REVIEW OF 115 CASES OF POSTMATURITY

GLADYS HILL, M.A., M.D., F.R.C.S., F.R.C.O.G. Senior Obstetrician

Department of Obstetrics and Gynaecology The Royal Free Hospital, London

BY

IN view of recent interest in the problem of post- maturity, we have investigated a series of 115 consecutive cases admitted to the maternity wards of the Royal Free Hospital during 1950- 51, in whom the actual date of delivery was 16 days or more later than the calculated date. Of these, 61.7 per cent were primigravidae or patients who had previously had only a miscar- riage, and 38.3 per cent were multigravidae.

The ages of the primigravidae ranged from 17 to 40 years, and of the multigravidae from 18 to 43 years. In the total series, 67.8 per cent of the patients were between 20 and 29 years.

We have included only those patients who had a regular menstrual cycle of not longer than 35 days; the majority had a cycle of 28 days, and where there was any doubt as to the date of the last normal menstrual period, or the regularity of the cycle, the case was excluded.

The expected date of delivery was calculated by adding 7 days and 9 months to the first day of the last full period; 64.8 per cent of the primi- gravidae and 56.8 per cent of the multigravidae were between 16 and 21 days postmature by this standard, and 2.9 per cent of the primigravidae and 6.8 per cent of the multigravidae were more than 35 days postmature. Twelve of the multi-

gravidae had been postmature in earlier preg- nancies.

CHARACTER OF LABOUR The onset of labour was spontaneous in 88

cases (76.5 per cent) and induced in 25 cases (21.7 per cent), and there were 2 elective Caesarean sections. The indications for inter- ference are considered in some detail below.

Labour was prolonged for 30 hours or more in 20 per cent of the series. In a previous survey of the labours of 166 patients who had been treated by us for infertility, and delivered in our wards, the infertile group showed 23.5 per cent with a similar prolongation of labour, and the corresponding Control group 19.9 per cent. Among the 25 cases in whom labour was induced, the duration was 30 hours or more in only 4 cases (16 per cent).

METHOD OF DELIVERY The method of delivery for the series is

analyzed in Table I. The instrumental rate of 11.2 per cent for the

whole series compares with a rate of 7.1 per cent for the Royal Free Hospital Maternity Depart- ment in 1950, and the Caesarean section rate of

TABLE I Analysis of Method of Delivery

Delivery

Spontaneous Instrumental Caesarean

Per cent Per cent Per cent section

1.7 - - Elective Caesarean section (2 cases) . . . . . . . . . Spontaneous onset of labour (88 cases) . . . . . . . . 86.4 10.2 3.4 Induction of labour (25 cases) . . . . . . . . . . . . 76.0 16.0 8.0

11.2 6.1 T O T A L S E R I E S (1 15 Cases) . . . . . . . . . . . . . . . 82.6

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6.1 per cent for these patients with a rate of 3.8 per cent for the Maternity Department in 1950.

The indications for instrumental delivery were :

Delay in second stage of labour 7 cases Persistent posterior position 3 cases Face presentation 1 case Foetal distress 2 cases

and for Caesarean section, as follows : Inco-ordinate uterine action with

foetal and maternal distress 3 cases Failure of trial labour 2 cases

Both patients on whom elective Caesarean section was performed had evidence of some dis- proportion, with a high cephalic presentation, and were considered unsuitable for induction by surgical rupture of the membranes because of this.

Mrs. H., para-0, aged 24, was 18 days overdue, with minor pelvic contraction at the brim and a high vertex.

Mrs. L., para-0, aged 38, was 33 days overdue, with general pelvic contraction and a high vertex.

There was evidence of foetal distress in labour in 7.8 per cent of the series, all primigravidae, but none among the 25 cases in whom labour had been induced.

As the number of cases in which labour was induced is small, some analysis of the factors governing the selection of these cases is perhaps indicated.

Fifteen were primigravidae and 10 multi- gravidae. Two cases were under 20 years of age, 14 between 20 and 29 years, 5 between 30 and 35 years, 1 aged 37 years, and 3 were 40 years or over. Fifteen cases were 16 to 21 days post- mature, 5 cases 22 to 28 days, 3 cases 29 to 35 days, and 2 cases over 35 days (42 and 45 days respectively).

