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Postmaturity
volume 80 numbn 1
July 1%0
American Joumal of
Obstetrics and Gynecology
Transactions of the Fifteenth Annual Meeting of the Society of Obstetricians and Gynaecologists of Canada
Postmaturity I. A. PERLIN, M.D., C.M., F.A.C.S., F.I.C.S., F.A.C.O.G. Halifax, Nova Scotia
D u R r N G the past few years, a considerable amount of controversial material has been written concerning the effects on both mother and child when a pregnancy extends beyond the expected date of delivery. The rather divided opinion has caused, at times, much concern among those who are clinically active in obstetrics. One school of thought as exemplified by Walker/ 2 Hamilton/ Moir, etc., is rather dogmatic in suggesting that no patient should be permitted to go beyond 42 weeks of pregnancy if fetal loss is to be prevented or unduly difficult labor avoided; whereas Browne/ the Margaret Hague group, Eastman,S and Daichman and Gold, 4 feel that no greater ill effects will occur in the postterm patient but rather that more trouble might well arise from the
routine induction of patients who have reached beyond the forty-second week. 4 • 5 • 8 It had been the impression in our Department at Dalhousie University that prolongation of pregnancy did not constitute a threat to mother or baby so that generally no interference was carried out and nature was allowed to take its course. During one of our refresher courses we were so intimidated by a visiting eminent obstetrician because of our attitude to so-called "postmaturity" that, as a result of his dogmatic expression of expected difficulties, within a few weeks of his lecture at least two patients were brought into the hospital for induction because they had gone more than two weeks past the expected date and both of these resulted in
Table I. Age distribution From the Department of Obstetrics and Gynecology, Dalhousie University This study was made possible through the aid of a Federal Health Grant. Presented at the Fifteenth Annual Meeting of the Society of Obstetricians and Gynaecologists of Canada, M ant Tremblant, Quebec, Sept. 11-13, 1959.
Postmature
Mature
Age (years)
No.
%
No.
Up to 25 25 to 35 35 and above Not clear
522 339 61 40
54.2 35.2 6.3 4.2
4,406 4,102 746 417
I
% 45.6 42.4
7.7 4.3
july_ J~~lf;i} Am. ]. Oh'it. & (_;vnf':t
2 Perlin
Table II. Relationship of parity to the degree of postmaturity ------------.---------------- ·----·-·-----·------------Postmature Mature No. Primiparas Multiparas
I
3,870 5,801
Total
2-3 weeks
I Over J,wee":_>_
3-5 weeks
%
No.
%
No.
%
No.
%
No.
40.0 60.0
446 516
46.4 53.6
299 347
46.3 53.7
133 146
47.7 52.3
14 2:{
I
(;;'0
37.8 62.2
-----·---·--"·--·
Table III. Comparison of the incidence of hypertension in mature and postmature patients Postmature Mature No. Normal Hypertension
I
8,089 1,582
Total
%
No.
83.6 16.4
819 143
2-3 weeks
%
No.
85.1 14.9
550 96
I Over
3-5 weeks
%
No.
%
No.
85.1 14.9
223 46
83.5 16.5
36 1
5 weeks
I
% 97.3 2. 7
Table IV. Incidence of toxemia and its relationship to degree of postmaturity Postmature Mature No. None Severe Mild Total toxemia
9,035 94 542 636
I
Total
2-3 weeks
I Over
3-5 weeks
%
No.
%
No.
%
No.
%
93.4 1.0 5.6 6.6
893 7 62 69
92.8 0.7 6.5 7.2
598 4 44 48
92.6 0.6 6.8 7.4
259 3 17 20
92.8 1.1 6.1 7.2
cesarean sections because of failed induction. As a result of this, we decided to analyze critically our own cases to see whether our impressions had been correct or not. A review of 12,000 consecutive deliveries at the Grace Maternity Hospital between 1950 and 1955 was carried out (years previous to visit mentioned above). The criterion used to identify the postmature case was by Naegle's Rule; i.e., a patient with a history of regular menstrual cycles of average duration, who remembered her last period date and whose pregnancy extended over 42 weeks was placed in the postmature group. The mature group was composed of those in the 38 to 42 weeks' range and the premature group were those under 38 weeks. Out of the 12,000 cases there were 962 socalled postmatures as compared with 9,671 matures (there were, in addition, 1,367 prematures) . Of the postmatures 646 were 2 to 3 weeks, 279 were 3 to 5 weeks, and 37 were over 5 weeks postmature.
No.
