Abnormal
Pregnancy
Miscarriage (Spontaneous Abortion)
Note to readers from
the Brookside Associates:
Although this page faithfully
reproduces the original Operational Medicine 2001, there is a
better (updated, with pictures) version of it in
Military Obstetrics & Gynecology. |
Miscarriage is the layman's term for spontaneous abortion, an unexpected 1st trimester
pregnancy loss.
Since the term "spontaneous abortion" may be misunderstood by laymen, the
word "miscarriage" is sometimes substituted.
Abortion
Loss of a pregnancy during the first 20 weeks of pregnancy, at a time that the fetus
cannot survive. Such a loss may be involuntary (a "spontaneous" abortion), or it
may be voluntary ("induced" or "elective" abortion).
Abortions are further categorized according to their degree of completion. These
categories include:
- Threatened
- Inevitable
- Incomplete
- Complete
- Septic
Such losses are common, occurring in about one out of every 6 pregnancies.
For the most part, these losses are unpredictable and unpreventable. About 2/3 are
caused by chromosome abnormalities incompatible with life. About 30% are caused by
placental malformations and are similarly not treatable. The remaining miscarriages are
caused by miscellaneous factors but are not usually associated with:
- Minor trauma
- Intercourse
- Medication
- Too much activity
Following a miscarriage, the chance of having another
miscarriage with the next pregnancy is about 1 in 6. Following two miscarriages in a row,
the odds of having a miscarriage with the next pregnancy is still about 1 in 6. After
three consecutive miscarriages, the risk of having a fourth is greater than 1 in 6, but
not very much greater.
Threatened
Abortion
A threatened abortion means the woman has experienced symptoms of bleeding or cramping.
At least one-third of all pregnant women will experience these symptoms. Half will go
on to abort spontaneously. The other half will see the bleeding and cramping disappear and
the remainder of the pregnancy will be normal. These women who go on to deliver their
babies at full term can be reassured that the bleeding in the first trimester will have no
effect on the baby and that you expect a full-term, normal, healthy baby.
Treatment of threatened abortion should be individualized. Many obstetricians recommend
bedrest in some form for women with a threatened abortion. There is no scientific evidence
that such treatment changes the outcome of the pregnancy in any way, although some women
may feel better if they are at rest. Other obstetricians feel that being up and active is
psychologically better for the patient and will not change the risk of later miscarriage.
Among these active women, strenuous physical activity is usually restricted, as is
intercourse.
In an operational setting, bedrest may prove very useful. While you are not changing
the outcome of the pregnancy (abnormal chromosomes will remain abnormal despite increased
maternal rest), you may effectively postpone the miscarriage until a safer time. (days to
possibly a week or two)
Complete
Abortion
A complete abortion means that all tissue has been passed
through the cervix.
This is the expected outcome for a pregnancy which was not
viable from the outset. Often, a fetus never forms (blighted ovum). The bleeding and
cramping steadily increases, leading up to an hour or two of fairly intense cramps. Then
the pregnancy tissue is passed into the vagina.
An examination demonstrates the active bleeding has slowed
or stopped, there is no tissue visible in the cervix, and the passed tissue appears
complete. Save in formalin any tissue which the patient has passed.
RH negative women receive an injection of Rhogam (hyperimmune Rh globulin) within 3 days of the
abortion. It may still be effective in preventing Rh sensitization if given within 7-10
days.
They are encouraged to have a restful day or two and a
follow-up examination in a week or two. Bleeding similar to a menstrual flow will continue
for a few days following the miscarriage and then gradually stop completely. A few women
will continue to spot until the next menstrual flow (2-6 weeks later).
Women seeking another pregnancy as soon as possible are
often advised to wait a month or two to allow them to re-establish a normal uterine lining
and to replenish their reserves. Prolonged waiting before trying again is not necessary.
Some physicians recommend routinely giving a uterotonic
drug (such a Methergine 0.2 mg PO TID x 2 days) to
minimize bleeding and encourage expelling of any remaining fragments of tissue.
It also may increase cramping and elevate blood pressure.
