Prevalence of contraceptive use in New Zealand women

To estimate the prevalence of contraceptive use among New Zealand women and to measure changes in contraceptive use since the last population-based prevalence estimates were published in 1988.

Nine hundred and four women, aged 35-69 years were randomly selected from the electoral roll. A postal questionnaire was used to gather information on contraceptive use, socio-demographic characteristics and risk factors for ovarian cancer. Data were collected in 2013-2015. Estimates of current and ever-use of contraceptives were made and compared with the findings of the 1988 study by Paul et al. In both studies, participants were members of the control arm of case-control studies.

The study by Paul et al had a response proportion of 84%, whereas that of the current study was 47%. Oral contraceptives had the highest prevalence of ever-use among women aged 35-69 years (89% [347/389]), followed by condom use (54% [211/389]) and vasectomy (44% [170/389]). Compared to the previous study, there has been an increase in ever-use of condoms (24% [185/767] to 64% [148/231]), vasectomy (26% [202/767] to 40% [92/231]) and oral contraceptives (75% [575/767] to 89% [205/231]) among women aged 35-54 years. In contrast, a lower prevalence of tubal ligation (22% [168/767] to 8% [19/231]) was observed.

The study demonstrates a change in patterns of contraceptive use among women aged 35-54 years. The prevalence of ever-use of oral contraceptives and vasectomy remains high in New Zealand compared with other countries.