by Anne on May 24, 2010
Cycling Woman Gloves
The team’s abortions and miscarriage are synonymous and denote the expulsion of the conceptus before the end before the end of 28th week of pregnancy. There is no sharp demarcation between late abortion and early premature labour; the division is merely one of descriptive convenience.
After the 28th week delivery of the fetus is considered to be viable. Before the end or 28th week delivery of the fetus is only notifiable in Britain if it is born alive, whereas all deliveries after that time must be notified.
Causes of abortion
Despite a long list of aetiological factors, in may cases the cause of a particular abortion is uncertain .the known causes include:
1. Malformation of the zygote. The commonest cause the cause of a particular abortion is an abnormality of the fetus or chorion which is server enough to cause fetal death. About 70 per cent of these are caused by chromosomal abnormalities, for which either percent may be responsible, although they mostly abortion of this type are not recurrent , so that the prognosis in later pregnancies is good unless several abortion of identical pattern have already occurred.
In some cases it is found that the amniotic sac dose not contain an embryo, a condition formerly described as a `blighted ovum`, but now as anembryonic gestation.
the chromosomal material is derived from the sperm. Partial molars have a triploid
chromosomal pattern .
2. Immunological rejection of the fetus. Many investigation of the immune responses of the mother to her fetus are now in progress .There is some disagreement about the results, but it appears that trophoblast shares some antigens with maternal lymphocytes. These cross-reactive (TLX) antigens are partly linked to other antigens. It is postulated that the mother mounts an antibody response against the TLX antigens, and this also protects the trophoblast from attack by failure of this mechanism, and this also protects the trophoblast from by failure by linked antigens. Some cause of recurrent abortion may be caused by failure of this mechanism, and injection of donor lymphocytes to stimulate the response has been proposed.
3. Genral disease of the mother. Pregnancy will often continue in spirit of maternal disease , but any illness may cause abortion if it is sufficiently sever, especially acute fevers. Maternal infection may involve the fetus, particularly rubella and syphilis, but also rarely malaria, brucellosis, toxoplasmosis, cytomegalic inclusion disease and listerosis.
In a few cases of rubella abortion occurs, but more often the infected fetus is born alive. Syphilis dose not early abortion, and it is an uncommon cause of late abortion; it is more likely to cause intrauterine fetal death after 28th week .
In diabetes the abortion rate is above average if the disease in not adequately controlled.
With hypertension and renal disease intrauterine fetal death may occur sometimes before the 28th week.
Server malnutrition will cause abortion, but it has to be of a degree which is unlikely to be seen in Britain. Although deficiency of vitamin E will cause abortion in experimental animal there is no evidence that it causes in woman as this substance is always present in adequate amount in the diet.
4. Uterine abnormalities. The incidence of abortion is increased if the uterus is double or septate, but in much such cause pregnancy is uneventful.
Retroversion of the uterus a cause not a cause of miscarriage, except in rare instances in which the uterus become incarcerated and is left untreated.
A fibromyoma of the uterus which is closely related to the cavity of the uterus may cause abortion, but other fibromyoma will not do so.
Laceration of the cervix which extend as far as the internal os may result in abortion in the middle trimester or in premature labour .Very rarely the cervical weakness is congenital; usually it is the result of obstetric damage or of injudicious surgical dilatation of the cervix. During pregnancy the unsupported membranes bulge through the cervix and rupture, when miscarriage follows.
5. Hormonal insufficiency. It is has been claimed that insufficient production of progesterone by the corpus luteum before the placenta is fully formed will lead to inadequate of the deciduas and abortion.
The evidence for this weak (see p. 286).
Both thyroid deficiency and hyperthyroidism may be contributory causes of abortion.
6. Drugs. Cytotoxic drugs or poisoning with lead may cause fetal death and abortion. Oxytocic drugs have been used to procure abortion; quinine, ergot and prostaglandins are sometime used as abortifacients, although the doses employed may have serious side effects.
7. Trauma. Server trauma to the uterus may cause detachment of the embryo, and this may also be caused by insertion of instrument or foreign bodies through the cervix. Abortion may follow surgical operations, for example myomectomy, and may also follow by condition complicated by server peritonitis.
