Risk factors and the choice of long-acting reversible contraception following medical abortion: effect on subsequent induced abortion and unwanted pregnancy

Abstract

Objective: To analyse the post-abortion effect of long-acting reversible contraception (LARC) plans and initiation on the risk of subsequent unwanted pregnancy and abortion.

Materials and methods: retrospective cohort study of 666 women who underwent medical abortion between January–May 2013 at Helsinki University Hospital, Finland. Altogether 159 (23.8%) women planning post-abortion use of levonorgestrel-releasing intrauterine system (LNG-IUS) participated in a randomized study and had an opportunity to receive the LNG-IUS free-of-charge from the hospital. The other 507 (76.2%) women planned and obtained their contraception according to clinical routine. Demographics, planned contraception, and LARC initiation at the time of the index abortion were collected. Data on subsequent abortions were retrieved from the Finnish Abortion Register and electronic patient files until the end of 2014.

Results: During the 21 months ([median], IQR 20–22) follow-up, 54(8.1%) women requested subsequent abortions. When adjusted for age, previous pregnancies, deliveries, induced abortions and gestational-age, planning LARC for post-abortion contraception failed to prevent subsequent abortion (33 abortions/360 women, 9.2%) compared to other contraceptive plans (21/306, 6.9%) (HR 1.22, 95% CI 0.68–2.17). However, verified LARC initiation decreased the abortion rate (4 abortions/177 women, 2.3%) compared to women with uncertain LARC initiation status (50/489, 10.2%) (HR 0.17, 95% CI 0.06–0.48). When adjusted for LARC initiation status, age <25 years was a risk factor for subsequent abortion (27 abortions/283 women, 9.5%) compared to women ≥25 years (27/383, 7.0%, HR1.95, 95% CI 1.04–3.67).

Conclusions: Initiation of LARC as part of abortion service at the time of medical abortion is an important means to prevent subsequent abortion, especially among young women.

Chinese abstract

目的：分析流产后应用长效可逆性避孕（LARC）计划以及其应用时间对后续意外怀孕和流产风险的影响。

对象和方法：对2013年1月至5月在芬兰赫尔辛基大学附属医院接受药物流产的666名妇女进行回顾性队列研究。159名（23.8％）计划用左炔诺孕酮宫内释放系统（LNG-IUS）的妇女参加了此随机研究, 并有机会从医院获取免费的LNG-IUS。其他507名（76.2％）女性按照临床常规避孕。收集流产时的人口统计学, 避孕方法及LARC置入时间指标。

结果：为期21个月（[中位数], IQR 20-22）的随访中, 54名（8.1％）妇女再次流产。在校正年龄, 怀孕, 分娩, 人工流产次数, 孕龄后发现, 与其他避孕方式（21 / 306,6.9 ％）相比, LARC用于流产后避孕未能有效防止再次流产（33次人工流产/ 360名妇女, 9.2％）（HR 1.22,95％CI 0.68-2.17）。然而, 与置入LARC时间不确定的女性（50/489, 10.2％）相比, 明确的LARC置入时间降低了流产率（4例流产/ 177例女性, 2.3％）（HR 0.17,95％CI 0.06-0.48）。当对LARC置入时间校正后, 与年龄≥25岁（27 / 383,7.0％）女性相比, 年龄<25岁（27次流产/ 283名女性, 9.5％, HR1.95,95％CI 1.04 -3.67）是再次流产的危险因素。

结论：在药物流产时置入LARC作为堕胎服务的一部分是预防后续流产的重要手段, 尤其是在年轻女性中。

Keywords:

• Abortion
• termination of pregnancy
• repeat abortion
• long-acting reversible contraception

Acknowledgements

We thank research nurse Pirjo Ikonen for her never failing management of the patients during the randomized study, and Jennifer Rowland for language revision.

Disclosure statement

O.H. has served on advisory boards for Bayer Healthcare and Gedeon Richter, and designed and lectured at educational events connected with these companies. O.H. has also lectured at educational events organized by Merck/MSD and Sandoz. The other authors (R.K. and M.M.) have no conflicts of interest to declare.

Additional information

Funding

This work was supported by the research grants from The Hospital District of Helsinki and Uusimaa, The Finnish Cultural Foundation (February 2014 and February 2017), Finnish-Norwegian Medical Foundation (June 2016), and Instrumentarium Science Foundation (March 2017). The funding sources of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.