Table 1 Comparison of maternal and pregnancy characteristics and outcomes between the different parity groups
From: The association between parity and spontaneous preterm birth: a population based study
Total | P0 | P1 | P2 | P3 | P4 | P-value* | |
|---|---|---|---|---|---|---|---|
Number of subjects (%) | 802,119 (100) | 367,676 (45.8) | 289,391 (36.1) | 105,014 (13.1) | 30,585 (3.8) | 9453 (1.2) | NA |
Mean GA in weeks (SD) | 39.1 (1.8) | 39.08 (2.0) | 39.18 (1.6) | 39.15 (1.7) | 39.03 (1.8) | 38.94 (2.0) | NA |
Mean maternal age (SD) | 30.8 (4.8) | 29.25 (4.9) | 31.53 (4.4) | 32.98 (4.3) | 34.03 (4.4) | 35.03 (4.5) | <.0001 |
Maternal age < 20 yrs (%) | 10,201 (1.3) | 9230 (2.5) | 902 (0.3) | 61 (0.1) | 7 (0.02) | 1 (0.01) | <.0001 |
Maternal age ≥ 40 yrs (%) | 24,797 (3.1) | 6891 (1.9) | 8505 (2.9) | 5310 (5.1) | 2785 (9.1) | 1306 (13.8) | <.0001 |
Non-White (%) | 152,899 (19.1) | 63,754 (17.3) | 49,303 (17.0) | 25,427 (24.2) | 10,650 (34.8) | 3765 (39.8) | <.0001 |
Low SES (%) | 197,136 (24.6) | 91,433 (24.9) | 65,885 (22.8) | 27,006 (25.7) | 9602 (31.4) | 3210 (34.0) | <.0001 |
Prior PTB (%) | 6858 (0.9) | 0 | 4208 (1.5) | 1825 (1.7) | 623 (2.0) | 202 (2.1) | <.0001 |
ART (%) | 29,763 (3.7) | 19,838 (5.4) | 8148 (2.8) | 1436 (1.4) | 276 (0.9) | 65 (0.7) | <.0001 |
Male fetal gender (%) | 409,097 (51.0) | 187,681 (51.1) | 147,586 (51.0) | 53,361 (50.8) | 15,588 (51.0) | 4881 (51.63) | 0.6184 |
Hypertension and preeclampsia (%) | 70,745 (8.8) | 43,656 (11.9) | 18,610 (6.4) | 5972 (5.7) | 1869 (6.1) | 638 (6.8) | <.0001 |
SGA < p10 (%) | 67,744 (8.5) | 30,252 (8.2) | 25,431 (8.8) | 8493 (8.1) | 2724 (8.9) | 844 (8.9) | 0.0002 |
Total PTB | 43,653 (5.4) | 25.483 (6.9) | 11,769 (4.1) | 4353 (4.2) | 1491 (4.9) | 557 (5.9) | NA |
Spontaneous PTB | 30,237 (3.8) | 18,171 (4.9) | 8065 (2.8) | 2761 (2.6) | 893 (2.9) | 347 (3.7) | NA |
Iatrogenic PTB | 13,416 (1.7) | 7312 (2.0) | 3704 (1.3) | 1592 (1.5) | 598 (2.0) | 210 (2.2) | NA |
Previous PTB in women with PTB | 1446 (8.0) | NA | 942 (8.0) | 343 (7.9) | 121 (8.1) | 40 (7.2) | NA |