A multicenter cohort study analysing the implementation of a new guideline for women with pregnancy of unknown location or ectopic pregnancy in the Netherlands

Objective: Evaluation of the implementation of a new guideline for diagnosis and treatment of women with pregnancy of unknown location (PUL) or ectopic pregnancy (EP).

Design: Multicenter retrospective cohort study.

Setting: Six hospitals in the Northern part of the Netherlands.

Population and methods: Women above 18-years old with a final diagnosis of PUL or EP between January 2012 to April 2020.

Main outcome measures: Diagnostic findings, type of treatment and outcomes, before and after implementation of the guideline. User interpretation of the guidelines.

Results: 1306 women with PUL (N = 289) or EP (N = 1017) were included. The amount of women diagnosed with PUL has significantly (P < 0.001) increased between the previous guideline (16.6 %; 115/693) and the new guideline (28.4 %;174/693). A significantly lower percentage of women, after implementation of the new guideline, underwent surgical management (odds ratio [OR] = 0.516, 95 % confidence interval [CI] 0.399 - 0.668P < 0.001) versus treatment with MTX (odds ratio [OR]=2.529, 95% confidence interval [CI] 1.719-3.723, P<0.001). The overall success of treatment with MTX was 80.5 % (N = 103) compared to 95.2 % (N = 907) of surgery (P < 0.007). There was no observed difference in adverse events or guideline adherence between the guidelines.

Conclusion: The implementation of the new guideline contributes to an increase in women diagnosed with PUL and treated with MTX. Treatment with MTX caused more complications and a lower treatment success compared to women undergoing surgery. This did not lead to an increase in adverse events between the guidelines. The overall adherence to the guidelines was equal.

Key message: Implementation of the new guideline contributes to an increase in women diagnosed with PUL and conservative treatment with methotrexate (a drug with a higher risk of complications and a lower successful treatment compared to surgery), however this did not lead to an increase in adverse events between the old and new guideline.