The proportion of time in which young never-married Colombian and Peruvian women are sexually experienced increased between 1985 and 1999, according to an analysis of Demographic and Health Survey (DHS) data.1Women's use of contraceptives—especially condoms—also increased in that time, but so did their conception rates. In both countries, contraceptive protection increased during each year and with each year of a woman's age; it was negatively associated with living in a town or rural setting and with having less than a secondary education.
To examine trends in sex, contraceptive use, conception and pregnancy resolution among young women, researchers used DHS calendar data collected in Colombia and Peru—two countries that had done much during the late 1980s and 1990s to address the sexual health needs of young people. From 1990 to 2000, three surveys were conducted in each country; each asked women aged 15-49 to create a month-by-month calendar documenting their contraceptive use, conceptions and births, and postpartum infecundability (amenorrhea and abstinence) for the five years prior to the interview, creating a study period from 1985 to 1999. In addition, the surveys asked respondents about their demographic characteristics, their age at first intercourse, the date of their first union and the planning status of their recent live births or current pregnancy.
The researchers confined their analysis to data from never-married women aged 15-24 during the calendar period. They classified each month by whether women were sexually inexperienced, sexually active and unprotected by contraception, sexually active and protected by contraception, or sexually active and naturally protected by postpartum infecundability. (Women were considered to be sexually active during every month after their sexual debut.) Conception rates were calculated for all never-married women and for sexually active women. The researchers used logistic and Poisson regression models to examine the effects of selected covariates on contraceptive protection and conception rates, respectively.
The age makeup of participants remained stable throughout the study period: About half (51-55%) of woman-years from both countries were contributed by 15-19-year-olds. The proportion of woman-years contributed by Colombian women with secondary or higher education increased from 63% to 74% between 1985-1989 and 1995-1999, and the proportion representing women living in an urban area increased from 54% to 79%. The educational attainment and locality of women in Peru remained stable: About 25% reported having less than a secondary education, and 70% living in a city.
Over the study period, the proportion of time in which women were sexually active increased: In 1985-1989, about 20% of Colombian and Peruvian woman-years were contributed by sexually experienced women, whereas by 1995-1999, the proportions had increased to 42% in Colombia and to 28% in Peru. Although the proportion of time in which women were sexually active and unprotected by contraception increased—from 13% to 19% in Colombia and from 13% to 17% in Peru, the proportions protected by contraception also increased—from 3% to 18% in Colombia and from 4% to 8% in Peru. Increased contraceptive protection in both countries was largely attributable to condom use, which increased by 20 percentage points in Columbia and 14 percentage points in Peru.
The conception rate among all single women increased over the study period, from 3.7 to 6.2 per 100 woman-years in Colombia and from 3.9 to 4.9 per 100 woman-years in Peru. However, the rates among sexually active women decreased from 22.7 to 16.7 in Colombia and from 23.3 to 20.2 in Peru. In Colombia, the proportion of pregnancies ending in abortion or miscarriage nearly doubled, from 7% in 1985-1990 to 13% in 1995-1999; the proportion in Peru stayed relatively stable at 8-10%. Of premarital pregnancies that resulted in live births, the proportion that were delivered after the woman married or began cohabiting decreased over the study period from 40% to 31% in Colombia and from 49% to 39% in Peru. However, the proportion delivered before a union was formed increased in Peru—from 43% to 51%. Examination of the proportion of premarital pregnancies ending in live birth that were wanted showed decreases in both countries during the study period—from 69% to 36% in Colombia and from 51% to 38% in Peru.
In multiple regression analysis, the odds of being protected by contraception increased during each calendar year in both Colombia and Peru (odds ratios, 1.1 each). Women aged 20-24 were significantly more likely than 15-19-year-olds to have practiced contraception (1.6 for Colombia; 1.4 for Peru); living in a town or rural area and having less than a secondary education were associated with reduced odds in both countries of being protected by contraception (0.5-0.7).
Using Poisson regression, the researchers found that conception rates among all women in Colombia and Peru increased in each calendar year (incidence rate ratios, 1.06 and 1.02, respectively); however, calendar year had no statistically significant effect on the rates for sexually active women. Among all women, having less than a secondary education and being 20-24 were significantly associated with increased rates of conception (1.6-2.1); living in a town or rural area rather than a city was significantly associated with increased conception rates in Peru (1.3) but not in Colombia. Among sexually active women, living in a town or rural area was significantly associated with increased conception rates in both Colombia (1.4) and Peru (1.2), and having less than a secondary education was associated with an increased rate in Colombia (1.5). In both countries, women aged 20-24 had reduced conception rates when compared with 15-19-year-olds (0.8 each).
The researchers comment that the overall trends for the two countries were "strikingly similar" and that programmatic strategies implemented in one may be effective in the other. Given that the increase in sexual exposure is outpacing the increase in contraceptive use, the researchers suggest that "programs and policies should continue to reinforce efforts to provide appropriate information and services to young single women." Also, they recommend that condom promotion continue, as condom use increased substantially in both countries over the study period; however, they note that a strategy that goes "beyond the focus on using contraceptives" is needed to "address the ever-increasing number of abortions and unwanted children who are born out of wedlock."
1. Ali MM, Cleland J and Shah IH, Trends in reproductive behavior among young single women in Colombia and Peru: 1985-1999, Demography, 2003, 40(4):659-673.