Table 2.
Major maternal and fetal adverse outcomes by preconception eGFR (ml/min per 1.73 m2)
| Adverse Outcomes | eGFR ≥90 | eGFR 60 to <90 | eGFR 45 to <60 | eGFR <45 |
|---|---|---|---|---|
| Pregnancies, N (%) | 522, 752 (92.4) | 42, 543 (7.5) | 479 (0.08) | 133 (0.02) |
| Children, N (%) | 532, 628 (92.3) | 43, 557 (7.6) | 490 (0.08) | 139 (0.02) |
| Primary outcomes,a N (%) | ||||
| Presence of at least one SMM indicator | 11,655 (2.2) | 1174 (2.8) | 46 (9.6)b | 29 (21.8)b |
| Preterm delivery (<37 weeks) | 50, 695 (9.5) | 4, 954 (11.4) | 109 (22.2)b | 56 (40.3)b |
| Very preterm delivery (<34 weeks) | 15,511 (2.9) | 1624 (3.7) | 52 (10.6)b | 29 (20.9)b |
| Low birthweightc (<2500 g) | 39,368 (7.4) | 3774 (8.7) | 98 (20.0)b | 53 (38.1)b |
| SGA 10th percentile | 54, 505 (10.2) | 4192 (9.6) | 69 (14.1) | 19 (13.7) |
| SGA fifth percentile | 26, 904 (5.1) | 2034 (4.7) | 39 (8.0) | 7 (5.0) |
| Secondary outcomes,a N (%) | ||||
| Maternal death | ≥39 (0.01) | <6 (0.01) | ||
| Admission to ICU | 3262 (0.6) | 346 (0.8) | 15 (3.1)b | 9 (6.8)b |
| Gestational hypertension | 24,706 (4.7) | 2494 (5.9) | 50 (10.4)b | 24 (18.0)b |
| Preeclampsia | 31,215 (6.0) | 3232 (7.6) | 72 (15.0)b | 33 (24.8)b |
| Acute renal failure (SMM indicator)d | 256 (0.0) | 75 (0.2) | 15 (3.1)b | 12 (9.0)b |
| Dialysis (SMM indicator) | ≥26 (0.0) | <6 (<1.0) | 9 (6.8)b | |
| Postpartum hemorrhage | 31,112 (6.0) | 2647 (6.2) | 32 (6.7) | 10 (7.5) |
| NICU admission | 22,443 (4.2) | 2056 (4.7) | 54 (11.0)b | 15 (10.8)b |
| Stillbirth | 3180 (0.6) | 319 (0.7) | ≥6 (≥1.2)b | <6 (<4.3) |
| Neonatal death | 1348 (0.3) | ≥141 (≥0.3) | <6 (<1.2) | 0 (0.0) |
In accordance with ICES privacy policies, cell sizes < 6 cannot be reported. SMM, Severe Maternal Morbidity; SGA, small for gestational age; NICU, neonatal intensive care unit.
We assessed maternal outcomes from the conception date to 90 days after delivery date and neonatal outcomes up to 28 days after delivery date. The denominators differ for both maternal (eGFR ≥90 N=522,752 pregnancies; eGFR 60 to <90 N=42, 543 pregnancies; eGFR 45 to <60 N=479 pregnancies; and eGFR <45 N=133 pregnancies) and fetal outcomes (eGFR ≥90 N=532,628 babies; eGFR 60 to <90 N=43, 557 babies; eGFR 45 to <60 N=490 babies; and eGFR <45 N=139).
Standardized difference ≥10% compared with preserved renal function (eGFR ≥90 ml/min per 1.73 m2) category. Note that the standardized difference has not been adjusted for correlation of pregnancies in women and is intended to be used as a descriptive statistics rather than making inferences about the characteristics.
<0.5% of deliveries had missing weight. These were classified as normal without loss of generality. The missing weights were fairly evenly distributed across the eGFR categories.
SMM indicators measured between 20 weeks of gestation and 42 days after the index delivery.