TA is a rare kind of chronic vascular inflammatory disease, and its aetiology is unclear. It is more common in young women and mainly affects the aorta and its major branches. TA has been reported to be associated with different human leucocyte antigen (HLA) alleles in different populations, and Asian countries have the highest incidence [3]. In the acute phase of TA, vessels showed inflammatory changes: inflammatory cell infiltration and neovascularization were observed in the media, and the intima of the vessels were thickened. In the healed phase, the vessels showed fibrosis. Scholars have reported that T cells and natural killer cells play an important role in the process of TA vascular injury. A 65-kDa heat shock protein is strongly expressed in the aortic tissue of TA patients, to which CD4 T cells respond [12]. Inflammatory and immune responses also play an important role in the pathogenesis of many pregnancy complications. During pregnancy, immune function, hormones and the microenvironment are all modified, and the cardiovascular system has to bear a heavier burden. At this period, the acute inflammatory reaction of blood vessels (especially the increasing level of interleukin-6 and tumour necrosis factor) may have adverse effects on pregnancy [13].
According to Comarmond c. et al [10], the activity of TA during pregnancy is associated with the occurrence of gestational complications. Our analysis is consistent with the fact that pregnant women with TA in the active phase are at increased risk of gestational complications, including preeclampsia, foetal growth restriction, foetal distress, premature delivery, and medical complications, mainly cardiovascular events. Therefore, more attention should be paid to patients with active TA during pregnancy, and prevention and treatment of complications should be given in a timely manner. In our series, most patients were diagnosed with TA before pregnancy. We retrospectively collected the medical follow-up information of TA for all patients before and during pregnancy and found that patients with active TA during pregnancy had a higher rate of irregular treatment than those with inactive TA during pregnancy. Therefore, patients with TA who plan to deliver a baby should be regularly followed up by physicians, and advice on the optimal timing of pregnancy should be given to avoid the negative effects of active TA on the mother and foetus. However, the current activity score is based on the general population, and there are no special criteria for pregnant women; thus, this score may not be accurate enough for the assessment of TA activity in pregnant women.
Although without statistical significance, we observed a trend that patients who had hypertension before pregnancy were more likely to be diagnosed with preeclampsia during pregnancy. As a result, TA patients with hypertension should be monitored closely during pregnancy.
Based on our results, the course of pregnancy may not affect the activity and severity of TA, which is consistent with previous literature. According to Matsumura A et al., in TA patients, the CRP scores and digital plethysmography results improve during the course of pregnancy, and these improvements continue for one year after delivery [14]. The secretion of corticosteroids from the adrenal grands and placenta increases during pregnancy, which may be the reason for such alleviation.
According to Suri V et al [15], TA patients with abdominal aorta and renal artery involvement have a higher rate of pregnancy complications, such as preeclampsia and intrauterine growth restriction. However, our study did not observe an association between the classification of TA and obstetrical complications. We speculated that although the involved vessels of different classifications were distinct, the systemic inflammatory response and cytokine changes were similar. Based on our data, the activity of the inflammatory state appeared to be more closely associated with gestational complications. In addition, TA is a rare disease, the number of pregnant patients with TA is small, and this study is a retrospective study; thus, these factors may be limitations of our analysis.