Content Validation of the Prenatal Evaluation and Referral for Lactation (PEARL) Tool Using a Delphi Method

Delayed onset of lactogenesis II or delayed secretory activation, defined as milk onset > 72 h postpartum, is a recognized barrier to successful breastfeeding initiation and duration. Prenatal identification and screening for risk factors associated with delayed secretory activation remains underutilized in maternal-child health services. This project aimed to develop and validate content for the Prenatal Evaluation and Referral for Lactation (PEARL) tool, a prenatal screening and referral instrument designed to identify lactation risk factors and guide anticipatory counseling and early referral to an International Board Certified Lactation Consultant (IBCLC) or breastfeeding medicine physician.

Tool development was informed by a structured literature review conducted on 2 October 2024, across four databases (CINAHL, PubMed, Scopus, and Embase), identifying clinical and other health factors associated with delayed lactogenesis II. A three-round Delphi process was used to establish content validity through multidisciplinary expert consensus. Item-level content validity (ICV) was evaluated using a predefined consensus threshold (≥0.80), while average-measures Intraclass Correlation Coefficients (ICC) were calculated as a complementary assessment of interrater consistency. Following tool refinement, a pilot implementation training was conducted to obtain preliminary feedback regarding clarity, usability, and implementation.

Twelve lactation experts were selected from 59 eligible respondents to participate in the Delphi process. Most of the proposed items achieved the predefined content validity threshold (ICV ≥ 0.80) across the first two Delphi rounds, resulting in refinement and consensus on the final PEARL instrument. Interrater reliability improved from moderate agreement in Round 1 (ICC = 0.769; 95% CI 0.425-0.953) to excellent agreement following refinement in Round 2 (ICC = 0.911; 95% CI 0.787-0.979). Qualitative feedback informed revisions to item wording, organization, and content. A pilot implementation training indicated that the tool was perceived as understandable, usable, and appropriate for prenatal practice.

The PEARL demonstrated strong evidence of content validity and preliminary implementation feasibility as a standardized prenatal lactation screening tool. Future research should evaluate additional psychometric properties, implementation outcomes, and prospective clinical performance to determine its effectiveness in improving referral practices and breastfeeding outcomes.