Maternal characteristics among women who have or have not undergone assisted human reproduction (AHR) treatment
| Characteristic | No. (%) of pregnancies* | p (GEE) | |
|---|---|---|---|
| Non-AHR n = 477 971 | AHR n = 21 909 | ||
| No. of women | 387391 | 18907 | – |
| Primiparous | 196246 (41.1) | 11993 (54.7) | < 0.001 |
| Singletons | 464472 (97.2) | 17790 (81.2) | < 0.001 |
| Multiple births | 13 539 (2.8) | 4119 (18.8) | |
| Twins | 13 214 (97.6) | 3896 (94.6) | 0.05 |
| Triplets | 311 (2.3) | 205 (5.0) | |
| Quadruplets | 14 (0.1) | 18 (0.4) | |
| Age at delivery, yr, mean ± SD | 30.1 ± 5.3 | 33.9 ± 4.9 | < 0.001 |
| Median (IQR) | 30 (27–34) | 34 (31–37) | |
| Age at delivery, yr | |||
| < 25 | 73840 (15.5) | 594 (2.7) | < 0.001 |
| 25–29 | 140553 (29.4) | 3455 (15.8) | |
| 30–34 | 166581 (34.9) | 8130 (37.1) | |
| ≥ 35 | 96997 (20.3) | 9730 (44.4) | |
| Missing data | 0 | 0 | |
| Ethnicity | |||
| General population | 321015 (82.9) | 15378 (81.3) | < 0.001 |
| Chinese | 12418 (3.2) | 735 (3.9) | |
| South Asian | 10993 (2.8) | 683 (3.6) | |
| Missing data | 42965 (11.1) | 2111 (11.2) | |
| Rural residence at delivery | 102084 (21.4) | 3215 (14.7) | < 0.001 |
| Urban residence at delivery | 375927 (78.6) | 18694 (85.3) | |
| Married | 333098 (69.7) | 19008 (86.8) | < 0.001 |
| Annual household income, $, median (IQR) | 83039 (69884–99112) | 76374 (68467–96758) | < 0.001 |
| Pre-existing diabetes at delivery | 5847 (1.2) | 430 (2.0) | 0.163 |
| Pre-existing cardiovascular disease at delivery | 5753 (1.2) | 304 (1.4) | 0.153 |
| Pre-existing renal disease at delivery | 17584 (3.7) | 544 (2.5) | < 0.001 |
| Gestational diabetes | 38646 (8.1) | 2264 (10.3) | 0.651 |
| Hypertensive disorders of pregnancy | 43537 (9.1) | 2586 (11.8) | 0.314 |
Note: GEE = generalized estimating equation, IQR = interquartile range, SD = standard deviation.
↵* Unless indicated otherwise.