乳頭変形を有する産褥期母親の母乳育児支援におけるホフマン運動：スコーピングレビューおよび探索的メタアナリシス

Hoffman's exercise is a widely promoted nonsurgical technique to assist breastfeeding among postpartum mothers with inverted or flat nipples. Prior reviews have suggested benefit but did not account for differences in effect by comparator, nor did they distinguish between-group from within-group change. This limits clinical guidance and planning for rigorous trials.

To present an analytic discussion that is comparator-aware, separates effect types, and foregrounds uncertainty; clarifying what the literature can credibly support and highlighting gaps in study design and reporting standards.

Across a small and heterogeneous evidence base (n = 10 studies), the quality of primary studies was critically low. This limited the appropriateness of definitive synthesis using meta-analytic methods. Nonetheless, acknowledging the risk of estimate inflation, we still conducted an exploratory, hypothesis-generating analysis. Stratification by comparator suggested a possible benefit versus routine care, but no clear advantage against the inverted syringe technique. Within-group pre-post improvements were common yet remained noncausal and vulnerable to confounding. Coupled with our wide prediction intervals and high risk of bias, these findings suggest that confident claims of effectiveness maybe premature in this population.

Current evidence neither supports strong effectiveness claims for Hoffman's exercise nor warrants abandoning the technique outright. Clinically, we suggest offering the exercise as part of a broader lactation-support bundle rather than presenting it as a stand-alone, proven or validated intervention. More robust data are needed to determine the clinical effectiveness of the technique.