Antibiotics (Doxycycline,
amoxicillin) are likewise prescribed by some.
While the usefulness of these medications in a civilian setting depends on circumstances,
they are probably very wise in an operational setting, particularly where sanitation may
be suboptimal.
If fever is present, IV broad-spectrum antibiotics are wise, to cover the possibility
that the complication of sepsis has developed. If the fever is high and the uterus tender,
septic abortion is probably present and you should make preparations for D&C (or
Medical Evacuation if D&C is not available locally.
If hemorrhage is present, bedrest, IV fluids, oxygen, and blood transfusion may be
necessary. Continuing hemorrhage suggests an "incomplete abortion" rather than a
"complete abortion" and your treatment should be reconsidered.
Incomplete
Abortion
With an incomplete abortion, some tissue remains behind
inside the uterus.
These typically present with continuing bleeding,
sometimes very heavy, and sporadic passing of small pieces of pregnancy tissue.
When available, ultrasound may reveal the presence of
identifiable tissue within the uterus. Serial quantitative
HCG levels can be measured if there is doubt about the completeness of a miscarriage.
Left alone, some of these cases of incomplete abortion
will eventually resolve spontaneously, but so long as there are non-viable pieces of
tissue inside the uterus, the risks of bleeding and infection continue.
Treatment consists of converting an incomplete abortion
into a complete abortion. Usually, this is done with a D&C (dilatation and curettage).
This minor operation can be performed under local anesthesia and takes just a few minutes.
- If D&C is not available, bedrest and oxytocin,
20 units (1 amp) in 1 Liter of any crystalloid IV fluid at 125 cc/hour may help the uterus
contract and expel the remainder of the pregnancy tissue, converting the incomplete
abortion to a complete abortion.
- Alternatively, ergonovine 0.2 mg P.O. or IM
three times daily for a few days may be effective.
- If fever is present, broad-spectrum antibiotics are wise, particularly if D&C is not
imminent.
- Any tissue fragments visibly protruding from the cervical
os can be grasped with a ring or dressing forceps and gently pulled straight out. This
simple and safe procedure will have a beneficial effect on the bleeding.
- Do not attempt to insert any instruments into the uterus unless you have had training to
do this since you may cause more harm than simply leaving things alone.
- If hemorrhage is present, bedrest, IV fluids, oxygen, and blood transfusion may be
necessary.
The decision for medical evacuation is difficult. Moving the patient will usually
increase the rate of bleeding. At the same time, uncontrolled hemorrhage will ultimately
be fatal. In general, an easy MEDEVAC is preferable to continued bedrest in the face of
unrelenting bleeding. If the MEDEVAC is dangerous, rough or lengthy, bedrest and
medication may be more advisable.
Inevitable
Abortion
Inevitable abortion means that a miscarriage is destined
to occur, but no tissue has yet been passed. This is sometimes called a "missed
abortion."
This diagnosis is best made by ultrasonic visualization of
the fetal heart and noting no movement. Alternatively, demonstrating no growth of the
fetus over a one week period in early pregnancy confirms an inevitable abortion.
When ultrasound is not available, the diagnosis of
inevitable abortion is made clinically. This clinical diagnosis is based on the presence
of life-threatening maternal hemorrhage, or bleeding and cramping associated with a
dilated cervix. In such clinical circumstances, the diagnosis of inevitable abortion can
be made with confidence.
When bleeding is heavy, an inevitable abortion is treated
as though it were an incomplete abortion. If bleeding is not heavy, then treatment may be
postponed until the patient is transferred to a definitive care area. At the definitive
care area, two alternative approaches are considered: D&C or awaiting a spontaneous
abortion. Each approach has its own merits and limitations:
- Awaiting a spontaneous abortion offers the benefit of
avoiding surgery, but commits the patient to a day or more of heavy bleeding and cramping.
A few of these women will experience an incomplete abortion and will need to have a
D&C anyway.
- Performing an automatic D&C has the benefit of quickly
resolving the issue of a missed abortion, but commits the patient to a surgical procedure
which carries some risks.
