URINARY EXCRETION OF ŒSTROGENS DURING PREGNANCY, LACTATION, AND THE RE-ESTABLISHMENT OF MENSTRUATION

URINARY EXCRETION OF ŒSTROGENS DURING PREGNANCY, LACTATION, AND THE RE-ESTABLISHMENT OF MENSTRUATION

704 lesions of quite the same histological pattern, and present for the same length of time, do not. A granulosa-cell tumour which behaves as a carcin...

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704 lesions of quite the same histological pattern, and present for the same length of time, do not. A granulosa-cell tumour which behaves as a carcinoma may be histologically indistinguishable from one that does not, and a similarly unpredictable future is associated with carcinoid tumours and with occasional melanotic growths. The fleshy, spindle-cell sarcomas, of whatever type, especially those in the subcutaneous region, form another tumour type whose future behaviour is far from predictrecur repeatedly and finally metastasise, apparently the same histological appearance Retained placental tissue provides a good do not. of this kind of difficulty. Two excised uteri example may show foci of persisting, hyperplastic trophoblast of apparently identical type ; yet one patient will die of chorionepithelioma, and the other live. Quite similar tissue may be found in uterine curettings from patients who have no subsequent hysterectomy and yet survive. There is little difficulty in finding evidence of atypical cell growth in such retained trophoblast-the trophoblast may consist of little else but atypical cells-or in finding The evidence of invasion, possibly on a grand scale. histopathologist’s problem is that there is no dependable

able ;

some

others of

correlation between these appearances and the later The occurrence of metastases (Park and Lees 1950). same lack of correlation applies in varying degree to the other neoplasms in this group, and for this reason accurate figures for incidence and curability are again extremely difficult to obtain. "

BORDERLINE" CASES The third group of tumours comprises the so-called borderline cases-those cases where the surgeon wants an answer to the question, Has this growth crossed the borderline to malignancyT It is very likely that there is no such definite borderline, but the pathologist will remember that the surgeon nearly always has to act as if there were. This borderline group is the main cause of worry in the diagnosis of biopsy material. When the pathologist uses the term " difficult " to describe these cases, he is not referring so much to purely histological difficulties (he can still recognise the various tissue components, and their arrangement) as to the lack of available knowledge of the clinical behaviour to be expected with such histological appearances-in other words, to a low level of clinical correlation. In these circumstances he cannot give his diagnosis with the same degree of confidence as in the straightforward group : nor can this be expected of him. Here we find ourselves in conflict with scientific discipline. For scientific purposes, remembering our obligation to provide as accurate data as we can for cancer study as a whole, we should, if we feel the evidence in favour of a diagnosis of malignancy to be inadequate, say that a diagnosis of cancer cannot be given. For practical purposes, since the welfare of the patient is in the balance, the scientific outlook has to be put on one side, and a diagnosis of cancer made if there is even The a moderate degree of suspicion of malignancy. difference between diagnosis for these two purposes can be reconciled by making the reservation that though, in the interests of the patient, a diagnosis of cancer has to be made, the case very possibly was not one of cancer at all : in other words, to quote from an earlier discussion of this matter, " it is legitimate to treat a patient because he might have cancer but not legitimate always to assume that if lie recovers he necessarily did have cancer (Park and Lees 1955).

Summary

and Conclusions

clinically manifest cases, surgeons and radiotherapists are dependent for their diagnosis of It is obvious, therefore, cancer upon the pathologist. that if comparisons of different forms of treatment In all but

or

of incidence of

cancer are

to be

valid, the patho.

