[Women age as a risk factor for maternal, fetal, neonatal and infant mortality]

Adolescent pregnancy and advanced maternal age are associated with increased risk for maternal, perinatal and infant death. However, the maternal age with the lowest reproductive risk has not been established.

To determine the range of maternal age with the lowest reproductive risk.

A population-based study (2005-2010) was performed analyzing raw data from vital statistics yearbooks of the National Institute of Statistics of Chile. The association of maternal, fetal, neonatal and infant mortality with maternal age was analyzed. The latter was stratified in quinquenniums, between ages 10 and 54 years. Maternal, fetal, neonatal and infant mortality rates were calculated for each quinquennium. The lowest rate was selected as a control group for risk analysis, which was estimated according to Odds Ratio with 95% confidence intervals.

Women of 20-29, 25-34 and under 30 years, had the lowest rate of fetal, neonatal/infant and maternal death, respectively. Women aged 45-49 years had the higher rate of maternal, fetal, neonatal and infant mortality. The risk of fetal, neonatal and infant mortality doubled from 40-44 years onwards, and maternal mortality from the age of 30-34 years.

Our results suggest that the maternal age range with the lesser general reproductive risk is between 20-29 years. This finding should be considered in future studies of reproductive risk and for an appropriate counseling about conception.