Septic
Abortion
During the course of any abortion, spontaneous or induced, infection may set in.
Such infections are characterized by fever, chills, uterine tenderness and
occasionally, peritonitis. The responsible bacteria are usually a mixed group of Strep,
coliforms and anaerobic organisms. These patients display a
spectrum of illness, ranging from mild, to very severe.
Usual treatment consists of bedrest, IV antibiotics, uterotonic agents, and complete
evacuation of the uterus. If the patient does not respond to these measures and is
deteriorating, surgical removal of the uterus, tubes and ovaries may be life-saving.
If your patient responds well and quickly to IV antibiotics and bedrest, you may safely
continue your treatment. Remember, though, that she has the potential for becoming
extremely ill very quickly and transfer to a definitive care facility should be
considered.
Evacuation of the uterus can be initiated with oxytocin, 20 units (1 amp) in 1 Liter of
any crystalloid IV fluid at 125 cc/hour or ergonovine
0.2 mg P.O. or IM three times daily. If the patient response is not favorable, D&C is
the next step.
IV antibiotics should be started immediately. Reasonable antibiotic choices parallel
those for PID, and include (Center for Disease Control, 1998):
1. Doxycycline 100 mg PO or IV
every 12 hours, PLUS either:
This is continued for at least 48 hours after clinical improvement. The Doxycycline is continued orally for 10-14 days.
2. ALTERNATIVE ANTIBIOTIC REGIMEN:
- Clindamycin 900 mg IV every 8
hours, PLUS
- Gentamicin, 2.0 mg/kg IV or IM,
followed by 1.5 mg/kg IV or IM, every 8 hours
This is continued for at least 48 hours after clinical improvement.
After IV therapy is completed, Doxycycline 100 mg
PO BID is given orally for 10-14 days.Clindamycin
450 mg PO daily may also be used for this purpose.
3. ANOTHER ALTERNATIVE ANTIBIOTIC REGIMEN:
4. ANOTHER ALTERNATIVE ANTIBIOTIC REGIMEN:
5. ANOTHER ALTERNATIVE ANTIBIOTIC REGIMEN:
Unruptured
Ectopic Pregnancy
A woman with an unruptured ectopic pregnancy may have the typical
unilateral pain, vaginal bleeding, and adnexal mass described in textbooks. Alternatively,
she may have minimal symptoms. A sensitive pregnancy is almost invariably positive.
Patients with a positive pregnancy test and unilateral pelvic pain or tenderness may
have an unruptured ectopic pregnancy and should have an ultrasound scan to confirm the
placement of the pregnancy. If ultrasound is not available, then it is best to arrange for
medical evacuation.
Alternative diagnoses which can cause similar symptoms include a corpus luteum ovarian
cyst commonly seen in early pregnancy, or occasionally appendicitis. PID is characterized
by bilateral rather than unilateral pain. With a threatened abortion, the pain is central
or suprapubic and the uterus itself may be tender.
While awaiting MEDEVAC, the following are wise precautions:
- Keep the patient on strict bedrest. She is less likely to rupture while lying absolutely
still.
- Keep a large-bore (#16) IV in place. If she should suddenly rupture and go into shock,
you can respond more quickly.
- Know her blood type and have a plan for possible transfusion.
- A gentle, smooth MEDEVAC is preferable to a rough one, even if it takes longer.
- The vibration during a helicopter ride or the jostling over rough roads in an ambulance
or truck may provoke the actual rupture. Try to minimize this risk and be prepared with IV
lines, IV fluids, oxygen, MAST (PASG) equipment, etc.
- If she develops peritoneal symptoms (right shoulder pain, rigidity, or rebound
tenderness), she may be starting to rupture and you should react appropriately.
Ruptured Ectopic Pregnancy
Women with a ruptured ectopic pregnancy will have pain, sometimes unilateral and
sometimes diffuse. Right shoulder pain suggests substantial blood loss. Within a few hours
(usually), the abdomen becomes rigid, and the patient goes into shock. Sensitive pregnancy tests are positive.
