Women who used contraceptive implants or injections after an abortion are a lot more likely to have another one, finds a large United Kingdom study. Long-acting reversible contraception (LARC) such as implants and Depo-Provera are often promoted as contraceptive method of choice for women undergoing abortion.

The authors found that women who used either implants or the contraceptive injection Depo-Provera were more likely to have another abortion 2-5 years after the first termination compared to those who used other methods. While LARC methods are 'effective', explain the authors, "discontinuation rates are high, and therefore make terminations more likely." 

Around one third of women have more than one abortion in the UK and the authors carried out a retrospective study using data from the Termination of Pregnancy Database in the NHS Grampian (Scotland) region between 1997 and 2003. They took into account factors, such as age, socioeconomic deprivation, previous obstetric history, and sexual health history.

Of the 13,621 women who had an abortion, 23.4% went on to have at least one more. 

Women aged below 20 years at the time of the first abortion had an estimated 5.59 times higher chance of having a repeat termination. Women with two previous live births at the time of their abortion had an estimated 1.51 higher likelihood of having repeat ones compared to women with a single termination. Poor women had an estimated 1.23 higher chance of having a repeat termination when compared to those in the least deprived group. Furthermore, these women were more likely to have been tested for blood-borne virus and were more likely to test positively for a chlamydia infection.

Women with more than one abortion were more likely to have had an implant as their post-termination contraceptive method. Women who were fitted with an implant after the first abortion had an estimated 1.78 times higher chance of another abortion compared to those with no method, or unknown or natural methods of contraception 2 years after the initial termination.

Like all observational studies, no firm conclusions about cause and effect can be drawn but like all observational studies, people with an agenda will do just that if it matches their political beliefs.

"From a public health perspective there is a need to identify women who are more likely to have repeat terminations and put in place targeted interventions to prevent unplanned pregnancies," write the authors from the University of Aberdeen and NHS Grampian.

Published in the Journal of Family Planning and Reproductive Health Care.