THE purpose of this paper is to give the management of contracted pelvis by surgical induction and the results obtained in a large maternity service. The safety of surgical induction per se has been demonstrated in the papers by Gibson (1952) and Tennent and Black (1954).Premature induction of labour for contracted pelvis is an early method of treatment used in the pre-Caesarean section era when in many cases it held out the only possibility of obtaining a living child. The method had fallen into disrepute due to the greater danger of prematurity to the child, and of sepsis to the mother, in comparison with the relative safety of Caesarean section. There have, however, been some consistent advocates of this procedure such as Drew Smythe (1950) though Johnstone (1955) stated that the Obstetric Congress of 1929 heard "the swan song of that most essentially British of Obstetric procedures the induction of premature labour for contracted pelvis".Induction of labour for contracted pelvis was commenced with caution in 1950 in the maternity units of the County of Lanark at the Maternity Hospital, Bellshill, and the William Smellie Memorial Hospital, Lanark. In the first year 30 per cent of all cases of contracted pelvis were induced but, as our fears were allayed, we became more confident and in the fifth year of the survey 77 per cent of all cases were induced. During the 5-year period 618 cases of contracted pelvis were delivered and of these 337 were treated by surgical induction and 281 were allowed to go into labour normally or were treated by elective Caesarean section. The figure of 281 includes a small proportion of unbooked cases admitted in labour.
MANAGEMENTAt the thirty-eighth week of pregnancy all cases of contracted pelvis or suspected contracted pelvis were referred from the antenatal clinics to the hospital for assessment under anaesthesia. Where possible radiological pelvimetry was carried out before this date and the plates and measurements were available at the time of assessment. Since the paper by Stewart et al. (1956) on the danger of leukaemia in childhood due to antenatal radiology, this procedure is now postponed till after delivery. Practically all cases were examined clinically and assessed by the writer personally. Under intravenous Pentothal anaesthesia, the type of pelvis, degree of contraction and the presence or absence of disproportion were noted.The membranes were ruptured irrespective of the condition of the cervix provided the following criteria were satisfied, namely-there was no obvious disproportion or only a minor degree of disproportion; the child was considered to be of a reasonable size; the vertex was presenting or external version was successful in a breech presentation; the patient was not an elderly primigravida; fertility was satisfactory and Caesarean section had not been performed on more than one occasion previously. The forewaters were ruptured though at the beginning of this survey hindwater rupture was the usual procedure.
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