All pregnant women will be tested for serology during each trimester of pregnancy and at delivery, together with a nasal swab. Children born to women with positive sawb or serology will be followed up for 3 years together with a control child born to negative mother.
In positive mothers, maternal antibodies at delivery will be characterized, placental transfer will be assessed. Persistence of antibodies in children at the age of 1 month and presence of antibodies in breast milk will be measured.
Occurence of premature birth, low birth weight, miscarriage, congenital malformations will be compared in positive and negative mothers. Follow up of children over the first 3 years of life will assess difference in susceptibility to infections and neurological developement in both groups.
