[Causality and hospital perinatal mortality trend at the Mexican Institute of Social Security, 1998-2002].

Objective: To analyze levels, trend and causes of hospital perinatal mortality at the Instituto Mexicano del Seguro Social (IMSS) during the 5 years from 1998 to 2002 to identify magnitude and related factors in our population and discuss some technical bases and epidemiologic aspects for planning strategies to contribute to its reduction.

Material And Methods: Descriptive study on the death certificates of 39,994 cases of perinatal deaths distributed among 19,108 fetal deaths of 28 weeks and more of gestation and 20,886 neonatal deaths 7 to days of life that occurred in IMSS hospitals during the reference period. With this information and the data on total births, dead or live from the official information system of our Institution, we established annual rates for the entire IMSS, including administrative regions and zones of medical services. We also generated 5-year cumulated numbers for frequencies and rates of perinatal death causes in the IMSS, using the codes of Tenth Revision of the International Diseases Classification.

Results: Hospital perinatal mortality at the IMSS showed a reduction from 1998 (13 per 1,000 births) to 2002 (11.4 per 1,000 births). That trend was observed in the four administrative regions and in the majority of number of medical services zones, but with many differences in levels. It was similar in proportions of fetal (47.8%) and neonatal deaths (52.2%). Two thirds of fetal mortality was linked to maternal complications during pregnancy and labor. A similar proportion of neonatal deaths was due to premature birth and its complications.