Figure 1.
Figure 2.
Figure 3a.
Figure 3b.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Stochastic Actor Oriented Model Estimates for Schools 2 and 3
| School 2 | School 3 | |
|---|---|---|
| Rate (Period 1) | 11.37 | 9.30 |
| (0.55) | (0.87) | |
| Rate (Period 2) | 10.31 | 5.00 |
| (0.47) | (0.31) | |
| Out degree | -3.32 | -4.16 |
| (0.03) | (0.04) | |
| Reciprocity | 2.16 | 2.60 |
| (0.05) | (0.08) | |
| Transitive Triplets | 0.44 | 0.61 |
| (0.02) | (0.03) | |
| Female Similarity | 0.18 | 0.35 |
| (0.03) | (0.04) | |
| Grade Similarity | 2.01 | 2.11 |
| (0.11) | (0.13) | |
| Pregnant alter | -0.34 | 0.09 |
| (1.42) | (0.24) | |
| Pregnant ego | -0.77 | -0.35 |
| (1.37) | (0.30) | |
| Pregnant similarity | -0.36 | 0.33 |
| (1.41) | (0.24) | |
| n nodes (preg. nodes) | 479 (21) | 850 (60) |
Separable Temporal Exponential Random Graph Models of Schools 2 and 3
| School 2 | School 3 | |||||||
|---|---|---|---|---|---|---|---|---|
| Formation | Dissolution | Formation | Dissolution | |||||
| Base | Covars. | Base | Covars. | Base | Covars. | Base | Covars. | |
| Edges | -6.40* | -6.52* | -6.56 | -1.47* | -6.92* | -7.52* | -0.76* | -1.65* |
| (0.03) | (0.04) | (0.03) | (0.06) | (0.03) | (0.05) | (0.04) | (0.08) | |
| Preg - Out | -0.70* | -0.37 | -0.85 | -0.77 | -0.61* | -0.51* | -0.51 | -0.31 |
| (0.03) | (0.31) | (0.45) | (0.52) | (0.18) | (0.19) | (0.28) | (0.30) | |
| Preg - In | -0.26 | 0.15 | -0.66 | -0.30 | -0.27 | -0.12 | -0.79* | 0.47 |
| (0.24) | (0.21) | (0.38) | -(0.45) | (0.16) | (0.16) | (0.30) | (0.05) | |
| Triad (gwesp) | 1.16* | 0.37* | 1.38* | 0.47* | ||||
| (0.03) | (0.04) | (0.05) | (0.05) | |||||
| Reciprocity | 3.18* | 1.75* | 3.68* | 1.38* | ||||
| (0.90) | (0.11) | (0.11) | (0.14) | |||||
| Gender Homophily | 0.11* | 0.64* | 0.34* | 0.68* | ||||
| (0.05) | (0.07) | (0.06) | (0.09) | |||||
Random Intercept Models of Change in Network Variables between Time 1 and Time 3 Surveys
| Out-nom. | In-nom | Recip. Friends | Centrality | |
|---|---|---|---|---|
| Intercept | -2.54* | -2.55* | -0.93* | -0.14 |
| (0.34) | (0.63) | (0.26) | (0.23) | |
| Pregnant | -0.77 | -1.01* | -0.28 | -0.01 |
| (0.47) | (0.42) | (0.24) | (0.02) | |
| Random Intercept | 0.20 | 1.93 | 0.24 | 0.35 |
| Student-level residual | 10.06 | 7.8 | 2.50 | 0.01 |
| n | 240 | 240 | 240 | 240 |
| School n | 7 | 7 | 7 | 7 |
Comparison of Pregnant Girls to Non-Pregnant Matched Girls and Not Matched Non-Pregnant Girls Using Mean Difference Testing and Standardized Biases_
