Identification and operative vs. conservative vs. no treatment trial of breastfeeding-impeding lingual frenulum in newborn infants (LINNE): protocol for a randomized controlled trial (RCT) embedded in a prospective observational cohort study in North

The lingual frenulum is an anatomical structure of the mouth. If it restricts the movement of the tongue, it is called a tongue-tie. Existing evidence has linked tongue-tie to breastfeeding difficulties. With growing emphasis on successful breastfeeding, the number of surgical interventions for tongue-tie has increased globally. However, the relationship between frenulum anatomy, its visual appearance, and functional impairment remains unclear. We initiated the LINNE project to study the neonatal oral structures and their treatments for breastfeeding problems. The aims are to define the prevalence and distribution of neonatal oral findings and their association with breastfeeding difficulties in a prospective cohort study, and to compare the efficacy and safety of surgical versus non-operative versus no treatment for tongue-tie in a RCT. The primary outcome of the RCT is successful breastfeeding at 1 month of age, defined by both infant feeding pattern and maternal breastfeeding experience. Participants are recruited in a tertiary-level university hospital, serving as the main maternity hospital of Northern Finland (Oulu University Hospital, Oulu, Finland). Patient eligibility for the RCT is determined upon the cohort study, using the validated LINNE scoring system, including the Pictorial Assessment Tool of Tongue-Tie in Breastfed Babies, the Maternal Breastfeeding Experience Scoring, and three anamnestic factors. Exclusion criteria include prematurity (gestation < 37.0 weeks), major chromosomal or other anomalies, serious infant or maternal illness, and non-breastfeeding mothers. For this exploratory trial, the study physicians recruit the participants, randomized using 1:1:1 ratio, to three study groups: (1) open, conservative, oral physiotherapy group, (2) open frenotomy group, (3) no treatment group—the parental blinding arm—where parents are informed of allocation to frenotomy, scheduled for a month later. The sample size is 84/group (total 252). The potential safety and harm measures include the clinical signs and symptoms of breastfeeding problems parents were instructed to watch for, parental contacts, their timings, and frenotomy complications. The present study will provide important new insights into the identification of clinically meaningful tongue-tie causing breastfeeding difficulties, its treatment indications, and the comparative efficacy and safety of different treatment options. EudraCT, 2022-001546-37, registered on April 13, 2022; https://www.clinicaltrialsregister.eu/ ClinicalTrials.gov, NCT05560750, registered on September 29, 2022; https://clinicaltrials.gov/search?cond=NCT05560750 First enrolment dates: The cohort study, October 3, 2022; RCT, October 7, 2022.