The value of a registry negative urine pregnancy test for the prediction of a future unintended pregnancy among young women

Background: Performance of urine pregnancy test in general adolescents’ clinic reflects caregiver or woman’s concern that there might be a pregnancy. We aimed to assess whether young-unmarried women in whom a negative urine pregnancy test was registered would be at increased risk of a future unintended pregnancy. Methods: The study cohort included consecutive women drafted by the Israeli military between 2013 and 2015. The risk of unintended pregnancy was compared between women with a negative urine pregnancy test (n = 2774), the study group, and those in whom urine pregnancy test was not carried out (n = 126,659), the control group. Results: During the study period, 2147 (1.7%) women experienced an unintended pregnancy. The risk of unintended pregnancy was significantly higher in patients in whom a past pregnancy test was negative 4.3% (n = 118), as compared with the control group 1.6% (n = 2028) (odds ratio [OR], 2.7; 95% confidence interval [CI], 2.23–3.26). In multivariate analysis history of a negative pregnancy test results was an independent predictor for a future unintended pregnancy (adjusted OR, 2.0; 95% CI, 1.63–2.52). Conclusions: A history of a negative pregnancy test among young conscripted women is a significant risk indicator for a future unintended pregnancy. Directed efforts should be made in this particular vulnerable group of patients.