# Hair collection protocol in 12-month-old infants

## TL;DR

Researchers developed a feasible and acceptable protocol for collecting hair from 12-month-old infants to measure cortisol levels, addressing a gap in existing literature.

## Contribution

The study introduces a novel hair collection protocol specifically designed for 12-month-old infants, with practical lessons to improve reproducibility and caregiver acceptance.

## Key findings

- 95.6% of caregivers consented to the hair collection procedure.
- Five practical lessons were identified to enhance the feasibility and comfort of the hair collection process.
- The protocol was found to be acceptable and will improve replicability for future research.

## Abstract

Most studies assessing hair cortisol were conducted with adults. As specific guidelines for infant hair collection are lacking, we developed a hair collection protocol for 12-month-old infants and assessed its acceptability and feasibility.

Out of the total (N = 45), 95.6 % (n = 43) of caregivers consented to the procedure, while one caregiver did not consent (2.2 %), and another requested the procedure to be halted before required amount of hair had been reached (2.2 %). Furthermore, two (4.4 %) infants did not have enough hair for collection. There was no attrition due to infant fussiness/crying.

We learned five lessons which can help to enhance reproducibility, mother's consent, and mother-infant comfort and acceptance of the procedure. The first lesson is to have the infant sit on the caregiver's lap to ensure the infant feels safe and remains relatively still. The second is to reassure caregivers by showing hair samples representing the amount to be cut as well as by clarifying no unaesthetic gaps would be visible. The third is to caress the infant's head to habituate them to the hair manipulation and to make soap bubbles as distractors. The fourth is to take extra care when securing the lock of hair for cutting because the infant scalp is thin and malleable. The fifth is to place a precision scale in the collection room to ensure the necessary weight is reached.

Our hair collection protocol developed for 12-month-old infants was deemed feasible and acceptable, filled an important literature gap concerning the absence of published protocols for infants, and will contribute to increase the replicability and collection efficiency for other research teams.

•We aimed to fill a literature gap by developing a feasible and acceptable hair collection protocol for 12-month-old infants.•Out of the total (N = 45), 95.6 % (n = 43) of caregivers consented to the procedure.•Lessons for a feasible collection: infant on caregiver's lap; showing hair samples to caregivers; caressing and making soap bubbles; care when pulling the infant hair for cutting.•Our hair collection protocol will contribute to increase the replicability for other research teams.

We aimed to fill a literature gap by developing a feasible and acceptable hair collection protocol for 12-month-old infants.

Out of the total (N = 45), 95.6 % (n = 43) of caregivers consented to the procedure.

Lessons for a feasible collection: infant on caregiver's lap; showing hair samples to caregivers; caressing and making soap bubbles; care when pulling the infant hair for cutting.

Our hair collection protocol will contribute to increase the replicability for other research teams.