What Is Pregnancy

PREGNANCY

Pregnancy occurs in a woman due to embeding or impregnation of a fertilised ovum or zygote, deep in the endometrium of the uterus. The ovum is fertilised in the isthmus of the fallopian tube within about 12 – 24 hours of ovulation and the fertilised ovum comes down in the uterine cavity by about the fourth day and its impregnation in the uterine wall occurs, after about 7 days, of fertilisation. The fertilised ovum is known as zygote and after impregnation it is known as embryo upto 8th week. After this period, it is termed as foetus. Pregnancy continues normally for 10 lunar months or 40 weeks, counting from the date of last cycle (9 calendar months ± 7 days from the date of start of L.M.P.).

Pregnancy may have extensive medicolegal implications. The medicolegal aspects may be concerning criminal or civil cases.

Medicolegal aspects of pregnancy –

A. Relating criminal cases-

PREGNANCY1. Execution of death sentence – When a pregnant woman is awarded capital punishment after being convicted in a criminal case, the execution of the punishment may be deferred until 6 months pass after the birth of the child of the pregnant convicted and condemned woman, so that, she can rear the child till that period. In some cases, the capital punishment may even be commuted to imprisonment.
2. When a woman due to advanced stage of pregnancy expresses her inability to with-stand the strain of trial in a criminal court, the trial of the case may be deferred to any future date as is felt reasonable by the court.
3. When pregnancy is claimed to be the result of rape, kidnapping and seduction.
4. Pregnancy in an unmarried girl of 16 yrs. or less and in a married girl of 15 yrs. or less point towards commission of the offence of rape.
5. A pregnant woman (unmarried) may bring a charge of criminal breach of trust against a man, who allegedly had intimate relationship with her (resulting in pregnancy), with promise to marry her.
6. When a woman claiming to be pregnant by a man, tries to blackmail him on social grounds.
7. Pregnancy of a woman, who had no access to her husband, within the reasonable period matching with the pregnancy, may be linked with a charge of adultery against the man, who is responsible for the woman’s pregnancy.
8. Pregnancy may be the cause of killing of an unmarried woman or a widow (Homicide).
9. Pregnant unmarried woman or widow may also commit suicide.
10. Question of pregnancy is intimately related with abortion or concealment of birth cases.

B. Relating civil cases –

11. Nullity of marriage – If at the time of marriage a woman is pregnant, then the marriage may be declared null and void.
12. If a woman had no access to her husband within the reasonable period matching with the duration of pregnancy then a decree of divorce may be allowed to the husband.
13. Inheritance of property – When pregnancy is followed by the death of the husband, the widow may claim a greater share of the ancestral property of the husband.
14. In divorce cases pregnant women are allowed higher maintenance allowance.
15. Compensation cases – Death of the husband of a pregnant woman may allow her a higher compensation.
16. Pregnancy beyond the scope of lawful wedlock makes the future baby illegitimate.
17. Working pregnant women are allowed additional leave facility.
18. A civil compensation case can be allowed for slanderous allegation of pregnancy against an unmarried woman or a widow.

Diagnosis of Pregnancy –

Diagnosis of pregnancy is ordinarily not difficult. But in medicolegal practices the diagnosis has to be full-proof. In contrast to the diagnosis for therapeutic purposes, where no litigation is involved and clinical steps can be taken according to the available signs and symptoms, the position of a medicolegist is somewhat different where assertion of pregnancy or its absence is expected to solve certain litigation and the opinion of the medical man in such a case has to be helpful for dear conception of the court of law. Accordingly, a man of Forensic Medicine prefers to categorise different signs as presumptive, probable and positive signs of pregnancy, so that he knows and can impress the court with due weightage about the chance of pregnancy in a woman.

A. Presumptive signs of pregnancy

Certain changes appear in the woman with pregnancy or within a short period after impregnation of the fertilized are mostly due to actions of certain hormones, exerting effects on different organs and metabolic activities of the body as well as due to mechanical causes.