Ultrasound can show fluid in the cul du sac but often fails to identify the ectopic
pregnancy itself. Nonetheless, ultrasound, when available, can be a useful diagnostic aid
in ruling out the presence of a normal, intrauterine pregnancy.
When ultrasound is unavailable, culdocentesis can demonstrate the presence of
significant amounts of non-clotting blood in the abdomen. While this doesn't confirm a
ruptured ectopic pregnancy, it is strongly suggestive of that. It provides a strong
indication for surgical intervention.
- Palpate the uterus to determine its' shape and orientation.
- Put a single-tooth tenaculum on the posterior lip of the cervix.
- Pull the cervix toward you, straightening the uterus and stabilizing the posterior
vaginal fornix.
- After prepping with antiseptic, penetrate the posterior fornix in the midline with a
spinal needle attached to a syringe. This will hurt. You will reach the peritoneal cavity
in less than 1 cm.
- Aspirate for fluid. Clear peritoneal fluid means no internal bleeding. Blood-tinged
fluid usually means a traumatic tap. Bloody fluid means some bleeding, but not much. Gross
blood suggests active bleeding. If there is doubt about the concentration of the blood in
the specimen, perform a hematocrit on the aspirated
fluid and compare it to the patient's hematocrit.
Treatment is immediate surgery to stop the bleeding. If surgery is not an available
option, stabilization and medical evacuation should be promptly arranged. While awaiting
MEDEVAC:
- Give oxygen, IV fluids and blood according to ATLS
guidelines.
- Keep the patient at absolute rest.
- Monitor urine output hourly with a Foley catheter.
- Take frequent vital signs to detect shock.
- Consider MAST trousers (PASG).
If abdominal surgery is not available, the outlook for a patient with a ruptured
ectopic pregnancy is fair. Aggressive fluid and blood replacement, oxygen and complete
bedrest will result in about a 50/50 chance of survival. If this approach is necessary,
remember:
- Try to maintain the urine output between 30 and 60 ml/hour.
- If the pulse is >100 or urine output <30, she needs more fluid.
- If she becomes short of breath and the lung sounds become "crackly," slow down
the fluids as she probably is becoming fluid overloaded.
- If she becomes short of breath and the lungs sounds dry, increase the fluids and give
blood as she is probably anemic and in need of more oxygen carrying capacity.
- As she loses blood into the abdomen, she will become distended. If she becomes so
distended she can't breath, put a chest tube into the abdomen through a small, midline
incision just below the umbilicus to drain off fluid or blood so she can breath.
- A MAST or PASG Suit can be very helpful in tamponading the internal bleeding. Seriously
consider it in this situation.
- She may ultimately require as many as 15 or 20 units of blood.
Blood
Transfusion
Incomplete abortion and ruptured ectopic pregnancy are two
of the most common medical emergencies requiring blood transfusion in women.
In a hospital setting, standard blood banking procedures
apply, with the use of carefully cross-matched blood components as needed by the clinical
situation.
In some operational settings, standard blood banking
procedures may not be applicable or available. In these cases, direct donor to victim
transfusion can be life-saving.
- Use a donor with O
negative blood ("Universal Donor"). Don't try to match, for example, a B+
victim to a B+ donor. While the accuracy of blood type records has improved, there is
still a significant inaccuracy rate (as high as 5%) in the medical record laboratory
reports, identification cards, and dog tags. If you try to match a B+ victim to a B+ donor
(type-specific blood transfusion), you are twice taking a 5% risk of a mismatch. It is
safer to take that risk only once. If the only available blood for a
Rh negative victim is Rh positive blood, Rhogam may be
used, in very large doses of 25-30, full-size, 300 microgram ampoules, IV, per unit of
blood, to neutralize the Rh sensitizing effects of the Rh positive blood.
- Arrange IV tubing so that there is a large-bore needle at
each end. This is facilitated by use of a 3-way stopcock. If this is not available, you
can simply cut off the tubing at the end and insert it into the hub of a needle. Sterile
petroleum jelly can provide a seal and the needle is held tightly to the IV tubing with
adhesive tape.
