Lack of correlation between a high caesarean section rate and improved prognosis for low-birthweight twins (less than 2500 g).

The impact of birth by caesarean section on perinatal mortality was estimated for 9368 low-birthweight twins (less than 2500 g) born in Sweden between 1973 and 1985, by using national data from the Medical Birth Registry, National Board of Health and Welfare, Stockholm. During this period the caesarean section rate increased from 7-10% to 45-50% while concomitantly a sharp decrease in the perinatal mortality rate occurred. A causal relation between the increased rate of abdominal delivery and the improved prognosis for low birthweight twins might be expected. However, analysis of the results failed to show any correlation between these two variables. Factors other than route of delivery seem to have a greater impact on fetal outcome.