RISK-FACTORS AND OUTCOMES ASSOCIATED WITH LOW-BIRTH-WEIGHT DELIVERY IN THE AUSTRALIAN-CAPITAL-TERRITORY 1989-90

The objectives of this study were to describe outcomes of low birthweight (LBW; <2500 g) babies born in the Australian Capital Territory (ACT) and to identify risk factors associated with LBW in the ACT A cohort study was conducted involving all births recorded in the ACT Maternal and Perinatal Data Collection sets for 1989-90. Status at discharge is presented for 9373 births each weighing more than 499 g born in the ACT in 1989 and 1990, classified by birthweight. Other outcomes are given for live births (n = 9309) only. Adjusted odds ratios for significant risk factors for LBW are given for 9084 singleton births whose computer records contained all relevant information. Perinatal mortality rates for LBW babies are consistent with other States, apart from 500-999 and 1500-1999 g babies which have higher rates. Eighteen per cent of LBW babies are transferred to other hospitals. Low birthweight babies are more likely than normal birthweight babies to have 1 and 5 min Apgar scores less than 7, to need resuscitation and to take more than 5 min to establish respiration. Risk of LBW is associated with maternal primiparity, age 35 years or more in primiparous women, history of one or more spontaneous abortions, induced abortions or perinatal deaths, chronic illness, public health insurance and single marital status, and with fetal female sex and congenital anomalies. Babies born weighing less than 2500 g in the ACT have more adverse outcomes and are much more likely to be transferred than normal birthweight babies. Modifiable risk factors for LBW relate to lower maternal socio-economic status. Measures to decrease the incidence of LBW and its subsequent costs will have greatest gains in this group of women.