Abstract
Purpose: Given elevated pregnancy rates, fluctuating sexual identity, and varying sexual experience among adolescent sexual minority women (ASMW; lesbian/bisexual identity, attraction to/sex with females), research should assess adolescent pregnancy by sexual attraction with identity and experience. This study examined associations of three aspects of sexuality—identity, attraction, and experience—with pregnancy among ASMW versus non-ASMW.
Methods: Population-weighted data were drawn from the 2002 to 2015 National Survey of Family Growth (NSFG), 15- to 19-year-old female subsample (n = 5481). Multivariable logistic regression models (adjusted for age, race/ethnicity, and survey cycle) compared pregnancy among ASMW versus non-ASMW by sexual identity, attraction, and experience separately, and in a combined model in which interaction of aspects of sexuality and survey cycle was tested. The combined model was then stratified by survey cycle.
Results: Although not significant in the combined model, sexual minority versus heterosexual identity (adjusted odds ratio [aOR] = 1.74, 95% confidence interval [CI] = 1.21–2.51, p = 0.003) and sexual minority versus exclusive male attraction (aOR = 1.49, 95% CI = 1.10–2.01, p = 0.011) individually predicted higher pregnancy odds. There was significant interaction between attraction and survey cycles. Sexual minority attraction predicted significantly decreased pregnancy odds (aOR = 0.59, 95% CI = 0.38–0.90, p = 0.014) in combined 2002 to mid-September 2013 NSFG data, but increased odds (aOR = 1.59, 95% CI = 0.63–4.02, p = 0.324) in the rest of 2013–2015.
Conclusion: These results suggest the importance of measuring sexual attraction when examining pregnancy disparities among ASMW. Sex education and teen pregnancy prevention programs should reflect sexual diversity.
Keywords: : adolescence, bisexuality, health disparities, pregnancy, sexual orientation
Introduction
Birth rates among U.S. adolescents decreased by 46% from 2007 to 2015.1 Although some adolescents may welcome the opportunity to have a baby, teen pregnancy is often associated with significant financial and social burdens.2 Rates of having been or made someone pregnant among sexual minority adolescents in general are estimated at two to seven times greater than those of their non sexual minority counterparts,3–5 yet few studies have focused on pregnancy among adolescent sexual minority women (ASMW; lesbian/bisexual identity, attraction to or sex with females). Existing analyses have included small sample sizes and few were population based.6
Research on ASMW and pregnancy has also been limited by inconsistent or incomplete sexual orientation measures that potentially obscure important differences across sexual minority subgroups.6 Sexual orientation is a complex construct with a range of conceptualizations.7,8 Three aspects of sexuality—sexual identity, attraction, and experience—are frequently considered to be components of sexual orientation that are related, but potentially independent of each other. According to the 2011–2013 National Survey of Family Growth (NSFG), 12.6% of heterosexually identified female respondents also indicated a history of same-sex partners; over 25% reported attraction to women or uncertain sexual attraction.9 In studies that have included women who identified as lesbian, up to 63%10 have indicated a history of sexual contact with men and 10% have reported both male and female partners in the previous year.11
Most studies examining pregnancy among ASMW have measured sexual orientation in terms of sexual identity alone,5,12 sexual experience alone,4 or a combination of sexual identity and experience.13–16 Compared to heterosexual identity and having exclusively male partners, both bisexual identity and having sex with male and female partners appear to be associated with increased odds6,16,17 of adolescent pregnancy, whereas lesbian identity is associated with lower odds.17
A dearth of research on pregnancy among ASMW has considered sexual attraction. Sexual attraction is a particularly relevant18,19 and easily understood measure18 of sexual orientation for adolescents, whose sexual identity may be in flux18 or who may not yet have had partnered sexual encounters.20 In the ASMW pregnancy studies that have referenced sexual attraction, it has been used merely to define sexual identity measures (e.g., “completely homosexual—gay/lesbian, attracted to persons of the same sex”),6,17,21 possibly overlooking adolescents whose sexual identity label does not convey the range of their sexual attraction.20,22–24 Given the complexities of sexuality, particularly among adolescents, sexual orientation should be measured in terms of attraction,19,23 in addition to identity and experience to accurately understand sexual minority-related health disparities25,26 such as teen pregnancy.
Mechanisms of pregnancy disparities among ASMW in the context of political and social change
Compared to non-ASMW, ASMW report more risk behaviors associated with adolescent pregnancy,3,5,16,21,25 possibly as functions of sexual minority stress.27 Risk behaviors include first sexual experience at age 14 or younger,3,5,21 having multiple sexual partners,16 having sex while intoxicated,3,5,16,25,28 and having sex without a barrier method.5,16,25,28 Higher rates of risk behaviors likely mediate the association between sexual minority status and higher pregnancy rates; the null association observed in previous studies that adjusted for sexual risk behaviors and substance use may be attributed to such mediation.13,15
A policy climate more supportive of sexual minorities may alleviate sexual minority stress and risk behaviors as coping responses.29,30 The turn of the 21st Century brought growing social acceptance of sexual minorities31,32 and a host of policy advances. From 2000 to 2009, the proportion of Americans viewing same-sex relationships as morally acceptable rose by 23%,32 and the proportion of U.S. adults condoning same-sex sexual behavior rose from 11% in 1973 to nearly 50% in 2014.31 Policy advances included a near doubling of the number of states legally prohibiting sexual minority discrimination (12 in 2000; 21 states plus Washington, D.C. in 2013),33 and the passage of the 2009 Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act.32 Although 2013 was seen as a turning point for sexual minority equality due to the Supreme Court's ruling against the Defense of Marriage Act33,34 (which preceded the 2015 ruling in favor of federal marriage equality35), several states continue to lack nondiscrimination and antibullying legal protections for sexual minorities.33
This study
To examine whether sexual attraction is also an important predictor of sexual minority adolescent pregnancy, and to examine how a fluctuating political and social climate might impact ASMW pregnancy outcomes,29,30 we drew from three cycles of the NSFG—2002, 2006–2010, and 2011–2015—to (1) assess the association of pregnancy with sexual orientation in terms of three aspects of sexuality (sexual identity, experience, and attraction) among adolescent women and (2) explore whether these associations differed across survey cycles.