36 0 1 1
5 weeks
I
% 97.3 0 2.7 2.7
e,
The term "postmaturity" is a troubling one, because it immediately suggests a pathological condition as far as the baby is concerned-that is, the subnourished-looking baby, with meconium-stained skin as a result of pre- or intradelivery distress-and yet this is not the usual picture when the pregnancy is prolonged. This type of baby can be seen at term and even in the premature group. It might be best, therefore, to use a term such as "prolonged pregnancy" (or, possibly, "postdate labor" as sug-
Table V. Position and presentation of the babies
I Postmature I Vertex anterior Vertex posterior Brow Face Breech Transverse Unknown
No. 842 37 2 5 31 5 40
Mature No. % 87.5 8,532 88.2 3.8 433 4.5 0.21 13 0.13 0.52 22 0.23 3.2 306 3.2 0.52 29 0.30 4.2 336 3.5
I
%
I
~..
Volumr 81) Number 1
"
Postmotunty
3
Table VI. Relationship of length of labor to the degree of postmaturity Postmature Total
Mature Hours of labor
No.
Up to 15 15 to 25 25 and up Not clear
6,031 2,117 1,157 366
% 62.3 21.9 12.0 3.8
No.
575 212 147 28
% 59.8 22.0 15.3 2.9
General considerations
There were significantly a greater number of postmature patients in the younger age group (Table I).
\·
No.
%
22 919 21
2.3 95.5 2.2
172 9,207 292
I
% 61.3 17.6 15.8 5.4
No.
171 49 44 15
-----·--····
I No.
i
···- ··- ·-.
(k)
7!U
26 6 5 0
10,,. . .:..') i
LS ()
·------------------
Complications of pregnancy
Mature No.
378 157 98 13
% 58.5 24.3 15.2 2.0
-------·· t.Vt'ekr
Oner .5
It has been reported that in the postmature group a large number are hypertensive during the postterm period or in labor. In this series there is little difference between the groups (in fact there is a slightly gTeater per cent in the mature group) (Table III). That toxemia is a problem in the postmature patient is not reflected in this series (Table IV). There is a slight trend ( 7.2 to
Table VII. Incidence of uterine inertia
Present Absent Not recorded
No.
3-5 weeks
It has been reported that postmaturity occurs mostly among primiparas. There were, in this series, more primiparas among the postmature group as compared to the mature group which probably coincides with the age incidence (Table II). Within the postmature group itself, however, there were more multiparas; and this relationship was not altered by the inn·easing degree of postmaturity (Table IJI.
gested by Daichman and Gold 4 ) • For the sake of simplicity, however, the terms "mature" and "postmature" will be used throughout this paper. The incidence of postmaturity in this series is 8.0 per cent, which is in the range of those reporting who have used the same criterion.
Postmature
2-3 weeks
% 1.8 95.2 3.0
Table VIII. Size of the baby in relation to the degree of postmaturity ------------,-------.----------------------------···· Postmature Mature
Total
2-3 weeks % No.
3-5 weeks
I
I Ove-rS weeks
No. %--~--No~-~% % 53 19.0 6 148 22.9 3,240 33.5 207 21.5 Under 7 23 418 64.7 189 67.7 65.5 5,729 59.2 630 7 to 9 77 10.1 34 12.1 8 6.9 12.4 Over 9 665 119 3 0.4 3 1.1 0 6 0.6 Not clearly recorded 37 0.4 ---'--------------------------------------------·---·Weight (pounds)
No.
I
No.
~,;;,---
16.2 62.2 2Ui
Table IX. Size of baby in relation to parity Primiparas Weight (pounds)
Under 7 7 to 9 Over 9 Not clearly recorded
No.
110 301 34 1
% 24.7 67.5 7.6 0.22
97 329 85 5
18.8 63.8 16.5 0.97
1,523 2,138 191 18
39.3 55.2 4.9 0.6
1,713 3.589 474 25
29.5 61.8 8.1 0.4
4 Perlin
Am.
