Prenatal Exposure to Emerging Contaminants and Children's Atopic Dermatitis

Inclusion Criteria: * Mother plans to proceed prenatal care and delivery in Minhang Maternal and Children Health Care Hospital * 12-14 weeks of singleton pregnancy, non-stillborn or miscarrying, offspring without familial hereditary skin diseases * Offspring plans to stay in Shanghai until 5 years and proceed follow-up at the Dermatology Department of Children's Hospital affiliated with Fudan University * signed informed consent. Exclusion Criteria: * Multiple pregnancies * perinatal death * a fetus with congenital skin or appendages disorders