AIM OF THE STUDY: To assess the views of obstetricians concerning the survival rate in neonates on the basis of gestational age and birth-weight, rate of severe handicap, and minimum gestational age for preventive and curative measures (steroids for foetal lung maturation and caesarean section in the event of acute foetal distress). Then, to compare these results with the outcomes observed in the referral centre for these obstetricians. METHOD: We circulated an anonymous questionnaire (two mailings between October 1995 and February 1996) to obstetricians in the Lausanne area. The replies were compared with prospective data from the Lausanne obstetric unit (1989-1995) and neonatal intensive care unit (1982-1993) backed by the neurodevelopmental outcome assessed by regular follow-up until the age of 8 1/2 years. RESULTS: We obtained 116 replies from the 270 specialists questioned (43% participation). The mortality rates in Lausanne are described by gestational age and birthweight, as is the rate of severe handicap. We observed significant overestimation of the mortality rate for premature infants between 25 and 31 weeks and for birthweights over 600 grams. The rate of severe handicap was widely overestimated for a gestational age below 28 weeks at delivery or a birthweight below 1500 g (prognosis 31.2% and 21.5% respectively, compared with actual figures of 7.4% and 6.8%). Moreover, distribution of replies showed marked heterogeneity between 26 and 29 weeks and between 600 and 1000 grams. The estimated minimum gestational age was 26 weeks (mean) for starting steroid therapy and 27 weeks for caesarean section for acute foetal distress. CONCLUSION: Assessment of prognosis by obstetricians did not correlate with our results and reflected the disparity of data found in the literature. Nevertheless, the implications of this discrepancy may be slight. The study stresses the efficacy of the regionalisation of perinatal care in the Lausanne area, where we observed only 6% of outborn weighting less than 1500 grams in the 18 maternity departments covered. The rate of completed antenatal steroid therapy (41% for infants below 1500 grams) appears to be favourable in our population compared with the literature. We advocate permanent information on local results regarding perinatal outcome, to enable individual obstetricians to consider the desirability of treating, transferring or even counselling or reassuring their patients.