Objective: to compare teenagers who become unintentionally pregnant and teenagers who have never been pregnant but are using contraception on matters related to family/partner stability, and communication with a parent or stable sexual partner about sexual matters.

Design: survey utilising self-completed questionnaire.

Setting: a hospital antenatal clinic and community-based family planning clinic.

Participants: 30 teenagers with an unplanned pregnancy and 31 'never-pregnant' teenagers using contraception.

Findings: the two groups were similar on demographic factors, mean age at which sexual intercourse was first experienced, total number of sexual partnerships, the number of teenagers having a current, regular boyfriend and mean length of the interval between when the teenagers first started going out with their boyfriend and when first sexual intercourse took place. Teenagers in the family planning clinic group were more likely to be living with both natural parents and to be still at school or in higher education. The mean length of time pregnant teenagers had been going out with their boyfriend was longer, they were more likely to be cohabiting with him and to be unemployed. Participants from the antenatal clinic group communicated more with their mothers about sexual matters than those in the family planning clinic group, who were more likely to seek this information from books. The family planning clinic participants were more likely to discuss personal rules and values with friends than those in the antenatal clinic group.

Implications for practice: to develop understanding of factors predisposing to unplanned pregnancy during adolescence and to implement measures to counter them, further studies to examine the influence of teenagers' perceptions of family relationships and future life prospects on contraception use and unplanned pregnancy were identified.