- Position the donor about 3 feet higher than the victim.
With the victim in a lower bunk, the donor would be in an upper bunk. With the victim on
the floor or on the deck, the donor would be on a cot or packing crate.
- Insert the IV into the donor and let the blood flow
downhill through the tube until it reaches the other end. Clamp the tubing just long
enough to insert the other end into the victims IV or vein.
- Unclamp the tubing and allow time for about 1 unit (500 cc)
of blood to flow into the victim. The exact amount of time would depend on the
caliber of the tubing and needle, length of the tubing, height of the donor above the
victim and doubtless other factors. In practice, allow about 10 minutes, but be prepared
to stop it earlier if the donor becomes light-headed or dizzy.
- Because fresh, whole blood has better oxygen-carrying
capacity than banked units of packed RBCs, and it is prewarmed, and because it contains
platelets, clotting factors and serum proteins, each unit has about twice the clinical
impact of a unit of packed cells from the bank. If, based on your clinical experience, you
believe a patient would benefit from two units of PRBCs from a blood bank, they will
generally do well with a single unit of fresh, whole blood.
- After the patient is transferred to a definitive care
facility, it will be easier for them to identify the true, native blood type (major and
minor blood groups) if they have a sample of blood taken from the patient prior to
any transfusions. If time permits and the tactical situation allows for it, try to draw a
single red-topped tube of the victim's blood prior to transfusion that you can send along
with the MEDEVAC for use by blood banks further up the line.
Maternal Trauma During
the First Trimester
During the first trimester, the uterus is protected within the pelvic bones. Trauma
during this time will either be so severe as to cause a miscarriage (spontaneous abortion
or fetal death), or else it will have no effect.
Miscarriage is a common event, normally occurring in one out of every 5 or 6
pregnancies. While trauma can cause 1st trimester pregnancy loss, it is exceedingly rare
in comparison with other causes of miscarriage.
Catastrophic trauma includes such types of injury as maternal death, hemorrhagic shock,
multiple compound fractures of the extremities, liver and spleen ruptures, to name a few.
Catastrophic trauma during the first trimester is associated with subsequent miscarriage.
Non-catastrophic trauma includes bumps, bruises, fractures of small bones (fingers,
toes), minor burns, etc. While such non-catastrophic injuries may be serious enough to
require treatment, they are not associated with miscarriages.
Maternal Trauma During the Second and
Third Trimester
Trauma occurring during the second and third trimester has different clinical
consequences than during the first trimester. First trimester, minor trauma is not
threatening to the pregnancy. During the second and third trimester, even relatively minor
trauma can have significant adverse effects on the fetus. Such adverse effects include
placental abruption, preterm labor, premature rupture of the membranes, uterine rupture,
and direct fetal injury.
- Rapid acceleration, deceleration, or a direct blow to the pregnant abdomen can cause
shearing of the placenta away from its underlying attachment to the uterus. When
this happens (placental abruption), the detached area will bleed and the detached area of
the placenta will no longer function to supply oxygen to the fetus. A complete abruption
is a disastrous event, life-threatening to both the fetus and the mother. Partial
placental abruptions may range the full gamut from insignificant to the striking
abnormalities seen in complete abruptions.
- Premature labor may be provoked. In these cases, regular uterine contractions begin
shortly after the trauma (within 4 hours) and progress steadily and result in delivery.
Premature rupture of the fetal membranes can also occur, within the first 4 hours of
injury and usually result in a premature delivery.
- Direct fetal injury may occur, resulting in contusions, fractures or fetal death.
- Uterine rupture can occur and usually result in the loss of the fetus.
The severity of the maternal injury may not correlate well with the frequency of
adverse pregnancy outcome. Even minor trauma can have very serious consequences for the
pregnancy.
The adverse effects, when they occur, are immediate (within the first few days of the
trauma). There is probably no increased risk of preterm delivery, depressed Apgar scores,
cesarean section or neonatal length of stay, after excluding the following immediate
adverse effects:
- Placental abruption within the first 72 hours of injury.
