Can’t solve puzzle of teen pregnancy? Norplant may supply missing piece

Method found effective in cutting teen-age pregnancy rates

Two new studies of Norplant use offer compelling evidence that this contraceptive method is highly effective, especially for controlling teen pregnancy.

Norplant use has declined since making a strong debut following its 1990 U.S. market approval. According to Contraceptive Technology Update’s 1996 Pill Survey, Norplant now accounts for 1% or less of teen patients’ contraceptive choices, with Depo-Provera gaining ground on oral contraceptives. (For more information on the Pill Survey, see CTU, October 1996, p. 17.)

Whether because of complaints of significant side effects, an environment of fear generated by the threat of lawsuits, or an interplay between the two, many family planning clinicians may not be giving the method due consideration, says Michael D. Rudnick, MD, PhD, director of Denver’s Westside Family Health Center’s teen clinic.

Norplant does have side effects, including bleeding, hair loss, and weight gain, Rudnick admits. But if patients are thoroughly counseled prior to insertion and guided through the initial months of adjustment, clinicians may discover that many patients find satisfaction with the method.

"What makes it particularly important for teens, it bridges the impulsivity, which is such a problem with contraception," Rudnick says. Because Norplant is a long-lasting contraceptive that is not as easily reversed as other methods, users are apt to stick with it longer. And for a teen, every month gained in avoiding pregnancy provides important time for her own physical and emotional growth, he notes.

"Even if I hold them off for a year, a 15-year-old mom is a better risk of not having a very low-birth-weight baby and being a successful parent than a 14-year old mom," Rudnick points out.

Norplant does have its share of side effects, Rudnick concedes. But the degree of the problem doesn’t match the decline in interest in the method, he concludes.

Take a closer look at the studies

Two studies presented at a poster session during the recent meeting of the Washington, DC-based American Public Health Association offer insight into teens’ acceptance of the Norplant method, as well as its effectiveness in preventing teen pregnancy.

Investigators with the Research Triangle Institute (RTI) of Research Triangle Park, NC, surveyed 2,477 women at family planning and postpartum clinics in two Southeastern major metropolitan areas to determine the following1:

• Which method — Norplant, Depo-Provera, or the Pill — do teens (ages 18 and under) continue to use longer, and which best protects them against pregnancy?

• When teens stop using these methods, do they continue to use contraception, and if so, do they choose effective methods?

• How do teens compare in these areas to women ages 19 and up?

The study was supported through a grant by the Bethesda, MD-based National Institute of Child Health and Human Development (NICHD), says Helen P. Koo, DrPH, RTI senior research demographer. NICHD issued a request for proposals in 1991 to examine why women would choose Norplant, the latest contraceptive available on the market.

When Depo-Provera entered the United States soon thereafter, additional funding was obtained from the Kaiser Family Foundation of Menlo Park, CA, for inclusion in the comparison study, Koo explains.

RTI researchers compared women who used Norplant and Depo-Provera against those women who were choosing the Pill, as well as the condom and tubal ligation.

Investigators conducted a baseline survey from July 1993 to October 1994, with a follow-up survey from November 1994 to April 1996. A second follow-up survey concludes in April. The probability sample of patients included white and African-American women who were using a birth control method different from the one, if any, they used in the previous three months.

The sample included 2,477 women. Many of the women were young (33% under age 19), predominantly African-American (84%), low-income (74% on Medicaid), and never married (81%). Many had experienced previous pregnancies, and two-thirds of those were unplanned.

Forty-one percent of the women chose the Pill at the time of the initial survey, with 30% selecting Depo-Provera, 12% selecting Norplant, 12% selecting sterilization, and 5% choosing condoms.

Proportional hazards models show that both age groups recorded the lowest discontinuation rates on Norplant. Just 11% of those ages 18 and younger had stopped the method by 12 months, compared to 12% for those 19 and older. With Depo-Provera, teens recorded lower discontinuation rates than the older women; 38% of teens discontinued use by 12 months, in contrast to the 47% rate for women ages 19 and older. This trend switched, though, when it came to the Pill. More than 50% of women ages 19 and up had discontinued pill use by 12 months, while 71% of teens surveyed had stopped during the same time period.

"After stopping use of these methods, women who had their implants removed were about equally likely to switch to another hormonal method or to a coitus-dependent method," Koo notes. This was true of both age groups.

