The likelihood of a woman having sexual intercourse before age 20 ranges from 46 percent to 63 percent in Brazil, Colombia, the Dominican Republic, Ecuador, El Salvador, Guatemala, Mexico, Peru and Trinidad and Tobago, according to data from the Demographic and Health Surveys. The probability of entering a union before age 20 is somewhat lower, ranging from 36 percent to 60 percent. And the likelihood of having a first child before the age of 20 ranges from 30 percent to 50 percent. In some of the countries, women aged 20-24 are less likely than those aged 40-45 to have experienced all three events before age 20, but in others there has been virtually no change or the decline has been erratic. Overall, teenagers in all the countries are better educated today than they were 25 years ago. However, in seven of the nine countries, among women with a primary education or less, those aged 20-24 are more likely than those aged 40-44 to have had first intercourse, first union and first birth before age 20. Among women who have had secondary schooling or more, the relationship between education and the likelihood of these three events is more erratic: Only in one country (Colombia) did the likelihood of all three events decrease between the youngest and the oldest cohorts of women with secondary schooling or more