Inclusion Criteria:  Vietnamese pregnant women in the first trimester of pregnancy and at delivery and subsequent live neonates at birth. Informed consent  Exclusion Criteria:  Women under 18 years old. Miscarriages Stillbirths Premature delivery before 34th gestational week Loss to follow-up maternal monitoring. Participation in another interventional study that influences management of labour at delivery or perinatal morbidity or mortality.