It has been brought to the editor’s attention that this article¹ describes a study which appears to be similar to three other publications.^2,3,4 The authors have confirmed to the editor that the four studies are related but separate studies that were part of a series of studies on different groups of participants. A contact from the Ethics Committee of Fujian Maternal and Child Health Hospital has confirmed to us that the Ethics Committee approved a series of four separate studies, and that the ethical approval number is 2020YJ181. The ethics committee contact was provided by the corresponding author.

The journal has not been able to obtain any verification of this explanation that is independent of the authors. This expression of concern alerts readers to the apparent similarities in patient groups, interventions, and outcome measures between the four studies. Appropriate editorial action will be taken if further information becomes available.

[1] Yu X-R, Lei Y-Q, Liu J-F, Wang Z-C, Cao H, Chen Q. Effect of breast milk oral care in infants who underwent surgical correction of ventricular septal defect. Cardiol Young 2021; 31: 2015–2018. DOI 10.1017/S1047951121001438.

[2] The effect of early oral stimulation with breast milk on the feeding behavior of infants after congenital cardiac surgery. J Cardiothorac Surg 2020; 15: 309. DOI 10.21037/tp-20-295.

[3] Effects of different oral care strategies on postoperative pneumonia in infants with mechanical ventilation after cardiac surgery: a prospective randomized controlled study. Transl Pediatr 2021; 10: 359–365.

[4] Comparison of the effect of breast milk and sodium bicarbonate solution for oral care in infants with tracheal intubation after cardiothoracic surgery. Breastfeed Med 2020; 16: 568–572. DOI 10.1089/bfm.2020.0239.