METHODS
A total of 38 healthy pregnant women who were planned to deliver
electively at gestational term by caesarean section were sampled in our
study at Birmingham Women’s Hospital, UK. Peripheral blood samples were
collected prior to the caesarean section and all women were not in labor
and had intact membranes. Cord blood samples were taken immediately
after delivery. A peripheral blood sample (up to 2 mL) was taken from
the neonate at 3 weeks of age. In addition to the blood samples, a
neonatal stool sample was collected at birth and at 3 weeks of age from
29 of the recruited neonates. Exclusion criteria included multiple
pregnancy, sepsis risk factors (especially maternal fever or
chorioamnionitis), GBS positivity in the current pregnancy, genetic
conditions of the fetus or the mother, maternal HIV, maternal TB,
maternal new-onset viral infection, maternal hypertensive disorder,
maternal endocrine condition or diabetes, maternal asthma and maternal
autoimmune conditions, as well as maternal medication other than
pregnancy supplements. Peripheral blood samples were also collected from
13 healthy, non-pregnant adults (male/female: 6/7).
Informed written consent was obtained from all pregnant women. The study
was reviewed and approved by the East Midlands – Nottingham 2 NHS
Research Ethics Committee (reference 16/EM/0379).