Prepregnancy Contraceptive Use Among Teens With Unintended Pregnancies Resulting in Live Births—Pregnancy Risk Assessment Monitoring System (PRAMS), 2004-2008 FREE

MMWR. 2012;61:25-29

1 figure, 1 table omitted

Approximately 400,000 teens aged 15-19 years give birth every year in the United States,¹ and the teen birth rate remains the highest in the developed world.² Teen childbearing is a public health concern because teen mothers are more likely to experience negative social outcomes, including school dropout.³ In addition, infants of teen mothers are more likely to be low birth weight and have lower academic achievement, and daughters of teen mothers are more likely to become teen mothers themselves.^4- 6 To learn why teens wishing to avoid pregnancy become pregnant, CDC analyzed data from the 2004-2008 Pregnancy Risk Assessment Monitoring System (PRAMS). This report describes estimated rates of self-reported prepregnancy contraceptive use among white, black, and Hispanic teen females aged 15-19 years with unintended pregnancies resulting in live births. Approximately one half (50.1%) of these teens were not using any method of birth control when they got pregnant, and of these, nearly one third (31.4%) believed they could not get pregnant at the time; 21.0% used a highly effective contraceptive method (although less than 1% used one of the most effective methods, such as an intrauterine device [IUD]); 24.2% used the moderately effective method of condoms; and 5.1% used the least effective methods, such as rhythm and withdrawal. To decrease teen birth rates, efforts are needed to reduce or delay the onset of sexual activity, provide factual information about the conditions under which pregnancy can occur, increase teens' motivation and negotiation skills for pregnancy prevention, improve access to contraceptives, and encourage use of more effective contraceptive methods.

The PRAMS surveillance system collects state-specific, population-based data on maternal attitudes and experiences before, during, and shortly after pregnancy. Thirty-seven states and New York City participate in the system, which covers approximately 75% of all live births in the United States. The PRAMS system employs a standardized data collection protocol, sampling women 2-6 months after they deliver a live infant. Women are selected based on a stratified sampling scheme applied to birth certificates each month. The mixed-mode data collection methodology includes mail questionnaires with telephone follow-up. PRAMS data are weighted for sample design, nonresponse, and noncoverage using the official population data provided by vital statistics agencies in the participating states.⁷ The CDC PRAMS protocol specifies that officially published data must meet or exceed minimum weighted response rates of 70% for years 2004-2006 and 65% for years 2007-2008. Weighted prevalences, trend tests, and percentage contrasts are calculated using statistical software to account for the complex sampling design.

PRAMS surveys include core questions for all state surveys, plus optional standard and state-developed questions. All respondents were asked the following core questions: “Thinking back to just before you got pregnant with your new baby, how did you feel about becoming pregnant?” Participants who responded “I wanted to be pregnant later” or “I didn't want to be pregnant then or at any time in the future” were classified as having an unintended pregnancy. Participants also were asked, “When you got pregnant with your new baby, were you or your husband or partner doing something to keep from getting pregnant?” Participants who reported not doing anything to keep from getting pregnant were then asked, “What were your or your husband's or partner's reasons for not doing anything to keep from getting pregnant?” This report includes data on nonuse of contraception and reasons for nonuse from the 19 states that achieved the required minimum weighted response rate for all 5 years, representing approximately 30% of all teen U.S. live births: Alaska, Arkansas, Colorado, Georgia, Hawaii, Illinois, Maryland, Maine, Michigan, Minnesota, Nebraska, New Jersey, New York, Oklahoma, Oregon, Rhode Island, Utah, Washington, and West Virginia.

For participants who reported doing something to keep from getting pregnant, six reporting states asked the standard question, “When you got pregnant with your new baby, what were you or your husband or partner doing to keep from getting pregnant?” Response options for 13 specific contraceptive methods were presented with instructions to “check all that apply.” For the purposes of this study, contraceptive methods were categorized by effectiveness based on published effectiveness rates for preventing pregnancy in typical use.⁸ Highly effective contraceptive methods included sterilization, IUD, injectable medroxyprogesterone (sold as Depo Provera and also known as the birth control shot), oral contraceptives, hormonal patch, and vaginal ring. The moderately effective category included condoms. The least effective category included diaphragm, cervical cap, contraceptive sponge, rhythm method, and withdrawal. This report includes contraceptive methods data from five states that achieved the required minimum weighted response rate for all 5 years, covering approximately 8% of all teen U.S. live births: Colorado, Michigan, Minnesota, Oregon, and Utah.

Weighted results were calculated within the PRAMS subpopulations of non-Hispanic white, non-Hispanic black, and Hispanic teen females (aged 15-19 years) who delivered a live infant and reported that their pregnancy was unintended. During 2004-2008, 73.2% (95% confidence interval [CI] = 71.9%-74.5%) of teen mothers within 19 PRAMS states who delivered a live infant reported that their pregnancy was unintended. Of these, approximately one half (50.1%; CI = 48.3%-52.0%) reported not using any method of contraception before getting pregnant. In 2004, 50.4% (CI = 46.6%-54.3%) of the teen mothers reported not using contraception; this rate remained stable until 2007, when it dropped to 45.2% (CI = 40.8%-49.8%), then rose in 2008 to 55.0% (CI = 50.8%-59.2%). A test for linear trend found no significant change over the 5-year period.