In a normal pregnancy coitus has no ill effect, but it is unwise in the cause of woman with a history of abortion in a previous pregnancy.
8. Acute emotional disturbance. Such as fright or bereavement may be followed by abortion , presumably because strong uterine contraction occurs. For such a cause to be accepted in a particular case the miscarriage must follow immediately upon the incident.
In the first 2 months of pregnancy of the embryo to the deciduas is so slight that separation may follow strong uterine contractions; more often the immediate cause of abortion is haemorrhage into the choriodecidual space. The exact cause of the haemorrhage is often unknown, but as result of it embryo become partly or completely separated from the deciduas.
Inmost cases the decidua basalis remain in the uterus, and the embryo with the whole or part of the decidua capsulair is spelled. Sometimes only the decidua caosularis is torn through and the embryo, surrounded by chorionic villi, is expelled; or the chorion and amino may be tore and then the fetus escapes uncovered.
Later, when the placenta is a definite structure, the fetus is usually expelled first , followed by placenta and membranes, but it is common for the small placenta to be retained, with continuing haemorrhag. Bacterial invasion of the retained products may occur.
An abortion is a miniature labour; the uterus contracts rhythmically, the cervix dilates
and when the internal os is sufficiently open, the embryo is expelled, completely or incompletely. If the embryo is entirely expelled, the contraction cease of a few days but eventually ceases, and the uterus involutes as it dose after normal labour.
In some cases of incomplete abortion a piece of placental tissue may remain in the uterus
because it is fixed at its base. Laminated layers of blood clot from upon it, is fixed at its base .A blood the clot into a polypoid mass, and described as a fibrinous or placental polyp.
Clinical varieties of abortion
The following terms are used to describe the clinical varieties:
1 . Threatened abortion 5 . Septic abortion
2 . Inevitable abortion 6 . Missed abortion (carneous mole).
3 . Complete abortion
4 . Incomplete abortion
1. Threatened abortion
In threatened abortion there is bleeding into the choriodecidual space but not of sufficient extent to kill the embryo. There are no painful uterine contractions and the cervix does not dilate.
The decision whether abortion is only threatened or is inevitable is important but often uncertain. Abortion dose not away occur even after repeated attacks of quit sharp bleeding, and it is not very unusual to meet cases in which haemorrhage has continued for some time and yet a health child has been born at term. These cases should, however, always be regarded seriously, since at any time profuse bleeding may occur and the abortion will then become inevitable. If bright red loss continues and increases in amount the prognosis is bad. A single bright loss followed by escape of old brown altered blood means that the initial loss has ceased. It is not uncommon in threatened abortion for such dark loss to go on for several days’s gradually diminishing in amount.
The partient is kept at rest bed (except for visits to the lavatory) until 2 days after red loss has ceased. Intercourse is forbidden. All pads and anything passed must be saved for examination, as this will assist diagnosis and avoid time -wasting conservative treatment if products of conception are seen. if the patient is restless and anxious a mild sedative may be given , but otherwise it is no value.
Opinion differs about the extent to which these patients should be examined. Much woman fear that an internal examination will increase the risk of miscarriage, but gentle examination and passage of a speculum have the advantage that any unexpected cause of bleeding such as a cervical polyp or even a carcinoma may be found, and that any dilatation of the cervix will be noted.
As Soon as the initial bellding has stopped an ultrasonic scan is performed .This will reveal whether or not the pregnancy is intact. Demonstration of an embryo with cardiovascular pulsation is essential, for even if an embryo is present it cannot be concluded that it so viable without this. With a high resolution real time mechanical sector scanner cardiac activity can consistently be recognized at 8 weeks. Demonstration of an empty gestation sac after 8 weeks is reliable evidence of absence or death of the embryo. Routine scanning of patients with threatened abortion has shown that a common cause of bleeding in the first trimester is a twin pregnancy for the surviving twin is good.
If the abortion is complete the uterus is indistinguishable from a normal non-pregnant uterus.
When a threatened abortion has settled down the patient should be reassured that the bleeding has not harmed the developing embryo (although the obsterician should near in mind the possibility of placental insufficiency in late pregnancy).
