Systemic Lupus Erythematosus (SLE) is an autoimmune disease which primarily affects women of child-bearing ages.1 Pregnancy in women with SLE is accompanied by a significant increase in risk for the mother and the baby.2,3 The development of preeclampsia is particularly common as an obstetric complication in patients with SLE.4 This complication which puts the mother’s life at risk, also increases the risk of the baby in the form of increased premature birth, low birth weight and foetal death.5 Furthermore, pregnancy in SLE patients may be accompanied by an increased risk of developing new flares of the disease both during pregnancy and during the postpartum period. These are general mild but in certain cases they may significantly compromise the obstetric prognosis.6 Among the main predictors of disease flare and poorer obstetric result is age, disease activity, serological profile and a background of lupus nephritis (LN).6,7

Little information is available on a national scale, with few studies and outdated publications.8,9 However, in recent years, care of SLE patients during pregnancy has changed considerably10–12 and this has led to simultaneous improvement in the prognosis of these patients. It may therefore be of interest to know whether the prognosis of pregnancy in SLE patients has changed in recent years in Spain.

The essential aims of this study were to: (a) study the impact of pregnancy on the course of SLE, particularly in the frequency of reactivation and its possible predictors; (b) study the impact of SLE in the development of pregnancy, paying particularly interest to the incidence of obstetric complications and (c) compare the data of our cohort with previously published cohorts in Spain.

This study describes the outcome of pregnancy in patients with SLE in a Spanish cohort followed up in a multidisciplinary unit in the 21 st century. Although it is true that the global obstetric outcome is similar to that of previous cohorts, we did observe certain changes in the therapeutic attitude which accompanied an improvement in the obstetric outcome. Furthermore, and although the rate of flares during pregnancy and after birth continued to be within the average parameters of other series, most flares were controlled with treatment and did not significantly impact obstetric prognosis.

From an epidemiological viewpoint there are 2 essential aspects to highlight when comparing the different cohorts. One determining factor could be age at conception. If we look at our cohort, mean age is approximately 4 years older than the mean age of the other studies.8,9 The fact that our pregnancies are those of older women is somewhat intrinsic to social and employment motives of this century, and implies a higher risk of APO, regardless of other variable such as the level of activity or organic damage. Unlike that presented in other Spanish studies, in our cohort, 14% of pregnancies occurred in non Caucasian women. It is worth highlighting that non Caucasian women had mostly planned pregnancies. These women were characterised by having a higher frequency of LN and greater organic damage, a consequence of a higher prevalence of HBP. Furthermore, non Caucasian women were significantly younger (p = .004) than Caucasian ones, a factor which is also related to recent studies with a worse prognosis of SLE in the pregnancy.6,7 Due to increased seriousness, more medication was required, even the use of corticoids and immunosuppressants. Despite all of this, and probably due to the exhaustive control of these patients in a multidisciplinary unit, the obstetric outcomes did not differ significantly from those of the Caucasian women.

The percentage of women with a flare up during pregnancy ranged between 25%–65% from some studies to others.6,23 These discrepancies were essentially due to 3 aspects: differences in the definition of flare, the use of different parameters to measure SLE activity,24,25 and the different therapeutic approach of patients during pregnancy.26 What the studies do appear to conclude is that the majority of flares are mild to moderate in severity and mostly affect cutaneous, musculoskeletal, haematological and renal levels. This study shows a very similar flare rate to the 3 Spanish studies and in general a lower one to that described in the literature. This low rate may be related to the low proportion of patients with an active disease at the time of conception,6 a low number of patients diagnosed with SLE in pregnancy, and the significant way in which the 3 studies were conducted in specific units dedicated to the care of these patients.

From a serological viewpoint, the prevalence of specific autoantibodies with potential impact on pregnancy is highly similar to that of other studies except there is a greater prevalence of antiphospholipid antibodies. In pregnancies with patients who are the carriers of anti-Ro/La positive antibodies we did not detect any cases of neonatal lupos. This can be explained by 2 events. Firstly, the frequency of neonatal lupus described in carriers of these antibodies is of 1%–2%27. Purely statistical probability reasons it is not surprising that in our cohort no cases with this complication arose. Secondly, the use of HCQ was linked to a drop in the probability of developing a neonatal lupus, and in this sense, a significant proportion of our patients were found to be in treatment with anti-malarial medication before pregnancy, which may also have contributed to the absence of cases. It should also be noted that although only a statistically significant rise in IGR in the carriers of these antibodies was detected, we noted a trend28 in the presentation of a higher number of obstetric complications which cannot be ignored. More preterm births appear to present, along with a greater need for induction of births, more caesareans births and more complicated births. In view of these results it seems reasonable that, apart from the NB control because of the probability of developing neonatal lupus the specialists in charge of these patients were aware of the potential risk of obstetric complications at the end of pregnancy and the need for a more exhaustive monitoring during the last three months of pregnancy.

The higher percentage of antiphospholipid antibodies in our series may be explained by a higher sensitivity of the ELISA technique, which in the previous century did not depend on beta-2 glycoprotein I, nor did it measure the antibodies against it. Globally, although we observed a lower NB rate in patients with APS positive serology, the obstetric outcome obtained in our patients was very similar to that of the patient who did not present with these antibodies. The main sign was the presence of early miscarriages, with preeclampsia and late foetal death being very rare. These outcomes are obviously the consequence of a high percentage of patients who had received antiplatelet and/or anticoagulant therapy during pregnancy. One of the notable aspects and which was confirmed by previous studies to ours in groups of patients who were carriers of antiphospholipid antibodies29 is the high frequency of cardiovascular risk factors in the carriers of the APS serology and more specifically a high rate of obesity and tobacco habit. Pre-pregnancy control of these factors in patients with SLE would undoubtedly contribute to a better outcome.

Regarding obstetric outcomes, ours are an improvement in some aspects to those of other studies. The rate of live NB is very similar in the 3 series and although in ours early miscarriages were more common, the rate of foetal death and voluntary interruption of pregnancy was clearly lower. Also, although the rate of caesarean births was very similar our frequency of preeclampsia, IGR and preterm birth was lower than that of the other 2 cohorts. In this sense, it is possible that the lower frequency of preeclampsia could be related to higher use of acetylsalicylic acid.30 In our study we were not able to assess the possible protective effect of the hydroxychoroquine in the development of preeclampsia5 because only one patient developed it.

With the inherent limitations of a small sample size, this study shows that although changes to the therapeutic approach and planning of pregnancy events in recent years have not had a direct impact on the rate of reactivation of SLE during pregnancy, they have led to an improvement in the obstetric results of our patients. The introduction of new, independent variables of the disease, such as age at conception, sociocultural origin and availability of multidisciplinary units for treating patients with autoimmune diseases during pregnancy should be considered in the result of the next studies.

The authors have no conflict of interests to declare.