Admission of term infants to neonatal intensive care: a population-based study.

BACKGROUND

Neonatal intensive care and special care nurseries provide a level of care that is both high in cost and low in volume. The aim of our study was to determine the rate of admission of term babies to neonatal intensive care in association with each method of giving birth among low-risk women.

METHODS

We examined the records of 1,001,249 women who gave birth in Australia during 1999 to 2002 using data from the National Perinatal Data Collection. Among low-risk women, we calculated the adjusted odds of admission to neonatal intensive care at term separated for each week of gestational age between 37 and 41 completed weeks. We also calculated the odds of admission to neonatal intensive care in association with cesarean section before or after the onset of labor, and vacuum or instrumental birth compared with unassisted vaginal birth at 40 weeks' gestation.

RESULTS

The overall rate of admission to neonatal intensive care of term babies was 8.9 percent for primiparas and 6.3 percent for multiparas. After a cesarean section before the onset of labor, the adjusted odds of admission among low-risk primiparas at 37 weeks' gestation were 12.08 (99% CI 8.64-16.89); at 38 weeks, 7.49 (99% CI 5.54-10.11); and at 39 weeks, 2.80 (99% CI 2.02-3.88). At 41 weeks, the adjusted odds were not significantly higher than those at 40 weeks' gestation. Among low-risk multiparas who had a cesarean section before the onset of labor, the adjusted odds of admission to neonatal intensive care at 37 weeks' gestation were 15.40 (99% CI 12.87-18.43); at 38 weeks, 12.13 (99% CI 10.37-14.19); and at 39 weeks, 5.09 (99% CI 4.31-6.00). At 41 weeks' gestation, the adjusted odds of admission were significantly lower than those at 40 weeks (AOR 0.64, 99% CI 0.47-0.88). Babies born after any operative method of birth were at increased odds of being admitted to neonatal intensive care compared with those born after unassisted vaginal birth at 40 weeks' gestation.

CONCLUSIONS

The adjusted odds of admission to neonatal intensive care for babies of low-risk women were increased after birth at 37 weeks' gestation. In a climate of rising cesarean sections, this information is important to women who may be considering elective procedures.