1. Amenorrhoea – After ovulation, there is formation of corpus luteum at the site of the ruptured graffian follicle of the ovary concerned. Ordinarily, this corpus luteum regresses after subsequent menstruation. The function of the corpus luteum is to liberate certain hormones, which prepares the endometrium for impregnation of the fertilized ovum, which when occurs, keeps the functioning of the corpus luteum in increasing degree for some months and in presence of active corpus luteum, due to the hormones liberated from it, further ovulation and menstruation are prevented. Thus, amenorrhoea is one of the early signs of pregnancy. In most circumstances, a woman first presumes conception with the missing of one period. But amenorrhoea is not the result of pregnancy alone. In circumstances of hormonal imbalance, some pathology in the ovary and the uterus, chronic debilitated conditions like tuberculosis, carcinoma and psychological imbalance, menstruation may cease temporarily and with menopause permanently. There are several reasons for menstrual irregularities when one or two periods may be missed. Conversely, even after pregnancy a woman may bleed for up to 2-3 occasions, at intervals of her usual cyclic periods.

2. Changes in Breasts – In pregnancy breasts enlarge. In the early period there are tingling and tense feeling. On palpation, the hypertrophied alveolar ducts give a nodular feeling. The shape is pendulous. Surface veins are prominent. Silvery striae may appear later. Areola is enlarged, darkly pigmented with Montgomery’s tubercles (enlarged sebaceous glands). Nipples are enlarged and on 3rd month onwards yields secretion of colostrum on squeezing of breast and nipple. Colostrum is a pale yellow secretion which contains free fat globules and large phagocytes containing fat globules. Some of the changes in breasts may occur in conditions other than pregnancy, like ovarian tumour.

3. Morning sickness – A general feeling of indisposition, during the early hours of the morning is a common occurrence after pregnancy. This constitute of lethargy, weakness sometime with feeling of heaviness in hands and legs.

4. Vomiting – Mild degree vomiting and nausea is a common phenomenon in all cases of pregnancy, particularly during the early morning hours. In some pregnant women, however, there may be excessive vomiting, a condition known as hyperemesis gravidarum.

5. Pigmentation of selective parts of the skin- The eyelids, the axilla and the areola of the breast darken during pregnancy.

6. Appearance of linea nigra – A vertical pigmented line appears over the midline of the abdomen, from umbilicus to symphysis pubis.

7. Striae gravidarum – Multiple transverse or oblique stripes appear over abdomen, including the flanks which are the result of fibrous change in the tissue, which occurs due to over-stretching of the abdominal wall. These may however, be present in any case, where the abdomen bulges out as in ascitis, abdominal particularly pelvic tumours and may even be seen in extremely obese women.

8. Increase in the frequency of micturition This occurs in 2 phases of pregnancy. During the first trimester, when the uterus enlarges in size, it exerts pressure over the urinary bladder and there is increase in the frequency of micturition. As the uterus enlarges further, and rises up to be accommodated in the abdomen, this symptom passes off temporarily for some months. But during the last months of pregnancy, when the uterus drops down, it again exerts pressure on the pelvic contents, including the urinary bladder, causing recurrence of increase in urinary frequency.

9. Easy fatigueability and irritable temperament are some of the additional non-specific symptoms of pregnancy.

10. Perverted desire for spicy food may be noticed from very early period.

11. Quickening – Foetal movement inside the uterus starts and is appreciated between 16th and 18th week in multigravida and between 18th and 20th week in primigravida. This is known as, quickening and the women, during this period is designated as “Quick with child.” It is appreciated earlier in multi, in comparison with primi due to the former’s previous experience, whereas, the latter takes some more time to appreciate this feeling as foetal movement. Peristaltic movement occasionally may be confused with movement of the foetus. Quickening has special medicolegal importance in that, if criminal abortion is caused in a woman, who is quick with child then the duration of punishment of imprisonment is increased and may extend up to 7 yrs.

