Contraceptive Use Among Postpartum Women --- 12 States and New York City, 2004--2006

Postpartum use of highly effective contraceptive methods can prevent unintended pregnancies and ensure adequate birth spacing. Unintended pregnancies and short interpregnancy intervals are associated with adverse maternal and infant outcomes (1,2). In 2001, the year for which the most recent data are available, 49% of all pregnancies were unintended (3), and 21% of women gave birth within 24 months of a previous birth (4). Two Healthy People 2010 goals are to increase the percentage of intended pregnancies to 70% (objective 9-1) and to reduce the percentage of births occurring within 24 months of a previous birth to 6% (objective 9-2) (5). To estimate the prevalence and types of contraception being used by women 2--9 months postpartum, CDC analyzed data from the 2004--2006 Pregnancy Risk Assessment Monitoring System (PRAMS) from 12 states and New York City. This report summarizes those results, which indicated that 88.0% of postpartum women reported current use of at least one contraceptive method; 61.7% reported using a method defined as highly effective, 20.0% used a method defined as moderately effective, and 6.4% used less effective methods. Rates of using highly effective contraceptive methods postpartum were lowest among Asian/Pacific Islanders (35.3%), women who had wanted to get pregnant sooner (49.9%), women aged ≥35 years (53.0%), and women who had no prenatal care (54.5%). State policy makers and health-care providers can use these results to promote use of highly effective contraception among postpartum women and target interventions for those with particularly low rates of usage, including women with no prenatal care.

PRAMS began in 1987 as an ongoing, state- and population-based surveillance system designed to monitor maternal behaviors and experiences that occur before, during, and after pregnancy among women who deliver live infants. The system currently is active in 39 reporting areas in the United States. PRAMS uses a mixed mode data-collection methodology; up to three self-administered questionnaires are mailed monthly to a stratified random sample of mothers selected from birth certificates 2--4 months after delivery (median = 3.7 months). Nonresponders receive follow-up telephone interviews. Self-reported survey data are linked to birth certificate data and weighted for sample design, nonresponse, and noncoverage to create annual PRAMS analysis data sets.*

The PRAMS questionnaire in each state includes core questions that appear on all PRAMS surveys, optional standard questions, and questions developed by the state. The 2004--2006 surveys incorporated various topics, including current contraceptive practices. Respondents were asked, "Are you or your husband or partner doing anything now to keep from getting pregnant?" (core question) and "What kind of birth control are you or your husband or partner using now to keep from getting pregnant?" (standard question). Participants who responded "no" to the first question were classified as using no method and were not asked the second question, which included response options for 13 specific contraceptive methods and "other," with instructions to "check all that apply." The standard question about postpartum contraceptive method type was used by 14 reporting areas; however, to minimize bias resulting from nonresponse, this report only includes data from 13 reporting areas that achieved overall weighted response rates of ≥70% for at least 1 year of the study period. Responses from Arkansas, Florida, Louisiana, Michigan, Mississippi, North Carolina, Nebraska, New York, New York City, Oregon, Rhode Island, South Carolina, and West Virginia were assessed for this report. To focus on postpartum women at risk for unintended pregnancy or short interpregnancy interval, responses from women who were currently pregnant (n = 362) or not currently sexually active (n = 3,615) were excluded. Respondents who answered "yes" to the core question and either did not respond to the second question (n = 267) or only responded "other" (n = 310) also were excluded.

Contraceptive methods were categorized by effectiveness based on published effectiveness rates for typical use (6). Women reporting use of more than one contraceptive method were classified as using the more effective method based on a hierarchy of effectiveness rates during the first year of typical use (6). Contraceptive effectiveness was categorized as highly effective (<10% of women experience an unintended pregnancy; includes sterilization, intrauterine device, shot, pill, patch, and ring), moderately effective (10%--15% failure rate; includes condoms), and less effective (>15% failure rate; includes diaphragm, cervical cap, sponge, rhythm, and withdrawal). Chi-square testing was used to identify statistically significant differences between subcategories of maternal characteristics.

