Gestational diabetes mellitus (GDM) is a type of diabetes mellitus with normal glucose metabolism before pregnancy. Pregnant women with prepubertal diabetes have complicated clinical experiences, and the effects of severe disease or poor glycemic control on mothers and infants. The incidence of gestational diabetes mellitus is very high, and the short-term and long-term complications of the mother and the child are higher. Through the detection of blood samples, we can not only obtain the basic information related to the disease such as blood cells and blood biochemistry, but also learn the important information such as enzymes, antibodies and cell metabolites in the blood that are conducive to the diagnosis of the disease. More importantly, blood contains genetic material (such as genomic DNA) that can be used to screen for genes and break down molecules. Placenta tissue examination can provide important cellular, biochemical, immunological and other information. However, due to the complex etiology of gestational diabetes. Especially associated with genetic or immunological factors, in the short term often cannot make a definite diagnosis, and patients in hospital time is limited, some check items such as gene detection, placental tissue can't complete them in hospital, need to return the patient's blood, cord blood and placenta tissue, to facilitate later further screening and biology research. This study intended to establish gestational diabetes patient's blood, cord blood and placenta tissue samples library, screening is closely related to the disease biomarkers, such as disease-causing gene mutations, susceptible gene mutation and protein metabolism product, so as to clarify disease relationship between genotype and clinical phenotype, the pathogenesis of diseases, etc., and provide the basis for the diagnosis of disease and treatment optimization.

the registry procedures: we collected data and blood samples from pregnant women diagnosed with GDM and matched healthy pregnant women as controls on the day admitted to hospital for delivery. All of the participants recruited were Han Chinese. Placental tissue was collected immediately after delivery and saved at -20 °C for analysis.

Inclusion Criteria:

1. The patient was older than 18 years old and had not been diagnosed with diabetes before pregnancy. A 75-gram glucose load examination was performed during 24-28 weeks of gestation：GDM should be diagnosed at any time in pregnancy if one or more of the listed criteria are met following a 75-gram glucose load: fasting PG ≥5.1 mmol/l; 1-hour PG ≥10.0mmol/l; 2-hour PG 8.5-11.0 mmol/l.
2. If the patient is younger than 18 years old, consent from parents or guardians is required;
3. Inclusion objects in line with the above sample sources;
4. Signed the informed consent;

Exclusion Criteria:

1. Refuse to sign the informed consent
2. Severe mental symptoms, unable to cooperate with blood collection

All of the subjects come from the Department of Obstetrics of Second Hospital Affiliateod to Zhejiang University Medical College, Hangzhou, Zhejiang Province。

At present, we only share partial data of patients with gestational diabetes: blood glucose, BMI, age, fetal birth weight and other general features。