The effect of smoking on early chorionic villous vascularisation

The aim of the study was to investigate whether first trimester chorionic villous vascularisation is different in women who smoked cigarettes before and during pregnancy in comparison with women who did not smoke. Placentas of smoking (>10 cigarettes/day, n = 13) and non-smoking women (n = 13), scheduled for a legal termination of a viable first trimester pregnancy for social indications, were retrieved. Placental tissues of 3-5 mm³ were whole mount CD31 immunofluorescence stained. Images of the CD31 immunofluorescence and contour of the villi were captured using an Optical Projection Tomography scanner. An immersive BARCO virtual reality system was used to create an enlarged interactive 3-dimensional hologram of the reconstructed images. Automatic volume measurements were performed using a flexible and robust segmentation algorithm that is based on a region-growing approach in combination with a neighbourhood variation threshold. The villous volume, vascular volume and vascular density were measured for the total chorionic villous tree as well as for its central and peripheral parts. No differences in maternal age and gestational age were found between non-smoking and smoking women. No differences were found in the total, central and peripheral villous tree volume and vascular volume. The central (13.4% vs. 9.5%, p=0.03) and peripheral (8.4% vs. 6.4%, p=0.02) villous tree vascular densities were increased in the smoking women as compared with the non-smoking women. In conclusion, chorionic villous vascularisation is already altered in first trimester of pregnancy in women who smoked cigarettes before and during pregnancy.