During 2004-2008, the rates of not using birth control among surveyed non-Hispanic white teens (49.7% [CI = 47.1%-52.3%]), non-Hispanic black teens (50.5% [CI = 46.9%-54.1%]), and Hispanic teens (50.6% [CI = 46.9%-54.2%]) were not significantly different. Teens not using contraception reported their reasons for nonuse. Many teens held misconceptions (e.g., 31.4% thought they could not get pregnant at the time, and 8.0% thought they, their husbands, or their partners were sterile) (Table). Nearly one quarter (23.6%) reported that their partner did not want to use contraception. Some teens (22.2% of respondents) indicated that they would not mind if they got pregnant. Other reasons included lack of access (13.1% reported having trouble getting birth control) and experiencing side effects from contraception (9.4%). Reasons for nonuse of contraception did not vary substantially by age, race, or ethnicity. However, Hispanic teens were more likely to report that they did not use contraception because they thought they could not get pregnant at the time (42.0%) than both non-Hispanic white (26.7%) and non-Hispanic black (31.9%) teens (p<0.001). Furthermore, Hispanic teens were less likely (4.2%) than non-Hispanic white (9.8%) and non-Hispanic black (12.2%) teens to report avoiding contraceptives because of side effects (p<0.001). Finally, older teens were more likely to report nonuse because of side effects of contraception (10.8%) than younger teens (6.8%) (p<0.01).

In the five states reporting contraceptive methods, 21.0% of teens reported using a highly effective method when they got pregnant, less than one quarter (24.2%) used a moderately effective method, and few teens (5.1%) used the least effective methods. Non-Hispanic black teens were significantly less likely to use highly effective methods of birth control (14.1%) compared with non-Hispanic white (23.0%; p<0.01) and Hispanic (20.4%; p<0.05) teens. The rates of contraceptive nonuse within the subset of five states (49.6%) were similar to the rates within the 19 states (50.1%).

Reported by: Ayanna T. Harrison, Lorrie Gavin, PhD, Philip A. Hastings, PhD, Div of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, CDC. Corresponding contributors: Ayanna T. Harrison, aharrison@cdc.gov, 770-488-5200, Lorrie Gavin, lgavin1@cdc.gov, 770-488-5200.

CDC Editorial Note: This report indicates that teens from 19 states who delivered a live infant from an unintended pregnancy have much lower rates of contraceptive use when compared with all sexually active teens.⁹ Half of teen mothers in this study did not use any contraception before getting pregnant; this compares with 16.5% of all sexually active teens reporting they did not use any method at last sexual intercourse.⁹ In addition, the National Survey of Family Growth estimates that at least 31% of all sexually active teens used the pill or other hormonal methods, and 55% used condoms at last sexual intercourse (versus 21.0% and 24.2%, respectively, in this study).⁹ Among teens, use of the most effective methods (i.e., long-acting reversible methods such as IUDs and implants) is low. Moreover, consistent use of other methods also is low. For example, the National Survey of Family Growth found that among sexually active teen females who reported using a condom, only 52% used the condom every time they engaged in sexual intercourse. Inconsistent use of contraception might explain the finding that 21% of teens in this study became pregnant despite use of highly effective methods.

The findings in this report are subject to at least three limitations. First, among teens having an unintended pregnancy resulting in a live birth, PRAMS contraceptive use data were available from 19 states, and contraceptive methods data were available from five states; hence, results are not representative of other U.S. states. Second, PRAMS data are self-reported and susceptible to recall and social desirability biases. Finally, the PRAMS survey does not ask participants about how consistently they used contraceptive methods.

These findings have several implications. First, rates of contraceptive use among sexually active teens might be improved by providing appropriate access to contraception, encouraging consistent use of more effective contraceptives, promoting condom use for protection against sexually transmitted infections including human immunodeficiency virus (HIV), and increasing teens' motivation to use contraception consistently. Second, health-care providers, parents, and educators could encourage delaying the onset of sexual activity and abstinence, provide factual information about the conditions about the conditions under which pregnancy can occur, increase teens' motivation to avoid pregnancy, and strengthen their negotiation skills for pregnancy prevention. Increasing teens' knowledge, skills, and motivation for effective contraceptive use could be an important strategy to prevent unintended teen pregnancy and childbearing.¹⁰

Mary Elizabeth O’Neil, MPH, Indu B. Ahluwalia, PhD, Leslie Harrison, MPH, LaTreace Harris, MPH, Nan Ruffo, MPA, and other members of the Pregnancy Risk Assessment Monitoring System team, Div of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, CDC.

Data from the National Survey of Family Growth indicate that 17% of sexually active teens aged 15-19 years report not using birth control when they last had sex. Of those using birth control, at least 31% used a hormonal method and 55% used condoms.

What is added by this report?

Data from the Pregnancy Risk Assessment Monitoring System (PRAMS) collected in 19 states during 2004-2008 indicated that among teens aged 15-19 years who became pregnant unintentionally and gave birth to a live infant, 50.1% reported doing nothing to prevent pregnancy. Of these teens, 31.4% thought they could not get pregnant at the time, 23.6% did not use contraception because their partner did not want to use it, and 22.1% did not mind getting pregnant. In the five states that asked about prepregnancy contraceptive methods, only 21.0% of these teens used a highly effective method of birth control, and 24.2% used the moderately effective method of condoms. These data offer insights about teens who give birth and face the risks of early childbearing, a critically important subset of all teens who have had sexual intercourse.

What are the implications for public health practice?

Health-care providers, community partners, and parents/guardians can work to prevent teen pregnancy by (1) providing appropriate education to reduce or delay onset of sexual activity; (2) increasing teens' motivation to avoid pregnancy; (3) teaching about the conditions under which pregnancy occurs; (4) providing access to contraception and encouraging use of more effective methods plus condoms to protect against both pregnancy and sexually transmitted infections, including human immunodeficiency virus; and (5) strengthening the skills of sexually active teens to negotiate contraceptive use with their partners.