Prevention of unintended pregnancies by using emergency contraception: the differences between levonorgestrel and ulipristal acetate. A theoretical model using data from a survey on the use of emergency contraception in Spain, 2017

Abstract

Objective: To estimate the differences in unintended pregnancies avoided using either levonorgestrel (LNG) or ulipristal acetate (UPA) emergency contraception (EC).

Design: Cross-sectional study.

Setting: Survey carried out in Spain.

Participants: 1000 Spanish women reporting unprotected sex in 2017.

Main measurements: EC use, reasons for not using EC, calculation of the number of unintended pregnancies avoided.

Results: 39% of Spanish women having had unprotected sex used EC. 61% of those women did not use EC and 11% did not know the existence of this resource. In 2017 the use of EC prevented 101,271 unintended pregnancies. If instead of using LNG every woman had used UPA another 15,979 additional pregnancies could have been prevented.

Conclusions: If all Spanish women having unprotected sex used EC we could expect a significant decrease in the number of unintended pregnancies and abortions. Using UPA instead of LNG would have a greater impact on that reduction with the corresponding benefit for women and society as a whole.

摘要

目的：比较左炔诺孕酮（LNG）和醋酸乌利司他（UPA）紧急避孕法（EC）避免意外怀孕的差异。

设计：横断面研究。

单位：调查在西班牙进行。

参与者：2017年有1000名西班牙女性报告发生无保护措施的性行为。

主要测量方法：使用及不使用紧急避孕法的原因, 避免意外怀孕的数量计算。

结果：39%的无保护措施性生活的西班牙妇女使用EC。61%的妇女没有使用EC, 11%的妇女不知道紧急避孕法的存在。2017年, EC预防意外怀孕101271例。若不使用左炔诺孕酮, 而换成每个妇女都使用UPA, 那么就可以防止15979例额外怀孕。

结论：如果所有进行无保护措施性生活的西班牙妇女都使用EC, 我们可以预期意外怀孕和流产的数量将会显著减少。使用醋酸乌利司他而不是左炔诺孕酮将对减少意外怀孕及流产产生更大的影响, 并为妇女和整个社会带来相应的好处。

The Chinese abstracts are translated by Prof. Dr. Xiangyan Ruan and her team: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China.

Keywords:

• Emergency contraception
• unintended pregnancy
• abortion
• Levonorgestrel
• Ulipristal acetate

Acknowledgements

The authors thank Weber Shandwick for providing the survey data and their assistance in editing and correcting the paper.

Disclosure statement

All the authors are members of the advisory Board of HRA Pharma.