Methods
Study design and procedures
The NSFG is a national survey weighted to be representative of the U.S. population 15–44 years of age, which began collecting sexual orientation data in its 2002 sample.36 Detailed descriptions of survey methodology are available elsewhere.36 Confidential participation was voluntary and participants gave written informed consent (those 15–17 years of age gave written assent following parental consent).37 A total of 5481 female NSFG respondents 15–19 years of age were included in this analysis (1150 out of 7643 female respondents in the 2002 cycle; 2284 out of 12,279 female respondents in the 2006–2010 cycle; and 2047 out of 8143 female respondents in the 2011–2015 cycle). The NSFG received institutional review board (IRB) approval from the National Center for Health Statistics within the Centers for Disease Control and Prevention. IRB exemption was obtained from the primary author's institutions (The New York State Psychiatric Institute and the City University of New York [CUNY]) for this study, which involved a secondary data analysis of publicly available data.
Measures
The primary independent variables were three aspects of sexual orientation: sexual identity, attraction, and experience. Sexual identity consisted of three categories: heterosexual or straight (reference); homosexual, gay, or lesbian; or bisexual. Although 92 adolescents reported an identity of “something else” in earlier survey cycles (2002: n = 80 and 2006–2010: n = 12), this category was not available as a response option in the 2011–2015 survey cycle and thus was excluded from this analysis. Only eight lesbian-identified adolescent women reported having ever been pregnant; thus, for multivariable analyses, sexual identity was collapsed into a dichotomous variable: heterosexual versus sexual minority identity (homosexual, gay, lesbian, or bisexual).
Sexual attraction comprised six categories in the NSFG: only attracted to males (reference); only attracted to females; mostly attracted to females; equally attracted to males and females; mostly attracted to males; or not sure. For the purposes of this analysis, responses were collapsed into a four-category variable: only attracted to males (reference); only attracted to females; attracted to both males and females; or not sure. Only three adolescent women who reported exclusive attraction to females also reported having ever been pregnant; therefore, responses were further collapsed into a dichotomous variable for multivariable analyses: attracted only to males versus sexual minority attraction (mostly attracted to males, equally attracted to males and females, and mostly or only attracted to females). Those who responded, “not sure” (n = 68) were excluded from multivariable analyses since we could not determine whether they were unsure of their sexual attraction or unsure of how to respond to the question.
Lifetime sexual experience (i.e., oral, vaginal, or anal sex) included sex with only male partners (reference); only female partners; both male and female partners; and no sexual contact. As adolescent women who had never had sexual contact or who had only had female partners would not have had the opportunity to get pregnant (assuming that adolescents would not have sought other means of becoming pregnant), they were excluded from multivariable analyses. For multivariable analyses, sexual experience was thus treated as a dichotomous variable: only lifetime male partners versus sexual minority experience (both male and female lifetime sexual partners).
Sexual risk behaviors included whether participants had ever had penile–vaginal intercourse; the number of male partners with whom the participant had ever had penile–vaginal intercourse (one, two, or three or more partners); any past-year transactional sex with male partners (exchanged money or drugs with a male for sex); any past-year condomless penile-vaginal intercourse with a male partner; and whether the participant had their first voluntary penile-vaginal intercourse at age 14 or younger.
Recreational drug use was assessed in terms of frequency of past-year use of five separate drugs: marijuana, cocaine, crack, crystal methamphetamine, and nonprescription injection drug use. Response options ranged from “never” to “about once a day.” We measured past-year drug use as having used any of these substances at least once in the past 12 months. Crystal methamphetamine use was not assessed in the 2002 sample, but was included in this analysis given that all but five respondents in later samples had used it in conjunction with other recreational drugs.
Alcohol use was assessed in terms of frequency of use within the past 12 months, with response options ranging from “never” to “about once a day.” We collapsed responses into a dichotomous variable, indicating whether the participant reported any alcohol use over the past year (all responses greater than “never”).
The primary outcome was whether respondents had ever been pregnant (≥1 pregnancy = yes and 0 pregnancies = no). Because the NSFG only asked about pregnancy intendedness for each unique pregnancy, whereas this analysis focused on having ever been pregnant, we created a variable indicating whether participants had ever had an intended pregnancy (n = 134). Since we did not observe significant differences between ASMW and non-ASMW, pregnancy intendedness was not included in multivariable analyses.
Additional covariates included survey cycle (2002, 2006–2010, and 2011–2015); self-reported age in years; and self-reported race/ethnicity (Hispanic, any race; Black/African American, non-Hispanic; White, non-Hispanic; and any other race, non-Hispanic).
Data analyses
Analyses were conducted on the merged 2002, 2006–2010, and 2011–2015 NSFG datasets, limited to the 5481 female respondents 15–19 years of age at the time of their interview. Weights were adjusted by dividing the original weight variable by three to account for the three survey cycles.38 We first describe the sample overall (including demographic characteristics, sexual orientation, and pregnancy and related behaviors), and then stratified on survey cycle using the Rao-Scott chi-square (Table 1). We also compared pregnancy-related behaviors (i.e., sexual risk and substance use) by sexual orientation identity, attraction, and experience (Table 2). Next, separate unadjusted logistic regression models explored the association of having ever been pregnant by each of the three aspects of sexual orientation (Table 3).
Table 1.
