Transient neonatal myasthenia gravis mediated by antibodies from a gestational surrogate: a case report

Transient neonatal myasthenia gravis (TNMG) is an autoimmune disorder caused by the transplacental transfer of maternal anti-acetylcholine receptor antibodies to the fetus, leading to temporary muscle weakness in the newborn. TNMG occurs in approximately 10%–20% of infants born to mothers with myasthenia gravis (MG). A male neonate was admitted to a local hospital at 13 h of age with feeding difficulties, a weak cry, hypotonia, and respiratory distress. After one month of therapy at a local hospital, the infant showed no clinical improvement and was transferred to our institution. Laboratory testing showed an elevated acetylcholine receptor (AChR) antibody level. A review of the medical history revealed that the infant had been born via gestational surrogacy, and the gestational surrogate had no known history of MG. Subsequent testing demonstrated that the gestational surrogate had a markedly elevated AChR antibody level. The infant was diagnosed with TNMG. Following treatment, the infant’s clinical condition improved, and he was discharged from our institution at 77 days of age. At the one-month follow-up after discharge, the infant remained clinically well. After four months of oral pyridostigmine therapy, the infant’s clinical symptoms resolved. This case describes a rare presentation of TNMG mediated by AChR antibodies transferred from a gestational surrogate with no prior diagnosis of MG. It underscores the importance of considering TNMG in neonates with unexplained hypotonia, feeding difficulties, and respiratory distress, particularly in the setting of gestational surrogacy.