Foetal Post-maturity and Prolongation of Pregnancy

Abstract

In 1922 W. J. Bailantyne and I published a paper entitled "The Problems of Foetal Post-maturity and Prolongation of Pregnancy." The opinions expressed were founded largely on the experience gained by the performance up to that time by one of us (F. J. B.) of over 500 post-mortem examinations of stillbirths and neonatal deaths. We emphasized the absence of any reliable criteria, clinical or pathological, for the diagnosis of post-maturity in the foetus or newborn child, but among our conclusions were the following: (1) the dangers to both mother and child are undoubted: they are chiefly associated with difficulty in the passage of the child; and (2) the treatment is prevention of postmaturity by induction of labour at or soon after the carefully calculated period of full-time gestation.At that time induction of labour was the method of treating disproportion in Britain, and it was because of the fear of disproportion and difficult labour that we advocated it.In this paper, which represents a somewhat new approach to the problem, the incidence and sequelae of induction of labour for post-maturity, as revealed in all the hospital annual clinical reports available to menamely, 32 reports from 20 hospitals-are reviewed. Table I shows most of the essential details, and it will be observed that, with one or two exceptions, all the reports are of recent date. Each hospital is designated by a capital letter, and where a number is attached to a letter (for example, Al), it indicates reports of succeeding years from the same hospital. Incidence of Induction of LabourOnly inductions done after the 40th week are included and those in which there are no additional indications for induction, such as toxaemia, disproportion, and so on.Caesarean section rates for all the hospital deliveries are included because a high rate might sometimes compensate for a low induction rate.It will be evident that there are wide differences in the incidence of induction for post-maturity. In hospital K during the year from July 1, 1949, to June 30, 1950, it was not do,ie once in 4,949 deliveries, whereas in hospitals L and 0 it was done in 3%, and in hospitals G and A4 in 2.7% and 2.1% respectively. In hospital K, in which there were no inductions for post-maturity, the stillbirth rate was the seventh lowest in the series, and in hospital R, in which induction was done very seldom (0.11 %) the stillbirth rate was the third lowest. In neither of these hospitals was caesarean section done for post-maturity. Examination of the stillbirth records of hospital K shows that no stillbirths resulted in women who had gone beyond 40 weeks' gestation, so that no babies were lost through failure to induce. The caesarean section rate in this hospital was 1.8%, the lowest in the entire series.It will be noted that some hospitals with a low induction rate for post-maturity had a very high perinatal mortality rate. This, however, seems to be due to other causes. Thus in hospital F, with 2,641 deliveries and no inductions for post-maturity, 75% of the patients we...