[Risk factors of retinopathy of prematurity in infants 32 to 36 weeks gestational age].

INTRODUCTION

In our study we determined possible risk factors for retinopathy of prematurity (ROP) in infants 32 to 36 completed weeks of gestational age based on a regional German neonatal database. We examined especially whether or not oxygen therapy over more than 3 days is related to a higher risk of ROP.

MATERIALS

We identified 7172 ophthalmologically examined infants, 32 to 36 completed weeks gestational age, born from 1990 to 1996. ROP was diagnosed in 195 (2.7 %). We examined the following variables as risk factors for ROP in infants receiving oxygen for less than 4 days: gestational age, sex, blood pH of 7.0 or less, body temperature of 36 degrees C or less, phototherapy, blood pO2 of 35 mm Hg or less, small-for-gestational age, sepsis, ventilation after birth, and blood transfusion.

RESULTS

Sex, blood pH of 7.0 or less, blood pO2 of 35 mm Hg or less, sepsis, phototherapy, and small-for-gestational age were not associated with a significant risk of ROP. A gestational age of 32 weeks compared to a gestational age of 36 weeks was associated with an increased risk of ROP (odds ratio, 2.95; 95 % confidence interval, 2.18 to 4.01). Ventilation after birth (adjusted OR, 2.29; 95 % CI, 1.70 to 3.15) and blood transfusion (adjusted OR, 5.28; 95 % CI, 3.80 to 7.23) increased the risk of ROP regardless of gestational age. Oxygen therapy for more than 3 days was not associated with an increased risk of ROP (OR, 1.06; 95 % CI, 0.67 to 1.70).

CONCLUSION

In neonates delivered between 32 and 36 weeks of gestation, the duration of oxygen supplementation should not necessitate an ophthalmological examination. A vigorous restriction of blood transfusions could reduce the incidence of ROP.