Sarah Millar


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    Evaluation of two low sensitivity urine pregnancy tests (1000 IU) used for self assessment following early medical abortion

    Sarah Millar, Sharon Cameron
    Chalmers Centre, Edinburgh, UK

    Introduction: The majority of women who have early medical abortion (EMA) at our service choose to confirm the success of the procedure by “self assessment” (a self-performed low sensitivity urinary pregnancy (LSUP) test at home two weeks after EMA). Women contact the abortion service if they have an invalid or positive result or symptoms of ongoing pregnancy. In 2014 we changed from a double cassette LSUP (Babyduo) to a single window LSUP (Check4) (both Quadratech diagnostics, UK). We predicted the Check4 test would be easier for women to use and interpret.
    Aims: To determine if the Check4 test improves the detection of ongoing pregnancies when compared with Babyduo and if there are any differences in reported invalid or positive results between the two tests.
    Methods: A retrospective database review identified women who had EMA “self assessment” in the 10 months before and 10 months after the introduction of the Check4 test. Fishers exact test and descriptive statistics were used for data analysis.
    Results: 1047 women were identified (n=492 Babyduo group and n=555 Check4 group). There were 2 ongoing pregnancies in the Babyduo group and 3 in the Check4 group. Significantly more invalid tests were reported in the Babyduo (n=18, 3.6%) than the Check4 group (n=6, 1.1%) (p=0.0064). Significantly more positive tests tests were reported in the Check4 (n=19, 3.4%) than the Babyduo group (6, 1.2%) (p=0.0244).
    Conclusion: The introduction of the Check4 LSUP has not altered the detection rates, or time to detection, of ongoing pregnancies. It has, however, been associated with fewer attendances for ‘invalid’ results and more for positive results. These findings may reflect that the single window Check4 test gives less margin for error in interpretation than the former double window test. We will continue to use the Check4 LSUP for EMA “self assessment” for this reason.