Would the blockage of a single lactiferous sinus interfere with delivery of milk to the nipple?

Yes, the blockage of a single lactiferous sinus can interfere with the delivery of milk to the nipple, but it may not completely prevent milk flow. Each nipple typically has multiple lactiferous sinuses, so milk can still be delivered through the other open sinuses. However, the blockage may lead to discomfort, engorgement, or a decrease in milk supply from that affected area. Overall, while it can impact milk delivery, it doesn't entirely obstruct breastfeeding.