Table 3. Primary and secondary outcomes.

Primary/secondary	Name of outcome	Specific measure to be used	Time points
Composite primary*	Large-for-gestational-age (child)	Birth weight ≥90th percentile for gestational ageUS birth certificate reference adjusted for parity and/or fetal sex48	Delivery
Composite primary*	Hypoglycaemia (child)	Blood glucose <35 mg/dL OR treatment <24 hours after birth with either IV, PO, or gel glucose therapy	<24 hours of birth
Composite primary*	Hyperbilirubinaemia (child)	Treated with phototherapy or exchange transfusion and treatment in the first postnatal week or kernicterus	Delivery to first postnatal week
Composite primary*	Fetal or neonatal death (child)	Death after randomisation and before hospital discharge or 30 days postnatal age if still hospitalised (excluding voluntary pregnancy termination)
Primary*	BMI (child)	kg/m2, continuous measureMeasurement using standardised scale and protocolUS CDC reference adjusted for child sex	2 years follow-up
Secondary	Hypertensive disorder of pregnancy (participant)	Diagnosis per ACOG criteria	Randomisation to delivery
Secondary	Gestational weight gain (participant)	Per Institute of Medicine guidelines (excess, within and less than weight gain recommendations and standardised z-scores)	Randomisation to delivery
Secondary	Preterm birth (child)	<37 weeks, ACOG best OB estimate	Delivery
Secondary	Small-for-gestational-age (child)	Birthweight <10th percentile for gestational ageUS birth certificate reference adjusted for parity and/or fetal sex48	Delivery
Secondary	Mode of delivery (participant)	Caesarean delivery, including primary vs repeat and by indication	Delivery
Secondary	Obstetric anal sphincter injuries (participant)	Per ACOG guidelines	Delivery
Secondary	Mechanical ventilation (child)	Requiring mechanical ventilation, by type and duration	<72 hours birth
Secondary	NICU admission (child)	Admitted to NICU or intermediate nursery	Discharge
Secondary	Oxygen support (child)	Requiring oxygen support, by type and duration	Discharge
Secondary	Respiratory distress syndrome (child)	Signs of respiratory distress on the basis of clinical features and oxygen or respiratory support for ≥6 hours	<72 hours birth
Secondary	Overweight, obesity (child)	BMI ≥85th percentile, BMI ≥95th percentile for age/sex.10	2 years follow-up
Secondary	Adiposity (child)	Triceps/subscapular skinfold thickness >90th percentile for age/sex; individual and sum of measures76	2 years follow-up
Secondary	Anthropometry (child)	Abdominal circumference; age-adjusted/sex-adjusted WHO z-scores for arm circumference.25	2 years follow-up
Secondary	Anthropometry (participant)	Waist and hip circumference, and ratio.	2 years follow-up
Secondary	BMI/obesity (participant)	Continuous, dichotomous (BMI ≥30 kg/m2).	2 years follow-up
Secondary	Adiposity (participant)	Thigh, triceps, subscapular, suprailiac skinfolds.	2 years follow-up
Secondary	Type 2 diabetes (participant)	A1c >6.5% OR fasting plasma glucose >126 mg/dL OR OGTT >200 mg/dL OR prior diagnosis per patient report	2 years follow-up
Secondary	Pre-diabetes (participant)	A1c 5.7%–6.4% OR fasting plasma glucose 100–125 mg/dL OR OGTT 140–199 mg/dL	Year follow-up
Secondary	Hypertension (participant)	Blood pressure (≥130 mm Hg systolic or ≥80 mm Hg diastolic at study visit), EHR or medication	2 years follow-up
Secondary	Treatment adherence/satisfaction (PRO)	Treatment Satisfaction Questionnaire for Medication58; Acceptability of Treatment20	6 weeks follow-up

^*The sample size of n=1572 provides 90% power, one-sided significance level of 0.025, to detect a non-inferiority margin of 8% of the composite RCT outcome (aim 1). For the follow-up (aim 2), a sample size of n=1415 provides 90% power to rule out an effect size of at least 0.172 (ie, 0.172 SD) or a 0.29 kg mean difference in child weight.

ACOGAmerican College of Obstetricians and GynecologistsBMIbody mass indexNICUneonatal intensive care unitOGTToral glucose tolerance testPROpatient-reported outcomeRCTrandomised controlled trial