Incidence rates of postpartum VTE per 100 000 person-years and IRRs for potential delivery, pregnancy, and preexisting risk factors (222 334 pregnancies)
| Variable . | Pregnancies, n (%) (total = 222 334) . | Postpartum VTE, n (total = 178) . | Rate (95% CI)* . | IRR (95% CI) unadjusted . |
|---|---|---|---|---|
| Demographic and lifestyle characteristics | ||||
| Maternal age at delivery | ||||
| 15-19 y | 12 927 (5.8) | 5 | 170 (70-408) | 0.43 (0.17-1.08) |
| 20-24 y | 36 960 (16.6) | 28 | 330 (228-478) | 0.84 (0.53-1.33) |
| 25-29 y | 58 207 (26.1) | 53 | 390 (298-551) | 1.00 |
| 30-34 y | 68 753 (30.9) | 37 | 228 (165-315) | 0.58 (0.38-8.90) |
| 35-39 y | 37 968 (17.0) | 44 | 491 (366-661) | 1.25 (0.84-1.87) |
| 40-44 y | 7 519 (3.3) | 11 | 325 (346-1 130) | 1.60 (0.83-3.06) |
| BMI (kg/m2) | ||||
| Normal (18.5-24.9) | 98 730 (44.4) | 60 | 259 (201-334) | 1.00 |
| Underweight (<18.5) | 7 339 (3.30) | 3 | 179 (56-545) | 0.67 (0.21-2.16) |
| Overweight (25-29.9) | 39 652 (17.8) | 33 | 353 (252-499) | 1.36 (0.89-2.09) |
| Obese (30-40) | 21 410 (9.6) | 28 | 558 (385-808) | 2.14 (1.37-3.36) |
| Class 3 obese (>40) | 2 731 (1.2) | 12 | 1 881 (1 068-3 312) | 7.24 (3.89-13.4) |
| Ethnicity | ||||
| White | 159 159 (71.5) | 129 | 347 (292-412) | 1.00 |
| Non white | 21 178 (9.5) | 21 | 430 (280-658) | 1.23 (0.78-1.96) |
| Missing | 41 997 (18.8) | 28 | 284 (196-411) | 0.81 (0.54-1.23) |
| Cigarette smoker | 51 731 (23.2) | 51 | 424 (322-558) | 1.24 (0.88-1.76) |
| Ex-smoker | 55 743 (25) | 36 | 275 (198-382) | 0.81 (0.55-1.19) |
| Preexisting comorbidities | ||||
| Varicose veins | 5 895 (2.65) | 16 | 1 154 (707-1884) | 3.59 (2.15-6.01) |
| Cardiac disease | 2 264 (1.0) | 5 | 945 (393-2271) | 2.80 (1.15-6.83) |
| Inflammatory bowel disease | 1 105 (0.5) | 4 | 1 545 (580-4 117) | 4.58 (1.69-12.3) |
| Preexisting hypertension | 13 814 (6.5) | 17 | 524 (326-844) | 1.68 (1.01-2.78) |
| Preexisting diabetes | 2 501 (1.1) | 4 | 685 (257-1 826) | 2.03 (0.75-5.46) |
| Preexisting renal disease | 1 493 (0.7) | 2 | 575 (143-2 300) | 1.68 (0.41-6.78) |
| Pregnancy characteristics and complications | ||||
| Antepartum hemorrhage | 10 329 (4.6) | 10 | 416 (224-774) | 1.22 (0.64-2.31) |
| Acute systemic infection | 26 572 (11.9) | 20 | 323 (208-550) | 0.93 (0.58-1.48) |
| Preeclampsia/eclampsia | 5 237 (2.3) | 14 | 1 148 (679-1938) | 3.54 (2.05-6.11) |
| Multiple birth | 3 282 (1.4) | 3 | 390 (125-1 211) | 1.14 (0.36-3.57) |
| Gestational hypertension | 11 796 (5.6) | 18 | 655 (413-1041) | 2.10 (1.28-3.43) |
| Gestational diabetes | 3 518 (1.6) | 4 | 486 (182-1294) | 1.44 (0.53-3.88) |
| Hyperemesis | 7 838 (3.53) | 9 | 494 (257-950) | 1.46 (0.74-2.86) |
| Delivery characteristics and complications | ||||
| Length of gestation | ||||
| Normal gestation | 184 744 (83.0) | 15 | 313 (264-370) | 1.00 |
| Preterm gestation | 17 112 (7.7) | 29 | 727 (505-1 047) | 2.31 (1.55-3.46) |
| Prolonged gestation | 20 478 (9.2) | 14 | 293 (173-494) | 0.93 (0.53-1.62) |
| Mode of delivery | ||||
| Spontaneous | 141 1207 (63.5) | 76 | 230 (184-288) | 1.00 |
| Assisted | 26 943 (12.1) | 19 | 304 (194-476) | 1.31 (0.79-2.18) |
| Elective cesarean | 22 341 (10.0) | 33 | 630 (448-886) | 2.73 (1.81-4.11) |
| Emergency cesarean | 31 843 (14.3) | 50 | 674 (511-890) | 2.92 (2.04-4.18) |
| Stillbirth | 1 356 (0.61) | 8 | 2 595 (1 297-5 189) | 7.86 (3.87-15.9) |
| Postpartum hemorrhage | 20 762 (9.34) | 30 | 629 (440-900) | 2.00 (1.35-2.96) |
