Analysis Links Risk Factors to Adverse Pregnancy Outcomes in Patients With SLE

Renal involvement, the presence of anti–double-stranded DNA antibodies (anti-DNAds), and younger age at disease onset all appear to increase the risk of the most serious adverse pregnancy outcomes in patients with systemic lupus erythematosus (SLE), according to a new study.

Other factors that indicate a greater risk of adverse outcomes include antiphospholipid antibody (APA) positivity, the presence of anti-Ro/SSA antibodies, and elevated erythrocyte sedimentation rate (ESR). The study was published in Musculoskeletal Care.

SLE most often is diagnosed among women of child-bearing age, and the disease has been associated with a significant risk of major adverse events in pregnancy, including gestational loss, preterm delivery, and preeclampsia, the authors wrote. Women also may face an increased risk of new flares during and immediately after pregnancy, they noted.

Although some risk factors for pregnant patients with SLE are known, and despite SLE treatment having improved in recent years, the authors added that significant knowledge gaps remain.

“[L]ittle is known on what the predictors for each adverse pregnancy outcome are and whether the prognosis of pregnancy in SLE patients has changed considerably in recent years,” they said.

The investigators decided to analyze cases of people with SLE who became pregnant to understand which risk factors were tied to specific adverse outcomes such as spontaneous abortion, stillbirth, preeclampsia, and neonatal lupus.

They retrospectively analyzed 135 cases of multiparous women with SLE who became pregnant between 1990 and 2020 and sought care at the authors’ outpatient autoimmune disease center. Of those women, 57 patients (42%) experienced adverse pregnancy outcomes. Of the adverse events, abortion (18%) and preeclampsia (7%) were the most common.

The authors compared clinical and analytical characteristics of the patients with and without adverse pregnancy outcomes and then performed additional analyses to see which factors were most closely tied to which outcomes. They found that the presence of anti-DNAds, renal involvement, APA positivity, ESR elevation, and C-reactive protein elevation were all risk factors for spontaneous abortion. Renal involvement, APA positivity, and ESR elevation also were risk factors for stillbirth.

However, the factors varied somewhat from among the adverse outcomes. For instance, while renal involvement was predictive of spontaneous abortion and stillbirth, it was not a predictive factor for preeclampsia or neonatal lupus. In addition, ESR elevation was a predictor of abortion, stillbirth, and preeclampsia but not neonatal lupus.

The investigators said their cohort had an overall 18% rate of fetal loss, which they said tracks with other research. However, only 4% of patients in the study experienced preterm birth, which is significantly lower than most other reports, they said.

As to whether improvements in SLE care have led to improvements in pregnancy outcomes for patients with SLE, the authors said they “observed improvement in pregnancy outcomes” in patients who received an SLE diagnosis after 2000. One reason, they said, has been higher rates of hydroxychloroquine (HCQ) use in recent decades.

“Our data highlight the improvement in pregnancy outcomes of lupus patients in the last decades by adequate disease control before pregnancy and treatment, especially with HCQ,” they concluded.

They said their study was limited by its single-center design and the inability to assess disease activity following pregnancy, which might have allowed investigators to capture changes to patients’ SLE Disease Activity Index scores during pregnancy. However, they said their findings are bolstered by the homogeneity in their prenatal care.

Reference

Sieiro CS, Morales CM, Castro CA, Fernández IG, Álvarez ED. Factors associated with adverse pregnancy outcomes in patients with systemic lupus erythematosus. Musculoskeletal Care. Published online May 26, 2022. doi:10.1002/msc.1658