Demographic Characteristics, Sexual Orientation, and Pregnancy and Related Behaviors by United States National Survey of Family Growth Survey Cycles 2002–2015, Females 15–19 Years of Age (N = 5481)
| Unweighted na(weighted %) | 2002 (n = 1150), Unweighted na(weighted %) | 2006–2010 (n = 2284), Unweighted na(weighted %) | 2011–2015 (n = 2047), Unweighted na(weighted %) | χ2/F | pb | |
|---|---|---|---|---|---|---|
| Demographic characteristics | ||||||
| Mean age (SE) | 17.08 (0.02) | 17.04 (0.04) | 17.10 (0.04) | 17.08 (0.04) | 0.38 | 0.538 |
| Race and ethnicity | ||||||
| Hispanic (any race) | 1397 (19.53) | 231 (15.46) | 531 (18.17) | 635 (22.78) | 7.93 | 0.019 |
| Black, non-Hispanic | 1122 (15.97) | 242 (15.24) | 456 (16.14) | 424 (16.29) | 0.31 | 0.855 |
| Other race, non-Hispanic | 331 (6.39) | 64 (5.69) | 139 (6.45) | 128 (8.43) | 6.77 | 0.849 |
| White, non-Hispanic | 2631 (58.11) | 613 (63.61) | 1158 (59.25) | 860 (54.14) | 11.86 | 0.003 |
| Sexual identity | ||||||
| Heterosexual | 4776 (90.18) | 952 (91.75) | 2057 (91.47) | 1767 (88.53) | 6.95 | 0.031 |
| Gay/lesbian | 95 (1.53) | 12 (1.05) | 39 (1.53) | 44 (1.79) | 2.14 | 0.343 |
| Bisexual | 439 (8.29) | 65 (7.20) | 160 (7.00) | 214 (9.69) | 5.62 | 0.060 |
| Sexual attraction | ||||||
| Only to males | 4361 (80.56) | 958 (84.03) | 1851 (82.48) | 1552 (77.28) | 18.21 | <0.001 |
| Only to females | 50 (0.83) | 4 (0.29) | 23 (1.05) | 23 (1.02) | 4.75 | 0.093 |
| To both | 978 (17.10) | 169 (14.67) | 377 (15.54) | 432 (19.52) | 10.63 | 0.005 |
| Not sure | 68 (1.51) | 14 (1.01) | 24 (0.93) | 30 (2.18) | 5.18 | 0.075 |
| Sexual experience (Lifetime) | ||||||
| Only males | 2578 (46.85) | 612 (52.59) | 1067 (44.19) | 899 (45.10) | 11.25 | 0.004 |
| Only females | 97 (1.76) | 17 (1.24) | 42 (1.89) | 38 (2.00) | 1.60 | 0.449 |
| Both | 580 (9.70) | 107 (9.34) | 242 (9.74) | 231 (9.90) | 0.19 | 0.909 |
| No sex partners | 2192 (41.67) | 413 (36.84) | 918 (44.18) | 861 (43.01) | 8.20 | 0.017 |
| Pregnancy and related behaviors | ||||||
| Ever been pregnant | 679 (10.36) | 180 (14.38) | 300 (11.24) | 199 (7.25) | 27.38 | <0.001 |
| Ever had intercoursec | 2523 (44.15) | 553 (46.76) | 1068 (43.25) | 902 (43.17) | 2.31 | 0.314 |
| Sexual risk with males (of those who have had intercoursec) | ||||||
| 1 Partner | 896 (42.00) | 204 (42.91) | 357 (38.69) | 335 (43.45) | 3.25 | 0.197 |
| 2 Partners | 412 (16.62) | 85 (15.36) | 181 (17.57) | 146 (16.83) | 0.07 | 0.964 |
| 3 or more partners | 921 (41.39) | 195 (41.74) | 412 (43.74) | 314 (39.71) | 1.64 | 0.440 |
| Past-year transactional sexd | 52 (2.02) | 20 (3.24) | 18 (1.57) | 14 (1.49) | 4.05 | 0.132 |
| Past-year condomless sexc | 1457 (60.98) | 349 (66.17) | 610 (59.29) | 498 (58.83) | 5.03 | 0.081 |
| First intercourse ≤age 14c | 240 (10.13) | 58 (12.05) | 115 (11.12) | 67 (7.11) | 8.00 | 0.018 |
| Past-year substance use | ||||||
| Any drug use | 1427 (25.68) | 330 (29.17) | 590 (24.38) | 507 (24.42) | 6.48 | 0.039 |
| Any alcohol use | 3270 (59.84) | 771 (66.79) | 1403 (59.69) | 1096 (55.79) | 17.50 | <0.001 |
Unweighted n may not add up to 100% of the total N due to missing data.
Results based on Rao-Scott modified chi-square tests. Bold indicates p < 0.05.
“Intercourse” and “sex” defined as penile–vaginal intercourse with male partner(s).
Exchanged money or drugs with a male for sex.
SE, standard error.
Table 2.
