ÆäÀÌÁö À̹ÌÁö
PDF
ePub

takes place when the mother is so far advanced in pregnancy that her situation must have been known by the husband, this will be considered a recognition of legitimacy.3

II. NORMAL DURATION OF PREGNANCY.

45. Date of conception, in general. Since the earliest historic times the normal duration of the period of gestation in woman has been held to be approximately nine calendar months, or ten lunar months. But the exact number of days necessary for the complete development of the fetus still remains open for discussion. The period is apparently not the same in all women, varying even in the different pregnancies of the same woman. The great difficulty in determining the duration of pregnancy arises from the fact that while the one end of the gestation can be determined by the day of delivery, the other end is always a matter of uncertainty. This uncertainty arises out of two factors: First, the time of conception, that is, the union of the spermatozoon with the ovum, is not coincident with coitus. Recent investigation leads to the belief that conception usually takes place in the Fallopian tube, and the time taken for the passage of the spermatozoa from the vagina to the tube has not yet been determined. Living spermatozoa have been found in the uterus and tubes one to two weeks after coition; but what the minimum time for the passage is, is still unsettled. Hence, we cannot say how long after coition conception occurs. In the computation of the duration of pregnancy Winckel allows five days as the period of conception, "Conceptionstermin," but that is only a careful estimate. Second, the appearance of the menstrual flow is not always coincident with the discharge of the ovum from the ovary. The general idea that ovulation is accompanied by menstruation is open. to the objection arising from the not infrequent cases where pregnancy begins in a period of amenorrhea. Ahlfeld mentions the case of a woman who was thirty-two years old when she first menstruated, though before that time she had had numerous children; and Leviot cites the case of a woman who, during a period of fourteen years, had borne four children, and yet had seen no menstrual discharge. Recently Leopold and Mironoff have made a most careful study of

5

[merged small][merged small][ocr errors][merged small]

the condition of the ovaries in relation to the period of menstruation. They examined the ovaries of forty-two women in whom the menstrual history was accurately known. In thirty cases they found that menstruation and ovulation occurred at the same time; in eleven cases there was no sign of ovulation connected with the last menstrual discharge, and in one case ovulation had evidently taken place in the middle of the intermenstrual period. Their conclusions were that:

1. Menstruation is usually accompanied by ovulation, but not seldom occurs independently.

2. Menstruation depends on the presence of the ovaries, and the proper development of the uterine mucous membrane, but is not dependent on the rupturing of the Graafian follicles.

3. Ovulation normally occurs at the time of menstruation, and needs several successive days of increased blood pressure in the ovaries; then it forms a typical corpus luteum.

4. Ovulation does occur, though seldom, independently of menstruation.

5. Often the delayed ovulation is due to the nonrupture of the unripe follicle. This forms a typical corpus luteum.

6. In the time of senile atrophy of the ovaries, normal follicles burst and form typical corpora lutea.

In view of these studies, if we estimate the duration of gestation as though ovulation took place at the time of menstruation, we probably will be correct; but we may be out by the entire menstrual period or any fraction of that time. That conception may take place either just after menstruation or just before the first missed period is commonly recognized, and used to explain the cases of apparently protracted pregnancies running just one month over the calculated time, and yet producing a not over-developed child. This possibility must always be considered in estimating the duration of the pregnancy.

46. Conclusions as to determination of exact duration.- In reference, then, to this uncertainty of the exact date of the beginning of pregnancy, a quotation from Auvard' seems appropriate: "Ce

7 Auvard, Travaux d'Obstétrique, t. two days, is to give one's self perfectly III., p. 358. "The vagueness which nat- useless work. Such an attempt will be urally surrounds the moment of con- fruitless until the day when, by new ception naturally reflects upon the de- means of investigation, we fix the termination of the duration of preg- moment of meeting of the male and fenancy. How is it possible to determine male elements; that is to say, of conthe duration of a condition of the com- ception. However, it seems that we may mencement of which one is ignorant? admit as an approximate and proTo discuss the period of pregnancy, and visional figure nine solar months, or 275 attempt to establish it within one or days. By allowing ten days leeway,

vague que enveloppe le moment de la conception rejaillit naturellement sur la fixation de la durée de la grossesse.

Comment dire la

durée d'un état dont on ignore le commencement? Discuter la longueur de la grossesse et essayer de l'établir à un ou deux jour près, est donc se donner une peine parfaitement inutile. Cette recherche ne deviendra fructueuse que le jour, où de nouveux moyens d'investigation, nous fixon sur le moment de la recontée des deux éléments mâle et femelle, c'est à dire de la conception. Jusque à cette époque, qui ne paraît pas devoir être prochaine, suspendons toutes conclusions. Tuotefois il semble qu'on puisse admettre comme chiffre approximat if et provisoire, neuf mois solaires, ou 275 jours. En laissant 10 jours d'alea, cinq avant et cinq après, on a la durée probable de la grossesse oscillant entre 270 et 280, neuf mois moins cinq ou plus cinq jours."

