Which factors predict pregnancy outcomes in SLE?

In women with systemic lupus erythematosus (SLE), factors such as disease activity prior to and during conception as well as the presence of secondary antiphospholipid syndrome convey heightened risk of adverse pregnancy outcomes, according to the results of a systematic review and meta-analysis.

Researchers searched multiple online databases for studies wherein preconception predictors of pregnancy outcomes in women with SLE were evaluated. The studies had to present original, quantitative data on pregnant women with SLE and reported on preconception risk factors on at least one of the outcomes as defined in the protocol. Exclusion criteria were a sample size of <20 patients, restriction to multiple pregnancies, unclear timing of prognostication, or exclusive reporting of a composite outcome.

Of the 6,705 unique articles initially identified, 72 were included in the meta-analysis, with a total of 10,355 pregnancies in 8,065 women with SLE. One potentially eligible study was retracted and therefore removed from the analysis. The reported outcomes included livebirth, pre-eclampsia, small for gestational age, preterm birth, pregnancy loss before and after 20 weeks of gestation, and SLE flares.

Pooled data showed that previous lupus nephritis was associated with reduced odds of livebirth (odds ratio [OR], 0.62; I²=0 percent), as well as increased odds of preterm birth (OR, 2.00; I²=17 percent) and pre-eclampsia (OR, 3.11; I²=0 percent). Meanwhile, chronic hypertension correlated with a higher likelihood of disease flare (OR, 2.50; I²=0 percent), preterm birth (OR, 2.65; I²=0 percent), and pre-eclampsia (OR, 5.86; I²=33 percent).

SLE disease activity at conception or preconception emerged as another risk factor, being associated with increased odds of preterm birth (OR, 2.91; I²=21 percent) and pre-eclampsia (OR, 2.32; I²=0 percent). Finally, while secondary antiphospholipid syndrome was associated with decreased livebirth probability (OR, 0.40; I²=0 percent), it also correlated with greater likelihood of pregnancy loss after 20 weeks of gestation (OR, 2.77; I²=0 percent) and preterm birth (OR, 1.65; I²=0 percent).

Risk-of-bias assessment indicated considerable bias in study attrition and confounding across studies.

The present data may help optimize patient-tailored risk assessment in preconception counselling, the researchers said.