medwireNews: In the past two decades pregnancy outcomes, including in-hospital maternal mortality, have improved among women with systemic lupus erythematosus (SLE), but further improvements are needed to reduce risks further, US research shows.
Bella Mehta (Hospital for Special Surgery, New York) and colleagues report in the Annals of Internal Medicine that in-hospital maternal mortality among women with SLE fell from a rate that was 34 times higher than that among women without SLE in in 1998–2000 to less than five-times higher in 2013–2015.
Nonetheless, “[m]ortality rates among pregnant women with SLE are still higher than for those without SLE, suggesting a continued need for improvement,” the researchers remark.
Using data from the US National Inpatient Sample (NIS) database, Mehta and co-investigators found that the in-hospital maternal death rate among women with SLE fell from 442 per 100,000 admissions during 1998–2000 to less than 50 per 100,000 in 2013–2015.
This rate of reduction was significantly greater than that observed among women without SLE, for whom the in-hospital maternal death rate fell from 13 to 10 cases per 100,000 between 1998–2000 and 2013–2015.
Fetal mortality also declined at a faster rate, albeit not significantly so, among women with SLE relative to those without SLE, falling from 268 to 153 deaths per 10,000 deliveries and 72 to 66 deaths per 10,000 deliveries, respectively, between the 1998–2000 and 2013–2015 periods.
Across the same time periods, rates of preeclampsia or eclampsia decreased in patients with SLE (9.5 to 9.1%) but increased in patients without SLE (3.3% to 4.1%), as did mean hospital lengths-of-stay, from 4.3 to 3.8 days in the SLE group and from 2.5 to 2.7 days in the control group.
Cesarean section rates increased both in patients with SLE (34.0 to 40.7%) and without it (21.2 to 31.7%), but the rate of change was significantly greater among the women without SLE.
Mehta et al say that the improved outcomes among women with SLE could be due to a number of reasons including improved diagnosis and referral of patients with mild disease, advice given to attempt pregnancy when the disease is in remission, and improved treatment, including the continuation of hydroxychloroquine throughout pregnancy.
However, the researchers note that since their study only included inpatient data, they potentially missed cases of early pregnancy loss and miscarriage, which are common complications of SLE.
They conclude that the study “provides nationwide evidence that SLE pregnancy outcomes have become markedly better in the past 2 decades and continue to improve.”
However, they note that “SLE pregnancy risks remain high, and more work is needed to ensure good pregnancy outcomes among women with SLE.”
In an accompanying editorial, Megan Clowse, from Duke University Medical Center in Durham, North Carolina, USA, raises concerns about the level of decline in maternal mortality in more recent years, highlighting the steep decrease observed between the 2010–2012 and 2013–2015 periods (from 140 to less that 50 maternal deaths per 100,000 births).
She says that “SLE pregnancy management has not advanced within the past 5 years to an extent great enough to explain such a large drop in mortality,” and instead suggests that the steep decline could be an artefact of the NIS data, which can be inaccurate when used to estimate rare events such as maternal deaths in women with SLE.
The results may therefore underestimate “the ongoing risk of pregnancy for women with SLE,” she writes.
By Laura Cowen
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