Pos0933 nailfold videocapillaroscopy as a possible biomarker to detect aberrant placental microcirculation in pregnant women: a pilot study

Background During pregnancy, exchanges between mother and fetus are provided by the placenta. Defects in the early stages of placentation prevent the creation of a high-flow, low-resistance circle resulting in an impaired maternal-fetal exchange. The development of aberrant microcirculation leads to placental abnormalities, detectable by placental histologic examination [1]. Objectives To assess whether nailfold videocapillaroscopy (NVC), in combination with umbilical artery doppler ultrasound (UA-dU), can detect microvascular status during pregnancy [2]; and to evaluate if NVC follow-up during pregnancy might operate as a red flag biomarker of placental microcirculation abnormalities. Methods We conducted a longitudinal observational exploratory study on 54 healthy pregnant women (age range 26-46 y) within the 16th gestational week, excluding those with cardiovascular comorbidities. We performed clinical, UA-dU and NVC evaluation with an optical probe (200x magnification) at each trimester of pregnancy and post-partum [3]. We performed an after-birth placenta histology (abPH) in a subgroup of 20 women (among the 54 women) who developed complications during pregnancy (e.g., gestational hypertension) evaluated through optical microscopic technique, according to Amsterdam criteria [4]. Results We noticed over time, in the whole cohort, a statistically significant increase in neo-angiogenesis (p<0.05), considering the absolute count of microvessel ramifications (abnormal shapes) (Figure 1a). Conversely, we did not observe any statistically significant variation in capillary density (n/linear mm), microhaemorrhages or dilated capillaries over time. Besides, a statistically significant difference in the absolute number of capillaries in the first trimester between subjects with and without areas of placental dysmaturity (aberrant placental microcirculation) was detected at abPH (7.0/mm ± 0.82 vs 8.2/mm ± 0.62; p=0.030), (Figure 1b). A receiver operating characteristic curve was drawn for calculating the Area Under the Curve (AUC: 0.87; 95%CI: 0.66–1.00), identifying the optimal discriminatory cut-off value for prediction of placental dysmaturity areas (≤7.50/mm capillaries, sensitivity: 88.9%; specificity: 75.0%). Of note, a similar difference was confirmed at the third trimester, although not reaching statistical significance (p=0.06). Not any significant association was found between UA-dU and any of the assessed NVC parameters. Conclusion This study confirms, in a large cohort of pregnant women, the NVC detection of increased neoangiogenesis over time, even during post-partum. In addition, this is the first report suggesting the possible role of NVC (capillary density) for the early detection of aberrant placental microcirculation noticeable at abPH. A study in pregnant patients affected by autoimmune connective tissue diseases has already started, using those findings as reference parameters. References [1]Rana S. et al. Circ Res, vol. 124, n. 7, pp. 1094–1112, Mar 2019. [2]Pacini G. et al. Microvasc Res, vol. 141, May 2022. [3]Smith V. et al. Autoimmun Rev vol. 19, n. 3. Elsevier B.V., Mar. 01, 2020. [4]Khong T.Y. et al. Arch Pathol Lab Med, Jul. 2016, vol. 140, n. 7, pp. 698–713 Acknowledgements: NIL. Disclosure of Interests None Declared.