The indications for induction were as follows : Postmaturity only 3 cases

In the other 22 cases, the indications in addition to the postmaturity were:

Previous postmaturity 1 case Previous postmaturity and age Previous postmaturity and Rhesus

incompatibility 1 case Previous stillbirth and age 1 case Rhesus incompatibility 3 cases Disproportion or abnormal pelvis 9 cases Toxaemia 3 cases

2 cases

JRNAL OF OBSTETRICS AND GYNAECOLOGY

Unstable presentation 1 case Premature rupture of membranes

(drug induction) 1 case

In 14 cases, a medical induction was success- ful. Ten of these went into labour after the administration of castor oil, an enema, and a hot bath; 2 patients following a course of oestro- gen injections; and 2 patients following a course of pitocin injections after the oil, enema, and bath.

In the 11 cases (44 per cent) which failed to go into labour after a medical induction (5 with drugs in addition to the oil-enema-and-bath routine) a surgical procedure was adopted, as follows :

Digital separation of membranes 1 case Digital separation of membranes,

followed by oestrogen injections 1 case Surgical rupture of membranes 9 cases Two of these still failed to go into labour; one responded to further oil, enema, and bath, and the other to further oestrogen injections.

THE PLACENTA In 40.9 per cent of the series, there was some

degree of abnormality of the placenta, obvious on inspection. The appearances suggested senility of placentae, with infarction and calci- fication. Of these abnormal placentae, 57.4 per cent were found among patients who were 16 to 21 days overdue. It is perhaps significant that among the 25 cases with labour induced, 60.9 per cent of the placentae showed some patho- logical change.

Postpartum haemorrhage occurred in 14.7 per cent of the series (compared with 10.1 per cent for the Royal Free Hospital Maternity Depart- ment in 1950), and, of these cases, 76.5 per cent lost between 20 and 30 ounces.

THE INFANT The birth weight of the infants varied from

5 pounds 8+ ounces to 10 pounds 10 ounces; 25.2 per cent were under 7 pounds, 40 per cent between 7 and 8 pounds; 33.9 per cent over 8 pounds, and 8.7 per cent over 9 pounds. Of the 113 live births, 40.7 per cent had regained their birth weight by the 7th day, 67.3 per cent by the 10th day, and 79.6 per cent on discharge from the ward.

REVIEW OF 115 CASES OF POSTMATURITY

Severe foetal asphyxia occurred in 6.1 per cent, and in one case the cord was found to be once tightly round the child’s neck. In 3 of the cases, labour had been induced.

Three infants showed some congenital abnor- mality; one a mild talipes equinus vams and left torticollis; another a cleft palate; and a third a spina bifida occulta (2.6 per cent of the series).

TOTAL INFANT WASTAGE There were 2 stillbirths, a rate of 17.4 per

1,000 for the series, as compared with 20.2 per 1,000 for the Maternity Department for 1950. In each case, foetal death occurred in the second stage of labour.

Mrs. H., para-0, aged 24, was 27 days overdue, and weighed 22 stones. The foetal heart was heard until just before delivery, which was spontaneous. There was excessive moulding of the skull, and death was due to intracranial injury, with small tentorial tears and sub-arachnoid haemorrhage. The baby weighed 6 pounds 12 ounces, and the placenta had numerous areas of calcification.

Mrs. M., para-0, aged 21, was 20 days overdue. X-ray pelvimetry showed no disproportion, and she was given a trial labour. Labour was prolonged to 87 hours 35 minutes, but the second stage lasted only lt hours. The foetal heart was last heard 5 minutes before delivery, which was by forceps for foetal distress. The postmortem cause of death was again intracranial injury. The baby weighed 9 pounds 1 ounce, and the placenta was clinically normal, though incomplete.

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There was 1 neonatal death in the series, giving a rate of 8.8 per 1,000 compared with 14.1 per 1,000 for the Maternity Department in 1950. It occurred on the 15th day, and was the child of a multigravida, aged 27 years, who was 22 days overdue. The mother was syphilitic, and received treatment during the latter half of preg- nancy only. Labour lasted 4 hours 12 minutes, and delivery was spontaneous. The baby weighed 5 pounds 13 ounces, and its Wasser- mann reaction was negative. The postmortem cause of death was atalectasis and broncho- pneumonia. The placenta was small and in- farcted, with considerable thrombosis of the vessels. There was no maternal death in the series.

SUMMARY AND CONCLUSIONS (1) 115 cases of postmaturity are analyzed. (2) The findings suggest that postmaturity per

se does not affect adversely the mother, her labour, or her infant.

(3) If, however, the postmaturity is associated with some other obstetric abnormality, e.g. dis- proportion, toxaemia, or Rhesus incompatibility, the postmature infant does appear to have a less good chance than the normally mature one. In these cases it would seem desirable to induce labour.