Unstudied infants: outcomes of moderately premature infants in the neonatal intensive care unit.

BACKGROUND

Newborns of 30-34 weeks gestation comprise 3.9% of all live births in the United States and 32% of all premature infants. They have been studied much less than very low birthweight infants.

OBJECTIVE

To measure in-hospital outcomes and readmission within three months of discharge of moderately premature infants.

DESIGN

Prospective cohort study including retrospective chart review and telephone interviews after discharge.

SETTING

Ten birth hospitals in California and Massachusetts.

PATIENTS

Surviving moderately premature infants born between October 2001 and February 2003.

MAIN OUTCOME MEASURES

(a) Occurrence of assisted ventilation during the hospital stay after birth; (b) adverse in-hospital outcomes-for example, necrotising enterocolitis; (c) readmission within three months of discharge.

RESULTS

With the use of prospective cluster sampling, 850 eligible infants and their families were identified, randomly selected, and enrolled. A total of 677 families completed a telephone interview three months after hospital discharge. During the birth stay, these babies experienced substantial morbidity: 45.7% experienced assisted ventilation, and 3.2% still required supplemental oxygen at 36 weeks. Readmission within three months occurred in 11.2% of the cohort and was higher among male infants and those with chronic lung disease.

CONCLUSIONS

Moderately premature infants experience significant morbidity, as evidenced by high rates of assisted ventilation, use of oxygen at 36 weeks, and readmission. Such morbidity deserves more research.