Baby’s muscle weakness traced to antibodies from a gestational surrogate

A male newborn who spent a month in hospital without improvement has been diagnosed with transient neonatal myasthenia gravis, a rare condition in which antibodies cross the placenta and cause temporary muscle weakness in the baby. The unusual feature of the case, reported in BMC Pediatrics, is that the antibodies came from a gestational surrogate who had never been diagnosed with myasthenia gravis.

The infant was admitted to a local hospital at 13 hours of age with feeding difficulties, a weak cry, hypotonia and respiratory distress. After one month of therapy there, he showed no clinical improvement and was transferred to the authors’ institution. Laboratory testing there revealed an elevated acetylcholine receptor (AChR) antibody level. A review of the medical history then showed that the infant had been born via gestational surrogacy, and that the surrogate had no known history of myasthenia gravis. Subsequent testing demonstrated that the surrogate herself had a markedly elevated AChR antibody level, and the infant was diagnosed with transient neonatal myasthenia gravis.

Transient neonatal myasthenia gravis 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. According to the report, it occurs in approximately 10% to 20% of infants born to mothers with myasthenia gravis. In this case, the antibody source was a surrogate with no prior diagnosis, which the authors describe as a rare presentation of the condition.

Following treatment, the infant’s clinical condition improved and he was discharged from the authors’ institution at 77 days of age. At the one-month follow-up after discharge, he remained clinically well. After four months of oral pyridostigmine therapy, his clinical symptoms resolved. The authors conclude that the case underscores the importance of considering transient neonatal myasthenia gravis in neonates with unexplained hypotonia, feeding difficulties and respiratory distress, particularly in the setting of gestational surrogacy. As a single case report, the findings describe one infant’s course and do not establish treatment efficacy more broadly.

Subject of Research: Transient neonatal myasthenia gravis caused by antibodies from a gestational surrogate

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

Article References: Gao, X., Feng, X., Liu, N., Zhao, W., Meng, C., & Wang, C. (2026). Transient neonatal myasthenia gravis mediated by antibodies from a gestational surrogate: a case report. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07903-2

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07903-2

Keywords: transient neonatal myasthenia gravis, myasthenia gravis, acetylcholine receptor antibodies, gestational surrogacy, neonatal hypotonia, case report, pyridostigmine, BMC Pediatrics, Transient, neonatal, myasthenia, gravis