Table 2 Outcomes measured

Clinical fetal/neonatal outcomes from clinical record (birth, 6–8 weeks post-natal where indicated)

 • Birth centile including large and small for gestational age (LGA; SGA); Intergrowth birth centile chart. LGA > 90th centile SGA < 10th centile

 • Birth weight (g)

 • Fetal macrosomia > 4 kg (yes/no)

 • Anthropometry: Head, chest, abdominal circumference; crown-rump length, crown-heel length (cm, birth); and weight (g) and head circumference (cm) (birth and 6–8 weeks post-natal)

 • Miscarriage before 23 + 6 gestation (yes/no) (as arising)

 • Stillbirth after 24 + 0 gestation (yes/no) (as arising)

 • Neonatal death < 28 days of life (yes/no) (as arising)

 • Preterm birth < 37 weeks gestation at birth (yes/no)

 • Gestation at birth (weeks)

 • Neonatal intensive care unit (NICU) admission (yes/no) and length of stay in days

 • Umbilical cord pH

 • Apgar score at 0, 5, 10 min [31]

 • Injury: clavicle, humeral, skull fracture (yes/no)

 • Hypoglycaemia requiring NICU treatment (yes/no)

 • Treatment for Respiratory distress syndrome (yes/no)

 • Treatment for hyperbilirubinaemia (yes/no)

Clinical maternal outcomes from clinical record (timepoints as indicated)

 • Weight (kg) (booking, 34–36 weeks)

 • Height (cm) (booking, 34–36 weeks)

 • Diabetes medications prescribed (type, quantity) (each appointment)

 • Hypoglycaemic episodes (if on insulin) (number/frequency) (each appointment)

 • Other adverse events (e.g. skin irritation) (each appointment)

 • Glycaemic control:

  • HbA1c baseline (34–36 weeks, 6– ~ 13 weeks post-natal)

  • SMBG daily diaries—fasting and post-meal glucose (each antenatal appointment; SMBG only)

  • Continuous glucose data—% time in target range (3.5–7.8 mmol/l), area under curve, % time in hypo- and hyperglycaemia, standard deviation and amplitude of glycaemic excursions, (baseline, 34–36 weeks)

 • Gestational hypertension/pre-eclampsia per NICE diagnostic criteria (yes/no) [32] (at birth)

 • Induction of labour (yes/no) (at birth)

 • Caesarean birth (pre-labour or intrapartum)/instrumental birth/vaginal birth (yes/no) (at birth)

 • Obstetric and sphincter injury (OASI) (yes/no) (at birth)

 • Shoulder dystocia (yes/no) (at birth)

 • Postpartum haemorrhage (yes/no) (at birth)

 • Maternal hospital stay (days) (at birth)

Psychosocial, behavioural, and health economic (patient reported) baseline and ~ 34–36 weeks gestation

 • Glucose monitoring experiences questionnaire (GME-Q) [33]

 • Diabetes self-care behaviours (diet, physical activity, medication adherence, glucose monitoring)

 • Pregnancy Physical Activity Questionnaire (PPAQ) [34]

 • UK Diabetes and Diet Questionnaire (UKDDQ) [35]

 • Voil’s DOSE medication non-adherence measure [36]

 • Anxiety and Depression: Hospital Anxiety and Depression Scale (HADS) [37]

 • Quality of life: SF-12v2 [38]; SF-6D [39]; EQ-5D-5L [40];

 • Patient reported resource use questionnaire Baseline/Visit 2 Mother Resource Questionnaire-study specific. Modified with public-patient involvement from the Mother and Baby Resource Questionnaire, with permission from Warwick Clinical Trials Unit