Patient 1 was a male neonate who, at 3 hours of life, presented with respiratory distress, hypotonia, and ventilator dependence. Genetic testing revealed a DMPK gene CTG repeat expansion (13/>83). Patient 2 was a male neonate who presented at 2 days of life after resuscitation for perinatal asphyxia, with hypotonia and ventilator dependence, complicated by hypoxic-ischemic encephalopathy and diaphragmatic eventration, which appears to represent the first such combination reported in China. Genetic testing showed a DMPK gene CTG repeat expansion (12/>83). Both cases were diagnosed with congenital myotonic dystrophy type 1. Congenital myotonic dystrophy type 1 is a rare and severe genetic disorder with low survival. When characteristic clinical manifestations appear, genetic testing and family counseling should be performed as early as possible to guide future pregnancies and reduce birth defects.