- Rupture of membranes within 4 hours of injury.
- Onset of labor within 4 hours of injury that resulted in delivery during the same
hospitalization.
- Fetal death within 7 days of the traumatic event.
Uterine contractions following trauma are common, although premature delivery caused by
preterm labor is not. Actual preterm delivery resulting from premature labor (in the
absence of abruption) probably occurs no more frequently among traumatized women than the
general population.
Placental
Abruption
Placental abruption is also known as a premature separation of the placenta. All
placentas normally detach from the uterus shortly after delivery of the baby. If any
portion of the placenta detaches prior to birth of the baby, this is called a placental
abruption.
A placental abruption may be partial or complete.
A complete abruption is a disastrous event. The fetus will die within
15-20 minutes. The mother will die soon afterward, from either blood loss or the
coagulation disorder which often occurs. Women with complete placental abruptions are
generally desperately ill with severe abdominal pain, shock, hemorrhage, a rigid and
unrelaxing uterus.
Partial placental abruptions may range from insignificant to the
striking abnormalities seen in complete abruptions.
Clinically, an abruption presents after 20
weeks gestation with abdominal cramping, uterine tenderness, contractions, and usually
some vaginal bleeding. Mild abruptions may resolve with bedrest and observation, but
the moderate to severe abruptions generally result in rapid labor and delivery of the
baby. If fetal distress is present (and it sometime is), rapid cesarean section may be
needed.
Because so many coagulation factors are
consumed with the internal hemorrhage, coagulopathy is common. This means that even after
delivery, the patient may continue to bleed because she can no longer effectively clot. In
a hospital setting, this can be treated with infusions of platelets, fresh frozen plasma
and cryoprecipitate. In an operational setting where these products are unavailable, fresh
whole blood transfusion will give good results.
Patients in an operational setting thought to
have at least some degree of placental abruption should be transferred to a definitive
care setting. While transporting her, have her lie on her left side, with IV fluid
support.
Placenta
Previa
Normally, the placenta is attached to the uterus in an
area remote from the cervix. Sometimes, the placenta is located in such a way that it
covers the cervix. This is called a placenta previa.
There are degrees of placenta previa:
A complete placenta previa means the entire cervix is covered. This
positioning makes it impossible for the fetus to pass through the birth canal without
causing maternal hemorrhage. This situation can only be resolved through cesarean section.
A marginal placenta previa means that only the margin or edge of the
placenta is covering the cervix. In this condition, it may be possible to achieve a
vaginal delivery if the maternal bleeding is not too great and the fetal head exerts
enough pressure on the placenta to push it out of the way and tamponade bleeding which may
occur.
Clinically, these patients present after 20 weeks with
painless vaginal bleeding, usually mild. An old rule of thumb is that the first bleed from
a placenta previa is not very heavy. For this reason, the first bleed is sometimes called
a "sentinel bleed."
Later episodes of bleeding can be very substantial and
very dangerous. Because a pelvic exam may provoke further bleeding it is important to
avoid a vaginal or rectal examination in pregnant women during the second half of their
pregnancy unless you are certain there is no placenta previa.
The location of the placenta is best established by
ultrasound. If ultrasound is not available, one reliable clinical method of ruling out
placenta previa is to check for fetal head engagement just above the pubic symphysis.
Using a thumb and forefinger and pressing into the maternal abdomen, the fetal head can be
palpated. If it is deeply engaged in the pelvis, it is basically impossible for a placenta
previa to be present because there is not enough room in the birth canal for both the
fetal head and a placenta previa. An x-ray of the pelvis (pelvimetry) can likewise rule
out a placenta previa, but only if the fetal head is deeply engaged. Otherwise, an x-ray
will usually not show the location of the placenta.
Patients suspected of having a placenta previa in an
operational setting need expeditious transport to a definitive care setting where
ultrasound and full obstetrical services are available.
Toxemia of
Pregnancy
Toxemia of pregnancy is a clinical syndrome characterized
by elevated blood pressure, protein in the urine, fluid retention and increased reflexes.