12. Jackquemier’s Sign – This is a change in the vagina, the mucous membrane of which alters from pink colour to violet or bluish, which occurs due to venous obstruction. There is also simultaneous softening of the vaginal wall with increased secretion. These changes are noticeable after 4th week of pregnancy.

B. Provable signs of Pregnancy

1. Enlargement of the abdomen – With increase in the size of the foetus and the uterus, the abdomen enlarges. But this does not occur until the duration of pregnancy is 12 weeks. Because, till this period, uterus remains in the pelvis below the level of the symphysis pubis. Then gradually the abdomen enlarges as the height of the uterus increases. The enlargement of the abdomen occurs for the rest of the period of pregnancy, though during the last month the uterus drops to some extent with lowering of the height. Enlargement of abdomen, is an important and essential change due to pregnancy but it is not specific of pregnancy. It may also occur due to ascitis, due to any tumour in any organ inside the abdomen, or may be even due to rapid obesity.

2. Height of Uterus – The increase in the size of the uterus follows more or less a definite rule during the period of pregnancy. Up to the 12th week of pregnancy, it is not palpable per abdomen. At the end of the 12th week however it may be just palpable above the symphysis pubis. After 16th week, it is 2″ above the symphysis pubis. At the end of the 5th week, it is 2″ below the umbilicus. At the end of 24th week, it is at the level of the umbilicus. At the end of 28th week, it is 2″ below the xiphisternum. At the end of 36th week it is at the level of xiphisternum. At full term, it is again 2″ below xiphisternum.

3. Hegar’s Sign – During the 2nd month of pregnancy, the body of the uterus becomes soft. The cervix remains comparatively firm. Hegar’s sigh is elicited by bimanual examination. 2 fingers of one hand is placed at the posterior fornix and fingers of the other hand is placed over midline, just above the svmphysis pubis. Finders of both the hands are brought closer, when the isthumus, part of the uterus is appreciated as soft compressible zone in between the very soft uterine body and firm and tough cervix below. Hegar’s sign becomes positive by the end of 6th week of pregnancy.

4. Anteroversion of Uterus – Uterus is usually anteroverted and this anteroversion increases during the first few months of pregnancy. The degree of anterior inclination decreases during the later phase.

5. Goodell’s sign – By the 4th month after pregnancy, the cervix is reasonably soft. This change starts occurring from the later part of the 2nd month and reach its optimum by the 4th month. By this time the external os is slightly enlarged in diameter. The change may occur in inflammatory condition of uterus and in case of new growth in the uterus.

6. Uterine Souffle – With increase in the size of uterus and the foetus inside, the circulation of blood in uterus is also increased. This increase in circulation causes flow of more amount of blood inside the uterus through the uterine vessels and thus, when the lateral aspects of fundus is auscultated, murmur is heard, which synchronises with the mother’s pulse beat.

It becomes appreciable from the end of 4th month. This type of sound may also be heard with the help of a stethoscope, when there is increased blood supply in the uterus due to any reason, like a new growth inside the uterus.

Uterine souffle must not be confused with foetal heart sound, which is more rapid in its rate and does not synchronise with the mother’s pulse.

7. Ballotment – Internal and External ballotments are objective signs of pregnancy, which can be elicited during the 4th or 5th month of pregnancy. Ballotment tests may be performed by external means as well as internal means. Accordingly, the tests are termed as internal ballotment test and external ballotment test. In ballotment test, actually the foetus is tossed in the amniotic fluid. In external ballotment test, grip of 2 fingers is applied over the lower part of uterus, the woman being in semi-inclined position. As the foetus takes lowest position inside the uterus, in this posture of women, it is closer to the fingers. By exerting thrust with the help of the fingers, the foetus can be made to move up in the amniotic fluid, just as a ball can be tossed up. After a while the foetus resettles again in the lower part of the uterus. In internal ballotment, the test is performed by pressing 2 fingers on 2 sides of the fornix and imparting a force for the upward movement of the foetus, which also resettles at the lower part of the uterus after a while. This test gives satisfactory positive result by 4th or 5th month of pregnancy when the quantity of amniotic fluid is comparatively more and in the amniotic fluid the foetus can thus be made to move freely. After 5th/6th month, these tests cannot be elicited in a good number of cases due to proportionate decrease in the quantity of the. amniotic fluid, in comparison with the size of the foetus. The test will give a negative result, if the quantity of amniotic fluid is less.

