Breastfeeding could effectively be associated with a lower risk of future type 2 diabetes (T2D) in women with gestational diabetes mellitus (GDM), but the short-term protective impact of puerperal breastfeeding on maternal metabolic recovery of GDM women remains unascertained. The investigators recruited GDM participants at 6-9 weeks postpartum and retrieved clinical diagnoses of GDM from electronic medical records. Feeding patterns were collected via phone calls. Glucose metabolism parameters and lipid profiling were performed on fasting plasma samples collected from patients 6-9 weeks postpartum (20 breastfeeding cases vs. 15 formula feeding cases).

Inclusion Criteria:

1. 18-35 years old;
2. gestational age greater than 37 weeks;
3. Body Mass Index (BMI) before pregnancy 18.5-28kg/m2;
4. Have normal listening and speaking skills, can communicate, and are willing to participate in this study.

Exclusion Criteria:

1. abnormal glucose metabolism or diabetes has been diagnosed before pregnancy;
2. assisted reproduction;
3. GDM patients requiring drug treatment;
4. The use of blood lipid regulation drugs;
5. other pregnancy complications and complications;
6. Suffering from heart, malignant tumor, kidney and other major organ diseases;
7. associated with neurological dysfunction and cognitive impairment;
8. Failure to cooperate with follow-up observers.

women (aged 18-35 years) who delivered live-born infants equal to or greater than 37 weeks of gestation at the Women's Hospital of Nanjing Medical University (Nanjing, China) and were not using medications affecting glucose tolerance, lipid regulation and not planning another pregnancy within the next 2 years were enrolled. All the participants received 75g OGTT at 24-28 weeks of gestation and were diagnosed with GDM based on the IADPSG criteria (International Association of Diabetes and Pregnancy Study Groups Consensus Panel et al.). At 6-8 weeks postpartum, all the participants were administered regularly for a post-natal health check-up to classify the body and genitals basically restored status. Fasting plasma samples were collected to measure plasma glucose, and insulin, and reclassify glucose metabolic status. Frequency and amount of breastmilk feeding and formula feeding for each woman were evaluated by trained research staff via telephone calls.