Pregnancy-Related Behaviors by Sexual Identity, Attraction, and Experience, United States National Survey of Family Growth Survey Cycles 2002–2015, Females 15–19 Years of Age (N = 5481)
| Total out of full sample N | Pregnancy-related behaviors by sexual identitya | ||||||
|---|---|---|---|---|---|---|---|
| Heterosexual (n = 4776) | Gay/Lesbian (n = 95) | Bisexual (n = 439) | |||||
| Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | χ2 | pb | ||
| Ever had intercoursec | 2523 (44.15) | 2144 (43.07) | 39 (34.28) | 277 (62.35) | 32.47 | <0.001 | |
| Sexual risk with males (of those who have had intercoursec) | |||||||
| ≥3 Lifetime sexc partners | 921 (41.39) | 754 (39.00) | 13 (45.18) | 134 (61.65) | 35.47 | <0.001 | |
| Past-year transactional sexd | 52 (2.02) | 30 (1.25) | 4 (6.30) | 13 (6.29) | 7.53 | 0.023 | |
| Past-year condomless sexc | 1457 (60.98) | 1244 (61.69) | 10 (11.62) | 161 (61.05) | 20.85 | <0.001 | |
| First intercourse ≤age 14c | 240 (10.13) | 208 (9.26) | 6 (25.40) | 24 (12.39) | 2.32 | 0.314 | |
| Past-year substance use | |||||||
| Any drug usee | 1427 (25.68) | 1133 (23.12) | 38 (45.90) | 214 (48.13) | 45.57 | <0.001 | |
| Any alcohol use | 3270 (59.84) | 2798 (58.36) | 65 (75.61) | 330 (75.59) | 35.53 | <0.001 | |
| Total out of full sample N | Pregnancy-related behaviors by sexual attractiona | ||||||
|---|---|---|---|---|---|---|---|
| Only to males (n = 4361) | Only to females (n = 50) | To both (n = 978) | Not sure (n = 68) | ||||
| Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | χ2 | pb | |
| Ever had intercoursec | 2523 (44.15) | 2483 (58.94) | 34 (77.43) | 374 (38.53) | 51 (69.81) | 57.91 | <0.001 |
| Sexual risk with males (of those who have had intercoursec) | |||||||
| ≥3 Lifetime sexc partners | 921 (41.39) | 637 (37.31) | 2 (14.84) | 276 (55.43) | 5 (73.51) | 21.41 | <0.001 |
| Past-year transactional sexd | 52 (2.02) | 30 (1.50) | 0 (0.00) | 19 (3.70) | 1 (1.61) | 2.72 | 0.099 |
| Past-year condomless sexc | 1457 (60.98) | 1073 (61.13) | 2 (8.01) | 371 (61.98) | 11 (77.35) | 10.25 | 0.017 |
| First intercourse ≤age 14c | 240 (10.13) | 175 (8.53) | 3 (50.30) | 61 (12.75) | 1 (0.37) | 6.70 | 0.082 |
| Past-year substance use | |||||||
| Any drug usee | 1427 (25.68) | 926 (20.75) | 21 (50.16) | 460 (47.15) | 18 (33.58) | 71.32 | <0.001 |
| Any alcohol use | 3270 (59.84) | 2462 (56.29) | 33 (70.74) | 741 (77.36) | 32 (50.35) | 62.80 | <0.001 |
| Total out of full sample N | Pregnancy-related behaviors by sexual experiencea | ||||||
|---|---|---|---|---|---|---|---|
| Only males (n = 2578) | Only females (n = 97) | Both (n = 580) | No sex partners (n = 2192) | ||||
| Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | Unweighted n (weighted %) | χ2 | pb | |
| Ever had intercoursec | 2523 (44.15) | 2002 (76.48) | 0 (0.00) | 509 (86.84) | 0 (0.00) | 0.97 | 0.325 |
| Sexual risk with males (of those who have had intercoursec) | |||||||
| ≥3 Lifetime sexc partners | 921 (41.39) | 660 (36.97) | N/A | 259 (62.73) | N/A | 13.76 | <0.001 |
| Past-year transactional sexd | 52 (2.02) | 27 (1.23) | N/A | 24 (5.75) | N/A | 6.83 | 0.009 |
| Past-year condomless sexc | 1457 (60.98) | 1117 (61.35) | N/A | 340 (59.69) | N/A | 0.21 | 0.647 |
| First intercourse ≤age 14c | 240 (10.13) | 186 (8.60) | N/A | 54 (14.92) | N/A | 4.71 | 0.030 |
| Past-year substance use | |||||||
| Any drug usee | 1427 (25.68) | 842 (33.26) | 32 (30.73) | 356 (60.89) | 191 (8.83) | 350.51 | <0.001 |
| Any alcohol use | 3270 (59.84) | 1867 (74.43) | 69 (75.92) | 499 (86.61) | 826 (36.68) | 462.43 | <0.001 |
Unweighted n may not add up to 100% of the total due to missing data.
Results based on Rao-Scott modified chi-square tests. Bold indicates p < 0.05.
“Intercourse” and “sex” defined as penile–vaginal intercourse with male partner(s).
Exchanged money or drugs with a male for sex.
Includes any past-year use of marijuana, cocaine, crack, crystal methamphetamine, and/or nonprescription injection drug use.
N/A, not applicable.
Table 3.
Unadjusted Odds of Pregnancy by Sexual Identity, Attraction, and Experience, United States National Survey of Family Growth Survey Cycles 2002–2015, Females 15–19 Years of Age (N = 5481)
| Sexual orientation | Ever been pregnant (n = 679) | OR (95% CI) | pb | Ever had an intended pregnancy (n = 134) | OR (95% CI) | pb | |
|---|---|---|---|---|---|---|---|
| Total Unweighted na(weighted % out of full sample N) | Unweighted na(weighted % out of sexuality aspects) | Unweighted na(weighted % out of ever pregnant) | |||||
| Sexual identity | |||||||
| Heterosexual | 4776 (90.18) | 565 (9.71) | 1.00 | 110 (18.06) | 1.00 | ||
| Gay/lesbian | 95 (1.53) | 8 (3.28) | 0.32 (0.14–0.71) | 0.005 | 1 (13.91) | 0.73 (0.08–6.27) | 0.776 |
| Bisexual | 439 (8.29) | 79 (16.73) | 1.87 (1.30–2.68) | 0.001 | 13 (26.88) | 1.67 (0.67–4.14) | 0.269 |
| Sexual attraction | |||||||
| Only to males | 4361 (80.56) | 513 (9.73) | 1.00 | 103 (18.36) | 1.00 | ||
| Only to females | 50 (0.83) | 3 (4.54) | 0.44 (0.12–1.68) | 0.229 | 0 (0.00) | N/A | |
| To both | 978 (17.10) | 152 (14.22) | 1.54 (1.16–2.04) | 0.003 | 28 (25.51) | 1.49 (0.75–2.96) | 0.250 |
| Not sure | 68 (1.51) | 6 (2.70) | 0.26 (0.09–0.70) | 0.008 | 1 (1.76) | N/A | |
| Sexual experience (Lifetime) | |||||||
| Only males | 2578 (46.85) | 522 (17.50) | 1.00 | 102 (18.82) | 1.00 | ||
| Only females | 97 (1.76) | N/A | N/A | N/A | |||
| Both | 580 (9.70) | 153 (19.01) | 1.11 (0.81–1.51) | 0.518 | 31 (24.26) | 1.38 (0.67–2.84) | 0.378 |
| No sex partners | 2192 (41.67) | N/A | N/A | N/A | |||
Unweighted n may not add up to 100% of the total due to missing data.