Table X. Comparative incidence of fetal distress Mature
I
Postmature No. o/o 4.6 44
I
Fetal distress
No.
o/o
In utero At birth 2-5 minutes Longer than 5 minutes
265
2.7
361
3.7
41
4.3
83
0.8
16
1.7
Table XI. Comparison of the incidence of fetal morbidity
I Postmature Morbidity
No. 2 2
Pneumonia Atelectasis Major feeding prob!em
I
5
Mature
o/o
No.
o/o
0.2 0.2
17 26
0.2 0.3
0.5
19
0.2
Table XII. Condition of babies on discharge from hospital Postmature
I Congenital abnormalities Birth injuries Stillbirth Death
No. 24 4 15 6
I
o/o 2.5 0.4 1.6 0.6
Mature No. 173 36 94 56
I
o/o 1.8 0.4 1.0 0.6
6.6-not significant) but the degree of postmaturity did not increase the amount of toxemia. However, as noted before, there were more primiparas in the postmature group which may account for the trend since 8.1 per cent of the toxemic patients of both groups were primiparas. Problems of labor and delivery
There is hardly any difference in the position and presentation of the babies between the two groups (Table V). One interesting point in this series is that breech presentation was present in both groups by the same percentage and within the usually reported range of 2 to 4 per cent. Taussig and others7• 10 have reported breech presentation to be rare in the postmature. If one looks at the very long labors (over 24 hours) one notes that a slightly, though
J.
July. 1%0 Obst. & Gyn-ec
not significantly, greater percentage of the cases were in the postmature group as cornpared to the mature (15.3 to 12.0); but the degree of postmaturity did not influence the number of long labors (Table VI). Method of delivery
There was no difference between the two groups in the manner in which delivery was effected; 94.1 per cent of the postmature patients were delivered spontaneously or by low forceps as compared with 94.9 per cent of the mature. The cesarean section rate was about the same: 3.1 per cent of the postmature and 3.3 per cent of the mature. Inertia is considered to be a problem when the pregnancy is prolonged. This series did not bear this out (Table VII). The baby
This series did agree with the reports generally that the longer the pregnancy the bigger the baby (Table VIII). It is interesting to note, however, that more of the large babies (9 pounds and over) were in the multiparous group who generally have the easier births (Table IX). One of the problems that has been emphasized so strongly by those who consider postmaturity a hazard has been that of fetal distress both in utero and after delivery. The rate has been quoted as being between 25 and 30 per cent. 7• 12 In our series there was only a small number showing signs of distress; about the same in both groups of cases (Table X). Did the babies from the postmature group present any greater number of problems? In this series they seemed to be as healthy as the mature babies (about 99 per cent in each showed no problems) (Table XI). The stillbirth and death rate were about the same for both groups (Table XII). Comment
From this series of cases we feel that we have not erred in the past by allowing our patients to go along in their pregnancies until spontaneous labor occurred.
..
•
•
...
Volume 80 Number 1
Postmaturity
Since there is a normal variation in all our physiological processes, it would seem unnatural to set a specific limit of time to a normal pregnancy. There is no doubt some danger associated with persistent induction of labor by whatever means; and if we were to follow through on the theory that pregnancy should be terminated after 42 weeks, than a failure of induction should lead to cesarean section. Here again we would be adding a real danger to both mother and child. Summary
1. Postmaturity pnm1para.
IS
not peculiar to the
REFERENCES
1. Bancroft-Livingstone, G., and Neill, D. W.: J. Obst. & Gynaec. Brit. Emp. 64: 498, 1957. 2. Browne, F. J.: Brit. M. J. 1: 851, 1957. 3. Calkins, L. A.: AM. J. 0BsT. & GYNEC. 68: 50, 1954. 4. Daichman, J., and Gold, E. M.: AM. J. 0BST. & GYNEC. 68: 1128, 1954. 5. Eastman, N. J.: Obst. & Gynec. Surv. 12: 476, 1957 .
.
.
5
2. Our previously (and still) held concept of noninterference when the pregnancy is prolonged did not result in any greater number of mishaps to either the mother or the baby. 3. The longer the pregnancy the heavier the baby, but this does not give a valid reason for earlier induction. There were more heavier babies among the multiparas and these had generally an easier labor and fewer distress problems. I am greatly indebted to Dr. H. B. Atlee, Professor Emeritus, and Dr. C. B. Stewart, Dean of Dalhousie Medical School, for their advice as to material and statistics.
6. Gibberd, C. F.: Lancet 1: 64, 1958. 7. Hamilton, C. J. K.: Brit. M. J. 2: 281, 1950. 8. Koosterman, G. J.: Obst. & Gynec. Surv. 12: 470, 1957. 9. Racker, Dudley: Lancet 2: 953, 1953 . 10. Taussig, F. J.: AM. J. 0BsT. & GYNF.c. 4'k 516, 1901. 11. Theobald, G. W.: Lancet 1: 59, 1959. 12. Walker, J.: J. Obst. & Gynaec. Brit. Emp. 61: 162, 1954.