8. Braxton-Hick’s sign – After 15 -16 weeks of pregnancy, there is intermittent contraction and relaxation of uterine muscles. The duration, of each contraction is for about a minute and the duration of relaxation is for about 5 minutes. The contraction is not a forceful one and is painless. Intermittent contraction may also occur due to other reasons of enlargement of uterus, including soft new growth.

9. Test for human chorionic gonadotropin in the urine – In case of pregnancy, there is secretion of HCG, at placental level. Thus, HCG can be detected in the pregnant woman’s serum and urine. It becomes detectable by the 2nd week of pregnancy and its concentration increases gradually with progress of gestation. The test for chorionic gonadotropin may be positive even up to 1 week after termination of pregnancy.

Methods

Biological tests for H.C.G. –

Human chorionic gonadotropin stimulates ovulation and spermatogenesis. This action of HCG is utilised for testing presence of pregnancy and the tests are known as biological tests for pregnancy.

(a) Aschheim-Zondek Test – This is the classical biological test, which has been substituted by other biological tests for pregnancy. In Aschheim Zondek test, immature female albino mouse of about 3-4 weeks old are used. About 3 – 4 ml of filtered morning urine (morning urine is most concentrated in all its constituents) of the woman said to be pregnant is injected subcutaneously, in the mouse, twice daily for 3 days. After lapse of another day, the mouse is sacrificed and the ovaries are searched for a haemorrhagic graffian follicle or corpus luteum, the presence of which is strongly indicative of pregnancy in the woman.

Disadvantage of the test –

1. It takes about 5 days for completing the test,
2. In each case, one animal has to be sacrificed.

(b) Rapid rat test – 2 ml. of the filtered morning urine of the woman is injected intra-peritoneally in immature female albino rats. The rat is killed sometime after 4-5 hrs. Extreme congestion of the ovaries indicates presence of HCG in the urine.

Disadvantage – Sacrifice of the animal is a disadvantage for this test also.

(c) Friedman test or Female rabbit test – An immature female rabbit of about 3 months old is selected and 5 ml of filtered morning urine of the woman is injected in the vein of its ear for 2 consecutive days and on the 3rd day the rabbit is killed and the ovaries are searched for presence of hemorrhage or ruptured graffian follicle, which indicates pregnancy in the woman.

Disadvantage – Here also the test takes 3 days time for completion and one animal has to be killed for each test.

(d) Hogben test or Female toad test – Matured female xenopas toad lay eggs anytime when stimulated for the same and if it gets a moist place for laying eggs, HCG acts as the alternative of mating as a stimulus. About 5 ml of the morning urine of the woman is injected in the dorsal lymph sac of the toad and it is kept confined with a bell-zar or some such thing, on a moist place. If the urine of the woman contains HCG, then the toad ovulates within 8 – 10 hours.

Advantage – 1. This test has an advantage over the 3 tests described above. Here the animal is not to be sacrificed on completion of the test. The toad can be used for several tests, each time after effect of HCG is over. 2. It takes moderate time for completion of test of pregnancy.

(e) Galli mainini test or Male toad test It is the most popular one of the biological tests for pregnancy. Rana tigrina and Rana hexadactyli are the two varieties of male toads, which are most suitable for the test.

Recognition of the male toad – The male toads of these varieties have a yellowish brown band on the ventral aspect of their necks. During mating, these toads can puff up the air sac at the posterior part of the fauces to produce attracting sound for the female.