Bold indicates p < 0.05.
CI, confidence interval; N/A, not applicable; OR, odds ratio.
Subsequently, separate multivariable logistic regression models explored the association of pregnancy by each aspect of sexual orientation (Model 1: odds of pregnancy by sexual identity; Model 2: by sexual attraction; and Model 3: by lifetime sexual experience). We then ran an additional model (Model 4) that simultaneously included all three measures of sexual orientation to look at their independent associations with pregnancy (Table 4). We examined correlations between each sexual orientation measure to ensure that all could be included in the same model. Aspects of sexuality were moderately correlated with Cramer's V coefficients ranging from 0.56 to 0.64.39 All four models adjusted for age, race/ethnicity, and survey cycle.
Table 4.
Odds of Pregnancy by Sexual Identity, Attraction, and Experience, United States National Survey of Family Growth Survey Cycles 2002–2015, Females 15–19 Years of Age (N = 5481)
| Model 1,aaOR (95% CI) | pb | Model 2,caOR (95% CI) | pb | Model 3,daOR (95% CI) | pb | Model 4,eaOR (95% CI) | pb | |
|---|---|---|---|---|---|---|---|---|
| Sexual orientation | ||||||||
| Sexual identity | ||||||||
| Heterosexual | 1.00 | 1.00 | ||||||
| Gay/lesbian or bisexual | 1.74 (1.21–2.51) | 0.003 | 1.25 (0.77–2.04) | 0.374 | ||||
| Sexual attraction | ||||||||
| Only to males | 1.00 | 1.00 | ||||||
| Only to females/to both | 1.49 (1.10–2.01) | 0.011 | 0.78 (0.52–1.18) | 0.235 | ||||
| Sexual experience (Lifetime) | ||||||||
| Only males | 1.00 | 1.00 | ||||||
| Both females and males | 1.32 (0.97–1.80) | 0.081 | 1.35 (0.92–1.98) | 0.130 | ||||
| Demographics and survey cycles | ||||||||
| Age (continuous) | 1.76 (1.59–1.95) | <0.001 | 1.76 (1.61–1.94) | <0.001 | 1.46 (1.31–1.62) | <0.001 | 1.44 (1.29–1.60) | <0.001 |
| Race and ethnicity | ||||||||
| Hispanic (any race) | 2.77 (2.08–3.69) | <0.001 | 2.63 (2.00–3.48) | <0.001 | 3.00 (2.26–3.97) | <0.001 | 3.05 (2.30–4.04) | <0.001 |
| Black, non-Hispanic | 3.23 (2.39–4.36) | <0.001 | 3.10 (2.32–4.13) | <0.001 | 2.92 (2.18–3.91) | <0.001 | 3.12 (2.30–4.25) | <0.001 |
| Other race, non-Hispanic | 1.54 (0.89–2.63) | 0.120 | 1.49 (0.85–2.59) | 0.161 | 1.77 (0.90–3.45) | 0.097 | 1.87 (1.02–3.43) | 0.035 |
| White, non-Hispanic | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Survey cycle | ||||||||
| 2002 | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| 2006–2010 | 0.67 (0.49–0.90) | 0.008 | 0.67 (0.50–0.89) | 0.006 | 0.77 (0.58–1.02) | 0.078 | 0.78 (0.58–1.04) | 0.091 |
| 2011–2015 | 0.39 (0.28–0.54) | <0.001 | 0.39 (0.28–0.54) | <0.001 | 0.42 (0.31–0.59) | <0.001 | 0.44 (0.32–0.62) | <0.001 |
Results based on multivariable logistic regression models that accounted for the complex sampling method and were weighted to the population. All models adjusted for age, race and ethnicity, and NSFG survey cycle.
Odds of pregnancy by sexual identity.
Bold indicates p < 0.05.
Odds of pregnancy by sexual attraction.
Odds of pregnancy by sexual experience.
Odds of pregnancy by sexual identity, sexual attraction, and sexual experience.
aOR, adjusted odds ratio; NSFG, National Survey of Family Growth.
Next, we assessed whether the association between sexual orientation and adolescent pregnancy differed across NSFG survey cycles by adding interaction terms for each sexual orientation measure by survey cycle to Model 4. Because 2013 was identified as a pivotal year for sexual minority equality,33,34 we also assessed whether sexual orientation and pregnancy associations differed between the combined 2002 to mid-September 2013 (labeled “old cycle”) and the latest release of NSFG data, late September 2013 to 2015 (labeled “new cycle”), in a separate run of Model 4 with the addition of interaction terms for sexual orientation by old and new survey cycles. Where we observed significant interaction, we stratified Model 4 by survey cycles to examine the direction of effect modification (Table 5). We describe trends in pregnancy among ASMW versus non-ASMW across survey cycles, focusing on significant interactions of sexual orientation and survey cycle.40
Table 5.
