Protecting against Respiratory tract Infections through human Milk Analysis.

We aim to identify mechanisms by which breast feeding prevents respiratory
tract infections. A healthy birth cohort (n=1000) will be set-up and studied
during the first year of life. Human milk will be collected repeatedly and
analysed to provide insights into the protective capacity of human milk
components against (respiratory tract) infections and allergies.
A subgroup will be further analyzed to obtain insight in transfer of maternal
immunity to the child. By collecting additional cord blood, amniotic fluid and
maternal blood samples, we will analyze the transfer of maternal immunity.

Primary objective:
1. To identify the components in human milk (e.g. nutrients, oligosaccharides,
fatty acids and (pathogen specific) immunoglobulins) that have a protective
effect against respiratory tract infections during the first year of life.

Secondary objective:
2. The underlying mechanism of the components in human milk that offer
protection from respiratory tract infections during the first year of life.
3. To identify the components in human milk (e.g. nutrients, oligosaccharides,
fatty acids and (pathogen specific) immunoglobulins) that have offer from
developing allergies during the first year of life and to identify the
underlying mechanism of these components.
4. To study the alterations in human milk composition at various time points.
5. To gain insight in the transfer of maternal immunity to their child via
human milk, amniotic fluid and the placenta.

The study is designed as a prospective observational cohort study, including
1000 healthy mother-child pairs. Directly after birth we will collect data from
all children enrolled through a questionnaire that is send to parents every 2
weeks. The questionnaires will be used to collect data about episodes of
(respiratory tract) infections and already developed allergies during the first
year of age.
Meanwhile, we will collect human milk samples at four time points: within 1
week postpartum and after 1 month, 3 months and 6 months postpartum. By
collecting human milk at these time points, we expect to collect samples from
all relevant time-dependent types of human milk. The human milk samples will be
stored until analysis at the biobank facility of the UMC Utrecht.
After analysis of human milk composition is performed and clinical data
collected, we will compare the two database in order to find beneficial
profiles of human milk components.

Additionally we will also collect additional samples to research what the
influence of breastfeeding is on immune development compared to other routes
that are enrolled in the transfer of maternal immunity to the neonate. This we
will de in a subgroup of 20 mother-child dyads. The samples that we will
collect are cord blood samples, a maternal blood sample and an amniotic fluid
sample. Jacobino et al. showed that antibodies retrieved form human amniotic
fluid protected mice pups against RSV-infections (JACOBINO2016). Very little is
known about the protective value antibody titers in cord blood. Active
placental transport of maternal antibodies to the neonatal blood has been
described, but little is known about the effectiveness of these antibodies
(KOHLER1966). To obtain more insight in the effect of the antibodies that are
being transferred by breastfeeding, we will compare the effect of breastfeeding
to the antibodies in cord blood and amniotic fluid. We will also collected
saliva samples in the children enrolled n this subgroup at 1 week, 1, 3, 6, and
12 months postpartum. Saliva samples will be used to study immune development
in children.

Only parents will be burdened by participating in this study. Parents will be
visited by researchers four times maximum. Children will not be affected by the
collection of human milk samples, since they are a rather small fraction of the
total amount of breastfeeding.
Apart from human milk collection, parents will have to fill in questionnaires
every 2 weeks that will take 1-2 minutes to complete. Additionally parents will
have to fill in three more extensive questionnaires that will take about 300
minutes each to complete (i.e. baseline, midterm and end-of-study
questionnaires). In total, the maximal estimated amount of hours will be 5-6
hours for each child.
There is a minimal risk associated with the venipuncture. Although considered
safe, rarely phlebitis, extravasation of blood, bruising and hematoma forming
following venipuncture have been reported. However, since complications form
venipunctures and expressing milk are rare, and we will decrease the risk of a
data breach as best as we can with our DMP, we asses these risks for mothers
acceptable. No risk is associated with the collection of amniotic fluid or
saliva.