"After stopping use of either Depo-Provera or the Pill, however, women were more likely to switch to less effective contraceptive practice (i.e., coitus-dependent methods and non-use while sexually active but not seeking pregnancy) than to another hormonal method. Furthermore, following both Depo-Provera and the Pill, teens were more likely to take up less effective practice than older women. And teens who quit using the Pill were twice as likely to take up less effective contraceptive practice than teens who stopped using Depo-Provera.

"Clearly, adolescents are best protected by Norplant, followed by Depo-Provera, and last by the Pill — both in terms of continuing their use and subsequently switching to an effective practice," RTI researchers conclude.

When looking at the study’s results, however, consider the motivation of teen contraceptive users when they were choosing a birth control method, says Koo.

"We have to be careful in how we interpret these results," she notes. "I think women, especially adolescents, who chose Norplant, were more motivated in the first place to prevent pregnancies than women or young girls who chose Depo-Provera or the Pill."

This motivation may account for Norplant users’ selection of other effective methods of birth control, such as Depo-Provera, when they decided to discontinue implant use, Koo says.

Norplant impacts Colorado repeat births

A study of the probability of repeat births among Medicaid births in Colorado shows a major decrease in births among women who chose Norplant for birth control to avert a second pregnancy.2

According to a life-table analysis of two cohorts of Colorado women who had their first Medicaid-funded birth in 1991 and 1992, the rate of repeat delivery within 24 months fell from 14.1% among 11,554 women who first delivered in 1991 to 10.6% among 13,624 women who first delivered in 1992, representing a 25% decline.

Sue Austin Ricketts, PhD, a demographer in the state’s Department of Public Health and Environment, Family and Community Health Services Division in Boulder, performed the study using the state’s Medicaid database containing 44,264 births and 9,759 implant insertions.

"What I think is the strength of the study is that it is so enormous," comments Ricketts. "It actually pertains to a third of the births in the state, because a third of our births are Medicaid births."

Mean age for the women studied was 24, with age distribution weighted toward young women in their late teens and early 20s. No data were available on race or marital status. The annual cohorts were separated by age into women who first gave birth as teens, and all women.

Birth rate five times higher without Norplant

When Ricketts looked at the effect of Norplant implants on the rate of repeat births, some startling statistics emerged.

Among the women of all ages whose births were paid for by Medicaid and who first delivered in 1992, 20% chose to have a Norplant insertion. Just 2.5% of these women went on to have a repeat delivery within two years, the study reveals. Women with the same characteristics who had not chosen Norplant six months after their first delivery experienced a repeat delivery rate of 12.6% in two years — a rate five times higher than implant users.

When Ricketts analyzed the data by both implant use and age, even more interesting data came to light.

"Nearly 30% of the women who first delivered as teen-agers in 1992 chose the implant," wrote Ricketts in Family Planning Perspectives. "Among these women, just 2.3% had a second delivery within two years, compared with 22.1% of comparable young women in the 1992 cohort who did not choose the implant — a rate nearly 10 times higher."

Is it time to reconsider Norplant?

If you’ve placed Norplant at the end of the contraceptive menu for your patients, perhaps it’s time to move it up on the list, says Robert A. Hatcher, MD, MPH, professor of gynecology and obstetrics at Emory University School of Medicine in Atlanta and chairman of the CTU editorial advisory board. (See his commentary on Norplant implants, p. 16.)

Rudnick agrees, and says you may find that with careful counseling, your teen patients will stay the course longer on Norplant. (Use the patient handout on Norplant in the September 1996 issue of CTU in aid in your counseling about the method.)

"We did a study [unpublished] after one year, and what we found was that less than 50% of our women who had started on pills are still taking them, and only 27.6% of our women who started on Depo-Provera were in for that fourth shot," he notes. "But for Norplant, 93.3% of the women who started are still on it after a year. And that is probably the case for a lot of people, if they’d look at their data a little harder."

References

1. Koo HP, Griffith JD, Nennstiel M. Adolescents’ use of Norplant and Depo-Provera: How do they do? Poster session at the November 1996 meeting of the American Public Health Association, New York City.

2. Ricketts SA. Repeat fertility and contraceptive implant use among Medicaid recipients in Colorado. Fam Plann Perspect 1996; 28:278-280,284.