Odds of Pregnancy by Sexual Identity, Attraction, and Experience (Model 4) Stratified by United States National Survey of Family Growth Old and New Survey Cycles, Females 15–19 Years of Age
| 2002-mid-September 2013 (old cycle; n = 4471), aOR (95% CI) | pa | Late September 2013–2015 (new cycle; n = 1010), aOR (95% CI) | pa | |
|---|---|---|---|---|
| Sexual orientation | ||||
| Sexual identity | ||||
| Heterosexual | 1.00 | 1.00 | ||
| Gay/lesbian or bisexual | 1.28 (0.72–2.26) | 0.402 | 1.15 (0.45–2.95) | 0.774 |
| Sexual attraction | ||||
| Only to males | 1.00 | 1.00 | ||
| Only to females/to both | 0.59 (0.38–0.90) | 0.014 | 1.59 (0.63–4.02) | 0.324 |
| Sexual experience (Lifetime) | ||||
| Only males | 1.00 | 1.00 | ||
| Both females and males | 1.61 (1.04–2.50) | 0.032 | 0.79 (0.37–1.71) | 0.555 |
| Demographics | ||||
| Age (continuous) | 1.45 (1.29–1.63) | <0.001 | 1.38 (1.01–1.88) | 0.044 |
| Race and ethnicity | ||||
| Hispanic (any race) | 2.23 (1.99–3.74) | <0.001 | 2.95 (1.61–5.43) | 0.001 |
| Black, non-Hispanic | 2.82 (2.00–4.00) | <0.001 | 3.13 (1.56–6.27) | 0.001 |
| Other race, non-Hispanic | 1.73 (0.92–3.25) | 0.092 | 1.96 (0.43–8.93) | 0.381 |
| White, non-Hispanic | 1.00 | 1.00 | ||
Results based on multivariable logistic regression models that accounted for the complex sampling method and were weighted to the population. All models adjusted for age and race and ethnicity.
Bold indicates p < 0.05.
Finally, to be consistent with research showing that substance use and sexual risk behaviors seemed to explain the relationship between sexual minority status and increased odds of teen pregnancy, we ran the stratified Model 4 with the addition of substance use (Model 5: any past-year drug use and any past-year alcohol use), followed by sexual risk behaviors (Model 6: number of lifetime male partners with whom the respondent had penile-vaginal intercourse, past year condomless sex, and first penile-vaginal intercourse at age 14 or younger [transactional sex was excluded due to small sample sizes in stratified models]; Table 6).
Table 6.
Odds of Pregnancy by Sexual Identity, Attraction, and Experience, Adjusted for Substance Use (Model 5) and Sexual Risk Behaviors (Model 6), Stratified by United States National Survey of Family Growth Old and New Survey Cycles, Females 15–19 Years of Age
| 2002-mid-September 2013 (old cycle; n = 4471), Model 5,aaOR (95% CI) | pb | Late September 2013–2015, (new cycle; n = 1010), Model 5,aaOR (95% CI) | pb | 2002-mid-September 2013 (old cycle; n = 4471), Model 6,caOR (95% CI) | pb | Late September 2013–2015 (new cycle; n = 1010), Model 6,caOR (95% CI) | pb | |
|---|---|---|---|---|---|---|---|---|
| Sexual orientation | ||||||||
| Sexual identity | ||||||||
| Heterosexual | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Gay/lesbian or bisexual | 1.21 (0.68–2.13) | 0.519 | 1.16 (0.46–2.93) | 0.750 | 1.72 (0.72–4.11) | 0.222 | 1.92 (0.28–13.35) | 0.508 |
| Sexual attraction | ||||||||
| Only to males | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Only to females/to both | 0.67 (0.44–1.02) | 0.059 | 1.58 (0.65–3.85) | 0.314 | 0.52 (0.26–1.02) | 0.056 | 1.30 (0.37–4.60) | 0.684 |
| Sexual experience (Lifetime) | ||||||||
| Only males | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Both females and males | 1.72 (1.10–2.69) | 0.017 | 0.83 (0.38–1.79) | 0.627 | 0.82 (0.39–1.74) | 0.611 | 0.69 (0.18–2.67) | 0.585 |
| Demographics | ||||||||
| Age (continuous) | 1.47 (1.30–1.65) | <0.001 | 1.47 (1.09–2.00) | 0.013 | 1.17 (0.95–1.43) | 0.138 | 1.60 (1.00–2.55) | 0.049 |
| Race and ethnicity | ||||||||
| Hispanic (any race) | 2.56 (1.89–3.47) | <0.001 | 2.90 (1.57–5.37) | 0.001 | 3.48 (2.35–5.16) | <0.001 | 3.01 (1.33–6.79) | 0.008 |
| Black, non-Hispanic | 2.42 (1.71–3.41) | <0.001 | 2.77 (1.36–5.63) | 0.005 | 2.47 (1.56–3.92) | <0.001 | 4.49 (1.30–15.45) | 0.018 |
| Other race, non-Hispanic | 1.67 (0.87–3.20) | 0.126 | 1.67 (0.36–7.74) | 0.513 | 1.45 (0.59–3.55) | 0.417 | 1.55 (0.28–8.51) | 0.618 |
| White, non-Hispanic | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Past-year substance use | ||||||||
| Any drug used | ||||||||
| No | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Yes | 0.87 (0.64–1.18) | 0.365 | 1.45 (0.90–2.33) | 0.131 | 0.49 (0.32–0.77) | 0.002 | 1.14 (0.51–2.54) | 0.750 |
| Any alcohol use | ||||||||
| No | 1.00 | 1.00 | 1.00 | 1.00 | ||||
| Yes | 0.51 (0.37–0.70) | <0.001 | 0.40 (0.23–0.68) | 0.001 | 0.38 (0.24–0.61) | <0.001 | 0.56 (0.27–1.14) | 0.111 |
| Sexual risk with males | ||||||||
| Lifetime male sex partnerse | ||||||||
| 1 partner | 1.00 | 1.00 | ||||||
| 2 partners | 1.41 (0.81–2.47) | 0.222 | 3.40 (1.10–10.57) | 0.034 | ||||
| 3 or more partners | 1.52 (0.95–2.42) | 0.079 | 0.92 (0.30–2.80) | 0.885 | ||||
| Past-year condomless sexe | ||||||||
| No | 1.00 | 1.00 | ||||||
| Yes | 4.46 (2.77–7.16) | <0.001 | 11.62 (3.93–34.38) | <0.001 | ||||
| First intercourse ≤age 14e | ||||||||
| No | 1.00 | 1.00 | ||||||
| Yes | 3.79 (1.98–7.24) | <0.001 | 4.86 (1.41–16.76) | 0.013 | ||||
Results based on multivariable logistic regression models that accounted for the complex sampling method and were weighted to the population.