Preparatory testing of the toads –

The above two described features also speak for the maturity of the toad. In addition, before subjecting these toads for HCG tests their cloacal urine is examined under microscope. If the cloacal urine contains spermatozoa then, the toad is unsuitable for the test and is rejected. If the cloacal urine is free from spermatozoa then the toad is injected with 5 ml of filtrated morning urine of the woman in its dorsal sacs. After an hour or two, another sample of cloacal urine is taken and is subjected to microscopical examination. If the urine which was free from spermatozoa before injection, shows presence of spermatozoa after 1 to 2 hours of injection, the presence of HCG in the urine of the woman is indicated and pregnancy is strongly suspected. To infer a result, another sample of cloacal urine after another 2 hours should be examined.

Advantages – 1. Time necessary for completion of the test is reasonably short. 2. The same animal is ready for the next test again just after about 24 hours.

Disadvantages – To be precise, the positive result of the test is only strongly indicative of presence of HCG in. the urine and is not confirmatory of pregnancy. In addition to pregnancy, this test is also positive in case of hydatidiform mole and chorion epithelioma. To exclude these two possibilities, instead of concentrated urine, dilute urine in different gradations of titration may be used, when we get positive result with high dilution of urine then, that is suggestive of hydatidiform mole or chorionepithelioma.

Serological tests for pregnancy –

(a)Haemagglutination inhibition test –

Materials required – (i) RBC, sensitized to antibody of HCG hormone, (ii) Anti HCG factor (Antibody), (iii) Morning urine sample of the supposedly pregnant woman.

The test is performed in a tube. i and ii are mixed in a test tube of 5 mm diameter (often an ampule containing i and ii in dried states is used, which has a circular ridge at the bottom). If the woman is pregnant and her urine contains HCG then, on addition of urine in the tube the antibody i.e. anti HCG factor will be neutralised and the cells (RBC) will then, gradually settle at the bottom around the ridge making a reddish circle. If there is no HCG in the urine then the anti HCG factor will not be neutralised and it will cause dumping or agglutination of the R.B.C.s, which are sensitised against anti-HCG hormone and there will be no red ring formation at the bottom.

(b) Direct agglutination test for presence of HCG in urine with latex particles – Latex particles are coated with anti HCG antibody. This is taken on a glass slide. Then 1 drop of morning urine of the woman is added to it. In case of pregnancy, the urine containing HCG hormone will react with the anti HCG antibody on the surface of the latex particles and there will be clumping of the particles.

(c) Indirect agglutination inhibition test – In this test, the latex particles are coated with HCG. The morning urine is first treated with anti HCG antibody. To this mixture above mentioned latex particles coated with HCG hormone is added. If the urine of the woman contains HCG due to pregnancy, then that will neutralise the anti HCG antibody after initial mixing of the two. If the urine does not contain HCG, then anti HCG antibody remains active and when the latex particles coated with HCG hormone are added at the 2nd stage of the test, then due to the active antibody present, there will be agglutination of the latex particles.

The serological tests are easy to perform and are more reliable than biological tests because the chance of error due to biological variability in animals are not there in serological tests. These, tests are also positive in hydatidiform mole or chorionepithelioma cases. In these conditions, the amount of HCG hormone excreted through urine is very high. Hence, the tests become positive with highly diluted urine which does not occur in case of urine of pregnant women.

(d) Radio immunoassay and ELISA test can also detect pregnancy with high degree accuracy (but chance of error cannot be eradicated completely).

C. Positive signs of Pregnancy

1. Auscultation of foetal heart sound – Foetal heart sounds are detectable after 18 – 20 weeks of pregnancy. The rate of foetal heart beat is about 160/mt at the early phase and about 120/mt near the terminal phase of pregnancy. Their location on the mother’s abdomen varies according to the intrauterine position of the foetus. F.H.S. is not synchronous with mother’s pulsation. So the two can easily be differentiated.

Even when there is pregnancy, foetal heart sound will be absent – (a) before 18 weeks of pregnancy, (b) when the foetus dies inside the uterus ; and it may not be audible in, (c) very obese women and in (d) hydramnios cases where there is excess of liquor amnii.

