Human milk is the most complete and correct way to feed a newborn, as it provides all the nutrients and bioactive factors essential for adequate growth and neurodevelopment. In special circumstances, such as prematurity or illness, breast milk is not always available, and donor human milk (DHM) is an option. Some studies have reported growth retardation in babies fed DHM, probably due to the less adequate nutritional composition. There are several factors that contribute to changes in its nutritional composition. Among the various factors, the following are worth highlighting: wide variety of donors with different characteristics (e.g. gestational age, lactation phase, diet); inconsistency of the collection method; impact of milk processing, i.e. the pasteurization process.

As the Human Milk Bank of North (BLHN - Banco de Leite Humano do Norte) is the first in the North region of Portugal, and there are few studies developed in this area in Portugal, the present project aims to study the influence of the following factors on the composition of the DHM:

• Pasteurization process;
• Dietary habits of donors;
• Body composition of donors.

Study design and sampling: observational study with a cross-sectional and prospective design. The sample will consist of mothers who donate human milk to the BLHN of the Centro Hospitalar de São João.

Data collection: in order to meet the objectives of the research project, a questionnaire was drawn up for the participants, to be administered on paper, in an interview format, in the context of an outpatient consultation.

The questionnaire lasts around 20 minutes and consists of sociodemographic information (age, household composition, marital status, nationality, educational qualifications, profession); personal history (pathologies, number of pregnancies and births, date of last birth, gender, age, birth weight and length of the newborn, presence of gestational diabetes, hypertension in pregnancy, pre-eclampsia, term or pre-term birth, twin pregnancy); anthropometric data and body composition of the donor; food frequency questionnaire; physical activity; nutritional composition of the donated milk before and after processing (pasteurization).

Inclusion Criteria:

• Human milk donors at BLHN
• Informed consent of the participant

Exclusion Criteria:

• None

Human milk donors from BLHN