July 1%0
American Joumal of
Obstetrics and Gynecology
Transactions of the Fifteenth Annual Meeting of the Society of Obstetricians and Gynaecologists of Canada
Postmaturity I. A. PERLIN, M.D., C.M., F.A.C.S., F.I.C.S., F.A.C.O.G. Halifax, Nova Scotia
D u R r N G the past few years, a considerable amount of controversial material has been written concerning the effects on both mother and child when a pregnancy extends beyond the expected date of delivery. The rather divided opinion has caused, at times, much concern among those who are clinically active in obstetrics. One school of thought as exemplified by Walker/ 2 Hamilton/ Moir, etc., is rather dogmatic in suggesting that no patient should be permitted to go beyond 42 weeks of pregnancy if fetal loss is to be prevented or unduly difficult labor avoided; whereas Browne/ the Margaret Hague group, Eastman,S and Daichman and Gold, 4 feel that no greater ill effects will occur in the postterm patient but rather that more trouble might well arise from the
routine induction of patients who have reached beyond the forty-second week. 4 • 5 • 8 It had been the impression in our Department at Dalhousie University that prolongation of pregnancy did not constitute a threat to mother or baby so that generally no interference was carried out and nature was allowed to take its course. During one of our refresher courses we were so intimidated by a visiting eminent obstetrician because of our attitude to so-called "postmaturity" that, as a result of his dogmatic expression of expected difficulties, within a few weeks of his lecture at least two patients were brought into the hospital for induction because they had gone more than two weeks past the expected date and both of these resulted in
Table I. Age distribution From the Department of Obstetrics and Gynecology, Dalhousie University This study was made possible through the aid of a Federal Health Grant. Presented at the Fifteenth Annual Meeting of the Society of Obstetricians and Gynaecologists of Canada, M ant Tremblant, Quebec, Sept. 11-13, 1959.
Postmature
Mature
Age (years)
No.
%
No.
Up to 25 25 to 35 35 and above Not clear
522 339 61 40
54.2 35.2 6.3 4.2
4,406 4,102 746 417
I
% 45.6 42.4
7.7 4.3
july_ J~~lf;i} Am. ]. Oh'it. & (_;vnf':t
2 Perlin
Table II. Relationship of parity to the degree of postmaturity ------------.---------------- ·----·-·-----·------------Postmature Mature No. Primiparas Multiparas
I
3,870 5,801
Total
2-3 weeks
I Over J,wee":_>_
3-5 weeks
%
No.
%
No.
%
No.
%
No.
40.0 60.0
446 516
46.4 53.6
299 347
46.3 53.7
133 146
47.7 52.3
14 2:{
I
(;;'0
37.8 62.2
-----·---·--"·--·
Table III. Comparison of the incidence of hypertension in mature and postmature patients Postmature Mature No. Normal Hypertension
I
8,089 1,582
Total
%
No.
83.6 16.4
819 143
2-3 weeks
%
No.
85.1 14.9
550 96
I Over
3-5 weeks
%
No.
%
No.
85.1 14.9
223 46
83.5 16.5
36 1
5 weeks
I
% 97.3 2. 7
Table IV. Incidence of toxemia and its relationship to degree of postmaturity Postmature Mature No. None Severe Mild Total toxemia
9,035 94 542 636
I
Total
2-3 weeks
I Over
3-5 weeks
%
No.
%
No.
%
No.
%
93.4 1.0 5.6 6.6
893 7 62 69
92.8 0.7 6.5 7.2
598 4 44 48
92.6 0.6 6.8 7.4
259 3 17 20
92.8 1.1 6.1 7.2
cesarean sections because of failed induction. As a result of this, we decided to analyze critically our own cases to see whether our impressions had been correct or not. A review of 12,000 consecutive deliveries at the Grace Maternity Hospital between 1950 and 1955 was carried out (years previous to visit mentioned above). The criterion used to identify the postmature case was by Naegle's Rule; i.e., a patient with a history of regular menstrual cycles of average duration, who remembered her last period date and whose pregnancy extended over 42 weeks was placed in the postmature group. The mature group was composed of those in the 38 to 42 weeks' range and the premature group were those under 38 weeks. Out of the 12,000 cases there were 962 socalled postmatures as compared with 9,671 matures (there were, in addition, 1,367 prematures) . Of the postmatures 646 were 2 to 3 weeks, 279 were 3 to 5 weeks, and 37 were over 5 weeks postmature.
No.
