Does Decreasing Mortality Increase Serious NeonatalNeurosensoric Morbidity?

Overview

Objective:
To investigate relation between the mortality and the incidence of serious neonatalneurosensoric morbidity in very low birth weight newborns (VLBWN, birth weigh < 1499 g) duringthe three periods as defined by different quality of the parinatal and neonatal care.Design: Retrospective analysis.Setting: Perinatal center of the General Faculty Hospital. 1st Medical Faculty Charles University,Prague.Subject and methods: All live-born VLBWN in 1987 - 2001 were divided according to their birth-dateto three five-year periods characterized by different quality of the perinatal and neonatal care.Ist period 1987 - 1991: the presurfactant aera with no standard use of antenatal steroids and withoutdefined border of the fetus viability; IInd period 1992 - 1996: the transient aera; IIIrd period 1997 -2001: the surfactant aera with standard use of the antenatal steroids, and defined border of the fetusviability. VLBWN were divided according to birth weight to three subgroups (p. h. < 750 g, p. h. = 750- 999 g, p. h. = 1000 - 1499 g).Mortality was defined by a death in our department until the discharge.VLBWnewborns classified as newborns with serious neonatal neurosensoric morbidity (NNsM) hadto have one of the following diagnoses at least: severe intraventricular haemorrhage (IVH gr. 3 - 4),posthemorhagic hydrocephaly (PHH), cystic periventricular leukomalacia (cPVL), meningitis, ventriculitis,encephalitis (M/E), retinopathy of prematurity > stage III (ROP > III st.). The
2 test wasused for statistic evaluation.Results: Therewere 873VLBWNborn and 208 of them died in thewhole period (1987 - 2001).Mortalitydecreased in 5 year periods gradually: Ist period 111/226 (49%); IInd period 55/217 (25 %); IIIrd period42/430 (10%). The decrease of mortality was significant in all weight categories (p < 0.001). Theincidence of NNsM was evaluated in 612 newborns and was similar in all periods regarding weightsubcategories < 1000 g, but decreased significantly in the weight category 1000 - 1499 g (14/215 (6%)vs 13/73 (18%), p < 0.01).Conclusion: Improvement in survival of extremely low birth-weight infants did not increase theincidence of serious neurosensoric morbidity and evenmore NNsM was reduced in haevier verypremature newborns during the nineties.

Key words:
very low-birth weight, mortality, neurosensoric morbidity, perinatal centers