Effects of postpartum hand expression on milk volume and breastfeeding outcomes: a systematic review and meta-analysis protocol
Weina Zhou, Liying ZhangIntroduction
Hand expression is a manual method of milk expression that requires no equipment and is commonly used in the early postpartum period, particularly when direct breastfeeding is not possible or not effective. Randomised trials have reported mixed findings across different maternal–infant contexts. This review aims to synthesise randomised evidence on the effects of postpartum hand expression on expressed milk volume and breastfeeding outcomes.
Methods and analysis
We will include individually randomised parallel-group controlled trials involving human postpartum women expressing breast milk in the early postpartum period. The intervention is postpartum hand expression; comparators will include electric or manual pump expression and usual care without structured hand-expression training. We will search PubMed, Embase, CINAHL, PsycINFO, Web of Science and CENTRAL from inception, without language or date restrictions and also search OpenGrey, ClinicalTrials.gov and WHO ICTRP, plus reference lists. Two reviewers will independently screen studies, extract data and assess risk of bias using the Risk of Bias tool for randomised trials, version 2. Eligible outcomes include expressed milk volume, breastfeeding outcomes, supplementation, time to onset of copious milk secretion and maternal outcomes. Where appropriate, we will conduct pairwise meta-analyses, calculating risk ratios for dichotomous outcomes and mean differences or standardised mean differences for continuous outcomes with 95% CIs. Heterogeneity will be assessed using χ² and I², with prespecified subgroup and sensitivity analyses. Certainty of evidence will be assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).
Ethics and dissemination
This study will be based on previous research findings, so that ethics approval is not required. Data searching commences in June 2026 and expects to complete in January, 2027. The findings will be disseminated through peer-reviewed journals and academic conferences.
PROSPERO registration number
CRD420261327070.