36 0 1 1
5 weeks
I
% 97.3 0 2.7 2.7
e,
The term "postmaturity" is a troubling one, because it immediately suggests a pathological condition as far as the baby is concerned-that is, the subnourished-looking baby, with meconium-stained skin as a result of pre- or intradelivery distress-and yet this is not the usual picture when the pregnancy is prolonged. This type of baby can be seen at term and even in the premature group. It might be best, therefore, to use a term such as "prolonged pregnancy" (or, possibly, "postdate labor" as sug-
Table V. Position and presentation of the babies
I Postmature I Vertex anterior Vertex posterior Brow Face Breech Transverse Unknown
No. 842 37 2 5 31 5 40
Mature No. % 87.5 8,532 88.2 3.8 433 4.5 0.21 13 0.13 0.52 22 0.23 3.2 306 3.2 0.52 29 0.30 4.2 336 3.5
I
%
I
~..
Volumr 81) Number 1
"
Postmotunty
3
Table VI. Relationship of length of labor to the degree of postmaturity Postmature Total
Mature Hours of labor
No.
Up to 15 15 to 25 25 and up Not clear
6,031 2,117 1,157 366
% 62.3 21.9 12.0 3.8
No.
575 212 147 28
% 59.8 22.0 15.3 2.9
General considerations
There were significantly a greater number of postmature patients in the younger age group (Table I).
\·
No.
%
22 919 21
2.3 95.5 2.2
172 9,207 292
I
% 61.3 17.6 15.8 5.4
No.
171 49 44 15
-----·--····
I No.
i
···- ··- ·-.
(k)
7!U
26 6 5 0
10,,. . .:..') i
LS ()
·------------------
Complications of pregnancy
Mature No.
378 157 98 13
% 58.5 24.3 15.2 2.0
-------·· t.Vt'ekr
Oner .5
It has been reported that in the postmature group a large number are hypertensive during the postterm period or in labor. In this series there is little difference between the groups (in fact there is a slightly gTeater per cent in the mature group) (Table III). That toxemia is a problem in the postmature patient is not reflected in this series (Table IV). There is a slight trend ( 7.2 to
Table VII. Incidence of uterine inertia
Present Absent Not recorded
No.
3-5 weeks
It has been reported that postmaturity occurs mostly among primiparas. There were, in this series, more primiparas among the postmature group as compared to the mature group which probably coincides with the age incidence (Table II). Within the postmature group itself, however, there were more multiparas; and this relationship was not altered by the inn·easing degree of postmaturity (Table IJI.
gested by Daichman and Gold 4 ) • For the sake of simplicity, however, the terms "mature" and "postmature" will be used throughout this paper. The incidence of postmaturity in this series is 8.0 per cent, which is in the range of those reporting who have used the same criterion.
Postmature
2-3 weeks
% 1.8 95.2 3.0
Table VIII. Size of the baby in relation to the degree of postmaturity ------------,-------.----------------------------···· Postmature Mature
Total
2-3 weeks % No.
3-5 weeks
I
I Ove-rS weeks
No. %--~--No~-~% % 53 19.0 6 148 22.9 3,240 33.5 207 21.5 Under 7 23 418 64.7 189 67.7 65.5 5,729 59.2 630 7 to 9 77 10.1 34 12.1 8 6.9 12.4 Over 9 665 119 3 0.4 3 1.1 0 6 0.6 Not clearly recorded 37 0.4 ---'--------------------------------------------·---·Weight (pounds)
No.
I
No.
~,;;,---
16.2 62.2 2Ui
Table IX. Size of baby in relation to parity Primiparas Weight (pounds)
Under 7 7 to 9 Over 9 Not clearly recorded
No.
110 301 34 1
% 24.7 67.5 7.6 0.22
97 329 85 5
18.8 63.8 16.5 0.97
1,523 2,138 191 18
39.3 55.2 4.9 0.6
1,713 3.589 474 25
29.5 61.8 8.1 0.4
4 Perlin
Am.
