Inclusion Criteria:  Pregnant women aged between 18 and 45 years old Pregnant women who attend the antenatal check-up at the selected clinics/hospitals Pregnant women with the gestational age of less than 12 weeks Pregnant women who plan to attend post-natal check-ups for at least one year at the same clinic/hospital  Exclusion Criteria:  Pregnant women who are diagnosed with immune deficiency Pregnant women who have a multiple pregnancy and preterm delivery (<37 weeks) Pregnant women who plan to move out of the study area in the next one year Pregnant women with fetal/newborn with congenital abnormalities