Long-term health data of children exposed to aspirin in utero is lacking. Therefore, we will assess children born to mothers from the APRIL trial who were randomized between low-dose aspirin (80 mg) and placebo. Women will be asked to fill out a questionnaire when her child is four years old. The main outcomes assessed is (neuro)development and behaviour. Additional outcomes include mortality (perinatal death and infant death up to 4 years of age), child’s growth and health related problems (i.e. information on surgery, medication use and hospital admissions).