Among 43,887 postpartum women in the sample, 88.0% reported current use of at least one method of contraception during 2004--2006 (Table 1). Women with the lowest rates of using at least one method included those with no prenatal care (76.9%), women who reported that for their most recent pregnancy they wanted to get pregnant sooner (80.1%), Asian/Pacific Islanders (82.8%), and women aged ≥35 years (83.2%) (Table 2). Among all respondents, 61.7% reported using highly effective contraceptive methods, 20.0% relied on moderately effective methods, 6.4% used less effective methods, and 12.0% used no method. Prevalence of using highly effective contraceptive methods varied from 43.2% in New York City to 79.3% in Mississippi (Table 1). Use of highly effective postpartum contraceptive methods also varied by the respondent's age, ranging from 53.0% among women aged ≥35 years to 72.9% among those aged <20 years; and by race, ranging from 35.3% among Asian/Pacific Islanders to 71.3% among black women and 71.5% among American Indian/Alaska Native women (Table 2). Women with Medicaid coverage before pregnancy had a higher rate of using highly effective methods (67.8%) than women without Medicaid (60.6%), and women with no prenatal care had a lower rate of using highly effective methods (54.5%) than women with early (60.5%) or late (66.5%) entry into prenatal care.

Reported by: M Whiteman, PhD, K Curtis, PhD, S Hillis, PhD, L Zapata, PhD, DV D'Angelo, MPH, SL Farr, PhD, Y Zhang, PhD, W Barfield, MD, P Marchbanks, PhD, Div of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion; CL Robbins, PhD, EIS Officer, CDC.

Editorial Note:

Despite availability and use of contraceptives, the overall unintended pregnancy rate in the United States has remained stable (3) and is one of the highest among industrialized nations (51 per 1,000 women annually) (2,3,5). In addition, the percentage of births occurring within 24 months of a previous birth increased from 11% in 1995 (5) to 21% in 2002 (4) (the most recent data available), moving away from the Healthy People 2010 target of 6% (5). Increased use of highly effective postpartum contraception is an important strategy to both prevent unintended pregnancy in the postpartum period and prevent short interpregnancy intervals (7).

This is the first population-based report to examine the prevalence of contraceptive use among postpartum women by contraceptive method effectiveness. The finding that 88% of postpartum women reported current use of some form of contraception is consistent with previous estimates of 78%--90% (7--10). Rates of using at least one method were generally uniform across reporting areas and maternal characteristics, although women with no prenatal care had the lowest rate at 76.4%. However, the findings indicate substantial variation in use of highly effective contraceptive methods by reporting area and maternal characteristics. For example, some subgroups with the lowest rates of highly effective contraceptive method use included Asian/Pacific Islanders (35.3%), women who reported that their most recent pregnancy was wanted sooner (49.9%), women aged ≥35 years (53.0%), and women who had no prenatal care (54.5%). Additional analyses and research are needed to determine reasons for the variations found in the use of highly effective methods by reporting area and maternal characteristics.

These findings point to possible missed opportunities for promoting healthy birth spacing and reducing unintended pregnancies. Women who do not receive prenatal care, for example, might benefit from more consultation about postpartum contraceptive options. This population likely does not routinely access preventive health-care services. Therefore, for these women the period after delivery and before hospital discharge might constitute an especially opportune time for health-care providers to promote the use of effective contraception postpartum and adequate birth spacing.

Although use of condoms for protection against sexually transmitted diseases was not a focus of the study, 13% of the women reported use of condoms along with a highly effective method. All women not using condoms should be counseled regarding the use of condoms for the prevention of sexually transmitted diseases, including human immunodeficiency virus infection.†

The findings in this report are subject to at least four limitations. First, although population based, these findings are not nationally representative and are generalizable only to mothers with recent live births in the 13 reporting areas. Second, because PRAMS data are self-reported, prevalence rates of desirable behaviors might be overestimated and those for undesirable behaviors might be underestimated. Third, the survey did not ascertain use of some additional contraceptive methods, such as spermicides, emergency contraception, and lactational amenorrhea. Finally, because of the survey skip pattern, information was not obtained about contraceptive methods used by women who might have incorrectly reported they were not doing anything currently to keep from getting pregnant. If this occurred, particularly among respondents who had a tubal ligation or whose partners had a vasectomy, the use of highly effective contraceptive methods might have been underestimated.

Knowing the characteristics associated with low rates of effective contraceptive use during the postpartum period will better enable health-care providers to target interventions. Health-care providers should consider encouraging postpartum women to use highly effective contraceptive methods to increase the proportion of pregnancies that are intended and promote healthy birth spacing.

Acknowledgments

The findings in this report are based, in part on contributions by members of the PRAMS Working Group; the CDC PRAMS Team, Div of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, CDC.

References

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Date last reviewed: 8/6/2009