OBJECTIVE To explore the maternal attitude towards the screening for structural abnormalities at the 11-13-week scan, according to the severity of the abnormality. A secondary aim was to analyse which maternal characteristics influence in the maternal response. METHODS This is a descriptive study based on the responses to 300 self-administrated questionnaires completed immediately before routine ultrasounds scan. RESULTS A totally of 296 (98.7%) women participated in the study. If the baby had any abnormality 93.9% would prefer to know at 12 weeks, 96.6% if the abnormality was lethal, 95.3% if the abnormality involves severe handicap, 91.2% if the abnormality can only be suspected, but not confirmed until the pregnancy is more advanced (16 or 20 weeks), 77.0% if the abnormality was minor and 79.4% women would like to know at 12 weeks if the baby appeared normal. Maternal age, gestational age at the time of the questionnaire and maternal attitude towards termination of pregnancy were the only factors affecting maternal responses. CONCLUSIONS Pregnant women prefer to be informed in the first trimester about any abnormality in their fetuses, even in cases of minor or only suspected abnormalities. © 2016 John Wiley & Sons, Ltd.