Adjusted for sexual identity, attraction, and experience simultaneously, as well as for age, race and ethnicity, and past-year drug and alcohol use.
Bold indicates p < 0.05.
Adjusted for sexual identity, attraction, and experience simultaneously, as well as for age, race and ethnicity, past-year drug and alcohol use, and sexual risk with males.
Includes any past-year use of marijuana, cocaine, crack, crystal methamphetamine, and/or nonprescription injection drug use.
“Intercourse” and “sex” defined as penile–vaginal intercourse with male partner(s).
All analyses accounted for the complex sampling method and were weighted to the population. Analyses were performed in SAS 9.3 (SAS Institute Inc., Cary, NC) using the proc survey functions. Statistical significance was set at an alpha of 0.05 for regression models and an alpha of 0.10 for interaction terms.41
Results
The mean age of the target population was 17.08 years (standard error [SE] = 0.02). Most of the sample (58.11%) identified as White, non-Hispanic. Overall, 4776 adolescent females identified as “heterosexual or straight” (90.18%), 95 (1.53%) as “homosexual, gay, or lesbian,” and 439 (8.29%) as “bisexual.” Nearly 18% reported any attraction to females (0.83% only attracted to females and 17.10% attracted to both males and females); over 11% had ever had a sexual experience with another female (1.76% exclusively female partners and 9.70% both male and female partners). Of the heterosexually identified respondents, 10.18% reported any attraction to females; 5.87% reported having ever had any sexual experience with a female partner (data not shown). Heterosexual identity decreased significantly from 2002 to 2015 (2002: 91.75%; 2006–2010: 91.47%; and 2011–2015: 88.53%, p = 0.031), as did exclusive attraction to males (2002: 84.03%; 2006–2010: 82.48%; and 2011–2015: 77.28%, p < 0.001) and rates of sexual experience with exclusively male partners (2002: 52.59%; 2006–2010: 44.19%; and 2011–2015: 45.10%, p = 0.004; Table 1). By contrast, self-reported attraction to both males and females rose significantly from 2002 to 2015 (2002: 14.67%; 2006–2010: 15.54%; and 2011–2015: 19.52%, p = 0.005).
Over a quarter of the overall sample (25.68%) reported past-year drug use and 59.84% reported past-year alcohol use. Of those who had ever had penile–vaginal intercourse, 41.39% reported having had penile–vaginal sex with three or more male partners; 2.02% reported past-year transactional sex; 60.98% past-year condomless sex; and 10.13% had their first penile–vaginal sexual intercourse at age 14 or younger. In total, 10.36% (n = 679) reported having ever been pregnant, with significantly decreasing rates across each survey cycle (2002: 14.38%; 2006–2010: 11.24%; and 2011–2015: 7.25%, p < 0.001; Table 1).
In general, sexual minority status was associated with the highest rates of pregnancy-related behaviors (i.e., sexual risk and substance use), regardless of whether sexual orientation was measured by sexual identity, attraction, or experience (Table 2). A significantly greater proportion of bisexually identified adolescent women (16.73%; odds ratio [OR] = 1.87, 95% confidence interval [CI] = 1.30–2.68, p = 0.001) and a significantly smaller proportion of gay/lesbian-identified adolescent women (3.28%; OR = 0.32, 95% CI = 0.14–0.71, p = 0.005) reported having ever been pregnant compared to heterosexually identified adolescent women (9.71%). The same pattern was observed for those who reported attraction to both males and females (14.22%; OR = 1.54, 95% CI = 1.16–2.04, p = 0.003) compared to those exclusively attracted to males (9.73%). Sex of sexual partners was not significantly associated with pregnancy in unadjusted regression models (Table 3).
After adjustment for age, race/ethnicity, and survey cycle, sexual minority identity (gay/lesbian or bisexual identity vs. heterosexual identity; adjusted odds ratio [aOR] = 1.74, 95% CI = 1.21–2.51, p = 0.003) and sexual minority attraction (attraction only to females or to both males and females vs. attraction only to males; aOR = 1.49, 95% CI = 1.10–2.01, p = 0.011) remained individually associated with increased odds of pregnancy (Table 4). In Model 4, which adjusted for sexual identity, attraction, and experience simultaneously, none of the sexual orientation measures remained significantly associated with pregnancy.
We did not observe significant interaction of sexual orientation measures and the three main survey cycles; however, there was significant interaction between sexual attraction and the more recently released late September 2013 to 2015 (new) cycle at alpha <0.10 (p = 0.052).41 Therefore, we stratified Model 4 by 2002 to mid-September 2013 (old) and new survey cycles (Table 5). In stratified models, we found that sexual minority attraction (only to females or to both males and females) versus exclusive attraction to males was associated with 41% decreased odds of pregnancy (95% CI = 0.38–0.90, p = 0.014) in the 2002 to mid-September 2013 survey cycles, but 1.59 times the odds of pregnancy in the late September 2013 to 2015 cycle (95% CI = 0.63–4.02, p = 0.324).
When past-year drug and alcohol use were added to the stratified Model 4 to create Model 5, followed by the addition of sexual risk behaviors in Model 6, the same trend persisted, but with the strength of the associations attenuated after the addition of sexual risk behaviors. Sexual minority attraction remained protective against pregnancy in the old survey cycles (Model 5, old cycle: aOR = 0.67, 95% CI = 0.44–1.02, p = 0.059; Model 6, old cycle: aOR = 0.52, 95% CI = 0.26–1.02, p = 0.056; and attenuated from aOR = 0.59, 95% CI = 0.38–0.90, p = 0.014 in Model 4), but predicted increased odds of pregnancy in the new cycle (Model 5, new cycle: aOR = 1.58, 95% CI = 0.65–3.85, p = 0.314; Model 6, new cycle: aOR = 1.30, 95% CI = 0.37–4.60, p = 0.684; and attenuated from aOR = 1.59, 95% CI = 0.63–4.02, p = 0.324 in Model 4), although none of the associations was significant (Table 6).