2. Inevitable abortion
A threatened abortion become inevitable when the bleeding increases greatly and uterine contractions become rhythmic and strong. The cervixes then begin to dilate and products of conception may sometimes be felt through the internal os. Before the 12th week it is quit common for the entire contents of the uterus to be extruded, and for the abortion to become complete. After the 12th week the membranes often rupture and the fetus is passed leaving the placenta behind, and then all the complication of incomplete abortion may arise.
Inevitable abortion, entopic pregnancy and some cases of hydatiform mole all present with the triad of pain, vaginal bleeding and amenorrhea. Both entopic pregnancy and early abortion are associated with a short period of amenorrhoea followed by irregular uterine haemorrhage. The duration of amenorrhoea in cases of entopic pregnancy before the patient has severe pain is usually short, and is almost invariably less then 10 weeks.
In abortion the bleeding is usually bright red, often accompanied by clots, and is more profuse then in entopic gestation in which the bleeding tends to be dark red or brown .
Vaginal bleeding in entopic pregnancy is usually preceded by sever abdominal pain, which start low down in one iliac fossa but rapidly spread across the lower abdomen. In abortion the pain is not so sever and occurs after the onset of bleeding; it is intermittent like labour pains.
In all cases of ectopic pregnancy except those with complete tubal rupture (in which the diagnosis of severe intraperitoneal bleeding with shock and generalized abdominal tenderness is usually obvious) there is a tender swelling to be felt separately from the uterus is unduly, which is either a tubal mole or a haematocele . If there any doubt, ultrasonic scanning or laparoscopy may be required.
Hydatidiform mole may be management of labour on a small scale. The uterus is unduly large, and the diagnosis can be confirmed by ultrasound or the finding of high levels of chorionic gonadotrophin in material urine or serum.
This can be summarized as the management of labour on a small scale. The uterus usually expels its contents unaided. Any examination must be made with strict aseptic technique. If the abortion is not quickly complete, or if haemorrhag become sever, the contents of the uterus are removed with a suction curette. Analgesics such as pethidine
100mg may be injected, and if bleeding is heavy ergometine 0.5 mg. Unless the patient is known to be rhesus positive she should also be give 100ug of anti-D gamma globulin.
3. Complete abortion
A complete abortion is one in which all the products of conception have been expelled. On examination, pain is absent and bleeding is slight and decreasing. The uterus is smller
then the period of amenorrhoea would suggest, and the cervix may be only slightly open. If the material passed has been saved for examination, it will be found that the whole of the conceptus is present.
Once the pain has ceased and the bleeding is minimal no further treatment is needed, but the patient should be warned to report at once if pain or bleeding recurs, or if she develops a temperature suggesting that there are retained product of conception which have become infected. Anti-D globulin is given (as above).
4. Incomplete abortion
This means that part of the products of conception, usually the fetus, has been passed but part, usually the placenta, has been retained. The amount of bleeding varies, but can be severe and accompanied by dangerous shock. It is possible for a woman to bleed so severely that within a few hours the haemoglobin level drops to 5g/ 100 ml. If there is still bleeding a week after an abortion which was thought to be complete it is in fact incomplete.
Treatment is is directed to preventing infection, controlling bleeding and obtaining an empty and involuted uterus. The chief risks associated with retained products are haemorrhage and sepsis, and it is unwise to leave a piece of placenta in the uterus for any length of time in the hope that it will be expelled.
If the bleeding is sever there may be shock. If a patient is moved to hospital before the shock is treated, it may increase to a dangerous degree during the journey. Such patients require immediately first aid, and a mobile emergency unit should be called upon to to administer blood in the woman’s home before the amoulance takes the patients to hospital. The blood pressure is monitored and ergometrine 0.5 mg should be given at once by intravenous injection. Even if the uterus is not empty, if the bleeding will often be reduced by the ergomenrine, although its action on the uterus is less early then in late pregnancy. Occasionally, bleeding persists because a large piece placenta is held in the cervical canal; the removal of this under direct vision, using a sterile speculum and sponge forceps, will allow uterine retraction and uterus the bleeding. The foot of the bed is raised and morphine 15 mg may be injected .when the blood pressure has reached a more normal level the patient is moved to hospital. There she is given an anaesthetic and the uterus is emptied by the gloved finger, suction curette or sponge forceps. The cervix will usually be open and will not need dilation. Ergometrine 0.5 mg is injected intramuscularly as soon as the uterus has been emptied. Anti-D globulin is given unless the patient is known to be rhesus positive.
