Stillbirth Cases Controls
(N = 9404) (N = 18808)
Maternal Demographic and Clinical Characteristics
Age at index stillbirth/birth, years [mean (SD)] 27.5 ± 5.8 27.5 ± 5.8
Race/ethnicity
Non-Hispanic
American Indian or Alaska Native 61 (0.6%) 101 (0.5%)
Asian 61 (0.6%) 153 (0.8%)
Native Hawaiian or Other Pacific Islander 51 (0.5%) 52 (0.3%)
Black or African American 62 (0.7%) 51 (0.3%)
White 6204 (66.0%) 13731 (73.0%)
Multiple Races 442 (4.7%) 692 (3.7%)
Hispanic 2301 (24.5%) 3994 (21.2%)
Unknown race/ethnicity 222 (2.4%) 34 (0.2%)
Mother’s birth year 1971.5 ± 12.9 1971.5 ± 12.9
Mother’s education at index birth
High school degree or less 4046 (43.0%) 7617 (40.5%)
Some college and college degree 4269 (45.4%) 9638 (51.2%)
Post-college 424 (4.5%) 1340 (7.1%)
Unknown 665 (7.1%) 213 (1.1%)
Number of prenatal visits2 6 (4-9) 11 (9-12)
Number of previous live births2 1 (0-2) 1 (0-2)
At least one previous live birth still living 5473 (58.2%) 12073 (64.2%)
Method of delivery
Cesarean and vaginal/forceps/vacuum 0 (0.0%) 27 (0.1%)
Cesarean only 678 (7.2%) 3495 (18.6%)
Vaginal/forceps/vacuum only 7310 (77.7%) 15216 (80.9%)
Others/Unknown 1416 (15.1%) 70 (0.4%)
Had at least one birth defect 686 (7.3%) 159 (0.8%)
Maternal Pre-Pregnancy Body Mass Index (BMI, kg/m2)2 24.0 (21.1-29.1) 23.2 (20.7-27.4)
Missing maternal pre-pregnancy BMI 3477 (37.0%) 5592 (29.7%)
Mother’s weight gain during index pregnancy (kg)2 8.2 (4.1-12.7) 13.6 (10.4-18.1)
Missing mother’s weight gain due to index pregnancy 3349 (35.6%) 5383 (28.6%)
Mother had gestational diabetes due to index pregnancy 141 (1.5%) 384 (2.0%)
Mother had pre-existing diabetes prior to index pregnancy 152 (1.6%) 110 (0.6%)
Mother had diabetes (gestational/pre-existing) during index pregnancy 302 (3.2%) 498 (2.6%)
Mother had gestational hypertension due to index pregnancy 1166 (12.4%) 1861 (9.9%)
Mother had chronic hypertension prior to index pregnancy 95 (1.0%) 115 (0.6%)
Paternal Demographic and Clinical Characteristics
Age at index stillbirth/birth, years 30.3 ± 6.4 30.1 ± 6.2
Race/ethnicity
Non-Hispanic
American Indian or Alaska Native 50 (0.5%) 59 (0.3%)
Asian 48 (0.5%) 105 (0.6%)
Native Hawaiian or Other Pacific Islander 39 (0.4%) 73 (0.4%)
Black or African American 71 (0.8%) 87 (0.5%)
White 5702 (60.6%) 13109 (69.7%)
Multiple Races 276 (2.9%) 640 (3.4%)
Hispanic 1517 (16.1%) 3132 (16.7%)
Unknown 1701 (18.1%) 1603 (8.5%)
Father’s birth year 1968.6 ± 13.4 1969.0 ± 13.2
Father’s education at index birth
High school degree or less 1891 (20.1%) 5904 (31.4%)
Some college and college degree 1992 (21.2%) 8729 (46.4%)
Post-college 605 (6.4%) 2641 (14.0%)
Unknown5 4916 (52.3%) 1534 (8.2%)
Index Stillborn/Live-born Demographic and Clinical Characteristics
Gestational Age, weeks2 29 (23-36) 39 (38-40)
Sex
Male 4735 (50.4%) 9778 (52.0%)
Female 4526 (48.1%) 9030 (48.0%)
Birth year 1999.0 ± 12.5 1999.0 ± 12.5
Any fetal structural anomalies or birth defects 1686 (7.3%) 159 (0.8%)
Birthweight, g2 1145 (440-2567) 3340 (3020-3646)
Any Stillbirth Family History
All relatives 912 (12.5%) 1524 (11.6%)
First-degree relatives 215 (3%) 387 (2.9%)
Second-degree relatives 277 (3.8%) 416 (3.2%)
Third-degree relatives 563 (7.7%) 911 (6.9%)