcomes are recorded in a registry. Objectives We aimed to evaluate the current practice at the Karolinska University Hospital for managing delivery of newborns at risk for AT deficiency, the predictive value of AT levels at birth, and the neonatal outcomes of newborns with AT deficiency. Patients/Methods This was an observational, retrospective study. All children born to mothers with AT deficiency at the Karolinska University Hospital 2003-2018 were identified from the registry and included in the study. Data were collected from the medical records and the registry. AT activity was measured postnatally and after 6 months of age. Results The total study cohort included 41 newborns. There was a significant association between low AT values postnatally and after 6 months of age (P = .001). Half (21/41) of the children were diagnosed with AT deficiency; two suffered from sinus thrombosis, which presented at 10 days of age. Both children with sinus thrombosis were delivered using vacuum extraction. Conclusions The current practice of testing newborns can in most cases predict inherited AT deficiency. The risk for thrombosis during the neonatal period is enhanced by the use of instrumental delivery.