Table 1.

Number of infants recruited, excluded and lost to follow-up

	3 months	8 months	18 months
Parents consented to the visit	156	180	182
Withdrew	12	8	6
Consented but not seen at visit
Died after consent obtained	4	1	–
Excluded for major sensory or motor impairment	5	4	2
Unable to reach the family to book the appointment	–	3	1
Did not attend booked visit (e.g. infant ill that day, family reasons)	8	28	38
Seen at visit but excluded
Multiple courses or a partial course of antenatal steroids, one infant exposed to hydrocortisone post-discharge	26	31	20
Invalid cortisol sample (insufficient saliva or fed <20 min prior)	2	16	23
Final N for the present study*	99	89	78

^*The final N at each age is the number of eligible infants seen at that visit who had a valid resting cortisol sample (thus equals the number of samples, total = 266). Of the N = 133 infants in the present study, 40 infants had a valid resting cortisol sample at all three visits, 53 infants at two visits and 40 at one visit.