The risks of pregnancy loss and of preterm birth were higher in women who had vasculitis before they conceived than in women who were diagnosed as having vasculitis after conception in a retrospective cohort study.
Women who conceived before receiving a diagnosis of vasculitis had a rate of pregnancy loss similar to the general population, whereas women who conceived after they had received a diagnosis of vasculitis had a significantly higher rate of pregnancy loss, reported Dr. Megan E. B. Clowse of the division of rheumatology and immunology at Duke University, Durham, N.C., and her associates in the Vasculitis Clinical Research Consortium.
Dr. Megan Clowse
The investigators examined pregnancy outcomes among women with vasculitis, as well as the outcomes of pregnancies fathered by men with the disease, because so little is known about the subject. Such pregnancies were rare until recent improvements in treatments helped patients survive longer and lead fuller lives.
"Our goal was to identify pregnancies that occurred within a large cohort of women and men with vasculitis and assess whether such pregnancies were at greater risk for adverse outcomes and whether vasculitis activity increased during pregnancy," the researchers wrote.
They invited patients listed in a registry of rare diseases to complete an anonymous questionnaire regarding their reproductive health. A total of 329 women (who had 496 pregnancies) and 107 men (who fathered 156 pregnancies) were included in the analysis (Arthritis Care Res. 2013 Feb. 11 [doi:10.1002/acr.21983]).
Among the women, 140 had granulomatosis with polyangiitis, 22 had microscopic polyangiitis, 59 had Churg-Strauss syndrome, 18 had polyarteritis nodosa, 43 had Behcet’s disease, and 46 had Takayasu’s arteritis. The mean age at diagnosis was 39.7 years (range, 10-78 years). The mean age at the time of the study was 47 years.
The rate of pregnancy loss was significantly higher among the women who had vasculitis when they conceived (33.8%) than it was among women who conceived before they were diagnosed as having vasculitis (22.4%), giving a relative risk of 1.77 (CI 1.02-3.09; P = .04). This 22.4% rate of pregnancy loss is comparable with that reported in the general population (15%-20%), while the rate found in women who already had vasculitis was significantly higher than that in the general population, Dr. Clowse and her associates said.
Similarly, the rate of preterm birth was significantly higher in pregnancies that occurred after a diagnosis of vasculitis (23.3%) than in pregnancies that occurred before a diagnosis of vasculitis (11.4%), giving a relative risk of 2.35 (CI 1.07-5.16; P =.03).
However, the researchers said, it is important to note that the maternal age at conception was approximately 5 years older for women who became pregnant after they had vasculitis, which could have influenced the increased morbidity in this group.
Most (59%) of the women who had vasculitis when they conceived reported no change in their disease activity during pregnancy, and another 23% reported an improvement in vasculitis activity during pregnancy. Only 18% of women who had vasculitis when they conceived reported increased symptoms during pregnancy. Increased disease activity did not have a statistically significant effect on pregnancy loss or preterm delivery.
Exposure to cyclophosphamide or prednisone did not appear to affect pregnancy outcomes. However, the numbers of pregnancies among women taking these medications was small.
Among the men, 61 had granulomatosis with polyangitis, 8 had microscopic polyangiitis, 24 had Churg-Strauss syndrome, 9 had polyarteritis nodosa, 4 had Behcet’s disease, and 1 had Takayasu’s arteritis. The average age at diagnosis was 54.6 years (range, 23-86 years)
Six men fathered 18 pregnancies after they had been diagnosed as having vasculitis, and 48 men fathered 138 pregnancies before they were diagnosed as having vasculitis. The rate of pregnancy loss was 41.2% for fathers with vasculitis and 23.0% for fathers who did not yet have a diagnosis of vasculitis, a difference that did not reach statistical significance.
One man treated with cyclophosphamide fathered two pregnancies within a few years that resulted in live births without complications. However, two other men who had received cyclophosphamide at least 10 years before fathering a pregnancy reported a total of seven pregnancy losses (including one with anencephaly) and four live births.
This study was limited in that it relied on retrospective self-report for diagnosis and was not powered to ascertain the role of confounding factors such as maternal age at the time of conception, prior pregnancy complications, and tobacco use. It also may have been biased because patients who had pregnancy difficulties may have been more likely than those who did not to complete a long questionnaire on that topic.