logical diagnoses they depend must be accurate. It has been pointed out that, even under optimum conditions, histological assessment of malignancy is far from absolute. In the case of early cancer, histological criteria of diagnosis are even less satisfactory,. and of lower practical value than pathologists would like. In such cases there may be quite legitimate differences in interpretation of the histology, and when this happens figures of incidence of early cancer will vary correspondingly. on

which

The property of invasiveness, on whose presence or absence depends frequently the diagnosis of " malignant"" or " not malignant," is particularly difficult to define, and therefore to recognise, in its early stages : indeed, in an attempt at its definition, I would go so far as to suggest, and not facetiously, that an abnormal over. growth of cells should be regarded as showing invasion only if it shows what every histopathologist would say was invasion. Pathologists should, by all means, persuade the clinician to provide them with as much in the way of clinical data as he can, informing him that, usually, the more help he gives them, the more they can give him. I would, however, suggest that the habit of always examining sections first, and reading the clinical data afterwards, is a valuable one. It should help to sharpen and clarify diagnostic criteria at that stage of cancer where we most need, yet most lack, sure definitionthe early stage. It has been shown that a diagnosis of cancer for practical purposes may at times, in borderline cases particularly, be inescapable ; but that it is legitimate for scientific purposes to have reservations about the accuracy of such a diagnosis, and to take this fact into account in the retrospective analysis of data. The term " histologically proved," when applied to cancer, is admissible only if proved " is used in its original and now almost obsolete sense of tried, tested, Its equation with " proof " in the legal or assessed." sense, with the implication that certain objectively defined, specific criteria have been satisfied, is not "

"

justifiable. I am most comments

grateful

to Prof. A. C. Lendrum for

during preparation

of the

script

for

helpful publication.

REFERENCES

Park, W. W., Lees, J. C. (1950) Arch. Path. (Lab. Med.) (1955) Cancer, 8, 320. —

49, 73.



URINARY EXCRETION OF ŒSTROGENS DURING PREGNANCY, LACTATION, AND THE RE-ESTABLISHMENT OF MENSTRUATION J. B. BROWN M.Sc. N.Z., Ph.D. Edin. From the Clinical Endocrinology Research Unit Research

(Medical

Council), University of Edinburgh

FEW reliable figures are available for the urinary excretion of oestriol, oestrone, and oestradiol-17p during pregnancy and lactation. Most of the published figures for early pregnancy and lactation were for total oestrogens, and many were obtained by semi-quantitative bio-assay methods (Pedersen-Bjergaard and Pedersen-Bjergaard 1948, Venning 1948, Jayle and Crepy 1952). Cohen, Marrian, and Watson (1935), using colorimetry, were the first to determine the urinary excretion of oestrogens during the last 6 months of pregnancy : they showed that costriol is quantitatively the most important urinary oestrogen during pregnancy, and that the amounts

705

Fig.I (subject 7)

. Menstrual period. and fig 2 (subject 8) show the amounts of cestriol, oestrone, and aestradiol excreted per 24 hours and also the variations in basal temperature, during a normal cycle, the cycle in which pregnancy occurred, and early pregnancy.

excreted rise from approximately 1 mg. per day at 3 months (the smallest amount they could measure accurately) to 20 mg. or more per day at 9 months. Later workers (Venning 1948, Clayton and Marrian 1950, Bradshaw and Jessop 1953) confirmed these findings and provided more information about the type and amounts of (Bstrogens excreted immediately preceding labour and

Placental

weight

1 lb. 12

9

Delivery 287 days after lb. 31/4 oz. (male).

oz.

Method

Complete 24-hour urine specimens were collected daily from subject 8 and approximately weekly from the others, until 2 weeks before the probable date of delivery, when daily collections were started. Subject 8 also collected all her urine during labour and delivery, 12-hourly for the next 4 days, and then daily until normal menstrual cycles were established. The amounts of oestriol, cestrone, and oestradiol-17 in each specimen were determined by the method

delivery. Recently a convenient, accurate, and apparently specific chemical method * for separately estimating cestriol, oestrone, and aestradiol-17 in human urine has been developed (Brown 1955a). ’

10, aged 29 ; para-0. Baby’s birth-weight

Szcbject L.M.P.

