Dynamic patterns of long-acting reversible contraceptive use in Mexico: Method mix shift between intrauterine devices...

Long-acting reversible contraceptive (LARC) methods are often grouped in contraception studies, although they differ in ways that may influence patient preferences and access. This study examines trends in intrauterine device (IUD) and implant use in Mexico, and identifies factors associated with implant use compared with IUD use.

We used the 2009, 2014, 2018, and 2023 waves of the Mexican National Survey of Demographic Dynamics (ENADID). The sample included women aged 15-45 currently using LARC. We described the characteristics of LARC users in 2023 and estimated percentage point changes in prevalence for implant and IUD use as a proportion of all modern method use across survey periods. Multivariable logistic regression identified factors associated with implant use versus IUD (reference) among LARC users in 2023.

The sample included 10,411 women (weighted N = 4,012,772). Between 2009 and 2023, implant use increased while IUD use declined, with the largest shifts between 2018 and 2023. During this period, implant use increased by 3.48 percentage points while IUD use declined by 3 percentage points, indicating a method mix shift of implants for IUDs rather than an overall expansion of LARC use. Younger age was associated with higher odds of implant use, with odds declining with increasing age. Women with one or two children had lower odds of implant use compared with nulliparous women.

Use of LARC methods in Mexico has shifted towards increased implant use and decreased IUD use, suggesting a shift between methods rather than expansion of overall LARC use.

Increasing implant use alongside declining IUD use may reflect improved access but could also indicate constrained contraceptive choice. Ensuring availability of both methods is essential to support informed, patient-centered, and contraceptive decision-making.