[The dynamics and structure of neonatal mortality in Bulgaria in the period of 1989-1998].

AIM OF THE STUDY

To follow and analyse the state and the structure of neonatal mortality rate (NMR) in the last ten years in Bulgaria.

MATERIAL AND METHODS

A retrospective study is fulfilled on the annual data of the National Health Statistic Institute concerning the NMR in a period of last ten years. Along to this the changes in the perinatal infant mortality rate (PIMR) including the stillbirth and the early NMR are studied. The results are analysed by a comparative method and presented graphically.

RESULTS

The unfavorable trends in the social and economic development of Bulgaria in the last decade are associated with a constant increase of PIMR--from 10.8% in 1989 to 12.9% in 1998, and of its components respectively: the stillbirth--from 5.9% to 7.4% and of the early NMR--from 4.9% to 5.8%. The NMR has increased from 7.3% since 1989 to 8.3% in 1998, the highest level being in 1991--10.4%. Besides the level of prematurely has increased constantly for the recent ten years--from 6.5% to 9.6%. The leading causes of neonatal mortality in Bulgaria are: perinatal asphyxia, congenital malformations, neonatal respiratory distress syndrome (RDS) and perinatal infections. They have remained the same for the recent five years. From them only the mortality caused by perinatal asphyxia has decreased in 1998--to 41.3% in comparison with 1994--43.7% and by congenital malformations--from 29.4% to 23.4% in 1998, the highest reduction being of the malformations of the neural system (2 folds) and of the gastrointestinal system (5 folds). The NMR of the low-birth weight infants (birth weight < 2500 g) has been 58.1% in 1997 and of the very low birth weight infants (< 1500 g)--276.3%. The NMR of both groups premature infants has decreased in 1998, respectively--to 47.6% and 191.4%. The NMR of the term-born infants has been 13.2% in 1997 and 11.1% in 1998.

CONCLUSIONS

The NMR in Bulgaria remains comparatively high, the larger part being on the account of the early NMR, and it has increased for the last ten years. The main causes of NMR have remained the same for the last five years in the leading place been the perinatal asphyxia, the congenital malformations and the neonatal RDS. There is a tendency to a decrease of the perinatal asphyxia and the congenital malformations as a course of NMR in the last five tears. The NMR of the premature infants has decreased in 1998 and is relatively low, but this may be due to the fact that a certain part of the deceased extremely low-birth weight infants (< 1000 g) has been still not registered.