The Relationship Between Kangaroo Mother Care Duration and Clinical Outcomes in Preterm and Low Birth-Weight Infants: A Dose–Response Meta-Analysis

BACKGROUND: Determining the optimal daily Kangaroo Mother Care (KMC) duration is important for improving outcomes in preterm and low birth-weight (LBW) infants, but existing evidence is mostly as broad categories rather than a continuous dose-response relationship. PURPOSE: To examine the dose-response association between daily KMC duration and 4 outcomes in preterm/LBW infants: weight gain and hospital stay (primary), breastfeeding (including direct feeding and receipt of expressed human milk) and hypothermia (secondary). DATA SOURCES: PubMed, Web of Science, Cochrane Library, China Biology Medicine, Wanfang, China National Knowledge Infrastructure, and CQVIP Chinese Journals Platform were searched from inception to May 31, 2025. STUDY SELECTION: Randomized controlled trials comparing Kangaroo Mother Care to conventional care in preterm or low birth-weight infants were eligible. Thirty-six trials meeting PICOS criteria with extractable daily KMC duration and at least 1 outcome were included. DATA EXTRACTION: Two reviewers independently screened records, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2 tool. Disagreements were resolved by discussion or consultation with a third reviewer. RESULTS: Across 36 RCTs (N = 4210), daily KMC duration had a nonlinear association with weight gain, with benefits increasing beyond approximately 11.8 hours per day. Hospital stay also showed a nonlinear association, with the greatest reduction at approximately 6 hours per day. Breastfeeding rates increased linearly with longer KMC duration, and each additional KMC hour lowered hypothermia odds. Because outcome trajectories differed, 6 hours per day best reduced hospital stay, while longer exposure may add growth benefit when feasible. IMPLICATIONS FOR PRACTICE AND RESEARCH: For preterm and LBW infants, use KMC when feasible. Approximately 6 hours per day reduces hospital stay; longer exposure may further benefit growth. Future trials should report daily and cumulative KMC exposure, initiation timing, daily continuation, and long-term outcomes.