| Pregnant | Matched Non-Preg | Not Matched Non-Preg | ||||||
|---|---|---|---|---|---|---|---|---|
| M | SD | M | SD | Std bias | M | SD | Std bias | |
| Out-Nominations | ||||||||
| Num. at first survey | 5.12 | 3.44 | 5.18 | 3.21 | -0.02 | 5.49 | 3.22 | -0.11 |
| Avg. diff. bt surveys | -3.15 | 3.29 | -2.38 | 3.16 | -0.23 | -2.01* | 3.47 | -0.35 |
| Num. maintained bt surveys | 0.65 | 0.90 | 1.03* | 1.32 | -0.42 | 1.41* | 1.47 | -0.85 |
| In-Nominations | ||||||||
| Num. at first survey | 4.48 | 3.39 | 4.29 | 3.62 | 0.06 | 4.78 | 3.66 | -0.09 |
| Avg. diff. bt surveys | -3.12 | 3.02 | -2.11* | 2.86 | -0.33 | -2.28* | 3.18 | -0.28 |
| Num. maintained bt surveys | 0.30 | 0.59 | 0.58* | 0.92 | -0.47 | 0.87* | 1.12 | -0.97 |
| Reciprocated Friends | ||||||||
| Num. at first survey | 1.60 | 1.53 | 1.74 | 1.70 | -0.09 | 1.98 | 1.74 | -0.25 |
| Avg. diff. bt surveys | -1.12 | 1.56 | -0.83 | 1.64 | -0.18 | -0.88 | 1.72 | -0.15 |
| Centrality | ||||||||
| Num. at first survey | 0.57 | 0.47 | 0.58 | 0.47 | -0.01 | 0.55 | 0.46 | 0.05 |
| Avg. diff. bt surveys | -0.27 | 0.87 | -0.24 | 0.86 | -0.04 | -0.23 | 0.83 | -0.05 |
| Covariates | ||||||||
| Age | 15.57 | 1.09 | 15.49 | 1.11 | 0.07 | 15.02* | 1.36 | 0.50 |
| White | 0.47 | 0.50 | 0.44 | 0.50 | 0.06 | 0.44 | 0.50 | 0.05 |
| Black | 0.22 | 0.42 | 0.23 | 0.42 | -0.03 | 0.16 | 0.37 | 0.13 |
| Hispanic | 0.52 | 1.47 | 0.66 | 1.65 | -0.09 | 0.91 | 2.19 | -0.27 |
| U.S. Born | 0.95 | 0.22 | 0.92 | 0.28 | 0.15 | 0.84* | 0.37 | 0.50 |
| Prior GPA | 2.31 | 0.73 | 2.39 | 0.68 | -0.10 | 3.07* | 0.69 | -1.04 |
| HIV/AIDS Expectations | 1.00 | 1.35 | 1.21 | 2.03 | -0.15 | 0.85 | 1.57 | 0.11 |
| Number in Household | 4.55 | 1.33 | 4.56 | 1.13 | 0.00 | 4.74 | 1.12 | -0.14 |
| Extracurricular | 0.33 | 0.48 | 0.32 | 0.47 | 0.04 | 0.14* | 0.34 | 0.41 |
| Get Along w. Teacher | 1.22 | 1.30 | 1.11 | 1.30 | 0.09 | 1.06 | 1.34 | 0.12 |
| Get Along w. Peers | 1.58 | 1.45 | 1.56 | 1.49 | 0.02 | 1.43 | 1.54 | 0.10 |
| Try in School | 1.78 | 0.61 | 1.76 | 0.66 | 0.05 | 1.58* | 0.59 | 0.34 |
| Tried Alcohol | 0.78 | 0.42 | 0.79 | 0.41 | -0.03 | 0.44* | 0.50 | 0.82 |
| Overall Health | 2.73 | 0.88 | 2.81 | 0.90 | -0.08 | 2.14* | 0.94 | 0.67 |
| Cigarette Consumption | 2.53 | 2.80 | 2.27 | 2.53 | 0.09 | 0.65* | 1.43 | 0.67 |
| Lie to Parents | 2.83 | 1.86 | 2.86 | 1.84 | -0.01 | 2.00* | 1.68 | 0.45 |
| Skip School | 1.57 | 1.69 | 1.44 | 1.68 | 0.08 | 0.35* | 0.77 | 0.72 |
