[Proposal for a death certificate to improve recording and reporting of perinatal mortality]

To analyze perinatal births and deaths recording at the Mexican Institute of Social Security (MISS), and to evaluate the correct classification of perinatal deaths.

From January to March 2000, data were collected from the 37 MISS districts on the total number of births and deaths occurring during 1999, deaths occurring before the seventh day of life, and gestational age and weight at birth. Early neonatal and infant mortality rates were analyzed including or separating newborns with < 1,000 g and < 28 weeks of gestational age.

During 1999 there were 634,892 live births--whose gestational age and birth weight are unknown- and 3,984 stillbirths > or = 28 gestation weeks. There were 4,556 newborns who died before the seventh day of extrauterine life; 1,385 of them (30.4%) weighted less than 1,000 g and had a gestational age < 28 weeks. The analysis of mortality with and without these newborns shows a decrease of two points in early neonatal and infant mortality rates.

This study shows that classification and reporting of perinatal mortality are inappropriate. A proposal is made to develop information systems that include weight and gestational age of all births. A new perinatal death certificate replacing current fetal and general death certificates would allow proper mortality classification and comparisons between countries.