Systematic follow-up of hyperbilirubinemia in neonates with a gestational age of 35 to 37 weeks.

Objectives: To determine the outcomes of an intervention for follow-up of bilirubinemia in the first week of life in a cohort of newborn infants with gestational ages between 35 0/7 and 37 6/7 weeks and to determine risk factors for readmission for phototherapy (total bilirubin > 18 mg/dL).

Methods: Retrospective cohort study carried out at a public teaching hospital. Neonates underwent periodic monitoring of total bilirubin levels (measured in plasma or by transcutaneous device) before and after discharge to assess the need for phototherapy. A systematic approach, based on risk percentiles of a bilirubin reference curve, was employed.

Results: The study sample comprised 392 neonates. Only one outpatient visit was required in 61.7% of newborns. Peak total bilirubin was ≥ 20 mg/dL in 34 neonates (8.7%), and reached 25-30 mg/dL in three (0.8%). Phototherapy was indicated after discharge in 74 neonates (18.9%). Weight loss between birth and first follow-up visit and total bilirubin above the 40th percentile at discharge were risk factors for requiring phototherapy. Total bilirubin above the 95th percentile at discharge was associated with greater risk of readmission (RR = 49.5 [6.6-370.3]). Weight loss between discharge and first follow-up visit was the sole independent clinical predictor (RR = 1.16 [1.04-1.17]).

Conclusion: Systematic follow-up during the first week of life was effective in preventing dangerous hyperbilirubinemia. Encouraging breastfeeding and discharging neonates only after weight loss has been stabilized may prevent readmission due to hyperbilirubinemia.