ABSTRACT
Nasal obstruction in pregnancy has many causes. Women who already have nasal obstruction prior to becoming pregnant may suffer considerable exacerbation of their blocked nose. ‘Rhinitis of pregnancy’ occurs in up to 30 per cent of pregnant women. ROP is related to altered hormonal levels although the exact mechanism leading to blockage is poorly understood. It is similarly seen in nasal blockage associated with the menstrual cycle. Topically applied oestrogens have produced congestion of the nasal mucosa and increased nasal resistance. Nasal vascular pooling may occur as a result of progesterone-linked nasal vascular smooth muscle relaxation. Increased vasoactive intestinal peptide, stimulated by progesterone and oxytocin, leads to increased nasal congestion. An allergic response to placental or fetal proteins may cause nasal congestion. Elevated blood volume in the third trimester of pregnancy also contributes to nasal blockage. Rhinitis of pregnancy can lead to blocked nose, rhinorrhoea, and sinusitis.
