Study: NCT03725878

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: Standard tertiary interventions of birth defects
Description: Couples eligible for reproductive policy are entitled to routine health cares including general health cares (health education, medical history inquiry, physical examinations, consulting guidance and pregnancy outcome follow-up) and medical examinations (laboratory examinations, virus screenings and image examinations). But nutrients status are not included in these examinations, such as folate, vitamin B12, and macroelements, et al. Regular antenatal cares are required, such as deformity screening by ultrasound. Routine neonatal screenings are conducted to diagnose infant with birth defect timely.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Standard tertiary interventions of birth defects
Description: Couples eligible for reproductive policy are entitled to routine health cares including general health cares (health education, medical history inquiry, physical examinations, consulting guidance and pregnancy outcome follow-up) and medical examinations (laboratory examinations, virus screenings and image examinations). But nutrients status are not included in these examinations, such as folate, vitamin B12, and macroelements, et al. Regular antenatal cares are required, such as deformity screening by ultrasound. Routine neonatal screenings are conducted to diagnose infant with birth defect timely.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Additional preconception health care
Description: Various studies have revealed that folate is essential in early embryo development, whereas folate level evaluation in periconception women is not included in routine health cares. Therefore, we evaluate subject's folate level by serum and red blood cell folate examination. By combination of folate supplement obtained by questionnaire,folate level evaluated by examinations and folate metabolism ability evaluated by genotyping key enzymes in folate metabolism, an individualized folic acid supplementary guide is given to subjects. Red blood cell folate concentration \>400 ng/ml before pregnancy is recommended.

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: Additional health care procedures during and after pregnancy
Description: Fetus with birth defect will be referred to a tertiary hospital to receive genetic assessments and prenatal diagnosis to reduce unnecessary abortions. A 6-months follow up will be conducted to follow children's birth outcomes. It also helps clinical team to give early diagnosis and treatment for children with birth defect to reduce disability and improve life quality of defect children.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Additional health care procedures during and after pregnancy
Description: Fetus with birth defect will be referred to a tertiary hospital to receive genetic assessments and prenatal diagnosis to reduce unnecessary abortions. A 6-months follow up will be conducted to follow children's birth outcomes. It also helps clinical team to give early diagnosis and treatment for children with birth defect to reduce disability and improve life quality of defect children.