In the same cases an incomplete abortion is not associated with severe bleeding, but the haemorrhage continues intermittently for same weeks and is due to a fibrinous polyp (p.165). The uterus remains bulky and the cervix is slightly dilated. Surgical evacuation of the uterus is then essential. Sometimes it is difficult to decide whether prolonged irregular bleeding after a miscarriage is due to a fibrinous polyp or to complete abortion followed by anovular bleeding from the endometrial, which may occur before the normal cycle is re-establish. In either event curettage is required, and histological examination of the material evacuated completes the diagnosis.
5. Septic abortion
The uterine cavity may become infected an abortion even beings, as a result of a criminal attempt to procure abortion by passing and unitarily instrument through the cervical canal. The patient has suprapubic pain and an increased temperature and pulse rate. There may be little bleeding or uterine contraction, and the cervical canal may remain closed. There may be abdominal rigidity and the uterus is very tender on bimanual examination.
In other cases infection follows incomplete abortion, and the symptoms and signs vary in severity.
The commonest infecting organisms in Britain at present are staphylococcus aureus, coliform and bactericides organisms, and clostridium welchii.
Formerly streptococci, both aerobic haemolytic and anaerobic, were often found. The most dangerous infection are now those with Gram-negative organisms which may cause endotrxic around the uterus, causing pelvic or blood stream to cause septicemia.
All cases are admitted to hospital. When the patient is first seen a speculum is passed and a swab is used to collect some discharge from the cervical canal, and a blood sample is taken. These are sent to the laboratory immediately for microscopy and culture and to determine the sensitivity of any organisms to antibiotics. There is much debate about the best choice. One combination that may be used is ampicillin 500mg 6-hourly with metronidazol 400mg 6-hourly by mouth. When the bacteriological report is available, treatment is reviewed. It is wise to continue antibiotic treatment for at least 5 day after the temperature has returned to normal. In case of incomplete septic abortion the treatment will partly depend on the amount of bleeding. If this slight, evacuation of the uterus can be deferred for 24 hours to allow time for antibiotic action, but any pieces of tissue lying in the cervical canal should be removed with sponge forceps; the escape. However, in many cases amount of bleeding is such that evacuation cannot be intramuscular injection of ergometrine 0.5 mg will assist in controlling bleeding.
In cases of septic abortion of more then 14 weeks gestation, if the dead fetus is retained an infusion of prostaglandins or oxytocin may be given in the hope of spontaneous delivery.
Laparotomy is always a desperate venture in these cases, but may be indicated if the vaginal vault has been lacerated or the uterus perforated. This may be certain if a radiograph show gas under the diaphragm or if there are signs of free fluid in the peritoneal cavity after a syringe has been used. Cases of clostridia infection require special mention. Dead placental tissues and blood clot are excellent media for the growth of anaerobic organisms. Some of these patients, usually after criminal interference, are desperately ill, with a pulse rate of over 140 per minute and a subnormal temperature. They are severely anaemic, because of haemolysis as well as blood loss, and they may be jaundiced. When clostridial infection is suspected on clinical or bacteriological ground, massive doses of penicillin are given. Any dead placental tissues should be removed surgically as soon as possible. If there is no blood transfusion and antibiotics, the possibility that the uterus has become gangrenous should be borne in mind. Hysterectomy is then indicated. Hyperbaric oxygen is used if it is available.
In all cases of septic abortion a careful watch is kept on the urinary output. Renal cortical or tubular necrosis may sometimes occur.
Another dangerous complication of septic abortion is circulatory failure due to peripheral vasodilatation caused by endotoxins released from coliform organisms which have invaded the blood stream.
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