Material

Using this method, a study has been made of the daily urinary oestrogen excretion of a woman from before the beginning of a normal pregnancy, up to delivery, and then during the puerperium, lactation, and the recommencement of normal menstruation. The subject of this complete study was a woman (subject 8) who had already contributed urine for oestrogen determination throughout A similar but less a menstrual cycle (Brown 1955b). record from another woman previously studied complete (subject 7) is also included, together with the results obtained from two other women who were studied from the 16th weeks of their pregnancies until the onset of labour. In all cases, the previous and present pregnancies were uncomplicated. Deliveries were spontaneous except in subject 10 for whom forceps were required. Lactation was established in all cases. Subject 7, aged 33 ; para-2 (2 and 6 years ago). Delivery 276 days after last menstrual period (L.M.r.). Baby’s birth-weight 8 lb. 12 oz. (male). Subject 8, aged 28 ; para-2 (2 and 3 years ago). Delivery 286 days after L.M.r. Baby’s birth-weight 8 lb. 31/40Z. (male). Placental weight 1 lb. 11 oz. Subject 9, aged 27 ; para-1 (2 years ago). Delivery 289 days after L.M.P. Baby’s birth-weight 8 lb. 15 oz. (female). Placental weight 1 lb. 15 oz. ’

*The two cestrogens 16-epi-cestriol and the keto-aestrogen

recently found

in human pregnancy urine (Marrian and Bauld 1955, Watson and Marrian 1955), are not determined by this method nor do they interfere with the results.

Fig

3-Excretion of aestriol, oestrone, and aestradiol during pregnancy in the four subjects, and during the puerperium in subject 8.

706 described by Brown (1955a), modified, as follows, for urines containing larger amounts of oestrogens than could be satisfactorily measured by the original method. The 24-hour urine volumes

were


EXCRETJON OF CESTRIOL, CESTRONE, AND DUUINQ LATE PREGNANCY EXPRESSED AS MG. PER SPECIMENS OF URINE

24-HOUR

diluted to 2500 ml. with

water ; according to the stage of pregnancy, 200, 100, 50, 20, 10 ml. portions of this were used for each determination, and complete specimens of the oestriol fraction, or aliquots of 1/2, 1/5’ or 1/20 were taken for colour development so that the final oestriol, oestrone, and oestradiol-173 colours were within the convenient range for colorimetry. Specimens of urine of less than 100 ml. were diluted to 100 ml. with water before acid hydrolysis, and half the volumes of hydrochloric acid, ether, and carbonate solutions recommended in the original method were used. After the evaporation stage, the original procedure was unaltered ; but if necessary, portions of the oestriol eluates from the chromatogram columns were taken for colour development. The loss of cestrogens during acid hydrolysis (Brown 1955a) is less evident when the urine is dilute than when it is concentrated, and is negligible in late pregnancy when the urine is diluted five times or more before hydrolysis. To show that the method used in this investigation is reliable at the aestrogen levels encountered in late pregnancy, recovery experiments were performed in which 200 Lg. of oestriol, 20 {jt.g. of oestrone. and 10 (jLg. of 03stradiol-17p were added to 10 ml. of male urine diluted to 100 ml. with water before acid hydrolysis : these amounts are equivalent to daily excretions of 50 mg. of oestriol, 5 mg. of cestrone, and 2-5 mg. of oestradiol17&bgr;. In twelve such experiments, the mean percentage recoveries with their standard deviations were oestriol, 81-3; cestrone, 83:1-4; and oestradiol, 814—which are within the ranges claimed for the method. or

Results



The results obtained from subjects 7 and 8 over a period which includes a complete menstrual cycle and the cycle in which pregnancy started are shown in figs. 1 and 2. In both women the urinary oestrogen levels were very similar in the two cycles up to about the 24th daysshowing the ovulation peaks and the subsequent luteal rise. In the first cycle the oestrogen levels then decreased

before the onset of menstruation ; but in the second cycle, when pregnancy had occurred, they continued to increase, and they began to increase rapidly about 7 weeks after the last menstrual period. Subject 7 had nausea at this time. The results from the four subjects throughout their pregnancies are shown in fig. 3 on a logarithmic scale. Those for subject 8 are also shown for a week after delivery. There was a rapid rise in the urinary levels of the three oestrogens throughout pregnancy, greatest 4 (subject 8)- During lactation and until the onset of menstruation excretion of aestriol, oestrone, and aestradiol was measured. Thereafter, until the end of the third menstrual period following delivery, pregnanediol was measured in addition and variations in basal temperature were recorded.

