HYPEREXTENSION OF THE HEAD IN BREECH PRESENTATION

IN the recent literature two cases of hyperextension of the foetus in utero have been described, one occurring in a breech presentation (Deacon, 1951) and the other (Denny, 1951) occurring in a transverse presentation, the so-called “flying foetus ”. In both cases delivery was by Caesarean section, owing to marked outlet contraction in the first case and the failure to perform external version in the second. The aetiology of the hyperextended attitude of the foetus is obscure. The attitude may be present in various presentations, and appears to be an occasional cause of face or brow presentation. Gibberd (1935) suggested that there was present a spasm of the extensor muscles of the foetus, and he described it later (1939) as a condition of excessive tone rather than one of actual muscle spasm. As the hyperextended attitude may occur with any position of the foetus it seems that this excessive tone of the extensor muscles is the most likely aetiological factor. This possibility is enhanced by the fact that, in most reported cases, the increased extensor tone of the foetus persists for a variable time following delivery. In the following two cases, a hyperextended attitude occurred in a breech presentation. In both cases normal assisted breech delivery was carried out.