[Trends and causes of maternal deaths from 1990 to 2018]

Previous studies have shown a decrease in the maternal mortality (MM) rates in Chile, with a trend towards stability since 2001. However, some of its associated causes such as high blood pressure, obesity, or maternal age, have increased in the last years.

To describe the trend and characteristics of MM in Chile between 1990 and 2018.

MM rates were calculated using death records available at the website of the Department of Health Statistics of the Ministry of Health, using the codes 630 to 679 of the International Classification Diseases (ICD)-9 (630-679) and O00-O99 from ICD-10. Live births were obtained from vital statistics of the National Statistics Institute (INE). The age at the time of death and the causes were recorded. Polynomial and Prais-Winsten modelings were applied.

There were 1,728 maternal deaths with an overall rate for the period of 23 / 100,000 live births. An inflection of the trend was observed in 2003, with a decrease between 1990-2003 and an increase between 2004-2018. While in the 1990-2003 period all age groups decreased their rate, in 2004-2018 it increased significantly in the 20-34 age group. Concerning the causes, "other obstetric conditions not classified elsewhere" showed a steady upward trend, particularly the late maternal deaths or deaths from sequelae of obstetric causes (O96-O97).

MM rates increased in Chile in recent years, mainly due to the increase in women aged 20 to 34 years and in causes referred to as "other obstetric conditions not classified elsewhere." It is possible that changes in risk factors and in the registries could explain this increase.