Two problems originating from the advanced use of medical technology in screening for malformations and in the care of preterm and low birthweight infants are presented: the impact of the increasing number of induced medical abortions and the differences in statistical definitions on perinatal mortality (PNM) figures. Data on 186,562 births registered in the Finnish Medical Birth Registry between 1987 and 1989 were studied, and 65,554 medical abortions (of which 1647 were performed after the sixteenth week of gestation) registered in the Abortion Registry between 1985 and 1990. A 115% increase in abortions for medical reasons in the period 1985-1990 was found. It was estimated that the trend accounted for up to one-third of the decline in PNM rate during that time. The perinatal mortality rate was strongly influenced by very small infants. The application of the Finnish version of the International Classification of Diseases, Ninth Revision (ICD-9) (including all livebirths and using both birthweight of 500 g and gestational age of 22 weeks as the criteria) resulted in PNM rates which were about 5% higher than according to ICD-9. We suggest that the impact of medical abortions on perinatal statistics has reduced the value of the perinatal mortality rate as an indicator of the standard of care.
PIP: Criteria vary for determining which newborns should be included in perinatal statistics. Identical criteria are also applied in different ways, while registration laws and data collection recommendations may also differ from one another. This situation is problematic, especially for international comparisons of perinatal mortality (PNM) rates. International efforts made to develop and unify these definitions have not, however, proved successful. In Europe, for example, there are at least five different definitions of stillbirth. The care of premature infants has developed rapidly, increasing the survival rate of very small newborns. On the other hand, more efficient methods have been introduced for screening malformations and other fetal diseases. The authors considered the effect of induced abortions for medical reasons upon the PNM rate as well as the impact of departures from the International Classification of Diseases, Ninth Revision (ICD-9), recommendations for calculating perinatal statistics currently used in Finland. Data were studied on 186,562 births registered in the Finnish Medical Birth Registry during 1987-89, as well as for 65,554 medical abortions registered in the Abortion Registry during 1985-90. There was a 115% increase in abortions for medical reasons during 1985-90. It is estimated that the trend accounted for up to one-third of the decline in PNM rate during that time. The PNM rate was strongly influenced by very small infants. The application of the Finnish version of the ICD-9 resulted in PNM rates approximately 5% higher than according to ICD-9. The impact of medical abortions upon perinatal statistics reduced the value of the PNM rate as an indicator of the standard of care.