Fig.

between the 6th and 20th weeks. The oestrone and cestradiol levels at labour were 100 times higher than those during the luteal phase of the menstrual cycle, the oeetradiol levels being about one-third of the cestrone levels. The urinary cestriol levels rose approximately 1000-fold during this time. The results obtained during the last weeks of pregnancy are shown in more detail in the accompanying table.

Subject8 During labour,

which lasted 3 hours, the urinary excretion calculated on a 24-hour basis was 44 mg. of costriol, 1.7 mg. of oestrone, and 0.85 mg. of aestradiol-17. After delivery, the urinary oestrogen levels fell rapidly. In the case of cestrone and cestradiol-17j3there was a linear relationship between the logarithm of the amounts excreted and the time after delivery, and normal nonpregnancy levels were reached within 5 days. In the case of oestriol this linear relationship did not apply so closely, and normal non-pregnancy levels were not reached until 25 days after delivery (fig. 4). Levels were low during lactation and reached a minimum (cestriol 1.0 {jLg., cestrone 3 g., cestradiol 0 tg. per 24 hours) at the time when lactation became inadequate and suckling was discontinued. Thereafter the amounts increased

slowly. There was slight vaginal bleeding on the 78th and on the 84th days after delivery when the cestriol and cestrone levels were both approximately 7 .g. per day. Soon

707 after this, measurable amounts of cestradiol- 17appeared in the urine and the levels of all three cestrogens rapidly increased and decreased in the manner characteristic of ovulation (Brown 1955b). However, the oestrogen levels did not rise again to a definite luteal maximum and menstrual bleeding began 8 days after the " ovulation " peak. That ovulation followed by a shortened luteal phase had occurred was confirmed by morning basal temperature and urinary pregnanediol measurements.t An ovulation peak followed by a somewhat shortened luteal phase of 10 days was seen during the next menstrual cycle, and during the third menstrual cycle there was a normal luteal maximum and the oestrogen levels throughout were almost identical with those during the menstrual cycle preceding pregnancy. Discussion

The results reported here are similar to those obtained by other workers, but they give a more detailed picture of some of the changes in urinary oestrogen levels during pregnancy, the puerperium, and lactation.

Level During Pregnancy The levels found during the menstrual cycle in which pregnancy occurred were very similar to those found during the preceding cycle up to the middle of the luteal phase, after which time they continued to rise slowly instead of falling as they do before menstruation. At about 7 weeks after the last menstrual period, the urinary oestrogen levels began to increase rapidly, being soon outside the range found during a menstrual cycle, and thereafter they followed a smooth exponential curve which flattened somewhat towards the end of pregnancy. The abrupt change in the oestrogen excretion curve at about 7 weeks might well be due to the changeover from the corpus luteum to the placenta as the major producer of cestrogens. This is earlier than the time suggested for this changeover by Venning (1948) who thought that it took place during the 2nd to 3rd months. However, many workers have noted that the removal of the corpus luteum, even during the first month of pregnancy, does not necessarilv cause abortion. Koff and Tulskv (1953) concluded from this evidence, and from their own studies on eight women in whom they estimated urinary pregnanediol before and after removing the corpus luteum, that by the 35th day the placenta by itself secretes enough progesterone to maintain pregnancy. This should apply equally to the cestrogens, and it would therefore seem that the rapid increase in oestrogen excretion observed at 7 weeks is caused mainly by placental production, and that even before this time the placenta is contributing increasingly to the cestrogen levels.

(Estrogen

(Estrogen Levels During and After Labour My findings during late pregnancy and

at the onset

of labour are very similar to those reported by other workers, and support the conclusions of Bradshaw and Jessop (1953) that there is no correlation between cestrogen excretion and the onset of labour. The considerable day-to-day variations in the excretion of cestrogens in the same woman and the variations in secretion between different women noted by Bradshaw and Jessop were also observed in my series. These differences are masked in the logarithmic scale used in fig. 3 but are shown more clearly in the table. The rapid decrease in the urinary cestrogen levels following delivery was consistent with sudden removal of the placental source and a continuous metabolism and renal excretion of the reniaining oestrogens. GEstriol was eliminated more slowly than cestrone and cestradiol17&bgr;—an interesting difference observed following single

intramuscular injections of these three oestrogens.

the pregnanediol measurements were kindly performed by Dr. A. Klopper using the method of Klopper, Michie, and Brown (1955).