| Postpartum acute systemic infection | 7 740 (3.4) | 18 | 1 291 (813-2049) | 4.07 (2.50-6.63) |
| Variable . | Pregnancies, n (%) (total = 222 334) . | Postpartum VTE, n (total = 178) . | Rate (95% CI)* . | IRR (95% CI) unadjusted . |
|---|---|---|---|---|
| Demographic and lifestyle characteristics | ||||
| Maternal age at delivery | ||||
| 15-19 y | 12 927 (5.8) | 5 | 170 (70-408) | 0.43 (0.17-1.08) |
| 20-24 y | 36 960 (16.6) | 28 | 330 (228-478) | 0.84 (0.53-1.33) |
| 25-29 y | 58 207 (26.1) | 53 | 390 (298-551) | 1.00 |
| 30-34 y | 68 753 (30.9) | 37 | 228 (165-315) | 0.58 (0.38-8.90) |
| 35-39 y | 37 968 (17.0) | 44 | 491 (366-661) | 1.25 (0.84-1.87) |
| 40-44 y | 7 519 (3.3) | 11 | 325 (346-1 130) | 1.60 (0.83-3.06) |
| BMI (kg/m2) | ||||
| Normal (18.5-24.9) | 98 730 (44.4) | 60 | 259 (201-334) | 1.00 |
| Underweight (<18.5) | 7 339 (3.30) | 3 | 179 (56-545) | 0.67 (0.21-2.16) |
| Overweight (25-29.9) | 39 652 (17.8) | 33 | 353 (252-499) | 1.36 (0.89-2.09) |
| Obese (30-40) | 21 410 (9.6) | 28 | 558 (385-808) | 2.14 (1.37-3.36) |
| Class 3 obese (>40) | 2 731 (1.2) | 12 | 1 881 (1 068-3 312) | 7.24 (3.89-13.4) |
| Ethnicity | ||||
| White | 159 159 (71.5) | 129 | 347 (292-412) | 1.00 |
| Non white | 21 178 (9.5) | 21 | 430 (280-658) | 1.23 (0.78-1.96) |
| Missing | 41 997 (18.8) | 28 | 284 (196-411) | 0.81 (0.54-1.23) |
| Cigarette smoker | 51 731 (23.2) | 51 | 424 (322-558) | 1.24 (0.88-1.76) |
| Ex-smoker | 55 743 (25) | 36 | 275 (198-382) | 0.81 (0.55-1.19) |
| Preexisting comorbidities | ||||
| Varicose veins | 5 895 (2.65) | 16 | 1 154 (707-1884) | 3.59 (2.15-6.01) |
| Cardiac disease | 2 264 (1.0) | 5 | 945 (393-2271) | 2.80 (1.15-6.83) |
| Inflammatory bowel disease | 1 105 (0.5) | 4 | 1 545 (580-4 117) | 4.58 (1.69-12.3) |
| Preexisting hypertension | 13 814 (6.5) | 17 | 524 (326-844) | 1.68 (1.01-2.78) |
| Preexisting diabetes | 2 501 (1.1) | 4 | 685 (257-1 826) | 2.03 (0.75-5.46) |
| Preexisting renal disease | 1 493 (0.7) | 2 | 575 (143-2 300) | 1.68 (0.41-6.78) |
| Pregnancy characteristics and complications | ||||
| Antepartum hemorrhage | 10 329 (4.6) | 10 | 416 (224-774) | 1.22 (0.64-2.31) |
| Acute systemic infection | 26 572 (11.9) | 20 | 323 (208-550) | 0.93 (0.58-1.48) |
| Preeclampsia/eclampsia | 5 237 (2.3) | 14 | 1 148 (679-1938) | 3.54 (2.05-6.11) |
| Multiple birth | 3 282 (1.4) | 3 | 390 (125-1 211) | 1.14 (0.36-3.57) |
| Gestational hypertension | 11 796 (5.6) | 18 | 655 (413-1041) | 2.10 (1.28-3.43) |
| Gestational diabetes | 3 518 (1.6) | 4 | 486 (182-1294) | 1.44 (0.53-3.88) |
| Hyperemesis | 7 838 (3.53) | 9 | 494 (257-950) | 1.46 (0.74-2.86) |
| Delivery characteristics and complications | ||||
| Length of gestation | ||||
| Normal gestation | 184 744 (83.0) | 15 | 313 (264-370) | 1.00 |
| Preterm gestation | 17 112 (7.7) | 29 | 727 (505-1 047) | 2.31 (1.55-3.46) |
| Prolonged gestation | 20 478 (9.2) | 14 | 293 (173-494) | 0.93 (0.53-1.62) |
| Mode of delivery | ||||
| Spontaneous | 141 1207 (63.5) | 76 | 230 (184-288) | 1.00 |
| Assisted | 26 943 (12.1) | 19 | 304 (194-476) | 1.31 (0.79-2.18) |
| Elective cesarean | 22 341 (10.0) | 33 | 630 (448-886) | 2.73 (1.81-4.11) |
| Emergency cesarean | 31 843 (14.3) | 50 | 674 (511-890) | 2.92 (2.04-4.18) |
| Stillbirth | 1 356 (0.61) | 8 | 2 595 (1 297-5 189) | 7.86 (3.87-15.9) |
| Postpartum hemorrhage | 20 762 (9.34) | 30 | 629 (440-900) | 2.00 (1.35-2.96) |
| Postpartum acute systemic infection | 7 740 (3.4) | 18 | 1 291 (813-2049) | 4.07 (2.50-6.63) |
Rate calculated per 100 000 person-years.