A comparative study of women who underwent prenatal cystic fibrosis (CF) carrier screening by either the 'two-step method' or the 'couple method' was carried out 2-4 years after testing. Recall of the screening test and test result, understanding of the implications of the test result, and reproductive intentions and behaviour were compared. Women screened by the two-step method were significantly better informed on the genetic implications of the test result and the significance of being a single gene carrier than their couple screen counterparts. Regardless of the method of screening, a majority of those who had received a negative test result erroneously believed that they were definitely not a carrier. However, women who intended having further children were significantly more likely to understand correctly that a negative test result meant that they were unlikely to be a CF carrier. The method of testing had no influence on reproductive intentions or behaviour. Differences in emphasis, content and presentation of pre-screening information and counselling between the two methods of screening are identified. Reasons for variation in the long-term understanding between women screened by the two methods are discussed.