National Partnership for Women & Families

Monthly Women's Health Research Review

IUDs, Contraceptive Implant Effectively Prevents Repeat Pregnancy Among Young Women, Study Finds

Summary of "Twelve-Month Contraceptive Continuation And Repeat Pregnancy Among Young Mothers Choosing Postdelivery Contraceptive Implants or Postplacental Intrauterine Devices," Cohen et al., Contraception, Oct. 13, 2015.

"Young mothers who initiate use of long-acting reversible contraceptives (LARCs) such as contraceptive implants and intrauterine devices (IUDs) have lower rates of repeat pregnancy than those who use shorter-acting methods and those who decline postpartum contraception," according to Rebecca Cohen of the Department of Obstetrics and Gynecology at the University of Colorado Anschutz Medical Center and colleagues.

The researchers wrote that "LARC methods are acceptable to adolescents, and uptake is high when these methods are offered to adolescents and young women in the postpartum period." However, Cohen and colleagues noted that while "[c]ontinuation rates of LARC methods are higher than with user-dependent methods such as oral contraceptive pills and injections ... IUDs and implants have not been directly compared when initiated in the immediate postpartum period." For their study, the researchers "hypothesize[d] that young mothers choosing postpartum implants prior to hospital discharge have lower rates of device discontinuation and lower rates of repeat pregnancy within 12 months of delivery than those choosing postplacental IUDs."

Materials and Methods

The study involved participants from the Colorado Adolescent Maternity Program (CAMP) at the Children's Hospital Colorado. Beginning in their second trimester, all patients received counseling on FDA-approved contraceptive methods.

All CAMP participants who delivered at the University of Colorado were eligible for this observational study, excluding women who:

  • Gave birth at a different hospital;
  • Placed the child up for adoption;
  • Had a stillbirth;
  • Started a LARC method after being discharged from the hospital; or
  • Chose a short-acting contraceptive method.

All study participants received their contraceptive of choice at no cost and were permitted to initiate a different method if they stopped using their initial method of birth control. According to the researchers, study participants who opted for a hormonal or copper IUD received the device immediately after delivery, while the women who chose a contraceptive implant received it before they were discharged.

Researchers used the CAMP Electronic Report on Adolescent Pregnancy (ERAP) to track information on contraception initiation, in addition to participants' demographic, reproductive and pregnancy-related data.

Results

According to the researchers, 479 CAMP participants gave birth at the University of Colorado Hospital between Jan. 1, 2010 and Dec. 31, 2011. All of the 244 patients (51%) who initiated LARC methods before being discharged from the hospital opted to participate in the study.

Among the participants, 82 "chose postplacental IUD (74 levonorgestrel and 8 copper) and 162 chose the contraceptive implant." The only statistically significant demographic difference researchers found between the two groups was that participants who selected the contraceptive implant were more likely to be primiparous (85%) compared to those who chose an IUD (74%).

The researchers also found that participants "who initiated use of contraceptive implants were more likely than those who chose postplacental IUDs to still be using the initial device at 6 months (97% vs. 71% ...) and 12 months (86% vs. 61%)."

Meanwhile, among participants who discontinued IUD use within 12 months, 14% (9/67) discontinued because of preference, while 25% (17/67) reported IUD expulsion. According to the researchers, the "[m]edian time to expulsion was 4.1 weeks," with 94% of expulsions "occur[ing] within 12 weeks of placement." Overall, "Participants recognized 15/17 (89%) of expulsions." The researchers also noted that "[n]o implant users reported expulsion or inadvertent removal," although "14% (19/135) requested removal."

According to the researchers, 3.5% (7/202) of participants became pregnant within 12 months of discontinuing LARC use, including two women in the implant group and five women in the IUD group. There were no pregnancies resulting from LARC failure. The researchers added that while pregnancy rates were similar between IUD and implant initiators at six months, a higher proportion of IUD initiators became pregnant by 12 months (7.6%) than implant initiators (1.5%).

The researchers noted that one of the five IUD initiators who became pregnant "had a recognized expulsion" and did not replace the IUD or begin a new contraceptive method. Meanwhile, three IUD initiators who became pregnant requested removal and "did not start alternative methods," while "one removed her own IUD and started a short-acting method." Of the two implant initiators who became pregnant after device removal," the researchers noted, one "initiated use of a short-acting method, and the other did not initiate an alternative method."

Discussion

"In our cohort of young mothers who initiated LARC devices prior to hospital discharge, 86% with implants and 61% with IUDs were still using that device at 12 months postpartum," with "[t]he difference in discontinuation rates between the two groups ... driven by IUD expulsions," the researchers wrote. They added, "Both postpartum contraceptive implants and postplacental IUDs were effective strategies to avoid repeat pregnancy by 12 months postpartum, with rates well below historical controls."

The researchers noted that "of the seven pregnancies that occurred in the cohort, only one was in a patient with an IUD expulsion ... likely because 15 of the 17 participants who experienced expulsion initiated another highly effective method [LARC or depot medroxyprogesterone acetate (Depo-Provera)] at the time the expulsion was recognized." Cohen and colleagues stated, in addition, that "[f]ive of the seven patients who became pregnant did not initiate any contraceptive method after LARC discontinuation."

Noting that both the IUD and implant "were effective at preventing repeat pregnancy within 1 year," Cohen and colleagues wrote, "Providers can recommend both postplacental IUDs and postpartum implants to adolescents and young women who wish to avoid rapid repeat pregnancy." However, they added that "because early expulsion of postplacental IUDs is common (25%) and may not be recognized by the patient (11% of expulsions), clinicians should emphasize the importance of follow-up to IUD initiators."