Characteristics of pregnancies to mothers with and without a record of systemic lupus erythematosus (SLE) (all pregnancies ≥20 weeks' gestation), New South Wales 2001–9
| Characteristics | SLE pregnancies* (n=1058) | Pregnancies without SLE (n=793 519) | Relative risk (95% CI) |
|---|---|---|---|
| Maternal factors | |||
| Age ≥35 years | 25.0 | 21.0 | 1.19 (1.07 to 1.32) |
| Smoking during pregnancy | 10.7 | 14.3 | 0.75 (0.63 to 0.89) |
| Assisted reproduction (any record) | 4.8 | 3.4 | 1.42 (1.09 to 1.86) |
| Pregnancy hypertension | 19.8 | 8.7 | 2.28 (2.02 to 2.57) |
| Diabetes (gestational or pre-existing) | 7.4 | 6.1 | 1.22 (0.98 to 1.51) |
| Renal impairment† | 15.2 | 2.9 | 5.29 (4.59 to 6.10) |
| One or more antenatal admissions | 38.8 | 21.5 | 1.81 (1.67 to 1.95) |
| Pregnancy outcomes | |||
| Delivery at tertiary referral hospital | 48.2 | 27.2 | 1.77 (1.66 to 1.89) |
| Twins, other multiple pregnancy | 1.3 | 1.6 | 0.84 (0.50 to 1.42) |
| Onset of labour | |||
| Spontaneous | 33.7 | 59.0 | 1.00 (referent) |
| Induced | 37.6 | 25.1 | 1.77 (1.65 to 1.89) |
| Prelabour caesarean | 28.6 | 15.8 | 2.17 (2.00 to 2.36) |
| Any caesarean birth | 42.3 | 27.6 | 1.53 (1.43 to 1.64) |
| Antepartum haemorrhage | 6.6 | 3.7 | 1.78 (1.42 to 2.23) |
| Postpartum haemorrhage | 9.4 | 7.6 | 1.23 (1.02 to 1.49) |
| Any thromboembolic event‡ | 1.51 | 0.17 | 9.11 (5.19 to 14.9) |
| Pulmonary embolism | |||
| Antepartum | 0.47 | 0.04 | 13.2 (5.45 to 31.8) |
| Puerperal§ | 0.76 | 0.06 | 13.5 (6.72 to 27.1) |
| Cerebral event | 0.28 | 0.01 | 30.8 (9.73 to 97.6) |
| Puerperal§ deep vein thrombosis | 0.47 | 0.08 | 6.08 (2.53 to 14.6) |
| Transfusion of blood product | 3.9 | 1.3 | 3.03 (2.24 to 4.09) |
| Infant outcomes | |||
| Preterm birth (<37 weeks) | |||
| 33–36 Weeks | 14.7 | 5.0 | 2.92 (2.51 to 3.40) |
| <33 Weeks | 8.5 | 1.7 | 5.03 (4.07 to 6.23) |
| Small for gestational age (<3rd centile) | 6.4 | 4.0 | 1.60 (1.27 to 2.02) |
| Perinatal mortality | 3.0 | 0.8 | 3.59 (2.55 to 5.06) |
| 5 min Apgar <7 | 4.7 | 2.0 | 2.36 (1.80 to 3.10) |
| Heart block | 0.38 | 0.01 | 37.5 (13.8 to 102) |
Results are shown as percentages.
↵* Includes diagnosis after second or later birth.
↵† Pre-eclampsia, glomerular or tubulo-interstitial disorder, renal biopsy or renal failure.
↵‡ Pulmonary embolism, cerebral event (cerebral ischaemia or infarction) or puerperal deep vein thrombosis.
↵§ Up to 6 weeks postpartum.