Recurrent Profound Hypothermia as a Presentation of Neonatal Adaptation Syndrome Following <i>In Utero</i> Fluvoxamine Exposure: A Case Report

Neonatal adaptation syndrome (NAS) due to in utero exposure to selective serotonin reuptake inhibitors (SSRIs) is well documented in literature but reports involving atypical agents such as fluvoxamine are scarce. Additionally, NAS usually presents within the first 48 h of life and commonly includes respiratory distress, feeding difficulty, irritability, and temperature instability. We describe what appears to be the first reported case of delayed onset, isolated, recurrent, and severe hypothermia beginning on day 3 of life in a term infant exposed to maternal fluvoxamine, an atypical SSRI. A male neonate born at 37 4/7 weeks to a mother treated with fluvoxamine throughout pregnancy developed profound hypothermia on day three of life, initially attributed to weight loss and environmental factors. After rewarming and an unremarkable sepsis workup, the infant was discharged. He represented 2 days later with recurrent severe hypothermia despite appropriate bundling, adequate feeding, and weight gain. A comprehensive and extensive evaluation—including infectious, endocrine, metabolic, neurologic, cardiac, and genetic testing—was normal; however, the infant continued to demonstrate recurrent hypothermia requiring intensive rewarming measures even while hospitalized. After exclusion of infectious, metabolic, endocrine, neurologic, and cardiac etiologies, NAS associated with in utero fluvoxamine exposure was considered the most likely diagnosis and a diagnosis of exclusion. Symptom resolution was temporally associated with a shift in intake from predominantly formula to primarily breast milk. This case expands the clinical spectrum of NAS associated with atypical SSRIs and highlights delayed, recurrent hypothermia as a potential presentation.