Investigating pregnancy outcomes among patients with ILD

Key takeaways:

• Normal expansion of chest wall and rises in maternal blood volume while pregnant may have negative impacts in those with ILD.
• Researchers observed poor pregnancy outcomes with very severe ILD.

BOSTON — Pregnant women with very severe interstitial lung disease had fewer term deliveries and more preterm births and miscarriages vs. women with a lower disease severity level, according to a presentation at the CHEST Annual Meeting.

For patients with ILD, Megan E.B. Clowse, MD, MPH, associate professor of medicine and population health sciences and chief of the division of rheumatology and immunology at Duke University School of Medicine, said normal changes related to the lungs and blood that happen while pregnant could have a negative impact. She highlighted that the first change is the expansion of the chest wall. With this change, there may not be adequate oxygen saturation as a result of parenchymal fibrosis.

The second change that occurs in normal pregnancy is a 50% rise in maternal blood volume, which is “particularly problematic” among those with ILD and pulmonary hypertension, Clowse said during her presentation.

“That huge fluid shift can be exceptionally dangerous, particularly in the days after delivery, and we see things like what they now call postpartum preeclampsia,” Clowse said.

To gain further understanding of pregnancy outcomes in ILD, Clowse shared findings from a retrospective study including 60 women with ILD secondary to autoimmune disease who delivered at Duke Hospital between 1996 and 2019 (86 pregnancies; 71% with sarcoidosis; 29% with connective tissue disease [CTD]).

Using FVC and DLCO percent-predicted value cutoffs, researchers grouped patients according to severity. Clowse’s presentation slide noted that 27 patients did not have a pulmonary function test, but the remaining 59 did, with most having mild/moderate disease (n = 30), followed by severe (n = 15), very severe (n = 7) and normal pulmonary function (n = 7).

Clowse noted that all seven women with very severe disease and 47% of the women with severe function had CTD-ILD. Among those with mild/moderate disease, a higher proportion of women had sarcoidosis vs. CTD-ILD (70% vs. 30%), and the same was true among those with a normal pulmonary function test (86% vs. 14%).

Significantly more patients with CTD-ILD vs. sarcoidosis were on a disease-modifying antirheumatic drug (86% vs. 15%; P < .0001), according to Clowse.

Between the seven women with very severe disease (< 40% predicted DLCO and FVC) and the women with all other ILD (n = 79), researchers found that those in the very severe group had a smaller proportion of term deliveries (16% vs. 63%) and a larger proportion of preterm births (28% vs. 9%), stillbirths (14% vs. 1%) and miscarriages (28% vs. 19%), according to the presentation slide.

When looking at the proportions observed in the group with all other ILD, Clowse said they “had quite good outcomes.”

Clowse also noted “surprisingly good” outcomes among the mothers, which included no deaths, “one patient who had a preterm induction for maternal pulmonary decompensation,” “one patient intubated for an asthma flare mid-pregnancy with EGPA” and four women with volume overload after delivery.

“That [volume overload] goes back to our patients who have cardiopulmonary compromise, and the shift in fluids postpartum can be really hazardous for those patients,” Clowse said.

“I actually usually beg the OBs to keep those patients in the hospital for a little bit longer because they can look great for the first couple of days, and then the wheels come off a couple days later,” Clowse continued.

Moving beyond this study, Clowse said she was disappointed in her search for more research on pregnancies in women with chronic lung disease.

One study she did discover and mention during her presentation included women with interstitial pneumonia with autoimmune features.

Taking the form of a chart review, researchers observed low documentation of contraception/family planning in pulmonary doctor notes (32%) and rheumatology doctor notes (57%) of these patients, according to Clowse’s slides.

“Interestingly, 80% of the patients were taking a teratogen, and there was no increase in contraception documentation in that population,” Clowse said. “That’s what I see over and over again. Even though we think it matters most with our patients taking a teratogen, somehow doctors still don’t really write down what kind of birth control people are on.”

According to Clowse, there are three factors that women who are sick and pregnant frequently have that lead to a sick baby: lack of planning, incompatible or no medications and active/unstable disease.

References:

• Clowse MEB, et al. Arthritis Care Res (Hoboken). 2023;doi:10.1002/acr.24814.
• Joerns E, et al. J Clin Rheumatol. 2023;doi:10.1097/RHU.0000000000001929.