VANCOUVER, B.C. — Monthly monitoring by rheumatologists of every pregnancy in every woman with systemic lupus erythematosus may be unnecessary, according to Dr. Michelle Petri.
A relatively small list of criteria can distinguish high-risk pregnancies in women with systemic lupus erythematosus (SLE) – ones that carry a higher likelihood of miscarriage, extreme prematurity, and SLE flare – from others, and signal the need for intensive monitoring by obstetricians and rheumatologists, Dr. Petri said at the meeting.
At present, however, there is little effort to make such distinctions, so most SLE pregnancies are subjected to monthly visits to rheumatologists and obstetricians, and, starting at week 26, weekly monitoring by obstetricians.
That's not always necessary; women are subjected to needless anxiety and hospital resources are wasted, Dr. Petri said.
Based on the Hopkins Lupus Cohort, a database that has been tracking several thousand patients with SLE over the past 25 years, Dr. Petri and her colleague, Duke University rheumatologist Dr. Megan Clowse, have identified those factors that truly put women and fetuses at risk during SLE pregnancies.
Pregnancy and the postpartum period are hard on the kidneys of women with SLE, though organ involvement elsewhere in the body tends to lessen, said Dr. Petri, professor of rheumatology at Johns Hopkins University, Baltimore.
“Proteinuria from active lupus significantly increases, and this continues even after delivery,” she added.
Therefore, pregnant women with lupus nephritis truly do need close monitoring. Dr. Petri recommended monthly urine protein-creatinine ratios to detect a worsening of the condition and the need for treatment.
She noted that the ranges on urine dipsticks are too broad; the dipstick is not adequate as a monitoring tool for nephritis.
In terms of fetal health, the risk of miscarriage doubles if, at the first pregnancy visit, a woman is proteinuric, thrombocytopenic, or hypertensive, or has a history of antiphospholipid syndrome.
The risk triples if two or more of these conditions are present, Dr. Petri said. The presence of antithyroid antibodies also increases the risk of miscarriage.
In addition, active SLE, especially if accompanied by anti–double-stranded DNA antibody or low complement levels, predicts extreme prematurity. Autoimmune thyroid disease also appears to be associated with preterm birth.
Screening for the various factors, “we can predict at the first pregnancy visit if there's going to be a poor outcome,” Dr. Petri said.
If the risk factors are present, monthly monitoring by a high-risk obstetrician, followed by weekly monitoring at week 26, are appropriate to gauge if, and when, a rescue delivery is needed.
Otherwise, and absent renal involvement in the pregnant patient, SLE pregnancies may not need to be classified as high risk, Dr. Petri said.
“Since we can stratify women at risk for miscarriage and extreme prematurity, and know the only organ we have to worry about is the kidney, we can come closer to using our resources appropriately,” Dr. Petri said.
To reassure women, rheumatologists should “get the word out to patients that high-risk interventions are not necessary for every [SLE pregnancy],” she said.
Dr. Petri said she had no disclosures to report.