This is a multicentre, parallel-group, open-label, pragmatic, randomised-control trial of early lifestyle intervention versus routine prenatal care by random allocation (1:1) in women with early abnormal glucose metabolism (EAGM) to compare the incidence of large-gestational age and preterm birth between two groups. The investigators aim to assess the effectiveness of early lifestyle interventions and to provide evidence for the optimal standard management for Chinese women with EAGM.

Women with early abnormal glucose metabolism (EAGM) , which is defined as fasting plasma glucose (FPG) 5.1-6.9 mmol/L and/or hemoglobin A1c (HbA1c) 5.7%-6.4% at before 14 weeks of gestation, will be recruited and randomized in a 1:1 ratio into the intervention or control group. The intervention will consist of a lifestyle intervention that comprises advice on diet, exercise, weight management and self-monitoring of blood glucose (SMBG) with feedback from healthcare professionals on results and insulin treatment if indicated. The educational session is delivered as an initial session following randomization followed by five follow-up sessions which will occur approximately every four months, either face-to-face during routine prenatal visits or via telephone consultation. Routine prenatal care will also be applied to the intervention group. Women in the control group will only receive routine prenatal care. Both groups will receive an OGTT test at 24-28 weeks of gestation unless insulin is needed before the OGTT test for suboptimally controlled blood glucose levels. Whether to continue the intervention depends on the OGTT results as women diagnosed with GDM or overt diabetes will continue intervention plus routine prenatal care until delivery while those will normal OGTT result will pause interventions and follow the routine prenatal care only until delivery. The primary outcome of our trial will be a composite of neonatal outcome including large-for-gestational age and preterm birth.

Inclusion Criteria:

• Over 18 years of age.
• Able to provide informed consent.
• Confirmed viable pregnancy on a nuchal translucency scan done between 11+0 and 13+6 weeks.
• Singleton pregnancies.
• An abnormal glucose metabolism determined by a blood test performed before 14 weeks, defined as FPG 5.1-6.9mmol/L and/or HbA1c 5.7-6.4%.

Exclusion Criteria:

• Pregestational diabetes (diagnosed as diabetes mellitus before pregnancy, or FPG≥7.0mmol/L, or HbA1c≥6.5% at the first prenatal visit), impaired fasting glucose or impaired glucose tolerance diagnosed before pregnancy.
• Plan for termination of pregnancy due to fetal anomaly identified at the first trimester scan.
• Use of medications known to interfere with glucose metabolism (e.g. corticosteroids, antipsychotic drugs) at the time of randomisation.
• Any other physical (serious medical conditions such as cancer, organ failure, epilepsy, paraplegia, disability) or psychological condition (e.g. learning difficulties, serious mental illness) that is likely to interfere with the conduct of the trial according to evaluation by the trial monitoring group.
• Women currently with hyperemesis gravidarum leading to dehydration or requiring hospitalization. If persisting vomiting resolves, the patient may be reassessed for inclusion in the trial up to and including 14+6 weeks of gestation, providing all other inclusion and exclusion criteria are met.