What Did the Unicamp Study Find?

Researchers from the Universidade Estadual de Campinas (Unicamp) interviewed 101 pregnant teenagers aged 12 to 20 attending the prenatal clinic at Hospital da Mulher (Caism) in Campinas, São Paulo, between 2017 and 2024. All participants lived in the greater Campinas metropolitan area. The results were published in The European Journal of Contraception & Reproductive Health Care.

How Common Is Unplanned Pregnancy Among Brazilian Teens?

A striking 84% of the study participants had not planned their current pregnancy. Nationally, Brazil's Sinasc data show that in 2023, 11.9% of all live births were to mothers aged 19 or under. Globally, the World Bank estimates that roughly 21 million girls aged 15–19 become pregnant every year in low- and middle-income countries, with about 12 million of those pregnancies ending in birth.

Who Are the Young Women Most Affected?

The median age of participants was 17. On average, they had their first sexual experience at 14 and their first pregnancy at 16. Most were students (58%), had completed 10–12 years of schooling (78%), and self-identified as parda (mixed race, 48.5%). The study followed approaches that extend adolescence beyond age 19, reflecting newer thinking on human development.

What Factors Reduce the Risk of Unplanned Pregnancy?

Researchers used the internationally validated London Measure of Unplanned Pregnancy (LMUP) rather than a single yes/no question, capturing the full complexity of reproductive intent. The analysis found that teenagers who lived with their partner had an 88% lower chance of an unplanned pregnancy — suggesting that relationship stability plays a meaningful role alongside contraceptive access and education.

Why Does This Matter for Brazil?

Brazil's teen pregnancy rate is four times higher than in developed countries. The Unicamp findings are part of sociologist Negli Gallardo-Alvarado's doctoral research and build on earlier published analyses of unplanned pregnancy in São Paulo state, bringing new focus specifically to adolescent patients.

Key Facts:
  • 84% of the 101 teen participants had unplanned pregnancies (Unicamp/Caism study).
  • In 2023, 11.9% of Brazilian live births were to mothers aged ≤19 (Sinasc).
  • Globally, ~21 million girls aged 15–19 become pregnant annually in low/middle-income countries.
  • Median participant age: 17; first sex at 14; first pregnancy at 16.
  • Living with a partner was linked to 88% lower odds of unplanned pregnancy.
  • Study used the validated LMUP tool; published in The European Journal of Contraception & Reproductive Health Care.