| n | 60 | 180 | 572 | |||||
Average Network Degrees and Network Densities at Time 1 and Time 3 by School
| School | n | Avg. Degree | Network Density | ||
|---|---|---|---|---|---|
| Time 1 | Time 3 | Time 1 | Time 3 | ||
| 1 | 121 | 3.78 | 2.31 | 0.031 | 0.019 |
| 2 | 479 | 3.88 | 2.73 | 0.008 | 0.006 |
| 3 | 850 | 2.08 | 1.26 | 0.002 | 0.001 |
| 4 | 70 | 2.61 | 2.73 | 0.038 | 0.04 |
| 5 | 76 | 2.26 | 1.84 | 0.03 | 0.25 |
| 6 | 92 | 2.88 | 1.55 | 0.051 | 0.027 |
| 7 | 46 | 4.02 | 1.57 | 0.098 | 0.038 |
Characteristics of Saturated Schools with One or More Pregnancy Occurrence
| School | Type | Urbanicity | Size | Grade | Region |
|---|---|---|---|---|---|
| 1 | Public | Rural | Small | K-12 | South |
| 2 | Public | Rural | Large | 9-12 | Midwest |
| 3 | Public | Suburban | Large | 10-12 | West |
| 4 | Public | Rural | Small | K-12 | Midwest |
| 5 | Private | Urban | Small | K-12 | South |
| 6 | Public | Suburban | Small | 6-8 | South |
| 7 | Catholic | Urban | Small | K-8 | Northeast |
Random Intercept Models of Number of Friendships Maintained between Time 1 and Time 3 Surveys
| Out-nom. | In-nom | |
|---|---|---|
| Intercept | 1.08* | 0.7* |
| (0.19) | (0.13) | |
| Pregnant | -0.37* | -0.28* |
| (0.18) | (0.13) | |
| Random Intercept | 0.12 | 0.06 |
| Student-level residual | 1.41 | 0.68 |
| n | 240 | 240 |
| School n | 7 | 7 |
Comparison of School Characteristics in Saturated Sample, Saturated Sample with Girls Experiencing a Pregnancy and Non-Saturated Sample Schools
| Saturated (w/girls) | Saturated (w/preg.) | Non-Saturated | |
|---|---|---|---|
| Urbanicity | |||
| Urban | 4 (26.7%) | 2 (28.6%) | 33 (30.0%) |
| Suburban | 6 (40.0%) | 2 (28.6%) | 63 (57.3%) |
| Rural | 5 (33.3%) | 3 (42.9%) | 14 (12.7%) |
| Region | |||
| West | 3 (20.0%) | 1 (14.3%) | 22 (20.0%) |
| Midwest | 5 (33.3%) | 2 (28.6%) | 22 (20.0%) |
| South | 4 (26.7%) | 3 (42.9%) | 49 (44.5%) |
| Northeast | 3 (20.0%) | 1 (14.3%) | 17 (15.5%) |
| School Size* | |||
| Small (1-400) | 13 (86.7%) | 5 (71.4%) | 16 (14.5%) |
| Medium (401-1000) | 0 (0.0%) | 0 (0.0%) | 59 (53.6%) |
| Large (1001-4000) | 2 (13.3%) | 2 (28.6%) | 35 (31.8%) |
| School Type* | |||
| Public | 10 (66.7%) | 5 (71.4%) | 104 (94.5%) |
| Private | 4 (26.7%) | 1 (14.3%) | 2 (1.8%) |
| Catholic | 1 (6.7%) | 1 (14.3%) | 4 (3.6%) |
| Grades* | |||
| Includes primary grades | 11 (73.3%) | 4 (57.1%) | 4 (3.6%) |
| No primary grades | 4 (26.7%) | 3 (42.9%) | 106 (96.4%) |
| n | 15 | 7 | 110 |