It occurs only during pregnancy and resolves completely after pregnancy. It is seen most
often as women approach full term, but it can occur as early as the 22nd week of
pregnancy. It's cause is unknown, but it occurs more often in:
- Women carrying their first child
- Multiple pregnancies
- Pregnancies with excessive amniotic fluid (polyhydramnios)
- Younger (<17) and older (>35) women
Ordinarily, blood pressure decreases during the middle
trimester, compared to pre-pregnancy levels. After the middle trimester, blood pressure
tends to rise back to the pre-pregnancy levels. Sometimes, blood pressure becomes
elevated.
Sustained blood pressures exceeding 140/90 are considered
abnormal and may indicate the presence of toxemia of pregnancy. For women with
pre-existing hypertension, a sustained worsening of their hypertension over pre-pregnancy
levels by 30 systolic and 15 diastolic is often used to indicate the possible presence of
super-imposed toxemia.
The presence of hypertension and proteinuria are essential
to the diagnosis of toxemia of pregnancy.
Pregnant women can normally lose up to 200 mg of protein
in the urine in 24 hours. If protein loss exceeds 300 mg in 24 hours, this is considered
proteinuria. Urine dipstick analysis for protein measures only a single point in time and
does not necessarily reflect protein loss over 24 hours. Nonetheless, assuming
average urine production of about a liter a day, and consistent loss throughout the
24 hour period*:
Category |
Negative |
Trace |
1+ |
2+ |
3+ |
4+ |
Dipstick Results |
<15 mg/dL |
15-29 mg/dL |
30 mg/dL |
100 mg/dl |
300 mg/dl |
>2000 mg/dL |
Equivalent
24-hour Results* |
<150 mg |
150-299 mg |
300-999 mg |
1000-2999 mg |
3-20 g |
>20 g |
Some but not all women with toxemia demonstrate fluid
retention (as evidenced by edema or sudden weight gain exceeding 2 pounds per week). Some
but not all women with toxemia will demonstrate increased reflexes (clonus).
Pre-eclampsia
Toxemia of pregnancy is subdivided into two categories: pre-eclampsia and eclampsia.
The difference is the presence of seizures in women with eclampsia.
The clinical course of pre-eclampsia is variable. Some women demonstrate a mild, stable
course of the disease, with modest elevations of blood pressure and no other symptoms
(mild pre-eclampsia). Others display a more aggressive disease, with deterioration of both
maternal and fetal condition (severe pre-eclampsia). Some of the points of differentiation
are listed here. Notice that there is no "moderate" pre-eclampsia, only mild and
severe.
Problem |
Mild Pre-Eclampsia |
Severe Pre-Eclampsia |
Blood Pressure |
>140/90 |
>160/110 |
Proteinuria |
1+ (300 mg/24 hours) |
2+ (1000 mg/24 hours) |
Edema |
+/- |
+/- |
Increased reflexes |
+/- |
+ |
Upper abdominal pain |
- |
+ |
Headache |
- |
+ |
Visual Disturbance |
- |
+ |
Decreased Urine Output |
- |
+ |
Elevation of Liver Enzymes |
- |
+ |
Decreased Platelets |
- |
+ |
Increased Bilirubin |
- |
+ |
Elevated Creatinine |
- |
+ |
The definitive treatment of pre-eclampsia is delivery. The urgency of delivery depends
on the gestational age and the severity of the disease. Severe pre-eclampsia usually
requires urgent delivery (within hours) more or less regardless of gestational age. In
this situation, the risk of serious complications (placental abruption, growth
restriction, liver failure, renal failure, hemorrhage, coagulopathy, seizures, death) will
generally take precedence over the fetal benefit of prolonging the pregnancy. Induction of
labor is preferred, unless the maternal condition is so tenuous and the cervix so
unfavorable that cesarean section is warranted.