2. Palpation of foetal parts per abdomen is a positive sign of pregnancy from 4th month onwards.

3. Perception of foetal movement is possible from 5th month of pregnancy.

4. Shadows of foetal bones by X’ray examination are available after 3rd month, when in X’ray plates skull shadow appears crescentic. Similarly, beaded appearance of vertebral column and ladder like arrangement of ribs and shadows of limb bones are also diagnostic.

5. Ultrasonography – This can diagnose pregnancy of 6th week duration and more.

Signs of pregnancy in dead subjects –

In dead subjects, in addition to external physical changes, internal examination shows : ‘(i) An enlarged uterus, (ii) A corpus luteum in an ovary in its progressive or regressive phase, (iii) Product of conception, either in the form of an embryo with decidual changes in the endometrium or, in the form of a foetus, placenta, etc.

Superfoetation – This is a type of twin pregnancy where, during the continuation of pregnancy an ovum is liberated in a subsequent cycle which gets fertilised followed by progressive development of both the fertilised ova. In such a condition one foetus always remains more matured and developed than the other. Delivery of both foetuses may occur in a single labour when one baby is perceivably larger and more developed than the other, or very rarely delivery of the younger foetus occurs at a later period after being fully matured. Some do not agree with the existence of the condition of superfoetation. According to them, what happens in reality is that in twin pregnancy when one foetus gets more blood supply and more nutrition, it develops more rapidly and grows larger in comparison to the other. Possibility of superfoetation is more in septate or double uterus cases. The period of gap between the fertilisations varies between 1-3 months.

Superfecundation – In cases, where two ova are discharged at a time in one ovulation period, the two ova may be fertilised by sperms of two different acts of coitus, occurring within a short period. The two fertilised ova grow simultaneously, though one may grow larger at the cost of the other. There being two placentas, circulation through one placenta may be better than the other.

Medicolegal aspects of superfoetation and superfecundation – These conditions are essentially twin pregnancies and being essentially the product of two separate sexual contacts, gross variations between the complexion and other features in the appearance of the two babies after birth gives rise to the doubt of adultery and infidelity and the paternity of either or both the babies may be disputed.

Foetus papyraseous or compressus – In twin pregnancy, one foetus may grow and develop more at the cost of the other. The latter may eventually die and get compressed and flattened gradually. Such a foetus is termed as foetus papyraseous or foetus compressus.

PSEUDOCYESIS – This means false or spurious pregnancy, when the woman believes that she is pregnant. She presents all or many subjective signs (symptoms) of pregnancy which are often accompanied by enlargement of abdomen due to disposition of fat or some pathological condition, e.g. an ovarian tumour. The woman may have imaginary or false feeling of movement of the “foetus” inside. If not diagnosed earlier, the condition may continue for about the full period of a pregnancy and the woman may even have false labour pain. All the symptoms vanish once the woman is informed that she is not pregnant. Pseudocyesis is seen in women who strongly desire for a child or who are afraid of being pregnant. Hence, it may occur both in young women or women who are close to or have just achieved their menopause.

Pregnancy without knowledge of the pregnant woman – Just in contrast with the condition of pseudocyesis, a pregnant woman may be ignorant of her pregnancy and may even go to labour without clear of knowledge of the same beforehand.

Maximum and Minimum period of pregnancy – Though normal period of gestation is about 280 days, a woman may over-carry the foetus to postmaturity up to the extent of a total period of gestation of more than 320 days and even up to about 350 days, with the foetus being alive and a live-birth being possible up to that extent.

Expulsion of prematured foetus may occur at any period before full term. But to have a live-birth of a viable foetus, delivery should occur after 210 days of pregnancy. Foetuses born alive, after 180 days of pregnancy may survive if proper care can be taken. Below this period of gestation also, foetuses born alive have survived but the chance for the same remains remote.

Viability of a child means, capability of a foetus to lead a separate life after birth. Ordinarily, a foetus becomes viable after 210 days of pregnancy but foetus born alive earlier can also be made to survive with proper care.