Sir, Couvade syndrome is a peculiar condition whereby an expectant father experiences somatic symptoms for which there is no physiological explanation. It is derived from an old French word for 'brooding' and was first described in 1865. A number of symptoms can occur, including nausea, epigastric discomfort, constipation, diarrhoea, headache, dizziness, food cravings, nosebleed, itch, muscle tremors and, most pertinently, toothache. It generally manifests during the third month of pregnancy before decreasing through the second trimester, then increasing again through the third trimester. There are various suggested aetiological theories, including a somatic expression of anxiety, ambivalence about fatherhood (linked to poor role modelling), viewing the foetus as a rival, and a mechanism to focus attention to the impending offspring.1 All of these are speculative.

The prevalence of Couvade in the UK has been estimated at between 11 and 50% of expectant fathers, although most data are decades old.1 It may be more common than realised owing to the lack of diagnostic criteria and awareness. Most diagnoses are made by exclusion of physical causes and it is self-limiting as it tends to resolve after childbirth. Treatments are not well studied but likely to include cognitive and psychological therapies, and GP involvement.

The relationship with toothache is interesting as in case series this is one of the commonest symptoms experienced.2 Significantly more toothache has been recorded among expectant fathers compared to matched controls.3 The reason for any link is unclear but suggested to be related to a belief that pregnancy damages a woman's teeth, a belief widely documented from historical times through to the late twentieth century. Indeed, references to toothache among expectant fathers were apparently made in 'Westward Ho!', a play from 1607, and Shakespeare's 'Much ado about nothing'.1 However, very little has been written about this association and I can find no mention in the dental literature.

Therefore, if a patient presents with unexplained toothache and has a pregnant partner, particularly if other unexplained symptoms are also present, perhaps the possibility of Couvade should be considered.