When an entrenched piece of evidence-based practice is challenged,1 there is a responsibility to mount a serious research protocol to scrutinise accepted practice. This study is weaker than that on which the previous evidence was based, and is very weak by most methodological standards. The study design is inadequate to provide an effective evaluation of the experimental hypothesis, which causes us ethical concerns.

The study comprised a “before–after” study design, conducted over 4¼ years. During the before period, lasting just over 2 years, women were encouraged to practice “baby-led” feeding, and records of 32 “exclusively breastfeeding” women were analysed retrospectively. In the subsequent 2-year period, 31 women studied prospectively were instructed to offer both breasts for 10 …