In milder cases, particularly if remote from term or with an unfavorable cervix,
treatment may range from hospitalization with close observation to initial stabilization
followed by induction of labor following preparation of the cervix over the course of
several days. In the most mild, selected cases, outpatient management might be considered
with careful monitoring of maternal and fetal condition.
Traditionally, magnesium sulfate has
been used to treat pre-eclampsia. Magnesium sulfate, in high enough doses, is a reasonably
effective anti-convulsant, mild anti-hypertensive and mild diuretic. While other agents
may be more potent in each of these individual areas, none combines all three of these
features into a single drug. The world's experience with magnesium sulfate to treat pre-eclampsia is
extensive and these unique features provide considerable reassurance in employing it in
these clinical settings. Magnesium sulfate
is given IM, IV or both. All are effective reasonably effective in preventing seizures.
Because the risk of eclampsia continues after delivery, MgSO4 is frequently continued for 24 to 48
hours after delivery.
- Magnesium sulfate 10 gm in a 50%
solution, one-half (5 gm) IM, injected deeply into each upper outer buttock quadrant.
Every 4 hours thereafter, Magnesium sulfate
5 gm IM is injected into alternating buttocks. Repeat injections are postponed if patellar
reflexes are absent. Because these injections are painful, 1 ml of 2% Xylocaine is sometimes added to the magnesium. This
schedule gives therapeutic levels of magnesium (4-7 meq/L)
- Because IM magnesium sulfate does not
initially achieve its therapeutic levels for 30 to 45 minutes, in cases of severe
pre-eclampsia, an IV bolus of magnesium sulfate
can be added. 4 gm magnesium sulfate as a
20% solution can be given slowly over at least 5 minutes, followed by the IM injections
described above.
- Magnesium sulfate 4 gm IV, slowly, over
at least 5 minutes, followed by 2 gm IV/hour.
The therapeutic margin (distance between effective dose
and toxicity) is relatively thin with magnesium
sulfate, so some precautions need to be taken to prevent overdose. The biggest problem
with MgSO4 is respiratory depression (10
meq/L) and respiratory arrest (>12 meq/L). Cardiovascular collapse occurs at levels
exceeding 25 meq/L. MgSO4 levels can be measured in a hospital setting, but clinical
management works about as well and is non-invasive.
The patellar reflexes (knee-jerk) disappear as magnesium
levels rise above 10 meq/L. Periodic checking of the patellar reflexes and withholding MgSO4 if reflexes are absent will usually keep
your patient away from respiratory arrest. This is particularly important if renal
function is impaired (as it often is in severe pre-eclampsia) since magnesium is cleared
entirely by the kidneys.
In the case of respiratory arrest or severe
respiratory depression, the effects of MgSO4
can be reversed by the administration of calcium.
If BP is persistently greater than 160/110,
administer an antihypertensive agent to lower the BP to levels closer to 140/90. One
commonly-used agent for this purpose is:
Eclampsia
Eclampsia means that maternal seizures have occurred in
association with toxemia of pregnancy.
These tonic/clonic episodes last for several minutes and
may result in bite lacerations of the tongue. During the convulsion, maternal respirations
stop and the patient turns blue because of the desaturated hemoglobin in her bloodstream.
As the attack ends, she gradually resumes breathing and her color returns. Typically, she
will remain comatose for varying lengths of time. If convulsions are frequent, she will
remain comatose throughout. If infrequent, she may become arousable between attacks. If
untreated, convulsions may become more frequent, followed by maternal death. In more
favorable circumstances, recovery occurs.
Eclampsia should be aggressively treated with magnesium sulfate (described above), followed
by prompt delivery, often requiring a cesarean section. If convulsions persist despite MgSO4, consider:
HELLP Syndrome
The HELLP Syndrome is characterized by:
This serious condition is associated with severe
pre-eclampsia and the treatment is similar...delivery with prophylaxis against maternal
seizures.
Unlike pre-eclampsia, patients with HELLP syndrome may
continue to experience clinical problems for days to weeks or even months.
If the HELLP syndrome is mild, it may gradually resolve
spontaneously, but more severe forms often require intensive, prolonged care to achieve a
favorable outcome.
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