The bi-directional dynamic cohort study is to learn about the effects of prenatal exposure to high blood glucose levels and postnatal nurturing environment factors on delayed language development in children. The study investigated the results of blood glucose screening during pregnancy for the children's mothers, and followed up on the blood glucose management effectiveness of pregnant women with abnormal blood glucose levels before delivery. Participants will be also surveyed the "S-S method for language development assessment, "gsell Scale", and "0-6 year-old family nurturing environment evaluation scale" to evaluate the language development and family nurturing environment.

Glucose management during pregnancy and the postnatal nurturing environment are keys to early detection and early intervention of language delay, which is important to reduce abnormal language development in children. In this study, mothers diagnosed with gestational diabetes mellitus in the department of hospital and offspring were used as participants. The investigators take a follow-up visit to participants' offspring using the S-S method of language development assessment, gsell Infant and Toddler Development Scale, and 0-6 years old family parenting environment evaluation scale. The bi-directional dynamic cohort study is to learn about the effects of prenatal exposure to high blood glucose levels and postnatal nurturing environment factors on delayed language development in children.

Inclusion Criteria:

• Children 1.5-2.5 years old with no serious underlying diseases and no hearing impairment.

Exclusion Criteria:

• diagnosed hearing impairment, organic dysarthria, oral disease; (ii) cerebral palsy;
• neurological and hereditary metabolic diseases; (iv) deaf father/mother.

The pregnant women with abnormal blood glucose levels and the offspring