47. Mode of reckoning duration of pregnancy, in general.—The modes of reckoning the duration of pregnancy are various. In some cases we have nothing to guide us but the signs that can be elicited from examination of the woman: the size of the uterus, the condition of the breasts, or the other signs that develop progressively during the pregnancy. In these cases the estimate must be still more indefinite than if we could believe the woman's statement about the cessation of the menses, the quickening, or the insemination.

8

48. From sensations of woman at coitus.- Much reliance is placed by some women upon peculiar sensations experienced at the moment of conception. In some instances, they are no doubt thus enabled to calculate the probable duration of pregnancy with certainty. Dr. Reid says that he has occasionally met with cases in which this mode of fixing the exact time of conception proved, by the result, to have been correct; but that, in a much larger number of instances, the females were very considerably out in reckoning by trusting to this evidence. As a general rule, he says, "it will prove most fallacious, and in disputed cases of legitimacy it is of far too uncertain a character to rely on." We may add, that these sensations are undefined in their nature, are unperceived by a great many women, have no necessary connection with conception, and, if referred to at a late period in the pregnancy or after delivery, the evidence must be utterly unworthy of consideration. Hence, in questions of paternity,

five before and five after, we have the probable duration of pregnancy varying between 270 and 280 days. Nine months less five or plus five days."

On the Duration of Pregnancy in the Human Female, Reid, Lancet, Lond., 1850.

the sensations alleged to have been perceived at the time by the woman cannot be regarded.

In an indictment for bastardy the mother will not be permitted to decide which of the connections about the same time was the operative cause of conception." "The organs of conception, like those of digestion," said Chief Justice Lewis, "perform their appropriate offices without the volition of the female. She is not conscious, at the moment of the occurrence, of what has taken place. It is only by inference that she can fix the paternity of her offspring. If her intercourse has been confined to one individual, there is no difficulty in drawing a correct conclusion from the premises. But, if she has exposed herself to the embraces of several, at or about the time she became pregnant, she has placed it out of her power to draw any safe conclusions on the subject. Where two causes are shown to exist, either of which is adequate to produce the effect, and there are no circumstances to determine the mind in favor of either, the true cause must necessarily remain uncertain."10

49. From quickening.- Another mode of reckoning the duration of pregnancy is from the period of quickening. This sign also is of very little value for accuracy. While it usually occurs in the eighteenth to the twentieth week, it is not infrequently felt in the sixteenth week or even earlier; and on the other hand, often is not recognized till after the twenty-second week; and some women have maintained that they have felt no movements of the child up to the time of labor.

The usual method of reckoning is

The general rule of Naegele is

50. From cessation of menses. from the cessation of the menses. followed by most obstetricians. According to that we count ahead nine calendar months and add seven days to the date on which the last menses appeared.11 That computed date is the one on which labor may be expected; but a latitude of a week before or after that day must always be allowed to include the majority of the cases; only a very few will fall on that particular day. As a basis for that rule the period of gestation is taken as 280 days. Here it must be remembered that ovulation may be a month off from the appearance of the menstrual flow, as shown by Leopold's studies; also that pregnancy may begin after the menses have been suspended for some other reason for a longer or shorter period;12 and still further, the

'Com. v. Fritz, 4 Clark (Pa.) 219; Com. v. M'Carty, 2 Clark (Pa.) 351; Wharton on Evidence, 1299.

1°Com. v. M'Carty, 2 Clark (Pa.) 351.
"Williams's Obstetrics, p. 171.
"See 3, ante.

menses may continue during a portion, or even the entire pregnaney, 18 However, from what have been supposed normal cases, various writers have estimated the duration of pregnancy from the last day of the menses as follows :14

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small]

Reckoning from the first day of the menses, another group of writ

[blocks in formation]

Estimating a mean from these cases, Auvard finds the average duration of pregnancy from the end of the last menses to be from 275 to 282 days, with a minimum of 246 (Gaston), and a maximum of 328 (Auvard). Auvard also attempts to determine any variation as due to the number of pregnancies through which the woman has gone, the duration of her menstrual period, and the duration of her intermenstrual period. None of these have any definite relation to the length of the pregnancy in the large number of cases from which the means are taken in Auvard's work.

51. From ten monthly periods.-Lowenhardt, in 1872, brought forward again the theory of Harvey, that the duration of pregnancy is ten menstrual periods.15 He made observations on a number of women, noting the period of ten menses, and on that tried to explain the variations from the generally calculated period of 280 days. But following that we get no more accurate results than from Naegele's rule.16

52. From single coitus. In a certain number of cases it is possible to date the pregnancy from a single coitus; and here the dura

18 See & 3, ante.

14

Auvard, Travaux d'Obstét. III., p.

Archiv f. Gynäk., 1872, III., p. 456. 1 Williams's Obstetrics, p. 172.

« ÀÌÀü°è¼Ó »