CHANGING OUTCOME FOR INFANTS OF BIRTH-WEIGHT 500-999 G BORN OUTSIDE LEVEL-3 CENTERS IN VICTORIA

The aim of this study of extremely low birth-weight (ELBW, birth-weigh t 500-999 g) infants born in Victoria was to determine the changes bet ween 3 distinct eras; 1979-80, 1985-87, and 1991-92, in the proportion s who were born outside level 3 perinatal centres (outborn), the propo rtions of outborn infants who were transferred after birth to a level 3 neonatal unit, the survival rate for outborn infants, and sensorineu ral impairment and disability rates in outborn survivors. The proporti on of ELBW Livebirths who were outborn fell significantly over success ive eras, from 30.2% (106 of 351) in 1979-80, to 23.0% (129 of 560) in 1985-87, and to 15.6% (67 of 429) in 1991-92. Between 1979-80 and 198 5-87, the proportions who were outborn fell predominantly in those of birth-weight from 800-999 g, whereas between 1985-87 and 1991-92 the p roportions who were outborn fell predominantly in those of birth-weigh t 500-799 g. The proportions of outborn infants who were transferred a fter birth to a level 3 neonatal unit were similar in the 3 eras, at 4 9.1%, 38.0% and 41.2%, respectively. The survival rates for outborn in fants were lower in each era than for infants born in a level 3 perina tal centre. Only 1 outborn infant not transferred after birth to a lev el-3 unit survived in any era. The survival rates for infants transfer red after birth were similar in the first 2 eras, but rose significant ly in 1991-92 (34.6%, 36.7% and 60.7%, respectively). The rates of sen sorineural impairments and disabilities in survivors fell significantl y between the first 2 eras, and remained low in the last era. It is pl easing that the proportion of tiny babies who were outborn fell signif icantly over time, reflecting increased referral of high-risk mothers to level 3 perinatal centres before birth. For ELBW outborn infants, s urvival prospects free of substantial disability are reasonable, but n ot as good as for those born in level 3 perinatal centres.