OBJECTIVE To determine the contribution of livebirths resulting from in-vitro fertilisation and related technologies (IVF) to the use of neonatal ventilator beds. METHODS A retrospective review of records of all livebirths from our hospital's IVF program and all IVF infants receiving mechanical ventilation in our neonatal intensive care unit for the period 1985-1989. We also reviewed records of labour ward deliveries, neonatal intensive care unit admissions and transfer requests in order to obtain comparative data for livebirths of non-IVF infants whose mothers had been booked to deliver in our hospital. METHODS A tertiary perinatal centre with a large IVF program and a Level 3 neonatal intensive care unit. RESULTS IVF livebirths accounted for 5.1% of total ventilator bed days. Compared with non-IVF booked livebirths, IVF babies were more likely to require ventilation (odds ratio, 7.41; P less than 0.0001) and used more ventilator bed days per 100 livebirths (rate ratio, 9.63; P less than 0.0001), largely due to preterm delivery of multiple pregnancies; 42.3% of IVF babies who required ventilation were from triplet births and 38.5% from twin births. Nevertheless, even IVF singletons used more ventilator bed days per 100 livebirths than non-IVF booked livebirths (rate ratio, 2.78; P less than 0.0001). IVF livebirths accounted for 9.9% of the 78% increase in ventilator bed days used in 1989 compared with 1985. CONCLUSIONS IVF livebirths accounted for only a small percentage of the overall use of neonatal ventilator beds, but consumed relatively more of such resources per livebirth than did non-IVF livebirths. The degree of risk of requiring ventilation is directly related to the number of infants in a multiple pregnancy, but even IVF singletons are at a relatively high risk of requiring ventilation.