Moderate-to-late preterm babies (born at a gestational age of 32 to 36 weeks) with no significant medical problems on admission are likely to be discharged at 36 weeks of postmenstrual age, according to a study recently published in the American Journal of Perinatology.

Alanna Higgins Joyce, M.D., M.P.H., of the Ann & Robert H. Lurie Children's Hospital of Chicago, and colleagues retrospectively conducted an electronic chart review on 12,498 infants admitted to a (NICU) from 2009 through 2015 to identify 3,240 moderate-to-late (32 0/7 and 36 6/7 weeks of gestation).

The researchers found that the mean postmenstrual age at discharge was 36 3/7 weeks. Significantly longer length of stay (LOS) was seen for infants who were small for gestational age. Significantly longer LOS was also seen for infants born between 34 and 36 6/7 weeks if they had . Additionally, longer LOS was seen for infants with admission diagnoses of neonatal abstinence syndrome, meconium aspiration syndrome, hydrops, hypoxic ischemic encephalopathy, biliary emesis, ABO incompatibly, or a genetic diagnosis.

"Clinicians, hospitals, and families all desire and deserve the most reliable estimates of discharge timing for all NICU infants," the authors write. "Our results indicate that for moderate-to-late preterm infants in the NICU with no other significant medical problems at admission, families can reasonably be counseled that discharge can be expected at 36 weeks of postmenstrual age."