Objectives To determine whether antenatal betamethasone prior to elective term caesarean section (CS) affects long term behavioural, cognitive or developmental outcome, and whether the risk of asthma or atopic disease is reduced.

Design A questionnaire based follow-up of a multicentre randomised controlled trial (Antenatal Steroids for Term Elective Caesarean Section, BMJ 2005).

Setting Four UK study centres from the original trial.

Participants 862 participants from the four largest recruiting centres, 92% of the original study. 824 (96%) were traced and 799 (93%) were successfully contacted. Fifty-one percent (407/799) completed and returned the questionnaire. The children were aged 8–15 years (median 12.2 years, 52% girls). 386 gave consent to contact schools with 352 (91%) reports received.

Main outcome measures Questionnaires including a strengths and difficulties questionnaire, International Study of Asthma and Allergies in Childhood, general health and school performance.

Results There were no significant differences between children whose mothers received betamethasone and controls for the mean total strengths and difficulties questionnaire scores and subscores for hyperactivity, emotional symptoms, prosocial behaviour, conduct or peer problems. 25 (12%) children whose mothers received betamethasone had reported learning difficulties compared with 27 (14%) control children. The proportion of children who achieved standard assessment tests KS2 exams level 4 or above for mathematics, English or science was similar as were the rates of ever reported wheeze (30% vs 30%), asthma (24% vs 21%), eczema (34% vs 37%) and hay fever (25% vs 27%).

Conclusions Antenatal betamethasone did not result in any adverse outcomes or reduction in asthma or atopy. It should be considered for elective CS at 37–38 weeks of gestation.

Trial registration: Original trial was preregistration, the trial publication is BMJ. 2005 Sep 24;331(7518):662.