Background Although several clinical studies have analysed the relationship between the levels of vascular endothelial growth factor (VEGF) and apelin-13 in venous blood and retinopathy of prematurity (ROP), no definitive conclusions have been reached. This study aimed to investigate the relationship between apelin-13 levels and VEGF levels and ROP. Methods Differences in plasma apelin-13 and VEGF levels were analysed in two groups of infants born with birth weight < 1500 g and gestational age < 32 weeks at Peking University People’ s Hospital. One group comprised infants diagnosed with ROP and the other group was a control group comprising infants without ROP. Results Apelin-13 levels were significantly lower in the ROP group than in the control group, while VEGF levels showed the opposite result (both P < 0.001). Infants with severe ROP had lower apelin-13 levels and higher VEGF levels than with mild ROP (both P < 0.05).The receiver operating characteristic curve for apelin-13 level as the indicator of ROP showed that a cut-off value of 119.6 pg/mL yielded a sensitivity of 84.8% and a specificity of 63.6%, while for VEGF level, the cut-off value of 84.3 pg/mL exhibited a sensitivity of 84.8% and a specificity of 66.7%. Conclusions Plasma apelin-13 and VEGF levels at 4–6 weeks of age may play a role in assisting the diagnosis of ROP.

Rationale: The etiology of non-immune hydrops fetalis is complex, and its prognosis is poor. One of its main causes is anemia. There are few reports on hydrops fetalis due to anemia caused by hereditary spherocytosis (HS), especially regarding its occurrence in the neonatal period. Thus, we report on a case of neonatal HS caused by a new SPTB gene mutation that was characterized by hydrops fetalis. Patient concerns: A neonate with intrauterine hydrops fetalis showed severe hyperbilirubinemia and anemia, reticulocytosis, and hepatosplenomegaly. Laboratory examination findings were normal. Diagnoses: Gene sequencing of the patient and his parents showed a de novo frameshift mutation in the patient's SPTB gene. Ultimately, the patient was diagnosed with HS. Interventions: Exchange and red blood cell transfusions were performed in the neonatal period. Outcomes: The child was discharged from the hospital 14 days postnatal because his hemoglobin and bilirubin levels were stable. Red blood cell transfusion was performed once in infancy; however, no further red blood cell transfusions were required within 2 years of age. Lessons: Hydrops fetalis can be a manifestation of HS. Genetic detection can help confirm the diagnosis of suspected neonatal HS undocumented by other laboratory examinations.