The amount of infection following caesarean operations changes according to the indication for the caesarean and the length of time the membranes have been ruptured. Antibiotics should be prescribed according to these parameters. It does not seem that the numbers of thrombo-embolic complications in this series were reduced by using heparin prophylactically in the usual doses. It does seem to us that women with real factors for this risk should receive heparin in high doses to lower blood coagulation.