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

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.