As women with systemic lupus erythematosus (SLE) live longer and healthier lives, more and more are asking whether they can or should become pregnant. Forty years ago, a rheumatologist would have been correct to discourage a woman with SLE who wanted to have a child; the rate of pregnancy loss for a woman with SLE was more than 40% at that time. In recent years, however, the success rate of SLE pregnancies has increased significantly. Currently, the risk of pregnancy loss for someone with SLE is roughly equivalent to that of a healthy woman.1 However, pregnancy in a woman with SLE is not always without complication.
Risks to the Fetus and Child
The birth of a healthy full-term baby following an easy pregnancy is the goal of every woman, but it may not be the reality for many women with SLE. Though fewer women with SLE will lose their pregnancy than in previous decades, many are still at increased risk for preterm birth. In general, a third of all SLE pregnancies deliver early – meaning prior to 37 weeks of gestation – and a significant minority will deliver in the even more dangerous period prior to 32 weeks gestation.2 Though most babies born to women with SLE are healthy, neonatal lupus manifesting as congenital heart block can occur in up to 2% of babies exposed to Ro/SSA and/or La/SSB antibodies.3 The immune system of babies born to women with SLE appears to be functionally intact, with few reports of significant infections or lasting immunodeficiency.4 While most children born to women with SLE have normal development and intelligence, there may be a modest increase in the rate of learning disabilities in elementary school–age boys.5 A small proportion of offspring (around 10%) will develop an autoimmune disease at some point in life.6
Risks to the Mother
The risks to the pregnant woman with SLE are low, but present. The maternal mortality rate among women with SLE is 20-fold higher than the maternal mortality for healthy women in the U.S.7 Though this risk may appear high, the absolute risk of death during the year of pregnancy does not appear to be greater than any other year that a woman lives with SLE. In a nationwide study of SLE pregnancies, the maternal mortality rate was 0.325%; the annual mortality rate for a non-pregnant woman with lupus is several times higher – between 0.7% and 2.5% in most studies.8,9 This study also found that increased risks for stroke, deep vein thrombosis, infection, and hematologic abnormalities among women with SLE were higher than in the general population. Up to one quarter of women with SLE will develop preeclampsia (hypertension and proteinuria related to pregnancy). The bulk of the evidence points to a modestly increased risk for SLE activity during pregnancy. Fortunately, severe SLE flares in pregnancy are not common, and the majority of symptoms are related to musculoskeletal and cutaneous disease.