Importance: Parent-infant bonding contributes to long-term infant health but may be disrupted by preterm birth.
Objective: To determine if parent-led, infant-directed singing, supported by a music therapist and initiated in the neonatal intensive care unit (NICU), improves parent-infant bonding at 6 and 12 months.
Design, setting, and participants: This randomized clinical trial was conducted in level III and IV NICUs in 5 countries between 2018 and 2022. Eligible participants were preterm infants (under 35 weeks' gestation) and their parents. Follow-up was conducted across 12 months (as part of the LongSTEP study) at home or in clinics. Final follow-up was conducted at 12 months' infant-corrected age. Data were analyzed from August 2022 to November 2022.
Intervention: Participants randomized to music therapy (MT) plus standard care or standard care alone during NICU admission, or to MT plus standard care or standard care alone postdischarge, using computer-generated randomization (ratio 1:1, block sizes of 2 or 4 varying randomly), stratified by site (51 allocated to MT NICU, 53 to MT postdischarge, 52 to both, and 50 to neither). MT consisted of parent-led, infant-directed singing tailored to infant responses and supported by a music therapist 3 times per week throughout hospitalization or 7 sessions across 6 months' postdischarge.
Main outcome and measure: Primary outcome was mother-infant bonding at 6 months' corrected age, measured by the Postpartum Bonding Questionnaire (PBQ), with follow-up at 12 months' corrected age, and analyzed intention-to-treat as group differences.
Results: Of 206 enrolled infants with 206 mothers (mean [SD] age, 33 [6] years) and 194 fathers (mean [SD] age, 36 [6] years) randomized at discharge, 196 (95.1%) completed assessments at 6 months and were analyzed. Estimated group effects for PBQ at 6 months' corrected age were 0.55 (95% CI, -2.20 to 3.30; P = .70) for MT in the NICU, 1.02 (95% CI, -1.72 to 3.76; P = .47) for MT postdischarge, and -0.20 (95% CI, -4.03 to 3.63; P = .92) for the interaction (12 months: MT in NICU, 0.17; 95% CI, -2.71 to 3.05; P = .91; MT postdischarge, 1.78; 95% CI, -1.13 to 4.70; P = .24; interaction, -1.68; 95% CI, -5.77 to 2.41; P = .42). There were no clinically important between-group differences for secondary variables.
Conclusions and relevance: In this randomized clinical trial, parent-led, infant-directed singing did not have clinically important effects on mother-infant bonding, but was safe and well-accepted.
Trial registration: ClinicalTrials.gov Identifier: NCT03564184.