TY - JOUR
T1 - “False positive” urine pregnancy test results after successful medication abortion
AU - Raymond, Elizabeth G.
AU - Anger, Holly A.
AU - Chong, Erica
AU - Haskell, Sue
AU - Grant, Melissa
AU - Boraas, Christy
AU - Tocce, Kristina
AU - Banks, Joey
AU - Kaneshiro, Bliss
AU - Baldwin, Maureen K.
AU - Coplon, Leah
AU - Bednarek, Paula
AU - Shochet, Tara
AU - Platais, Ingrida
N1 - Funding Information:
Declarations of interest: Bliss Kaneshiro received research salary support through an institutional grant from Estetra Pharmaceuticals, Sebela Pharmaceuticals, and Merck, Sharpe, Dohme. Financial support: This work was supported by the Tara Health Foundation, the Hopewell Fund, and two anonymous donors. These donors had no role in the study design, in the collection, analysis and interpretation of data, in the writing of the report, or in the decision to submit the article for publication.
Funding Information:
Financial support: This work was supported by the Tara Health Foundation, the Hopewell Fund, and two anonymous donors. These donors had no role in the study design, in the collection, analysis and interpretation of data, in the writing of the report, or in the decision to submit the article for publication.
Publisher Copyright:
© 2021
PY - 2021/6
Y1 - 2021/6
N2 - Objective: To examine the proportion of high-sensitivity urine pregnancy test (HSPT) results that were positive by time after successful medication abortion. Study design: We used data from an ongoing study that provides mifepristone and misoprostol for medication abortion by direct-to-patient telemedicine and mail. Providers evaluated abortion outcomes by patient interview and clinical tests per clinical judgment and participant preference. We identified all participants enrolled July 2016 to September, 2020 who had an HSPT result and no indication of viable pregnancy after treatment. We used logistic regression to examine the association between the timing of the initial post-treatment HSPT, gestational age, and the proportion of HSPTs that gave a positive result. Results: Of the 472 participants in our analysis, 88 (19%) had positive initial HSPTs. The proportions that were positive at ≤20 days, 21 to 27 days, 28 to 34 days, and ≥35 days after mifepristone ingestion was 14 of 29 (48%), 15 of 58 (26%), 49 of 258 (19%), and 10 of 127 (8%), respectively (p < 0.001). Gestational age at mifepristone ingestion was not significantly related to positive HSPT results (p = 0.28). Multivariable logistic regression confirmed both findings and did not identify a statistically significant interaction between these variables. In the 67 participants who relied solely on further HSPTs to confirm abortion outcome, the median interval between the initial positive test and first negative test was 14 days. Conclusions: The proportion of participants with positive HSPTs declined with time after successful medication abortion. However, nearly one-fifth of participants with complete abortion had positive tests 4 weeks after treatment. Implications: HSPTs provide an inexpensive, convenient option for confirming success of medication abortion at home. However, a substantial minority of patients without ongoing pregnancy have positive HSPT results. Development of a symptom-based strategy for medication abortion outcome assessment without any confirmatory tests should be a priority.
AB - Objective: To examine the proportion of high-sensitivity urine pregnancy test (HSPT) results that were positive by time after successful medication abortion. Study design: We used data from an ongoing study that provides mifepristone and misoprostol for medication abortion by direct-to-patient telemedicine and mail. Providers evaluated abortion outcomes by patient interview and clinical tests per clinical judgment and participant preference. We identified all participants enrolled July 2016 to September, 2020 who had an HSPT result and no indication of viable pregnancy after treatment. We used logistic regression to examine the association between the timing of the initial post-treatment HSPT, gestational age, and the proportion of HSPTs that gave a positive result. Results: Of the 472 participants in our analysis, 88 (19%) had positive initial HSPTs. The proportions that were positive at ≤20 days, 21 to 27 days, 28 to 34 days, and ≥35 days after mifepristone ingestion was 14 of 29 (48%), 15 of 58 (26%), 49 of 258 (19%), and 10 of 127 (8%), respectively (p < 0.001). Gestational age at mifepristone ingestion was not significantly related to positive HSPT results (p = 0.28). Multivariable logistic regression confirmed both findings and did not identify a statistically significant interaction between these variables. In the 67 participants who relied solely on further HSPTs to confirm abortion outcome, the median interval between the initial positive test and first negative test was 14 days. Conclusions: The proportion of participants with positive HSPTs declined with time after successful medication abortion. However, nearly one-fifth of participants with complete abortion had positive tests 4 weeks after treatment. Implications: HSPTs provide an inexpensive, convenient option for confirming success of medication abortion at home. However, a substantial minority of patients without ongoing pregnancy have positive HSPT results. Development of a symptom-based strategy for medication abortion outcome assessment without any confirmatory tests should be a priority.
KW - False positive
KW - Gestational age
KW - High-sensitivity urine pregnancy test
KW - Medication abortion
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U2 - 10.1016/j.contraception.2021.02.004
DO - 10.1016/j.contraception.2021.02.004
M3 - Article
C2 - 33596414
AN - SCOPUS:85102147038
SN - 0010-7824
VL - 103
SP - 400
EP - 403
JO - Contraception
JF - Contraception
IS - 6
ER -