[Changes in causes of mortality in very low birth weight neonates].

OBJECTIVE

Investigate the total mortality and changes in cause-specific mortality among very low birth weight (VLBW) infants.

DESIGN

Retrospective epidemiological study.

SETTING

Institute for the Care of Mother and Child, Prague, Czech Republic.

METHODS

Five hundred and fourteen inborn patients (1/1996-12/2001) were retrospectively analysed from our database. We divided our study group into two sub-groups according to their birth weight: under 999 grams (extremely low birth weight group, ELBW, n = 193) and 1000-1499 grams (very low birth weight group, VLBW, n = 321). For statistical analysis the Epi Info 6 (CDC, U.S.) software package was used.

RESULTS

Total mortality was 9.5% (23.0% in ELBW group, 1.2% in VLBW group). The main causes of death in ELBW group were (in order to magnitude): sepsis (49%, early to late onset sepsis ratio 1:4), severe periventricular-intraventricular haemorrhage grade III and IV (PVH-IVH, 20%), respiratory distress syndrome (13%) and other causes (bronchopulmonary dysplasia, renal failure, non-oliguric hyperkalemia: 18%). While in the VLBW group there were three cases of death due to sepsis and one due to PVH-IVH (1.2%).

CONCLUSIONS

According to frequency analysis, sepsis is the leading cause of death among ELBW and severe PVH-IVH and other causes follow. While looking for strength of association in two most often causes (sepsis, PVH-IVH) we found highest risk of death among ELBW newborns with PVH-IVH, but not statistically significant (OR 2.63; 95% CI 0.68, 9.83). Respiratory distress syndrome, formerly reported leading cause of infant death, seems to move to lower order, probably due to introduction of new therapeutic tools into clinical perinatal practice (corticosteroids, surfactant, new modes of artificial ventilation).