Birth centers in Australia: a national population-based study of perinatal mortality associated with giving birth in a birth center.

BACKGROUND Perinatal mortality is a rare outcome among babies born at term in developed countries after normal uncomplicated pregnancies; consequently, the numbers involved in large databases of routinely collected statistics provide a meaningful evaluation of these uncommon events. The National Perinatal Data Collection records the place of birth and information on the outcomes of pregnancy and childbirth for all women who give birth each year in Australia. Our objective was to describe the perinatal mortality associated with giving birth in "alongside hospital" birth centers in Australia during 1999 to 2002 using nationally collected data. METHODS This population-based study included all 1,001,249 women who gave birth in Australia during 1999 to 2002. Of these women, 21,800 (2.18%) gave birth in a birth center. Selected perinatal outcomes (including stillbirths and neonatal deaths) were described for the 4-year study period separately for first-time mothers and for women having a second or subsequent birth. A further comparison was made between deaths of low-risk term babies born in hospitals compared with deaths of term babies born in birth centers. RESULTS The total perinatal death rate attributed to birth centers was significantly lower than that attributed to hospitals (1.51/1,000 vs 10.03/1,000). The perinatal mortality rate among term births to primiparas in birth centers compared with term births among low-risk primiparas in hospitals was 1.4 versus 1.9 per 1,000; the perinatal mortality rate among term births to multiparas in birth centers compared with term births among low-risk multiparas in hospitals was 0.6 versus 1.6 per 1,000. CONCLUSIONS This study using Australian national data showed that the overall rate of perinatal mortality was lower in alongside hospital birth centers than in hospitals irrespective of the mother's parity.