Table X. Comparative incidence of fetal distress Mature
I
Postmature No. o/o 4.6 44
I
Fetal distress
No.
o/o
In utero At birth 2-5 minutes Longer than 5 minutes
265
2.7
361
3.7
41
4.3
83
0.8
16
1.7
Table XI. Comparison of the incidence of fetal morbidity
I Postmature Morbidity
No. 2 2
Pneumonia Atelectasis Major feeding prob!em
I
5
Mature
o/o
No.
o/o
0.2 0.2
17 26
0.2 0.3
0.5
19
0.2
Table XII. Condition of babies on discharge from hospital Postmature
I Congenital abnormalities Birth injuries Stillbirth Death
No. 24 4 15 6
I
o/o 2.5 0.4 1.6 0.6
Mature No. 173 36 94 56
I
o/o 1.8 0.4 1.0 0.6
6.6-not significant) but the degree of postmaturity did not increase the amount of toxemia. However, as noted before, there were more primiparas in the postmature group which may account for the trend since 8.1 per cent of the toxemic patients of both groups were primiparas. Problems of labor and delivery
There is hardly any difference in the position and presentation of the babies between the two groups (Table V). One interesting point in this series is that breech presentation was present in both groups by the same percentage and within the usually reported range of 2 to 4 per cent. Taussig and others7• 10 have reported breech presentation to be rare in the postmature. If one looks at the very long labors (over 24 hours) one notes that a slightly, though
J.
July. 1%0 Obst. & Gyn-ec
not significantly, greater percentage of the cases were in the postmature group as cornpared to the mature (15.3 to 12.0); but the degree of postmaturity did not influence the number of long labors (Table VI). Method of delivery
There was no difference between the two groups in the manner in which delivery was effected; 94.1 per cent of the postmature patients were delivered spontaneously or by low forceps as compared with 94.9 per cent of the mature. The cesarean section rate was about the same: 3.1 per cent of the postmature and 3.3 per cent of the mature. Inertia is considered to be a problem when the pregnancy is prolonged. This series did not bear this out (Table VII). The baby
This series did agree with the reports generally that the longer the pregnancy the bigger the baby (Table VIII). It is interesting to note, however, that more of the large babies (9 pounds and over) were in the multiparous group who generally have the easier births (Table IX). One of the problems that has been emphasized so strongly by those who consider postmaturity a hazard has been that of fetal distress both in utero and after delivery. The rate has been quoted as being between 25 and 30 per cent. 7• 12 In our series there was only a small number showing signs of distress; about the same in both groups of cases (Table X). Did the babies from the postmature group present any greater number of problems? In this series they seemed to be as healthy as the mature babies (about 99 per cent in each showed no problems) (Table XI). The stillbirth and death rate were about the same for both groups (Table XII). Comment
From this series of cases we feel that we have not erred in the past by allowing our patients to go along in their pregnancies until spontaneous labor occurred.
..
•
•
...
Volume 80 Number 1
Postmaturity
Since there is a normal variation in all our physiological processes, it would seem unnatural to set a specific limit of time to a normal pregnancy. There is no doubt some danger associated with persistent induction of labor by whatever means; and if we were to follow through on the theory that pregnancy should be terminated after 42 weeks, than a failure of induction should lead to cesarean section. Here again we would be adding a real danger to both mother and child. Summary
1. Postmaturity pnm1para.
IS
not peculiar to the
REFERENCES
1. Bancroft-Livingstone, G., and Neill, D. W.: J. Obst. & Gynaec. Brit. Emp. 64: 498, 1957. 2. Browne, F. J.: Brit. M. J. 1: 851, 1957. 3. Calkins, L. A.: AM. J. 0BsT. & GYNEC. 68: 50, 1954. 4. Daichman, J., and Gold, E. M.: AM. J. 0BST. & GYNEC. 68: 1128, 1954. 5. Eastman, N. J.: Obst. & Gynec. Surv. 12: 476, 1957 .
.
.
5
2. Our previously (and still) held concept of noninterference when the pregnancy is prolonged did not result in any greater number of mishaps to either the mother or the baby. 3. The longer the pregnancy the heavier the baby, but this does not give a valid reason for earlier induction. There were more heavier babies among the multiparas and these had generally an easier labor and fewer distress problems. I am greatly indebted to Dr. H. B. Atlee, Professor Emeritus, and Dr. C. B. Stewart, Dean of Dalhousie Medical School, for their advice as to material and statistics.
6. Gibberd, C. F.: Lancet 1: 64, 1958. 7. Hamilton, C. J. K.: Brit. M. J. 2: 281, 1950. 8. Koosterman, G. J.: Obst. & Gynec. Surv. 12: 470, 1957. 9. Racker, Dudley: Lancet 2: 953, 1953 . 10. Taussig, F. J.: AM. J. 0BsT. & GYNF.c. 4'k 516, 1901. 11. Theobald, G. W.: Lancet 1: 59, 1959. 12. Walker, J.: J. Obst. & Gynaec. Brit. Emp. 61: 162, 1954.