Discussion
We found that among adolescent women, sexual minority identity and attraction individually predicted increased odds of pregnancy compared to heterosexual identity and exclusive attraction to males. These associations were driven by bisexually identified and both-sex attracted women given that there were, respectively, only eight gay/lesbian-identified and three exclusively same-sex attracted women in the sexual minority identity and attraction categories, who had ever been pregnant. Our findings on sexual minority identity echo those of others.6,16,17 Our results showing an association between sexual minority attraction (again, primarily both-sex attraction) and adolescent pregnancy demonstrate that attraction is also an important aspect of understanding ASMW health disparities.18,19,23 However, after adjustment for sexual identity, attraction, and experience simultaneously, neither sexual minority identity nor attraction remained significant predictors of ASMW pregnancy disparities. Sexual minority experience (i.e., having had both male and female partners) was not significantly associated with increased odds of pregnancy in this sample.
Because of the rapidly evolving political and social climate for sexual minorities in the United States, we also explored whether the associations were modified by survey cycle. Interestingly, the only aspect of sexual orientation that significantly interacted with survey cycles was sexual attraction. In stratified models, sexual minority attraction (vs. exclusive attraction to males) was associated with significantly lower odds of pregnancy in older NSFG survey cycles, but increased odds in the most recent cycle, despite a more supportive policy environment that would be expected to mitigate ASMW pregnancy disparities.29,30
The pregnancy disparities observed in the most recent NSFG data for adolescent women with attraction to both males and females may be understood in terms of access to social support, minority stress and discrimination, and internalized stigma. In another study that examined pregnancy trends among adolescent sexual minorities, those who had experienced pregnancy had a significantly greater likelihood of also having experienced stigma and discrimination compared to sexual minority adolescents who had not experienced pregnancy.5 For adolescents attracted to both males and females, who outwardly assume a bisexual or other nonmonosexual (e.g., queer or pansexual) identity, social support may be more accessible in the form of community connections with other bisexual or nonmonosexual identified individuals, which may alleviate stress associated with bisexual stigma42 (e.g., negative stereotypes of bisexuality as synonymous with promiscuity and discounting bisexuality as a temporary phase rather than a true identity).43 For adolescent women who are attracted to both males and females, but who do not self-identify as bisexual or another nonmonosexual identity, however, such community support may not be as accessible.
Research has shown that internalized bisexual stigma (i.e., inwardly focusing bisexual stigma and stereotypes)43 is especially elevated among people who report both same- and different-sex attraction without identifying as bisexual/nonmonosexual,43 whereas coming out as such seems to attenuate internalized stigma.44 Although attitudes toward lesbian and gay identity have become more positive in recent years, perceptions of bisexuality remain negative,45 despite policy advances in support of sexual minorities more broadly. Policies that support same-sex relationships may not address ongoing bisexual stigma and stereotyping.46–48
Adolescent women who express attraction to both males and females may engage in more sex with male partners to conceal their attraction to females and to cope with both bisexual stigma and expectations of heteronormativity.49 Heteronormative sexual health education and services that overlook sexual diversity, however, may lead to both-sex attracted adolescent women discounting their pregnancy risk and lacking knowledge for pregnancy prevention in the context of their sexual relationships with male partners.49 Thus, the combined impact of sexual minority stress, lack of social support, stigma, and invisibility may explain ongoing pregnancy disparities among ASMW attracted to both males and females.
Limitations
The study findings should be understood in light of their limitations. First, data were self-report, thus vulnerable to social desirability bias. Second, the NSFG presents cross-sectional data in each survey cycle, limiting our ability to assess the timing of risk behaviors as they related to pregnancy outcomes. Third, the NSFG is a nationally representative sample of the U.S. population, with population weights for sample adjustment based on the U.S. census and for nonresponse and probability of selection. Still, the data are not weighted to sexual orientation since there are no existing population-level sexual orientation data. The NSFG also excludes individuals who are unhoused and institutionalized, thus further limiting generalizability.
In addition, although the NSFG is a large national health survey, the subsample of adolescent women—especially those who are sexual minorities—was much smaller, preventing multivariable analyses of group differences in pregnancy. Despite these limitations, this study provides important information about how teen pregnancy varies by aspects of sexuality—including sexual attraction—among adolescent women in the United States, which may be useful for planning teen pregnancy prevention programs.13
Conclusion
To explicate the underlying mechanisms driving ASMW pregnancy disparities, future research should measure sexual attraction in addition to sexual identity and experience. More population-based research is also needed to expand on existing studies that have drawn from small samples and qualitative data. Finally, sex education and teen pregnancy prevention programs should reflect sexual diversity through imagery, language, and resources that acknowledge adolescents' ranges of sexual attraction. To address the unique needs of ASMW regardless of their sexual identity, all sexual and reproductive health programs and services would benefit from movement beyond assumptions of heterosexuality among adolescent women and recognition of adolescent sexual fluidity.
Acknowledgments
The authors acknowledge Nicholas Grosskopf, EdD and Aimee Campbell, PhD for their consultation. Dr. Margaret Paschen-Wolff is now supported by a training grant (T32 MH019139; Principal Investigator, Theodorus Sandfort, PhD) from the National Institute of Mental Health at the HIV Center for Clinical and Behavioral Studies at the New York State Psychiatric Institute and Columbia University (P30-MH43520; Center Principal Investigator: Robert Remien, PhD).
Disclaimer
The findings and conclusions in the article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Author Disclosure Statement
No competing financial interests exist.
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