Risk of abortion within 1-2 years after childbirth in relation to contraceptive choice: a retrospective cohort study.

The primary objective of the study was to investigate whether the choice of long-acting reversible contraception (LARC) was associated with the risk of abortion over a period of 24 months postpartum. The secondary objective was to analyse whether other significant factors were affecting the risk of abortion during this period. In this retrospective cohort study, we analysed 11,066 women who had delivered in three Swedish cities during 2013 and 2014. Demographic and medical variables were obtained from medical records. Attendance at the postpartum visit, choice of postpartum contraception and history of abortion was noted. Logistic regression analysis was performed to assess factors associated with the risk of abortion. The main outcome measure was the proportion of women with abortion up to 24 months postpartum. Data from 11,066 women were included in the final analysis. Within 12-24 months after delivery 2.5% of women had an abortion. The choice of LARC after childbirth reduced the risk of subsequent abortion (odds ratio 0.74; 95% confidence interval [CI] 0.60, 0.91;  =  .005). Smoking, age <25 years and have had a previous abortion significantly increased the risk of abortion during follow-up, whereas exclusive breastfeeding decreased the risk. Increasing the proportion of women who choose LARC postpartum could decrease the risk of abortion for up to 2 years after childbirth.