Œstrogen Levels During Lactation and the Puerperium The oestrogen levels during lactation were low and were within the range normally found during the early part of a menstrual cycle. After lactation ceased, the oestrogen levels began to increase slowly until the regular rise and fall found during a menstrual cycle was observed. It may be significant that, after the period of lactation amenorrhcea, slight menstrual bleeding occurred when the oestriol and oestrone levels were each approximately µg. per 24 hours.

7

for

Such levels, when maintained

period, might represent the minimum amounts of oestrogens required for stimulating endometrial growth ; and yet, being within the range normally found at menstruation (Brown 1955b), they might make the stimulated endometrium unstable and precipitate a

menstruation. During the first menstrual periods after delivery, ovulation took place, but during the first two periods the luteal phases were abnormally short (8 and 10 days). This is contrary to the belief that the luteal phase always lasts about 14 days. It is possible to envisage a luteal phase so evanescent that it cannot be detected. By all the usual criteria such a menstrual cycle would be considered anovular, and it may well be that brevity of the luteal phase is the explanation of some of the apparently anovular cycles following delivery. The third menstrual cycle appeared to be normal in all respects, and during this cycle the urinary oestrogen levels were almost the same as those found during the menstrual cycle preceding pregnancy. This is a further example of the constancy in the pattern and amounts of oestrogens excreted during different menstrual cycles.

Summary

urinary excretion of cestriol, cestrone, and œstradiol-17&bgr; during conception, pregnancy, the puerperium, lactation, and the recommencement of menstruaThe

tion has been measured in women. A new chemical method of estimation was employed. The results are discussed. I wish to thank Prof. G. F. Marrian, F.R.S., and Prof. R. J. Kellar, for their interest in this work. I am also grateful to the wives of colleagues who contributed the urine specimens, and especially to the one who made possible the complete study over a period of 17 months. I am also indebted to Mr. H. A. F. Blair and Miss Janet Mackie for their skilled technical assistance. REFERENCES

Bradshaw, T. E. T., Jessop, W. J. E. (1953) J. Endocrin. 9, 427. Brown, J. B. (1955a) Biochem. J. 60, 185. (1955b) Lancet, i, 320. Clayton, B. E.. Marrian, G. F. (1950) J. Endocrin. 6, 332. Cohen, S. L., Marrian, G. F., Watson, M. (1935) Lancet, i, 674. Jayle, M. F., Crépy, O. (1952) Ann. Biol. clin. 10, 44. Klopper, A., Michie, E. A., Brown, J. B. (1955) J. Endocrin. 12, 209. Koff, A. K., Tulsky, A. S. (1953) Surg. Clin. N. Amer. 33, 3. Marrian, G. F., Bauld, W. S. (1955) Biochem. J. 59, 136. Pedersen-Bjergaard, G., Pedersen-Bjergaard, K. (1948) Acta endocr., Copenhagen, 1, 263. Venning, E. H. (1948) Obstet. Surv., Baltim. 3, 661. Watson, E. J. D., Marrian, G. F. (1955) Biochem. J. 61, xxiv. —

" General education ... is bound to differ according to the different lines of specialisation being followed. It is no good whatever thinking that by laying on a course in literature and a course in current affairs it is possible to give both your scientists and your classics the, general education which they need in addition to their special studies. What you must try to do is to make them see their own line of study as one amongst many, and make them see where it stands in the general fabric of human knowledge. You must persuade or cajole or force your scientists to write English coherently. You must make them see that there are other approaches to reality than that of quantity and experiment, and get into their heads some appreciation of literary and artistic and moral values. You must make them see how science has affected human life and give them enough history to enable them to do this ... general education in its profoundest sense is an essential part of specialist education."-H. D. P. LEE, M.A., headmaster, Winchester College. Report of Rome Universities Conference, 1955, p. 19.