Study Protocol for a Stepped-Wedge Cluster (Nested) Randomized Controlled Trial of Antenatal Colostrum Expression (ACE) Instruction in First-Time Mothers: The ACE Study

Background: Although many mothers initiate breastfeeding, supplementation with human-milk substitutes (formula) during the birth hospitalization is common and has been associated with early breastfeeding cessation. Colostrum hand expressed in the last few weeks before birth, known as antenatal colostrum expression (ACE), can be used instead of human-milk substitutes. However, evidence is lacking on the efficacy of ACE on breastfeeding outcomes and in non-diabetic mothers. Methods and Planned Analysis: This multicenter stepped-wedge cluster (nested) randomized controlled trial aims to recruit 945 nulliparous pregnant individuals. The trial is conducted in two phases. During Phase 1, control group participants are under standard care. During Phase 2, participants are randomized to ACE instruction via a pre-recorded online video or a one-on-one session with a midwife. Adjusted logistic regression analysis will be used to examine the relationship between ACE instruction and breastfeeding outcomes. Research Aims and Questions: Primary aim: (1) Does advising pregnant individuals to practice ACE and providing instruction improve exclusive breastfeeding rates at 4 months postpartum? Secondary research questions: (2) Do individuals who practice ACE have higher rates of exclusive breastfeeding during the initial hospital stay after birth? (3) Is teaching ACE via an online video non-inferior to one-on-one instruction from a midwife? (4) Does expressing colostrum in pregnancy influence time to secretory activation, or (5) result in any differences in the composition of postnatal colostrum? Discussion: Trial findings have important implications for maternity practice, with the online video providing an easily accessible opportunity for ACE education as part of standard antenatal care.