TABLE 1.
Maternal characteristics by fertility group and plurality
| Singletons |
Twins |
Triplets+a |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IVF | IVF | IVF | ||||||||||||||||
| Fertile | Subfertile | A-fresh | A-thawed | D-fresh | D-thawed | Fertile | Subfertile | A-fresh | A-thawed | D-fresh | D-thawed | Fertile | Subfertile | A-fresh | A-thawed | D-fresh | D-thawed | |
| N, pregnancies | 1,326,650 | 9142 | 56,037 | 16,997 | 8129 | 3574 | 19,116 | 1951 | 22,858 | 4686 | 4921 | 1041 | 352 | 205 | 1359 | 281 | 168 | 55 |
| Maternal age, y | ||||||||||||||||||
| Mean (SD) | 28.7 (5.9) | 33.7 (5.2) | 35.0 (4.3) | 35.0 (4.3) | 42.1 (4.7) | 42.9 (5.1) | 29.7 (5.8) | 34.5 (5.4) | 33.9 (4.0) | 34.2 (4.1) | 41.8 (4.8) | 42.4 (5.2) | 31.2 (5.6) | 32.9 (5.2) | 33.8 (3.9) | 33.8 (4.2) | 40.8 (4.7) | 42.9 (5.2) |
| % | ||||||||||||||||||
| 18–29 | 55.3 | 21.0 | 10.5 | 9.9 | 1.3 | 1.7 | 48.1 | 16.4 | 14.5 | 12.0 | 1.7 | 2.1 | 36.8 | 24.8 | 15.0 | 17.5 | 1.2 | 0.0 |
| 30–34 | 26.9 | 36.0 | 34.0 | 35.1 | 6.2 | 5.8 | 30.1 | 37.5 | 40.7 | 41.6 | 7.0 | 6.9 | 36.7 | 43.4 | 39.4 | 39.4 | 8.0 | 5.5 |
| 35–37 | 10.3 | 19.6 | 24.9 | 26.4 | 7.5 | 7.1 | 12.5 | 21.2 | 25.0 | 25.0 | 8.9 | 8.2 | 14.2 | 13.8 | 26.5 | 24.0 | 14.3 | 12.7 |
| 38–40 | 5.3 | 13.8 | 20.1 | 18.7 | 15.4 | 12.3 | 6.6 | 12.6 | 15.3 | 15.0 | 15.8 | 14.0 | 8.1 | 10.0 | 15.3 | 13.7 | 19.4 | 10.9 |
| ≥41 | 2.1 | 9.5 | 10.5 | 9.9 | 69.6 | 73.2 | 2.7 | 12.3 | 4.4 | 6.4 | 66.7 | 68.9 | 4.2 | 8.0 | 3.8 | 5.5 | 57.1 | 70.9 |
| Hispanic ethnicity, % | 26.4 | 7.3 | 8.6 | 9.4 | 8.0 | 9.4 | 20.7 | 6.8 | 11.1 | 13.3 | 8.2 | 6.7 | 18.8 | 9.9 | 4.8 | 5.3 | 4.5 | 5.2 |
| Race, % | ||||||||||||||||||
| White | 76.7 | 86.7 | 81.7 | 78.3 | 83.7 | 83.7 | 75.2 | 85.7 | 83.9 | 78.3 | 83.9 | 84.3 | 79.0 | 91.4 | 86.3 | 77.8 | 84.8 | 84.6 |
| Black | 13.2 | 4.0 | 4.8 | 5.3 | 4.5 | 5.2 | 17.4 | 4.1 | 4.4 | 6.1 | 5.3 | 4.9 | 15.0 | 3.3 | 5.3 | 9.2 | 6.6 | 11.5 |
| Asian | 9.5 | 8.9 | 13.2 | 16.1 | 11.5 | 10.9 | 7.0 | 10.0 | 11.5 | 15.4 | 10.5 | 10.6 | 5.2 | 4.6 | 8.4 | 12.6 | 7.9 | 3.8 |
| Other | 0.5 | 0.3 | 0.2 | 0.3 | 0.2 | 0.3 | 0.4 | 0.2 | 0.2 | 0.2 | 0.3 | 0.2 | 0.7 | 0.7 | 0.0 | 0.4 | 0.6 | 0.0 |
| Education, % | ||||||||||||||||||
| <8th Grade | 4.7 | 0.3 | 0.3 | 0.6 | 0.4 | 0.3 | 3.6 | 0.3 | 0.3 | 0.3 | 0.4 | 1.2 | 1.8 | 0.0 | 0.2 | 2.6 | 1.2 | 0.0 |
| Some high school | 12.1 | 1.5 | 1.0 | 1.2 | 0.9 | 0.8 | 10.3 | 1.3 | 1.0 | 1.0 | 0.8 | 0.8 | 6.7 | 1.6 | 1.4 | 2.1 | 0.0 | 0.0 |
| High school graduate or GED | 24.4 | 8.3 | 7.1 | 7.7 | 6.8 | 6.1 | 23.1 | 8.1 | 7.7 | 7.6 | 7.1 | 6.4 | 21.1 | 11.0 | 12.1 | 9.9 | 10.7 | 12.3 |
| Some college or associate degree | 27.0 | 20.9 | 18.5 | 18.1 | 16.3 | 18.6 | 27.2 | 17.8 | 19.6 | 19.2 | 17.2 | 20.5 | 27.2 | 28.1 | 23.1 | 26.6 | 24.1 | 20.4 |
| Bachelor’s degree | 20.3 | 37.5 | 39.8 | 38.8 | 39.6 | 38.7 | 22.1 | 37.0 | 40.4 | 38.7 | 39.5 | 37.0 | 25.6 | 29.8 | 35.3 | 35.2 | 36.7 | 52.5 |
| Postgraduate | 11.6 | 31.6 | 33.3 | 33.6 | 36.1 | 35.4 | 13.6 | 35.5 | 31.0 | 33.1 | 34.9 | 34.1 | 17.6 | 29.5 | 27.9 | 23.7 | 27.2 | 14.8 |
| Parity, % | ||||||||||||||||||
| Nulliparous | 38.7 | 56.4 | 70.0 | 51.9 | 69.9 | 50.9 | 20.2 | 29.7 | 40.4 | 32.2 | 39.3 | 29.7 | 16.1 | 16.9 | 26.8 | 21.6 | 25.3 | 17.4 |
| 1 | 33.0 | 29.9 | 22.4 | 34.1 | 21.7 | 35.7 | 35.4 | 42.0 | 43.6 | 42.5 | 43.1 | 41.0 | 26.0 | 28.0 | 29.4 | 27.8 | 29.6 | 25.9 |
| ≥2 | 28.2 | 13.6 | 7.6 | 14.0 | 8.4 | 13.4 | 44.5 | 28.3 | 16.0 | 25.3 | 17.6 | 29.2 | 57.9 | 55.1 | 43.8 | 50.6 | 45.1 | 56.7 |
Missing: age 0.012%, race 5.8%, parity 20%, education 1.5%; length of gestation 0.9%.
Means are weighted; SDs are not weighted.
GED, General Educational Development; IVF, in vitro fertilization.
a
Includes triplets, quadruplets, quintuplets, and sextuplets.
Luke et al. Risk of severe maternal morbidity. Am J Obstet Gynecol 2019.